bluuebunny/crossref_metadata_2025 huggingface dataset:
P2Y2 Receptor Deficiency Reduces Vascular Inflammation and Atherosclerosis in Mice
Authors: Seye Cheikh
Published: June 2021

The P2Y2 receptor (P2Y2R) is a primary regulator of vascular cell adhesion molecule‐1 which plays a key role in recruitment of inflammatory cells in atherosclerosis. The objective of this study was to evaluate the consequence of P2Y2R ablation in the development of atherosclerosis.

Methods and results

Apolipoprotein E‐deficient (ApoE−/−)mice with genetic ablation of P2Y2R developed significantly smaller atherosclerotic lesions in the aortic sinus as compared to Apoe−/− littermates when fed a chow diet. Strikingly, lesions of Apoe−/−/P2Y2R−/−mice displayed a sharp decrease in macrophage infiltration and VCAM‐1 immunostaining. ApoE−/−mice exhibited spontaneous high blood levels of soluble VCAM‐1 (sVCAM‐1) and knockout of P2Y2Rdrastically lowered sVCAM‐1. Basal levels of sVCAM‐1 were detected by Elisa in primary endothelial cells of ApoE−/−mice but not in those from Apoe−/−/P2Y2R−/−mice. The P2Y2R agonists induced a rapid release of sVCAM‐1 from cultured endothelial cells from wild type but not P2Y2R−/−mice, suggesting that VCAM‐1 is part of a specific shedding pathway mediated through P2Y2R activation. Notably, inhibition of the pro‐protein convertase furin or specific knockdown of the metalloproteinase ADAM10 inhibited basal and nucleotide‐stimulated sVCAM‐1 release.

Conclusion

Inactivation of P2Y2R protects against atherosclerosis, suggesting that drugs targeting this receptor could prevent recruitment of inflammatory cells.
Cigarette Smoking Affects Human Semen Quality in Synergy with Functional Nrf2 Polymorphisms
Authors: Huang Zhaofeng , Yu Bolan
Published: June 2021

Study in smoking consequences with the knowledge of genetic background would help to understand the interaction of genes and smoking on male fertility. In this study, we examined two genetic variants of erythroid 2Crelated factor 2 (Nrf2), mRNA expression levels of Nrf2, catalase, superoxide dismutase isoenzyme‐2(SOD2), and glutathione S‐transferase‐M1, and seminal SOD activities in 314 heavy smokers and 314 age‐matched nonsmokers. Results showed that the Nrf2 rs6721961 TT genotype was associated with low semen quality in heavy smokers with an OR (95%CI) of 2.381(1.112–5.120), and this variant had a higher frequency in heavy smokers with low semen quality than in those with high quality (P=0.011). Heavy smokers with this genotype had significantly decreased sperm concentration and sperm count (P=0.0154 and P=0.0214) compared to non‐carriers, in addition to negatively affected sperm progressive motility and immotility rate (P=0.0537 and P=0.0543). Smoking also significantly decreased seminal SOD activity (P<0.05) and altered Nrf2 and SOD2 mRNA expression in heavy smokers with this variant. Our study suggests a novel synergetic effect of smoking and Nrf2 functional polymorphisms on human spermatogenesis. This study was supported by NSFC (81102474, 31170831), Guangdong Natural Science Foundation (S2011040003768), GTIB (12A52021552) and Guangzhou Medical University (2011C09).
Modulation of Autophagy Affects the Hepatic Pathology in Alcoholic and Non‐alcoholic Liver Diseases
Authors: Zhang Hao , Khambu Bilon , Chen Xiaoyun , Yin Xiao‐Ming
Published: June 2021

Macroautophagy is a cellular degradation process that can remove subcellular organelles including lipid droplets. We explored whether modulation of autophagy could affect the progression of alcoholic and non‐alcoholic liver diseases. C57BL/6 mice were given ethanol via intraperitoneal injection (acute) or by a 4‐week oral feeding regime (chronic), or given high fat diet for 12 weeks. An autophagy enhancer, carbamazepine or rapamycin, or an autophagy inhibitor, chloroquine, was given before the sacrifice. Activation of autophagy, level of hepatic steatosis, and blood levels of triglycerides, liver enzyme, glucose and insulin were measured. Carbamazepine, as well as rapamycin, could activate, and enhance ethanol‐induced, macroautophagy in hepatocytes in vitro and in vivo. In both acute and chronic ethanol condition, macroautophagy could be activated. The levels of hepatic steatosis and liver injury could be further enhanced by chloroquine, but reduced by carbamazepine. The protective effects of carbamazepine and rapamycin in reducing steatosis and in improving insulin sensitivity could be also demonstrated in high fat diet‐induced non‐alcoholic fatty liver condition. These findings indicate that pharmacological modulation of macroautophagy in the liver can be an effective strategy for reducing fatty liver condition and liver injury.
Role of HO‐1 in neuroblastoma resistance to Bortezomib
Authors: Furfaro AnnaLisa , Piras Sabrina , Passalacqua Mario , Domenicotti Cinzia , Pronzato Maria Adelaide , Marinari Umberto Maria , Moretta Lorenzo , Traverso Nicola , Nitti Mariapaola
Published: June 2021

