bluuebunny/crossref_metadata_2025 huggingface dataset:
An Ultra pH‐Sensitive and Aptamer‐Equipped hollow gold nanosphere for Selective Killing of Tumor Cells
Authors: Zhao Nianxi , You Jian , Zeng Zihua , Li Chun , Zu Youli
Published: June 2021

Nanotechnology has often been applied in the drug delivery systems for the treatment of cancer. An ideal nanoscale system for drug delivery should be able to selectively deliver and rapidly release the carried therapeutic drug(s) in cancer cells and, more importantly, not react to off‐target cells. To reach this goal, we formulated a selective chemotherapeutic using a hollow gold nanosphere (HAuNS) equipped with a biomarker‐specific aptamer (Apt) and loaded with the chemotherapy drug doxorubicin (DOX). The formed Apt‐HAuNS‐Dox, approximately 42 nm in diameter, specifically bound to lymphoma tumor cells and did not react to control cells. Through aptamer‐mediated selective cell binding, the Apt‐HAuNS‐Dox was internalized exclusively into the targeted tumor cells and then released the DOX intracellularly. Of note, although the formed Apt‐HAuNS‐Dox was stable under normal biological conditions (pH 7.4), it appeared ultrasensitive to pH change and rapidly released 80% of the loaded DOX within 2 hours at pH 5.0, a condition seen in cell lysosomes. Functional assays using cell mixtures showed that the Apt‐HAuNS‐Dox selectively killed lymphoma tumor cells, but had no effect on the growth of the off‐target cells in the same cultures, indicating this ultra‐pH‐sensitive Apt‐HAuNS‐Dox can selectively treat cancer through specific aptamer guidance and have no side effects on normal tissue.
Helium inhalation induces caveolin secretion to blood
Authors: Weber Nina Claudia , Schilling Jan M , Finley J Cameron , Irvine Megan , Kellerhals Sarah E , Niesman Ingrid R , Roth David M , Preckel Benedikt , Hollmann Markus W , Patel Hemal H
Published: June 2021

Caveolae are cholesterol and sphingolipid enriched invaginations of the plasma membrane and are considered a subset of lipid rafts. Caveolins (Cav), the structural proteins essential for caveolae formation, are critically involved in isoflurane‐induced protection of the heart. The noble gas helium (He) mimics isoflurane‐induced cardioprotection but the molecular mechanisms is unknown. We hypothesize that He influences Cav signaling in vivo in mice. C57BL/6 mice inhaled either 70% He (n=8) or 30% oxygen (n=8) for 20 min. Thirty min or 24 h after inhalation hearts were excised. Cav‐1/3 expression was determined after sucrose density fractionation of whole heart tissue. A cholesterol assay of whole heart samples was performed. Serum of these animals was tested for Cav‐1/3.

He inhalation decreased Cav‐1 (0.4±0.1) and 3 (0.7±0.1, vs con 1.7±0.3 and 1.2±0.2, respectively, p<0.05) expression after 24 h. Buoyant Cav enriched fractions supported the results showing lower Cav‐1 and 3 levels. Cholesterol levels where significantly lower after He inhalation (1.7±0.1 vs con 2.4±0.3). Subcellular fractions showed lower levels of Cav‐1/3 mostly in cytosolic and mitochondrial fractions. In contrast, Cav‐1/3 showed accumulation in serum in He mice 24 h after exposure.

These data indicate that Cav‐1 and 3 are secreted into the blood after He inhalation in mice, suggesting circulation factors may be involved in inducing organ protection by He.
Adenosine A2A receptor modulates vascular response in soluble epoxide hydrolase‐null mice through cyp2j‐epoxygenases and PPARγ
Authors: Nayeem Mohammed A , Pradhan Isha , Mustafa S Jamal , Morisseau Christophe , Falck John R , Zeldin Darryl C
Published: June 2021

The interaction between adenosine and sEH in vascular response is not known. Therefore, we hypothesized that lack of sEH enhances adenosine‐induced relaxation through A2A AR via cyp2j‐epoxygenases and PPARγ. sEH−/− showed an increase in A2A AR (31%), cyp2j (65%) & PPARγ (36%), and decrease in A1AR (30%) & PPARα (27%) vs. sEH+/+. NECA (adenosine analog), CGS 21680 (A2AAR‐agonist) & GW 7647 (PPARα‐agonist)‐induced responses were tested with L‐NAME (NO‐inhibitor), ZM‐241385, SCH‐58261 (A2AAR‐antagonists), 14,15‐EEZE (EETs‐antagonist), AUDA, t‐AUCB (sEH‐inhibitors) & T0070907 (PPARγ‐antagonist). NECA‐induced relaxation was higher in sEH−/− (+12.94 ± 3.2%) vs. sEH+/+(−5.35 ± 5.2%), that was blocked by ZM‐241385 (−22.42 ± 1.9%) & SCH‐58261(−30.04 ± 4.2%). CGS‐21680‐induced relaxation was higher in sEH−/−(+37.4 ± 5.4%) vs. sEH+/+(+2.14 ± 2.8%), that was not blocked by L‐NAME (p>;0.05), whereas 14,15‐EEZE did (p<0.05). Also, AUDA & t‐AUCB did not change CGS‐21680‐induced response in sEH−/− (p>;0.05), but reversed in sEH+/+ (AUDA: +45.33±4.1%, t‐AUCB: +63.37±7.2). GW 7647 did not relax vs. CGS 21680 in sEH−/−(p<0.05), and T0070907 blocked CGS 21680 induced relaxation in sEH−/−(+9.40 ± 3.1). These data suggest that A2AAR‐induced relaxation in sEH−/− may depend on the up‐regulation of cyp2j, PPARγ and down‐regulation of A1AR, PPARα. Supported (BGF‐WVU, STF‐WVU, HL027339, HL094447, GM31278 & z01 ES025034).
The oligomerized polyphenol oligonol ameliorates high glucose‐ and TNF‐α‐induced NADPH oxidase activation and insulin signaling down‐regulation in vascular endothelial cells
Authors: Yokoo Hiroki , Taguchi Kumiko , Hattori Yuichi
Published: June 2021

Endothelial dysfunction plays a key role in the pathogenesis of diabetic vascular disease. We investigated to explore the possible mechanism(s) by which the oligomerized polyphenol oligonol, used as an efficacious healthy aging dietary supplement, may be beneficial to endothelial cell dysfunction in diabetes. Porcine aortic endothelial cells were cultured in the presence of high glucose and TNF‐α with or without oligonol. In the presence of high glucose and TNF‐α, treatment of cells with oligonol prevented the increased expression level of the NADPH oxidase (Nox) subunit p67Phox and the enhanced production of radical oxygen. Furthermore, the impaired phosphorylated levels of Akt and GSK‐3β and the down‐regulated expression level of insulin receptors were improved by oligonol treatment. These results indicate that oligonol can decrease the oxidative stress through inhibition of Nox activity and amend the insulin signaling pathway in the endothelial cells under conditions that mimic diabetes. This mechanism may offer an important standpoint for the beneficial cardiovascular health effects of oligonol.
Evidence of NSAID partitioning into splanchnic lymphatics: Possible route to avoid first‐pass hepatic metabolism
Authors: Lichtenberger Lenard Michael , Phan Tri , Dial Elizabeth
Published: June 2021

Aspirin and related NSAIDs rapidly undergo hydrolysis in blood and first‐pass hepatic metabolism. To better understand aspirin bioavailability in rodents we investigated whether a significant fraction of the drug may directly partition into the splanchnic lymphatics to promote NSAID circulatory half‐life and activity.

Methods

Fasted male Sprague Dawley rats, some of which were orally pretreated 0.5, 1 and 5 hrs earlier with aspirin (pulverized Immediate‐release Walgreens OTC aspirin in water at doses of 40 and 100 mg/kg), were placed under isoflurane anesthesia and after laparotomy the splachnic lymphatic was cannulated and lymph collected for the subsequent 60–120 min. At euthanasia, blood was also collected. Samples of lymph and blood were analyzed for the presence of salicylic acid (SA) and platelet thromboxane (TxB2) conc, using established colorimetiric and RIA procedures.

Results

We determined that lymph SA conc increased in a time‐ and dose‐dependent fashion after oral administration of aspirin and represented ~60% of circulating SA levels (using the 1 hr time point). Furthermore, aspirin dosing inhibited both lymph and plasma TxB2 conc by >;80%, 5hrs post‐treatment.

Conclusion

A significant fraction of intragastrically administered aspirin partitions into the lymphatic circulation in rats, which may be a critical factor in assuring the drug's bioavailability and therapeutic activity.
Stable gastric pentadecapeptide BPC 157 for colitis and multiple sclerosis: Healing of cysteamine‐colitis and colon‐colon‐ anastomosis
Authors: Sikiric Predrag , Klicek Robert , Kolenc Danijela , Suran Jelena , Drmic Domagoj , Brcic Luka , Aralica Gorana , Seiwerth Sven , Rucman Rudolf
Published: June 2021

BPC 157 is interesting as an original anti‐ulcer peptide (GEPPPGKPADDAGLV,M.W. 1419) stable in human gastric juice more than 24 hours, successful in trials for inflammatory bowel disease, phase II, wound treatment, no toxicity or side effects reported, LD1 not achieved, effective alone without carrier. The dehiscence of colonic anastomosis is associated with high mortality and morbidity rates. As a result, the problem of healing after a colon resection requires a suitable solution, especially in inflammatory bowel disease with compromised healing. As a possible solution we suggest the use of BPC 157 which may also be effective for treating inflammatory bowel disease complications. After cysteamine (400 mg/kg ir) colon‐colon anastomosis was created in rats. The sacrifice was at day 3, 5,7, and 14. BPC 157 (10μg/kg, 10 ng/kg) was applied ip once daily or in drinking water (0.16 μg/ml/12ml/day) till the sacrifice. Controls poor presentation did not heal cysteamine colitis and colon‐colon anastomosis; BPC 157 simultaneously induced healing of both, the anastomosis and the ulcerative colitis. Thereby, this evidence advocates BPC 157 in inflammatory bowel disease. Interestingly, accordingly with application of agents used in ulcerative colitis (i.e., natalizumab), the most recent evidence suggests its use also in multiple sclerosis therapy. Supported by Grant 108–1083570‐3635, Croatia
Regulator of G‐protein Signaling 5 reduces HeyA8 ovarian cancer cell proliferation and extends survival in a murine tumor model
Authors: Altman Molly K , Beedle Aaron , Murph Mandi
Published: June 2021

The regulator of G‐protein signaling 5 (RGS5) belongs to a family of GTPase activators that terminate signaling cascades initiated by extracellular mediators and GPCRs. One RGS5 role is as a pericyte biomarker influencing the switch to angiogenesis during malignant progression. Its other role is to promote apoptosis in hypoxic environments. We set out to clarify the extent to which RGS5 expression regulates tumor progression – whether it plays a pathogenic or protective role. We thus constructed an inducible gene expression system to achieve RGS5 expression in HeyA8‐ MDR ovarian cancer cells. Through this we observed that inducible RGS5 expression significantly reduces in vitro BrdU‐positive HeyA8‐MDR cells. Interestingly, mice bearing RGS5‐ expressing tumors demonstrated an increase in survival compared with controls, which might be attributed to the vast regions of necrosis observed by pathological examination. Additionally, mice bearing RGS5‐expressing tumors were less likely to have ulcerated tumors. Taken together, this data supports the idea that temporal expression and stabilization of RGS5 could be a valuable tactic within the context of a multi‐component approach for modulating tumor progression.
In search of endocannabinoid degradation enzymes inhibitors in nutmeg
Authors: El‐Alfy Abir T , Joseph Sharon , Brahmbhatt Akshar
Published: June 2021