Neuroblastoma (NB) is the most common solid tumor in childhood and is characterized by a poor prognosis due to the gain of a chemoresistant phenotype. Among the most recent anticancer therapies Bortezomib (BTZ) has shown impressive clinical activity to overcome cancer cell resistance to conventional therapy. The availability of antioxidants is recognized as one of the critical mechanisms in the development of cancer cell resistance and the up‐regulation of heme oxygenase‐1 (HO‐1) seems to play a key role. We analyzed the effects of BTZ on two different NB cell lines, SHSY‐5Y and HTLA‐230, well known respectively as sensitive and resistant to therapy, pointing out the role of HO‐1. SHSY‐5Y exposure to 5–40nM BTZ was able to strongly reduce cell proliferation while the same treatment was less effective on HTLA. Moreover, BTZ treatment was able to strongly up‐regulate HO‐1 in HTLA, while only a slight induction was observed in SHSY‐5Y. However, HO‐1 silencing was able to further decrease the proliferation rate of HTLA cells exposed to BTZ. In conclusion, we believe that proteasome inhibition could be a useful therapeutic approach against NB but the inhibition of HO‐1 should be considered in order to improve the effectiveness and prevent chemoresistance.

Grants: PRIN2009M8FKBB_002 and Genoa University
A Targeted Iron‐based MRI Contrast for Tumor Detection
Authors: Mills David R. , Walsh Edward G. , Brilliant Kate E. , Hixson Douglas C. , Park William K.C.
Published: June 2021

A genetically modified ferritin has been examined for its properties as a tumor‐selective MRI contrast agent. The engineered ferritin was derived from Archaeoglobus fulgidus, which stores a significantly greater quantity of iron than wild type ferritins. Relaxivity measurements were taken at 3 Tesla of ferritin particles uniformly distributed in an agarose gel to assess relaxivities r1 and r2. The r1 and r2 values of the modified ferritin were significantly higher (r1=1290 mM‐1 s‐1 and r2=5742 mM‐1 s‐1) than values observed for endogenous ferritin (e.g., horse spleen, r1=0.674 mM‐1 s‐1, r2=95.54 mM‐1 s‐1). Modified iron enriched ferritin was conjugated with a monoclonal antibody against rat Necl‐5, an immunoglobulin‐like cell surface glycoprotein and ortholog of the human poliovirus receptor CD155. While Necl‐5 is barely detectable in normal epithelial cells, it is dramatically upregulated in many human and rodent carcinomas. In vitro studies showed strong reactivity of the nanoconjugate to transformed Necl‐5 positive rat prostate epithelial cells. Furthermore, magnetic resonance imaging (MRI) demonstrated a significant T2 contrast with negligible T1 effect owing to the heterogeneous nanoconjugate distribution when bound to cells. These findings highlight the utility of the modified ferritin construct as a novel MRI contrast agent that can be manipulated to target antigen‐specific tissues.
Comparison of micro‐bubble assisted p53, pRB, and p130 gene therapy in combination with radiation therapy in prostate cancer in vitro and in vivo
Authors: Nande Rounak Paramjeet , Gossman Michael S. , Lopez Jeffrey P. , Howard Candace M. , Denvir James , Claudio Pier Paolo
Published: June 2021

We used a novel approach using adenoviral (Ad) delivery of cell cycle proteins encapsulated in microbubbles (MBs), in combination with radiation to target p53 & pRB mutant prostate cancer cells. MBs deliver therapeutic Ads, combined with ultrasound (US)‐targeted MB destruction (UTMD), allowing for a site‐specific gene transfer system.

In vitro: DU145 radio‐resistant human prostate cancer cells were exposed to 10 & 20Gy of x‐ray radiation. Immediately after irradiation, cells were transduced with Ads carrying p53, pRb, or p130. In vivo: Tumors were grown to a volume of 200 mm3 in nude mice on their flanks. Mice were treated with intravenous (IV) injections of the Ads ± MB. IV treatments were compared to intratumoral (IT) injections of the Ads. Combinational therapy groups were irradiated at 8Gy, & injected intravenously with MB/Ads ± US, every week for 4 weeks.

Higher percentage of cell death was observed in 20Gy vs. 10Gy irradiated cells. Cells transduced with adenoviruses carrying RB, p53, and p130 showed a decreasing order of cell death. Statistically significant reduction of the US‐targeted MB/p53 or RB Ad transduced tumors was observed when compared to IT treatments or radiation alone. US targeted MB/Ads in combination with x‐ray radiation therapy resulted in the most efficient treatment.