The inhibition of endocannabinoid metabolizing enzymes offers a novel therapeutic target for treatment of depression and anxiety. Previous studies in our laboratory have established cannabis‐like effects of nutmeg extracts in animal models. However, these effects were not coupled to binding to cannabinoid receptors. The main purpose of our study was to examine the effect of nutmeg extracts on the activity of fatty acid amide hydrolase (FAAH) and monoacylglyceryl lipase (MAGL). Total nutmeg extract (TE) was prepared and successively extracted with solvents of various polarities. The extracts were fingerprinted by HPLC and tested for FAAH and MAGL inhibition against positive controls. The total extract showed a concentration‐dependent inhibition for both FAAH and MAGL with IC50 values of 17.71 and 5.17 mg/mL, respectively. The dichloromethane and ethylacetate fractions showed the highest enzyme inhibition. The IC50 values of FAAH and MAGL inhibition by the ethylacetate fraction were 15.21and 49.42 mg/mL, respectively. The IC50 values of FAAH and MAGL inhibition by the dichloromethane fraction were 32.00 and 32.86 mg/mL, respectively. Inhibition of endocannabinoid metabolizing enzymes by nutmeg extracts explains the cannabis‐like effect exerted by nutmeg. Such inhibition also offers potential utilization of nutmeg compounds for indirect modulation of the endocannabinoid system.
The occurrence and management of pediatric poisonings in Lenasia, South Africa
Authors: Ahmed Ayesha Yusuf , Moch Shirra
Published: June 2021

Gauteng is South Africa's most populated and urbanized province. There is no local Poison Information Centre (PIC), and poisoning rates are unknown, as the failing healthcare system precludes adequate record‐keeping with regard to rate and classification of incidents. The time necessary to obtain accurate poisoning statistics through a prospective, multi‐hospital longitudinal study could leave the province underserviced for several years. It was thus decided to conduct a cross‐sectional survey in a single suburb, Lenasia (population 150 000) as a case‐study approach to establish an estimate of the occurrence and management of poisonings in this region.

Self administered questionnaires were distributed to parents/guardians of children attending a random sample of creches and primary schools in Lenasia. Questions concerned the number and storage level of poisonous household substances stored, rate of ingestion of the substances by the children, management of poisoning cases and knowledge of PIC's.

A total of 4530 questionnaires were handed out, 1730 (38.1%) were returned completed and 175 (10.1%) participants reported 256 cases of accidental poisoning. Medication, household detergents, rat poison, and paraffin were the most common substances ingested. There is a lack of knowledge of PIC's, and prevention and management of poisoning, suggesting there should be more public education on this issue.
A novel role for GABA and glutamate in pericyte‐mediated regulation of medullary blood flow
Authors: Dunn Kadeshia Natasha , Kelley Stephen P , Crawford Carol , Wildman Scott S P , Peppiatt‐Wildman Claire M
Published: June 2021

GABA and its synthesising enzyme, glutamate decarboxylase, have been detected in the rat kidney [1–2]. GABA has also been found in human plasma and urine [3–4] and most recently, a renoprotective role for GABA has been suggested [5]. We are systematically investigating functional roles for GABA and glutamate in the mammalian kidney.

Contractile pericytes regulate vasa recta diameter in response to a number of endogenous vasoactive agents and in doing so regulate medullary blood flow (MBF) [6]. We have utilised the live kidney slice model [6] to demonstrate GABA‐mediated constriction of vasa recta that was significantly greater at pericyte sites than at non‐pericyte sites (p< 0.01). Conversely, the GABA substrate glutamate (100 μM) caused a significantly greater vasodilation of vasa recta at pericyte sites compared to non‐pericyte sites (p< 0.05).

Data presented here identifies a novel role for GABA and glutamate in pericyte‐mediated regulation of vasa recta diameter and thus MBF.
Progressive increase in collecting duct basal/apical AQP2 expression ratio with increasing depth along the corticopapillary axis positively correlates with maximum urine concentrating capacity
Authors: Espineira Madeline , Gilbert Rebecca L , Pannabecker Thomas L
Published: June 2021

Our goal is to determine if AQP2 expression patterns in the renal medullary collecting duct (CD) contribute to the ability of the kangaroo rat to produce a more highly concentrated urine than that of the Munich‐Wistar rat. Inner medullas from kidneys of moderately concentrating animals were embedded in Spurrs and 1 μm thick transverse sections cut at 500 μm intervals throughout the corticopapillary axis and labeled for AQP2. Apical and basal plasma membrane AQP2 expression levels were quantified on a pixel‐by‐pixel basis in each CD in 0.11 mm2 sections. The basal/apical AQP2 expression ratio at 1000 μm below the outer medulla is nearly equal in both species (~0.50), whereas at 4500 μm below the outer medulla, the basal/apical AQP2 expression ratio is greater in the CD of kangaroo rat (~1.2) relative to Munich‐Wistar rat (~0.70). Prior studies have shown that transepithelial water permeability of the inner two‐thirds of Sprague‐Dawley rat isolated perfused inner medullary CDs markedly exceeds that of the outer third without vasopressin. The high water permeable segment correlates with high basal/apical AQP2 expression ratios. A heightened basal/apical AQP2 expression ratio in kangaroo rat CD is consistent with prior studies indicating peritubular hypertonicity is a regulatory factor of CD water permeability and basal/apical AQP2 expression ratios. NIDDK DK083338, NSF IOS095285, APS/NIDDK STEP‐UP, WAESO.
Biomarkers of kidney disease identified using a novel rat model and evaluated in human CKD patients
Authors: Harmon Ashlyn C. , Johnson Ashley C. , Driesbach Albert , Garrett Michael R.
Published: June 2021

Urine exosomes are cell‐like vesicles that originate from kidney tubules under normal and pathological conditions. Proteins and mRNA contained within these exosomes can potentially provide a rich source of non‐invasive biomarkers to predict chronic kidney disease (CKD) progression. We have developed a novel rat model [S.SHR(11)] that demonstrates accelerated kidney injury and decreased kidney function compared to the already susceptible Dahl salt‐sensitive (S) rat. Global shotgun proteomics was performed using multidimensional protein identification technology (MuDPIT) on exosome samples collected from each strain. A total of 403 unique proteins were identified and ~5% demonstrated a two‐fold difference between strains. In particular, ERK2 and ATP9A were increased in S.SHR(11) and confirmed by western blot analysis in isolated exosomes. Both proteins were evaluated in urine exosomes from a unique CKD population collected at the University. CKD patients exhibited prominent expression in exosomes, which was either greatly reduced (ERK2) or not observed in healthy subjects (ATP9A). In summary, we have successfully used a novel rat model to identify biomarkers that correlate with decline in kidney function. The continuation of these studies could provide specific noninvasive biomarkers to better predict decline in kidney function in humans. Supported by RO1‐HL094446 (MRG) and T32‐HL105324 (ACH).
Individual Differences in Cardiac and Vascular Components of the Pressor Responses to Isometric Handgrip Exercise in Humans
Authors: Watanabe Kazuhito , Ichinose Masashi , Tahara Rei , Nishiyasu Takeshi
Published: June 2021

The aim of this study was to test the hypotheses that, in humans, cardiac output (CO) and total peripheral vascular resistance (TPR) responses to isometric exercise vary among individuals, and that the individual differences are related to the muscle metaboreflex and the arterial baroreflex functions. Healthy subjects (n = 32) performed 1‐min isometric handgrip exercise (HG) at 50% of maximal voluntary contraction, followed by a 4‐min period of post‐exercise muscle ischemia (PEMI) to selectively maintain activation of the muscle metaboreflex. In 11 subjects the pressor response to HG occurred solely by the increase in CO, but in 18 subjects it occurred due to both the increases in CO and TPR, and further it occurred solely via the increase in TPR in 3 subjects. Thus the pressor components varied widely among subjects. The CO and TPR responses during HG were positively correlated with those responses during PEMI, respectively. In addition, the CO response to PEMI was negatively correlated with the PEMI‐induced changes in an index of cardiac vagal tone and cardiac baroreflex sensitivity. We conclude that CO and TPR responses to HG vary among individuals, and that the individual differences in components of the pressor response could be attributed in part to the variations in the muscle metaboreflex and the arterial baroreflex functions. This study was supported by the grants from Japan Society for the Promotion of Science.
Astrocytes influence SON and PVN neurosecretory and presympathetic neuronal excitability via activation of an extrasynaptic NMDA/A‐type K+ channel coupling mechanism
Authors: Naskar Krishna , Stern Javier E.
Published: June 2021

We showed that activation of extrasynaptic NMDARs (eNMDARs) by ambient glutamate under astrocytic control inhibited the voltage‐gated K+ current IA in neurosecretory vasopressin (VP) and PVN‐RVLM presympathetic neurons. Here, we aimed to address: i) whether the eNMDARs/IA coupling increases the firing activity of neurosecretory and presympathetic PVN neurons, and ii) whether this effect involves an imbalanced interaction with the opposing IT Ca2+ current. Patch clamp recordings were obtained from identified eGFP‐VP and PVN‐RVLM neurons. We found that activation of eNMDARs following blockade of astrocyte glutamate transporters (DHK 300μM) increased the firing activity of VP and PVN‐RVLM neurons in response to depolarizing pulses (~62%, P <0.05). This effect involved shorter latency to first spike, increased total number of action potentials, and duration of firing burst. These effects were prevented following IA blockade with 4AP (P>;0.2 in 4AP). In the presence of the IT channel blockade (mibefradil), the DHK excitatory effect was reduced to ~30%, P<0.05). Our studies indicate that activation of eNMDARs increases neuronal excitability of hypothalamic neurons by inhibiting IA function, an effect that is in part dependent on an enhanced activation of IT. Thus, the eNMDAR/IA coupling stands as a functionally relevant mechanism by which astrocytes influence hypothalamic neurohumoral outflow.
Subfornical organ: a novel site for the actions of cholecystokinin
Authors: Ahmed Al‐Shaimaa Faissal , Ferguson Alastair V. , Sharkey Keith A.
Published: June 2021

The subfornical organ (SFO) is an important sensory circumventricular organ implicated in the regulation of fluid homeostasis and energy balance. We examined the response of SFO neurons to cholecystokinin (CCK) using the functional activation markers c‐Fos and p‐ERK. The number of c‐Fos and p‐ ERK immunoreactive SFO neurons were determined in 18 hr‐fasted rats in response to vehicle, CCK (16μg/kg, i.p.) alone or CCK in combination with a CCK1 or a CCK2 receptor antagonist (Devazepide; 600 μg/kg and L‐365,120 [L‐365]; 100 μg/kg, respectively). The nucleus of the solitary tract (NTS) was used as a positive control region for CCK‐induced activity. After 90 min, CCK induced a significant increase in the number of c‐Fos neurons in the NTS (259.2±20.8) compared to vehicle (47.5±2.5). Similarly, in the SFO, c‐Fos was expressed in 40.5 ± 10.6 neurons in CCK‐treated compared to 6.6 ±2.7 in vehicle‐treated rats (n=4/group). Devazepide significantly reduced the effects of CCK in the NTS but not in SFO. L‐365 blocked the effects of CCK in both regions. After 15 min, CCK increased the number of p‐ERK neurons in NTS (27.0±4.0) as well as SFO (18.0±4.0) compared to vehicle (8.0 ±2.6 and 4.3±0.6 respectively). Both devazepide and L‐365 reduced CCK induced p‐ERK in NTS, but only L‐365 reduced it in the SFO. In conclusion, SFO represents a novel CNS site at which circulating CCK may act to influence autonomic control centers in the hypothalamus.
Photic stimulation is required to elicit estrogen‐induced anorexia in rats
Authors: Mabuchi Kaori , Takano Azusa , Hara Yayoi , Morimoto Keiko , Takamata Akira
Published: June 2021