Combination treatments of radiation and UTMD increase the treatment potential of therapy resistant prostate cancer.
Development of ssDNA‐based aptamers specific to PSMA
Authors: Yuan Bin , Zhao Nianxi , Pei Sung‐nan , Zu Youli
Published: June 2021

Prostate‐specific membrane antigen (PSMA) has been considered a valuable biomarker for specific imaging detection and selective targeted therapy of prostate cancer. Compared to antibodies, the aptamers, a new class of molecular probes, have more flexibility, less blood resistance and much less immunogenicity in vivo. However, the biostability of RNA‐based aptamers for PSMA is still a major concern for in vivo use. So we employed a unique SELEX approach by combination of both cell‐based selection and biomarker‐based enrichment to develop ssDNA aptamers specific to PSMA. The cultured PSMA‐positive prostate cancer cells LNCaP was used for cell‐SELEX. After 10 rounds of positive cell selection and 6 rounds of counter‐selection, the enriched ssDNA aptamers were labeled with Cy5 fluorescent reporter and their cell binding capacity was evaluated. Flow cytometry analysis revealed that 84% of LNCaP cells were highlighted by the enriched ssDNA aptamers at the concentration of 50nM, similar to that stained by anti‐PSMA antibodies. In control experiments, no binding of the enriched ssDNA aptamers to the PSMA‐negative cancer cells were observed under the same condition. Sequence analysis and sensitivity/specificity assays of the enriched aptamers are currently undergoing. The results will be presented at the meeting. Supported by NIH grants R01 CA151955.
Bacterial stimulation of endogenous hydrogen sulfide synthesis: a novel mechanism for resolution and repair in the colon
Authors: Flannigan Kyle , Verdu Elena , Wallace John
Published: June 2021

Hydrogen sulfide (H2S) is an important signaling molecule throughout the gastrointestinal (GI) tract. Colonic H2S synthesis is markedly increased during experimental colitis in rats, and contributes to the resolution of inflammation and healing of ulcers. The triggers responsible for this up‐regulation of colonic H2S synthesis are unclear. Therefore, we tested whether bacterial signals at the epithelial surface may be important stimuli for upregulation of endogenous H2S synthesis, helping drive resolution and mucosal repair. Germ‐free NIH Swiss mice (6 weeks of age; n≥4) were orally gavaged with feces (200 μL; 5% wt/ vol) from mice raised in specific pathogen free (SPF) conditions. Inoculated mice were housed in SPF conditions and euthanized at day 2 or 7 post‐inoculation. Colonic tissue from germ‐free control mice produced very low amounts of H2S. Within 2 days of inoculation with SPF flora, a significant increase in colonic H2S synthesis was observed (>;2‐fold; p<0.05), which further increased to 5‐fold (p<0.01) by 7 days post‐inoculation. We previously found that bacterial‐derived H2S does not contribute to what is measured as colonic H2S synthesis. These results support the hypothesis that bacterial factors can up‐regulate colonic H2S, which could be an important signaling mechanism for driving the repair of mucosal injury. Supported by the Crohn's and Colitis Foundation of Canada (CCFC).
Antiviral activity of Bifidobacterium longum SPM1205, 1206 and Lactobacillus ruminis SPM0211 against rotavirus
Authors: Kang Joo‐Yeon , Lee Do‐Kyung , Kim Min‐Ji , Park Jae‐Eun , Shin Hea‐Soon , Ha Nam‐Joo
Published: June 2021

Rotavirus is the most common cause of severe gastroenteritis and dehydrating diarrhea in infants and young children worldwide. Currently, rotavirus vaccines have shown good tolerance and significant efficacy. However, these vaccines are limits and restrictions. Probiotic bacteria, such as Lactobacillus spp. and Bifidobacterium spp. is reported the multiple potential health effects including blocking gastroenteric pathogens, enhancing the immune response and antiviral effects. The aim of this study was to assess the antiviral activity of 3 Lactobacillus spp. and 14 Bifidobacterium spp. isolated from healthy Korean against rotavirus. In this study, we evaluated the in vitro antiviral activity of these probiotics against rotavirus by plaque assay. All of them were not toxic to vero and caco‐2 cells. B. longum SPM1205, 1206 and L. ruminis SPM 0211 have shown significant antiviral activity against rotavirus compared to control group. These results suggest that B. longum SPM1205, 1206 and L. ruminis SPM0211 are potential new therapeutic tool against rotavirus.
Peripheral and central NK1 receptors in emesis control in Suncus murinus
Authors: Rudd John A , Cheng Frankie HM. , Moreaux Benoit
Published: June 2021

Brain penetrant tachykinin NK1 receptor antagonists are known to reduce cisplatin‐induced emesis in ferrets. In the present studies, we investigate the role of central versus peripheral NK1 receptors in the mechanism of emesis in S. murinus. R116301 was selected as a reference brain penetrant NK1 receptor antagonist, and R115614 was used as a peripherally restricted antagonist; both have similar affinity for S. murinus NK1 receptors (PA2~8) and in vivo potency to reduce substance P‐induced plasma extravasation (ID50 ~2.9 μmol/kg). Drugs or vehicle were administered s.c, or i.c.v. 30 min prior to nicotine (30.7 μmol/kg, s.c.), copper sulphate.5H2O (480.6 μmol/kg, i.g.), or cisplatin (100 μmol/kg, i.p).

Peripheral Studies

R116301 (23–53 mmol/kg, s.c) attenuated nicotine‐ and cisplatin‐induced emesis by 76 and 52 %, respectively (P<0.05). R115614 (30–70 mmol/kg, s.c) reduced copper sulphate‐ and cisplatin‐induced emesis by 75 and 50 %, respectively (P<0.05).