Estrogen replacement in ovariectomized (OVX) rats reduces food intake specifically during the light phase. To test the hypothesis that enhanced response to photic stimulation during the light phase is involved in the mechanism for the anorexigenic and anti‐obesity effects of estrogen, we examined the effects of exposure to a constant dark environment (DD) and estrogen replacement on food intake and body weight change in OVX rats. Female Wistar rats were ovariectomized and implanted with either an estradiol (E2) or a cholesterol (Veh) capsule. Rats were then exposed to DD for 2 weeks. Other rats exposed to the12 h/12 h‐light/dark cycle condition (LD) served as control. Exposure to DD increased food intake during the subjective day but did not during the subjective night, and increased daily food intake in the E2 group. These changes occurred without phase shifting. DD exposure did not alter food intake either during the subjective day or night in the Veh group. Physical activity was increased by DD exposure during the subjective day in the both groups, and significantly decreased during the subjective night in the Veh group. Body weight gain under DD in the both groups was larger compared with that under LD. These data indicate that the anorexigenic effect of estrogen is dependent on the light environment, while photic stimulation attenuates body weight gain regardless of E2 replacement or physical activity.
Comparison of floor aerobics and treadmill walking on cognitive changes and participant satisfaction
Authors: Larsen Julie , Hansen Char‐Lee , Schmitter‐Edgecombe Maureen , Knuth Judy
Published: June 2021

Aerobic exercise improves cognitive function in many populations. We hypothesized that floor aerobics would increase cognitive function to a greater extent than treadmill walking because of the varied movements and the need to respond quickly to oral cues. We also hypothesized that women would prefer aerobics over treadmill walking based on workout quality and enjoyment of exercise. Twenty‐two women were randomized into an exercise modality: floor aerobics, treadmill walking, or a stretching control group. Moderately intense exercise classes were held three days per week for seven weeks. We assessed satisfaction with exercise modality using a Likert scale. We also assessed cognition at baseline, midterm, and post‐intervention using a standard neuropsychological test battery. Statistical analyses revealed that floor aerobics led to significantly greater improvements in processing speed than did treadmill walking. Participants expressed near‐significant preference for floor aerobics over treadmill walking as well. Therefore, floor aerobics appears to be a more acceptable modality for an exercise intervention to improve cognitive function. This project was funded by a College of Pharmacy Seed Grant from Washington State University.
Less exercise, more effects: Enhancement of cognitive functions associated with hippocampal BDNF signaling by voluntary resistance wheel running in adult rats
Authors: LEE MIN CHUL , Liu Yu Fan , Inoue Koshiro , Okamoto Masahiro , Soya Hideaki
Published: June 2021

Voluntary wheel running (WR) has beneficial effects on hippocampal cognitive functions if done abundantly. However it is still uncertain whether resistance wheel running would be the same. Voluntary resistance wheel running with a load (RWR) is a suitable model, since it allows increased work levels and resultant fast‐twitch muscular adaptation. Here we examined whether RWR has beneficial effects on cognitive functions with increased hippocampal BDNF signaling. We used 10‐week‐old male Wistar rats and divided randomly into sedentary (Sed), WR, and RWR (a load of 30% of b.w.) groups for 4 weeks. To access spatial learning and memory, rats were tested in the Morris water maze task. The protein levels of BDNF and its signaling molecules (TrkB, p‐ CREB) were detected by Western blotting. We found that even the average running distance were significantly reduced, the average work levels were drastically increased for the RWR group. Both WR and RWR improved spatial learning, while only RWR group enhanced spatial memory compared with Sed. RWR increased hippocampal BDNF, TrkB and p‐CREB protein levels, while WR increased only BDNF. There were correlations between spatial memory and BDNF (r = 0.41), p‐CREB (r = 0.44) and work levels (r = 0.77). These results suggest providing new evidence that RWR, even with short distance, is beneficial for enhancing hippocampal cognitive functions associated with hippocampal BDNF signaling.
Endothelial cells from different vascular bed respond to secondhand smoke differently under dynamic shear stress.
Authors: Yin Wei , Ngwe Ek Ching , Rubenstein David Alan
Published: June 2021

Secondhand smoke (SHS) has been reported to affect endothelial cells (EC) activities, but it is unclear if this effect would be altered under flow conditions. The goal of this study was to investigate if EC from different vascular beds would respond to SHS differently under dynamic shear stress. Human coronary artery EC (HCAEC), human umbilical vein EC (HUVEC) and human pulmonary artery EC (HPAEC) were grown to confluence and treated with SHS extract overnight. Cells were then exposed to pulsatile shear stress (0.1–1 Pa) in a cone and plate shearing device for 1 hour at 37°C. EC activation was measured by cell surface ICAM‐1 expression using a solid phase ELISA approach. The results demonstrated that SHS increased cell surface ICAM‐1 expression significantly on HCAEC, but did not have much effect on HUVEC and HPAEC. After EC were exposed to dynamic shear stress, ICAM‐1 expression on HCAEC decreased to the level observed on untreated cells. No change was observed with HUVEC. For HPAEC, shear stress decreased ICAM‐1 expression significantly, compared to untreated cells. These results demonstrated that EC from different vascular beds respond to SHS differently, and SHS could be more damaging to EC located in coronary arteries. Physiological pulsatile shear stress could inhibit cell activation in HCAEC and HPAEC, suggesting its protective role for arterial EC. This work is support by OCAST HR10–027.
Endurance exercise training attenuates fibrosis and collagen cross‐linking in myocardium of aged F344BNF1 rats
Authors: Wright Kathryn Jean , Betik Andrew , Thomas Melissa , Hepple Russell , Belke Darrell
Published: June 2021

The objective of the study was to determine if endurance exercise training (ET) could attenuate the age‐related increase in fibrosis and collagen cross‐linking in the myocardium of the heart, which is thought to be a cause of the age‐related decline in diastolic function. Fisher 344 × Brown Norway F1 rats underwent ET from late middle age into senescence. Genes for collagen synthesis and degradation were assessed by polymerase chain reaction. Matrix metalloproteinase (MMP) activity was assessed using EnzChek Gelatinase/Collagenase Assay kit, and collagen cross‐linking was determined indirectly by immunohistochemical staining for advanced glycation end‐products. Tissue inhibitor of matrix metalloproteinase‐1 (TIMP1) gene expression, TIMP and MMP1 protein expression, and MMP activity increased with age but with no ET effect. ET attenuated the age‐related increase in fibrosis and collagen cross‐linking, while increasing survival rate. This could have attenuated the age‐related decline in myocardial compliance and in turn have helped attenuate the decrease in diastolic function generally seen with aging. This work was supported by an operating grant from CIHR (MOP 57808).
α1‐adrenergic receptor activation mimics ischemic postconditioning
Authors: Janota Danielle Marie , Yun June
Published: June 2021