Central Studies

R116301 (10–100 nmol, i.c.v.) antagonised nicotine‐induced emesis 89 % (P<0.05), while R115614 (100–500 nmol, i.c.v.) was incative (P>;0.05). In conclusion, centrally located tachykinin NK1 receptors play an important role in the emetic reflex but peripherally located NK1 receptors may also be involved in some causes of emesis.
Role of Calcium‐Sensing Receptor (CaSR) on Gastric Acid Secretion in Isolated Mouse Stomachs
Authors: Takeuchi Koji , Hayashi Shusaku , Amagase Kikuko , Aihara Eitaro
Published: June 2021

In the present study, we examined the effect of cinacalcet, a CaSR agonist, on basal and stimulated gastric acid secretion in mice. Male ddY mice were used after 18 h fasting. Under urethane anesthesia, the stomach was isolated, mounted between two halves of a lucite chamber, and acid secretion was measured at pH 5.0 with 2 mM NaOH using a pH‐stat method in vitro. Histamine was added to the serosal solution. Cinacalcet was added 30 min before histamine, while CYN154806 (a somatostatin SST2 receptor antagonist) was added 30 min before cinacalcet treatment. Cinacalcet dose‐dependently and significantly suppressed the acid secretion in response to histamine, although this agent alone slightly increased the secretion. The inhibitory effect of cinacalcet was dose‐dependently reverted by pretreatment with CYN154806. Immunohistochemial study demonstrated the localization of CaSR in the stomach D cells. These results suggest that CaSR is involved in the regulatory mechanism of gastric acid secretion. It is assumed that the stimulation of CaSR negatively modulates the acid secretory response to histamine through the release of somatostatin and the activation of SST2 receptors.
RGS2 repression increases susceptibility of mice to interleukin‐ 13‐induced airway hyperresponsiveness
Authors: Xie Yan , Jiang Haihong , Abel Peter W. , Casale Thomas B. , Panettieri Reynold A. , Tu Yaping
Published: June 2021

G‐protein coupled receptors (GPCRs) are important regulators of cells involved in asthma. We recently reported that RGS2, a selective modulator of Gq‐coupled GPCRs, is a key regulator of airway hyperresponsiveness (AHR), the pathophysiologic hallmark of asthma. Since immunohistochemistry staining showed 50% repression of RGS2 protein in bronchial epithelium and smooth muscle of asthma patients as compared to non‐asthmatics, we further investigated the pathological importance of RGS2 repression in asthma. Th2 cytokine interleukin‐13 (IL‐13) is necessary and sufficient to induce AHR in mice. We found that intranasal administration of IL‐13 decreased RGS2 expression in airways and caused AHR in mice, assessed by Western blot and invasive tracheostomy. Although both hetero‐ and homozygous naïve RGS2 knockout (KO) mice exhibit spontaneous AHR, IL‐13 treatment further augmented AHR in RGS2 KO mice. Interestingly, deletion of RGS2 gene significantly enhanced IL‐13‐ induced airway remodeling, including increased peribronchial fibrosis and smooth muscle in mice. Thus, we speculate that RGS2 is an important gene regulating AHR, and RGS2 repression increases susceptibility of mice to IL‐13‐induced AHR in part through the promotion of airway remodeling. American Asthma Foundation (to Y.T.), Nebraska LB595 and 692 (to Y.T. and T.B.C.), NIH R01 HL097796 and P30 ES013508 (to R.A.P.).
Possible Efficacy Related Differences Among Cannabinoid Agonists
Authors: Chopda Girish , Bergman Jack , Vemuri Kiran , Makriyannis Alex , Paronis Carol A
Published: June 2021

Currently, there are scant in vivo data showing that cannabinoid (CB) agonists vary in efficacy. Here, we show that the efficacy of two CB agonists ‐ Δ9‐tetrahydrocannabinol (THC) and the 3‐ adamantyl CB AM4054 ‐ can be differentiated with CB antagonists in a warm‐water (52°C) tail withdrawal antinociception assay in CD1 mice and in drug discrimination studies in AM4054‐ trained monkeys. In mice, both THC and AM4054 produced 100% maximum possible effects (MPE) with ED50 values of 21.0 and 0.28 mg/kg, respectively. Rimonabant, 1–30 mg/kg, similarly antagonized both drugs, producing parallel rightward shifts of the dose‐effect functions, e.g., 3‐ to 10‐fold rightward shifts after 10 mg/kg rimonabant, with recovery in ≤ 24hr. In contrast, pretreatment with 0.1–10 mg/kg AM6538, a pyrazole analog of rimonabant, produced rightward then downward shifts of the agonist dose‐effect functions, and recovery was prolonged. Thus, after 3.2 mg/kg AM6538, THC (up to 300 mg/kg) produced <30%MPE; comparable doses of AM4054 still produced >;65%MPE and, after 10 mg/kg AM6538, antagonism was evident for >;2 days. In squirrel monkeys, AM6538 antagonized the discriminative‐stimulus effects of AM4054 dose‐dependently and, after the highest dose (5.6 mg/kg), for up to 10 days. These results suggest that differences in CB efficacy in vivo can be revealed with long‐acting CB antagonists such as AM6538. [Supported by: DA023142, DA026795]
Attenuation of Cocaine‐Induced Behaviors by the Sigma Receptor Ligand YZ‐185
Authors: Sage Andrew S. , Fan Kuo‐Hsien , Lever John R. , Lever Susan Z. , Miller Dennis K.
Published: June 2021