Ischemic postconditioning has been shown to reduce injury in response to ischemia/reperfusion. Because of limitations on the clinical use of ischemic postconditioning protocols, pharmacological agents that elicit a postconditioning (PostC) effect are highly desired. Previous studies have shown that stimulation of alpha1‐adrenergic receptors (α1‐ARs) is cardioprotective, thus, the objective of this study was to determine the effectiveness and investigate possible mechanisms of α1‐AR stimulation in PostC of cardiac myocytes. Adult rat ventricular myocytes and HL‐1 cardiac myocytes were subjected to simulated ischemia‐reperfusion injury. Cell membrane permeability, evaluated by measuring released lactate dehydrogenase (LDH) or propidium iodide uptake (PI), was used as an estimate of cell death. Lower amounts of LDH and PI uptake were detected when α1‐ARs were stimulated at the onset of reperfusion. Prior studies suggest that increased autophagy (ATG) following ischemia is protective. Addition of ATG activator rapamycin at reperfusion onset decreased cell death and was comparable to that observed with α1‐AR stimulation. Further, α1‐AR‐mediated reductions in cell death were reversed in the presence of ATG inhibitor, 3‐ Methyladenine. Our results suggest that α1‐AR stimulation at the onset of reperfusion can reduce cardiac myocyte death, which may be mediated through regulation of autophagy.
Telomere uncapping causes cellular senescence and inflammation in arteries: implications for arterial aging
Authors: Morgan Richard G , Ives Stephen J , Lesniewski Lisa A , Cawthon Richard M , Andtbacka Robert HI , Noyes R Dirk , Denchi Eros L , Richardson Russell S , Donato Anthony J
Published: June 2021

Telomere shortening has been associated with age‐related cardiovascular diseases. However, the uncapping of telomeres may have a greater impact on arterial aging, as it leads to cyclin dependent kinase inhibitor 1A (P21)‐induced senescence and subsequent inflammation. In arteries from 61 younger (YA) and older adults (OA), we assessed age‐related telomere uncapping (ChIP: p‐H2A.X (ser139) localization to telomeres), senescence (P21 mRNA) and inflammation (TNFA, MCP1 mRNA). Aging leads to greater telomere uncapping (YA: 1.0±0.1 vs OA: 2.3±0.5, P = 0.02), as well as greater senescence (P ≤ 0.04) and inflammation (both P < 0.06). Telomere uncapping was not associated with telomere shortening in human arteries (r = −0.09, P = 0.20). To provide proof of concept that telomere uncapping induces senescence and inflammation, we utilized a transgenic mouse model of inducible telomeric repeat factor 2 (trf2) deletion that results in telomere uncapping (trf2+/+: 3.0±1.1 vs trf2−/−: 4.7± 0.5, P = 0.07). There was greater senescence (P < 0.03) and inflammation (P ≤ 0.08) in aortas from trf2−/− (n = 6) compared with trf2+/+ mice (n = 8), despite no change in telomere length (P = 0.49). Here we are the first to demonstrate age‐related telomere uncapping in human arteries and, using a novel mouse model of terf2 deletion, demonstrate that telomere uncapping induces senescence and inflammation in arteries.

Support: NIA‐AG040297, U. CoA
Resistance exercise training reverses age‐related impairments in macro and microvascular blood flow and the associated blunted muscle protein synthesis response to nutrition
Authors: Phillips Bethan , Atherton Philip , Varadhan Krishna , Limb Marie , Rennie Michael , Smith Kenneth , Williams John
Published: June 2021

Perfusion of the skeletal muscle microvasculature in response to nutrition is central for muscle maintenance (protein anabolism) and whole‐body glucose homeostasis (glucose disposal), both of which can be compromised in older age. We explored links between muscle microvascular blood volume [flow] (MBV) and protein synthesis (MPS) under postabsorptive and postprandial (IV Glamin and 20% dextrose; blood glucose ~7.5 mmol·l−1) conditions in 10 young (~23 y) and 10 older (~71 y) men. In a second group of 10 older men (~73 y) we studied these responses after 20 wk resistance‐exercise training (RET). We measured leg [femoral artery] blood flow (LBF) by Doppler ultrasound, muscle MBV by contrast‐enhanced ultrasound (CEUS), MPS using [1, 2‐13C2] leucine tracer and plasma insulin by ELISA. Increases in LBF (0.51±0.02 vs. 0.57±0.04 l·min−1, P<0.05), MBV (+25±10%, P<0.05) and MPS (0.04±0.004 vs. 0.08±0.001%·h−1, P<0.05) were evident in untrained young but not older men after nutrition. In contrast, older men exhibited rejuvenated LBF (0.38±0.03 vs. 0.42±0.04 l·min−1, P<0.05), MBV (+44±11%, P<0.05) and MPS (0.04±0.004 vs. 0.07±0.006 %·h−1, P<0.05) responses to nutrition after RET, despite plasma insulin and glucose clearance responses remaining blunted (vs. young). We conclude that RET revitalizes age‐related declines in LBF, MBV and MPS responses to nutrition, independent of modified insulin or glucose kinetics.
Effects of dietary nitrate supplementation on NO‐mediated vasodilation during local heating in healthy humans
Authors: Keen Jeremy Thomas , Levitt Erica Lynne , Wong Brett James
Published: June 2021