YZ‐185 (N‐phenylpropyl‐N′‐(3‐methoxyphenethyl)piperazine) is a sigma receptor ligand that binds with greater affinity to the σ1 than to the σ2 sigma receptor subtype (Ki values ≈ 1.4 and 10.2 nM, respectively) in brain. In a dose‐dependent manner and at doses that did not alter basal locomotor activity, YZ‐185 pretreatment attenuated cocaine‐induced hyperactivity in mice. YZ‐185 did not produce conditioned place preference or aversion in mice; however, it attenuated both the induction and expression of conditioned place preference to cocaine. These results indicate a role for sigma receptors in cocaine's locomotor‐activating and conditioned‐rewarding properties and support the use of N‐phenylpropyl‐ N′‐substituted piperazine ligands to investigate cocaine's effects.
Optogenetic and pharmacological activation of beta‐adrenergic receptor signaling in the basolateral amygdala promotes anxiety and aversive behavior
Authors: Siuda Edward R , Al‐Hasani Ream , McCall Jordan G , Chang Steven D , Anderson Sonya L , Bruchas Michael R
Published: June 2021

Beta2 adrenergic receptors (B2ARs) are clinical targets for a variety of therapeutic indications, however the role and neural circuitry of these Gs‐signaling GPCRs in anxiety and other affective disorders remain unresolved. Here we investigated the role of B2AR signaling in negative affective behaviors including anxiety and aversion. First, utilizing behavioral pharmacology, we manipulated B2AR signaling within the basolateral amygdala (BLA) of C57/BL6 mice through infusion of agonists, antagonists and putative biased ligands. We then examined these effects in behavioral models of anxiety (open field test) and aversive behavior (place aversion). Second, chimeric rhodopsin and B2AR receptors (B2OptoXRs) were packaged into lenti‐viral vectors under a CaMKII promoter and injected into the BLA. Using real‐time place conditioning, we show that mice display a robust aversive response to the conditioning chamber compared to control mice following light stimulation. Further, utilizing the open field test (OFT), we found that when B2OptoXRs are stimulated in the BLA, mice display a dramatic reduction in the time spent in the center of the arena with no significant changes in locomotor activity. Taken together, these data support that activation of B2ARs in excitatory neurons of the BLA is sufficient to produce avoidance and anxiogenic‐like behavioral responses. Funded by NIDA: R00DA025182 and McDonnell Center for Systems Neuroscience (MRB)
Aryl hydrocarbon receptor‐dependence of dioxin effects on constitutive mouse hepatic cytochromes P450 and growth hormone signaling components
Authors: Riddick David S , Lee Chunja
Published: June 2021

The aryl hydrocarbon receptor (AHR) has physiological roles in the absence of exposure to exogenous ligands and mediates adaptive and toxic responses to the environmental pollutant, 2,3,7,8‐tetracholorodibenzo‐p‐dioxin (TCDD). A readily metabolized AHR agonist, 3‐methylcholanthrene, disrupts expression of mouse hepatic growth hormone (GH) signaling components and suppresses cytochrome P450 2D9 (Cyp2d9), a male‐specific gene controlled by pulsatile GH via signal transducer and activator of transcription 5b (STAT5b). Using TCDD as an essentially non‐metabolized AHR agonist and Ahr−/− mice as a model to determine the AHR‐dependence of biological responses, we show that two mouse hepatic STAT5b target genes, Cyp2d9 and major urinary protein 2 (Mup2), are suppressed by TCDD in an AHR‐dependent manner. TCDD also decreased hepatic mRNA levels for GH receptor, Janus kinase 2, and STAT5a/b with AHR‐dependence. Without inducing selected hepatic inflammatory markers, TCDD caused AHR‐dependent induction of Cyp1a1 and NADPH‐cytochrome P450 oxidoreductase (Por) and suppression of Cyp3a11. In vehicle‐treated mice, basal mRNA levels for CYP2D9, CYP3A11, POR, serum amyloid protein P, and MUP2 were influenced by Ahr genetic status. We conclude that AHR activation per se leads to dysregulation of hepatic GH signaling components and suppression of some, but not all, STAT5b target genes. [Support: CIHR]
Therapeutic efficacy of MJ33, a novel inhibitor of phospholipase A2 (PLA2) of peroxiredoxin 6 (Prdx6), in LPS‐induced acute lung injury (ALI)
Authors: Lee Intae , Dodia Chandra , Chatterjee Shampa , Feinstein Sheldon I , Fisher Aron B
Published: June 2021

We have shown that peroxiredoxin 6 (Prdx6) on PLA2 activity is required for activation of NOX2 and subsequent generation of ROS in normal cells and have proposed a role for it in LPS‐induced acute lung injury (ALI). We evaluated MJ33, a novel inhibitor of PLA2 activity of Prdx6, for its therapeutic efficacy in ALI. Our recent studies of MJ33 displayed its avid lung uptake (67–86%), >;85% inhibition of phospholipase A2 (PLA2) activity, and high margin of safety in the intact mouse [toxic dose= >;25μmol/kg; PLA2 inhibitory dose= ~0.02μmol/kg]. ROS generation by endothelial cells in vitro was increased 16–24h post LPS treatment. This increase was significantly reduced by MJ33. LPS (0111:B4 from E. coli, 1–5mg/kg) was administered intratracheally. 4nmol MJ33 in unilamellar liposomes was administered intratracheally or intravenously either concurrently or 2 h post LPS. LPS significantly increased lung infiltration with increasing in inflammatory cells, lung permeability [protein levels, lung wet to dry ratio, leakage of FITC‐dextran into the lung lavage fluid], lipid peroxidation [TBARS and 8‐isoprostanes], and protein oxidation [protein carbonylation]. MJ33 dramatically reduced all of these measured parameters. These findings show that MJ33 can suppress the manifestation of oxidant stress associated with lung inflammation and the activation of NOX2.

Supported by NHLBI‐R01‐HL105509.
Effects of aerobic exercise training on obese female mice: metabolic and autonomic evaluation
Authors: Sartori Michelle , de Souza Leandro Eziquiel , de Souza Pamella Ramona , Santos Fernando , De Angelis Kátia , Irigoyen Maria Claudia
Published: June 2021

The aim of this study was to evaluate the metabolic and autonomic parameters in trained youth obese mice. Female ob/ob mice (4 weeks old) were randomized into sedentary (OS, n=11) or trained (OT, n=8) (treadmill,5 days/w, 60 min/d, during 8 wks) groups. Blood glucose was measured by reagent strips. Blood pressure signals were recorded using a data acquisition system. The OT group had higher exercise capacity compared to the OS group. OT group had reduced body weight, white adipose tissue and blood glucose (45±2g, 6.1±1g and 133±3g mg/dL) compared to OS group (50±2g, 6.1±1g and 169±8 mg/dL). Exercise training improved glucose tolerance in trained group (OS: 27961±6501 vs. OT: 18258±6283 mg/dL/min). Mean arterial pressure and heart rate were similar between groups. The trained group showed increase in heart rate variability compared with sedentary group (OT: 50±12 vs. OS: 33±8ms2). Blood pressure variability and low frequency band were higher in OS group (23 ± 3mmHg2 and 7 ± 1 mmHg2) compared to OT (15 ± 2 mmHg2 and 5 ± 1 mmHg2). Moreover, the spontaneous baroreflex sensitivity, represented by alpha index, was lower in sedentary group (1.2 ± 0.3 ms/mmHg) compared to trained group (1.9 ± 0.2 ms/mmHg). In conclusion, our results suggest that physical training during lifespan can be effective inattenuating the increase in weight and blood glucose and improving blood pressure variability in obese mice.

FAPESP 2011/20859–0
Adding prebiotic fiber to a maternal high fat, sucrose diet during pregnancy and lactation reduces offspring body fat in Sprague‐Dawley rats
Authors: Paul Heather Anne , Bomhof Marc R , Reimer Raylene A
Published: June 2021

The prebiotic fiber oligofructose (OFS) may help reduce the negative effects associated with intake of a high‐fat/high sucrose (HFS) diet during pregnancy and lactation. Obesity was induced in female SD rats (n=90) with a HFS diet for 10 wk. Top weight gainers were randomized to 1 of 3 groups for pregnancy and lactation (n=14 per group): 1) HFS; 2) HFS + 10% OFS; 3) Weight matched (WM) to group 2. A 4th lean control (LC) group was kept on standard AIN‐93G diet. Primary outcomes included maternal and offspring body weight (BW) and composition (via DXA). Secondary outcomes included an oral glucose tolerance test, satiety hormone analysis and fecal microbiota profiles. At baseline, obesity induced dams had significantly higher BW (p<0.001) and fasting glucose (p<0.05) than LC. During gestation, BW was lower in LC than all other groups (p=0.001) up to 1 day before due date, then was only lower than the HFS dams; OFS and WM dams were not different than LC. At weaning, HFS dams had higher % body fat than all other groups (p<0.015). Gestational glycemic response was highest in HFS dams (p<0.05). Offspring of HFS dams had higher % body fat than all other groups (p<0.001); offspring of OFS dams were no different then LC or WM pups. Gut microbiota and satiety hormone analysis is ongoing. In conclusion, consumption of OFS during pregnancy and lactation normalizes the high body fat found in HFS‐fed dams and their offspring. Funded by CIHR, AIHS, NSERC.

Grant Funding Source: CIHR, NSERC, AIHS
Renal autoregulation is not impaired during early streptozotocin diabetes mellitus (DM) in Long‐Evans rats
Authors: Mitrou Nick , Hansen Fahimeh , Morrison Sidney , Mousavi Paymon , Hong Clara , Cupples William
Published: June 2021