Nitrate supplementation in the form of beetroot juice (BRJ) has been shown to increase NO where nitrate can be converted to nitrite and NO through both NOS‐independent and dependent pathways. We hypothesized BRJ would augment the NO‐dependent component of cutaneous thermal hyperemia. Six subjects were equipped with two microdialysis fibers on the forearm and randomly assigned to lactated Ringer's (control) or 20mM L‐NAME (NOS inhibitor). Site 1 was perfused with LNAME once a plateau in the local heating response was achieved to quantify NO‐dependent vasodilation. Skin blood flow via laser‐Doppler flowmetry (LDF) and mean arterial pressure were measured; cutaneous vascular conductance (CVC) was calculated as LDF/MAP and normalized to %CVCmax. Subjects reported to the lab for pre‐and post‐supplement local heating protocols. Dietary intervention consisted of 1 shot of BRJ (.45g nitrates; 5mM) for 3 days. There was no significant difference between %NO contribution to local heating pre‐BRJ (60 ± 4 %CVCmax) and post‐BRJ (63% ± 2 %CVCmax) supplementation. These data suggest BRJ does not improve NO‐mediated vasodilation in the cutaneous vasculature in response to local heating in healthy humans.
Coronary blood flow during cold air breathing: mechanistic insights using pharmacological blockade
Authors: Muller Matthew D , Gao Zhaohui , Mast Jessica L , Leuenberger Urs A , Sinoway Lawrence I
Published: June 2021

Recent work from our laboratory has demonstrated that cold air inhalation (CAI) impairs coronary blood flow velocity (CBV) in healthy humans. The first objective of this study was to determine if blockade of oropharyngeal afferents would improve coronary perfusion during CAI. The second objective was to determine if systemic beta‐adrenergic blockade would improve coronary perfusion during CAI. In study 1, ten subjects received upper airway anesthesia with lidocaine then underwent CAI (−15 to − 30°C) for 5 minutes. In study 2, eight subjects received intravenous propranolol prior to CAI. Control experiments were performed on separate days. HR, MAP, and CBV (from Doppler echocardiography) were obtained. Rate pressure product (RPP) was used as an index of myocardial O2 demand and CBV was an index of myocardial O2 supply; changes (Δ) from baseline were calculated. In study 1, lidocaine blocked the gag reflex but did not affect ΔRPP (428 ± 159 vs 496 ± 339) or ΔCBV (0.8 ± 1.2 vs 0.9 ± 0.9 cm/sec) to CAI compared to control. In study 2, intravenous propranolol lowered resting HR and completely blocked the HR increase to isoproterenol. Further, propranolol lowered O2 demand in response to CAI (ΔRPP=169 ± 285 vs 1106 ± 360) compared to control. These data indicate that the detrimental effects of CAI on the coronary circulation are due in part to activation of beta‐adrenergic receptors. Supported by NIH P01 HL096570 and UL1 TR000127.
Chemosensitive neurons in the retrotrapezoid nucleus (RTN) express SK channels with low Ca2+ affinity
Authors: Chen Xinnian , Hawryluk Joanna , Tzingounis Anastasios V , Mulkey Daniel K
Published: June 2021

Chemosensitive RTN neurons regulate breathing in response to changes in tissue CO2/H+. despite the importance of these cells, little is known regarding molecular determinants of their intrinsic excitability. We have recently determined that RTN chemoreceptors express Ca2+‐activated small conductance K+ (SK) channels, however, the role of these channels in chemoreceptor function is unknown. Here, we use electrophysiological and computational approaches to explore SK channel function in RTN neurons. In brain slices (300 μm thick) from rat pups (P7–12), cell‐attached recordings of membrane potential show that bath application of apamin (selective SK channel blocker) decreased amplitude of the after hyperpolarization (AHP) evoked by depolarizing current injection but did not affect baseline activity. Based on computer simulations, we predict that under baseline conditions and high Ca2+ pump activity, [Ca2+]i should be sufficient to activate SK channels with a typical Ca2+affinity of < 1μM. Therefore, we predict that RTN neurons express SK channels with low Ca2+ affinity possibly due to high casein kinase‐2 (CK2) activity. Consistent with this possibility, we found that TBB (a selective CK2 inhibitor) eliminated spontaneous activity of RTN neurons as expected for activation of a K+ conductance. These results suggest that the contribution of SK channels to activity of RTN neurons is regulated by CK2 activity.
Chemosensory control by purinergic signaling within the retrotrapezoid nucleus (RTN) in conscious rats
Authors: Barna Bárbara F , Takakura Ana C , Mulkey Daniel K , Moreira Thiago S
Published: June 2021

The RTN contains a population of CO2/H+‐sensitive neurons that send excitatory projections to respiratory centers to regulate breathing (i.e., chemoreceptors). Evidence also suggests that ATP, possibly released by astrocytes, is an important mediator of RTN chemoreceptor activity. However, this possibility has yet to be tested in conscious animals. The goal of this study is to determine if purinergic signaling in the RTN contributes to breathing under resting conditions and during central chemoreflex activation in unrestrained awake rats. Male Wistar rats (280–300 g) with bilateral stainless steel cannulas implanted into the RTN were used. Bilateral RTN injections of PPADS (P2‐receptor antagonist: 5 mM ‐ 50 nl) did not change baseline minute ventilation (VE), mean arterial pressure (MAP), or heart rate (HR). However, PPADS treated animals exhibited reduced tidal volume (VT) (6.6 ± 0.14 vs. saline: 9.1 ± 1.4 ml/kg) and VE (748 ± 2.5 vs. saline: 1257 ± 239 ml/kg/min) responses to hypercapnia (7% CO2). CO2‐induced changes in respiratory frequency, MAP and HR were not affected by PPADS. These results suggest that CO2‐evoked ATP release in the RTN contributes to control of breathing in conscious animals
Toll‐like receptor 4 (TLR4) mediates cavernosal dysfunction in diabetic rats
Authors: Nunes Kenia Pedrosa , Carrilo‐Sepulveda Maria Alicia , Szasz Theodora , Webb R. Clinton
Published: June 2021