Diabetes is a leading cause of chronic kidney disease and increases susceptibility to blood pressure induced glomerular injury. Autoregulation is the only mechanism that protects the glomeruli when blood pressure fluctuates. Impaired autoregulation has been reported in early DM and attributed to increased nitric oxide (NO) but intact autoregulation has been demonstrated in established DM. We hypothesized that intrarenal NO increases in early DM with corresponding impairment of autoregulation and that neuronal NOS (nNOS) contributes to the increased NO. Male Long‐Evans rats were divided into two groups: one week diabetic (N=5) and one week intact (N=3). Diabetes was induced with streptozotocin (60mg/kg i.v.) and depot insulin was used to keep blood glucose ~20–24 mmol/L. Rats were anaesthetized (isoflurane) and their left kidneys were exposed. Renal perfusion pressure was forced with a servo‐controlled aortic occluder and the resulting renal blood flow was measured with an ultrasound flow probe during control, nNOS inhibition (L‐VNIO) and non selective NOS inhibition (L‐NAME). Renal autoregulation was intact in all animals except one intact animal. nNOS protein distribution was similar and was little response to either NOS inhibitor in all rats. We conclude that renal autoregulation is not impaired, and that intrarenal NO does not play a role in early diabetes in these rats. Supported by CIHR MOP‐102694.
Resveratrol induces acute endothelium‐dependent renal vasodilation
Authors: Gordish Kevin L , Beierwaltes William H
Published: June 2021

Resveratrol induces vasorelaxation in endothelium‐intact aortic strips through a nitric oxide (NO) mediated mechanism. We hypothesized resveratrol may act as an acute renal vasodilator through NO and/or prostanoid‐mediated mechanisms. In anesthetized rats, dose response experiments found 5.0 mg/kg resveratrol increased renal blood flow (RBF) by 8% (from 6.98±0.42 to 7.54±0.17 ml/min/gkw n=8 p<0.002), and decreased renal vascular resistance (RVR) by 18% from 15.00±1.65 to 12.32±1.20 ARU (p<0.002). Heart rate (HR) and mean arterial pressure (MAP) remained unchanged. To test NO involvement, we administered 5.0 mg/kg resveratrol, before and after 10 mg/kg b.w. NOS inhibitor L‐NAME. L‐NAME increased MAP 38 mm Hg, decreased RBF by 39%, and doubled RVR. L‐NAME reduced the increase in RBF to resveratrol by 54% (from 0.59±0.05 to 0.27±0.06 ml/min/gkw, n=10 p<0.001). To test the role of endothelium‐derived prostanoids in resveratrol‐induced vasodilation, rats were treated with 10 mg/kg b.w. indomethacin. This treatment did not alter baselines or resveratrol‐induced vasodilation; and L‐NAME reduced resveratrol‐induced vasodilation by 44% from 0.50±0.09 to 0.28±0.06 ml/min/gkw (n=10 p<0.04) as before. We conclude acute intravenous resveratrol acts as an acute renal vasodilator, partially mediated by endothelial NO production but not by vasodilatory prostanoids. (NIH 5P01HL090550–04)
Prox1 expression in the ascending thin limb of Henle's loop is regulated by osmolality
Authors: Kim Jin , Kim Yu‐Mi , Kim Wan‐Young , Nam Sun‐Ah
Published: June 2021

The transcription factor Prospero‐related homeobox 1 (Prox1) is expressed in various internal organs and is related to their differentiations. In a previous study, we found that Prox1 was transiently expressed in the differentiating ascending thin limb (ATL) of Henle's loop in the developing renal papilla and remained only in the ATL in the initial part of renal papilla in adult mouse kidney. Furthermore, Prox1 was expressed in the osmotic conditions within the optimal range in vitro. In the present study, we extend our experiments to the in vivo situation. We examined whether osmolality affects the expression and distribution of Prox1 in the renal medulla in both postnatal developing mice and adult mice. In the first experiment, adult male C57BL/6 mice were randomly divided into 3 groups: dehydrated mice given minimum water, hydrated mice given 3% sucrose in water, and control mice given free access to water for 7 day. In the second experiment, one‐day‐ old pups were administered daily subcutaneous injections of furosemide (30 mg/kg) or vehicle for 4 or 7 days. In the first experiment, the immunoreactivity for Prox1 in the ATL was weak in the initial part of the renal papilla but not in the terminal part of the renal papilla of the normal adult mouse. However, in the hydrated mice, Prox1 was expressed not only in the initial part of the renal papilla but also in the terminal part of the renal papilla. Moreover, the intensity of immunoreactivity for Prox1 was increased in the hydrated mice but markedly decreased in the dehydrated mice compared to the control group. In the second experiment, the immunoreactivity for Prox1 was considerably decreased in the papillae of furosemide–treated group, where the development of the ATL of Henle's loop was delayed, compare to vehicle–treated group. These results suggested that the expression of Prox1 was regulated by osmolality and was required for the differentiation and maintenance of ATL in the developing and adult mouse kidney, respectively.
Vascular smooth muscle specific deletion of the leptin receptor attenuates leptin‐induced vascular dysfunction
Authors: Coleman T. Taylor , Stec David E. , Ryan Michael J.
Published: June 2021