Vascular abnormalities associated with diabetes mellitus constitute a major cause of erectile dysfunction (ED). The immune system activates toll‐like receptors (TLRs), and increased TLR4 has been found in diabetic patients. We hypothesized that TLR4 mediates vascular dysfunction in diabetic corpus cavernosum (CC) by increasing contractility. Functional experiments using CC tissue from STZ‐induced diabetic rats (65mg/Kg s.c.,5 weeks), western blot analysis and cavernosal vascular smooth muscle cells (VSMC) were used. Results showed that increased CC contraction from adrenergic stimulation with phenylephrine (PE, 10−9–10−4M) was abolished by a specific TLR4 inhibitor CLI‐095 (10−5M; 35′), demonstrating that blockade of this receptor decreases adrenergic sensitivity in diabetic CC (Log EC50: 5.72±0.05 vs. 5.04±0.06, p≤0.05). The maximum contraction elicited by PE (10−4M) in diabetic rats plus CLI‐095 was significantly decreased in comparison to that in non‐treated diabetic rats (7.92±0.35 vs. 12.34±0.43 mN respectively). TLR4 was significantly increased in CC from STZ‐induced diabetic rats. Immunofluorescence of cultured cavernosal VSMC stimulated for 12h with high glucose (25mM) suggests that increased TLR4 expression was triggered by hyperglycemia in CC. In conclusion, these results indicate an involvement of TLR4 in impaired erectile function during diabetes.
Novel anti‐atherogenic effects of trivalent chromium in vascular smooth muscle cells: therapeutic implication for diabetic vascular complications
Authors: Ganguly Rituparna , Sahu Soumyadip , Raman Priya
Published: June 2021

Trivalent chromium (Cr) is proposed to have a therapeutic potential in glycemic and cardiovascular health. While emerging evidence support a protective role of Cr in atherosclerosis, the underlying mechanisms of Cr action in diabetic vascular disease remain unknown. Diabetic patients have increased incidence of vascular smooth muscle cell (VSMC) migration and proliferation, key events leading to initiation and development of atherosclerosis. The present study provides the first evidence that Cr inhibits high glucose (30mM) induced migration and proliferation of human aortic SMC (HASMC) coupled to attenuation of ERK1/2 phosphorylation. We showed earlier that Cr downregulates a potent proatherogenic matricellular protein Thrombospondin‐1 (TSP‐1), known to accelerate initiation of atherosclerosis, concomitant to a decrease in protein O‐glycosylation. We now further demonstrate that this decrease in TSP‐1 expression is accompanied by reduction in expression of Glutamine: fructose‐6‐phosphate amidotransferase (GFAT), the key rate limiting enzyme of hexosamine pathway of glucose metabolism. Additionally, we found that Cr inhibits high glucose‐induced oxidative stress via reduction in cellular reactive oxygen species (ROS). Together, these data suggest TSP‐1 as a potential therapeutic target of Cr and provide a novel anti‐atherogenic mechanism for Cr in diabetic atherosclerotic complications.
Lysophosphatidic acid induces reactive oxygen species generation through PLC/PKC/Nox Pathway in PC‐3 prostate cancer cells
Authors: Lin Chu‐Cheng , Lin Chuan‐En , Lin Yueh‐Chien , Lee Hsinyu
Published: June 2021

Prostate cancer is one of the most frequently diagnosed cancers in males. PC‐3 is a popular cell model for investigating late prostate cancer behaviors. Lysophosphatidic acid (LPA) is a lysophospholipid that mediates several cell behaviors in cancers such as proliferation, migration and adhesion. In our previous study, LPA enhances VEGF‐C expression in PC‐3 cells through activating the generation of reactive oxygen species (ROS), which is known as an important secondary messenger in cancer progression. By using flow cytometry, we found that LPA triggers ROS generation within ten minutes and ROS production can be suppressed by antioxidant, N‐acetylcysteine. In addition, LPA1/3 antagonist Ki16425 treatment and siRNA transfection efficiently suppressed the LPA induced ROS production that indicates LPA1 and LPA3 are involved in this pathway. As downstream signals of LPA, PLC and PKC were also suggested to participate in LPA induced ROS generation by using specific inhibitors and siRNAs. Furthermore, NADPH oxidase inhibitor DPI can block this ROS generation pathway. Overall, we demonstrated that LPA induces ROS generation through PLC/PKC/Nox pathway in PC‐3 prostate cancer cells.
Activation of CaMKKα Stimulates Skeletal Muscle Glucose Uptake in Insulin Resistant Mice
Authors: Witczak Carol A , Hinkley J. Matthew , Ferey Jeremie L , Smith Cheryl A.S. , Gilliam Laura A.A. , Brault Jeffrey J
Published: June 2021

Activation of Ca2+/calmodulin‐dependent protein kinase kinase α (CaMKKα) signaling stimulates skeletal muscle glucose uptake in healthy, insulin‐sensitive mice. The goal of this study was to determine if CaMKKα could stimulate glucose uptake in muscle from insulin resistant mice. To induce insulin resistance, male C57BL6/J mice were fed a high fat (60% kcal fat) diet. After 12 weeks, insulin (600 μU/ml)‐stimulated ex vivo muscle [3H]‐2‐deoxyglucose uptake was significantly decreased (30%) in high fat fed mice, demonstrating skeletal muscle insulin resistance. To stimulate CaMKKα signaling, muscles from control and insulin‐resistant mice were transfected with plasmid DNA containing constitutively active CaMKKα or empty vector by in vivo electroporation. After 2 weeks, active CaMKKα protein levels were robustly increased and were not different between control and insulin‐resistant mice. In vivo muscle [3H]‐2‐deoxyglucose uptake was examined in the absence of insulin stimulation. In both control and insulin‐resistant mice, active CaMKKα increased glucose uptake ~2‐fold. Collectively, these results show that activation of CaMKKα signaling can stimulate glucose uptake in both insulin‐sensitive and insulin‐resistant skeletal muscle, and suggest that CaMKKα may be a novel therapeutic target for impaired muscle glucose uptake in type 2 diabetes. SUPPORT: NIH R00AR056298, ECU start‐up funds.