Obesity is a risk factor for cardiovascular disease and is associated with increased plasma levels of the adipose derived hormone leptin. Vascular smooth muscle cells (VSMC) express leptin receptors (LepR); however, their physiological role is unclear. We hypothesized that leptin, at levels to mimic morbid obesity, impairs vascular function. In order to test this, we used wild type and VSMC‐LepR deficient mice (VSMC‐LepR KO) created with a tamoxifen inducible VSMC specific cre recombinase system to delete the LepR gene. 10–12 week old wild type and VSMC‐LepR KO mice were fed a diet containing tamoxifen (0.5 mg/kg) for six weeks, after which vascular reactivity was studied in isolated carotid arteries using an organ chamber bath. Vessels were incubated with leptin (100 ng/ml) or vehicle (0.1 mM Tris HCl) for 30 minutes. Tamoxifen treatment alone did not alter vascular responses to the endothelial dependent or smooth muscle dependent agonist acetylcholine (ACh) or sodium nitroprusside (SNP), respectively. Leptin impaired ACh (10−6 M) induced relaxation in wild type vessels (28±12% vs 88±12%, p<0.05); however, this impairment was markedly blunted in VSMC‐LepR KO (61±12%, p<0.05). These data show that leptin directly impairs vascular function via a leptin receptor mediated mechanism, suggesting a potential pathogenic role for leptin to increase cardiovascular risk during obesity. HL085907, HL051971, HL088421
Regulation of Renal Sodium Excretion by Medullary NLRP3 Inflammasome Activation beyond Turning on Inflammation
Authors: Xia Min , Xiong Jing , Abais Justine M. , Boini Krishna M. , Li Pin‐Lan
Published: June 2021

NLRP3 inflammasomes were found abundant in the renal medulla and their activation altered the renal function and increased the salt sensitivity of arterial blood pressure (AP). The present study further explored the mechanisms mediating the effects of NLRP3 inflammasomes on renal excretory function, which may be independent of typical inflammatory response. In anesthetized mice, intramedullary infusion of NLRP3 inflammasome activators, monosodium urate (MSU) or ATP induced significant decreases in sodium excretion by more than 50% and medullary blood flow (MBF) by 15% without changes in mean AP and renal cortical blood flow (CBF). Pre‐infusion of caspase‐1 inhibitor, Ac‐YVAD‐CMK abolished MSU or ATP‐induced decreases in renal sodium excretion and MBF. By co‐immunoprecipitation analysis, inflammasome component proteins ASC, caspase‐1 and NLRP3 were found to interact more actively in the renal medulla with infusion of MSU or ATP compared to control mice, suggesting enhanced inflammasome formation. Moreover, the caspase‐1 activity was shown significantly increased by 1.5 folds in the renal medulla receiving MSU or ATP, which was accompanied by a 20% increase in local IL‐1β level. Interestingly, SOD mimetic TEMPOL was found to not only block increases in O2− levels induced by MSU or ATP, but also prevent caspase‐1 activation and IL‐1β production. Correspondingly, MSU or ATP‐induced reduction of sodium excretion and renal MBF were reversed by TEMPOL. In additional group of mice, direct infusion of IL‐1β (10 ng/kg/min) into the renal medulla mimicked the effects of MSU or ATP, reducing sodium excretion by 35% and MBF by 10%. Taken together, our results support the view that beyond turning on inflammation, activation of NLRP3 inflammasomes in the renal medulla has direct effects on renal vessels and tubules to induce sodium retention, ultimately resulting in hypertension (Supported by NIH grants HL057244, HL‐75316 and DK54927).
Sympathetic and cardiovagal baroreflex sensitivity in humans: Comparison of Valsalva's maneuver and spontaneous methodologies
Authors: Yang Huan , Carter Jason R
Published: June 2021

Valsalva's maneuver (VM) and spontaneous techniques have been used to assess sympathetic (sBRS) and cardiovagal (cBRS) baroreflex sensitivity, but the intra‐individual reliability between these methodologies has not been examined. We hypothesized that spontaneous BRS would be positively correlated to VM BRS. Heart rate (HR), blood pressure (BP), and muscle sympathetic nerve activity (MSNA) were measured in 28 healthy subjects (age, 23±1 yr; 14 men, 14 women) during 10min supine rest and 3 VM at 40mmHg expiratory pressure (15s, 1min recovery). For spontaneous BRS, relations between diastolic BP and MSNA were used to determine sBRS, while relations between systolic BP and RR interval were used to determine cBRS. During VM, sBRS was the ratio of MSNA and the maximum diastolic BP reduction during early phase II, and cBRS was derived from linear relations between systolic BP and RR interval during early phase II (i.e. hypotensive stimulus) and phase IV (i.e. hypertensive stimulus). Spontaneous sBRS was significantly correlated to VM sBRS (r=0.516, p=0.036). Spontaneous cBRS (up‐up sequence) was correlated to VM phase IV cBRS (r=0.356, p=0.048). In contrast, spontaneous cBRS (down‐down sequence) was not correlated to VM phase II cBRS (r=0.128, p=0.295). In conclusion, our findings demonstrate low ‐to‐ moderate associations between spontaneous and VM estimates of sBRS and cBRS. Supported by NIH (HL‐ 098676).
Effect of mental stress on skin sympathetic nerve activity: Are responses reproducible?
Authors: Ray Chester A , Sauder Charity L , Muller Matthew D
Published: June 2021

The primary aim of this study was to quantify the effect of mental stress (MS) on skin sympathetic nerve activity (SSNA). There is limited quantitative data showing SSNA response to MS. Previous studies report divergent MSNA responses to MS. The second aim was to determine the reproducibility of SSNA to MS within a given day and 1 week later. Ten subjects (26±1 yr.) performed two bouts of mental arithmetic lasting 3 min. The bouts were separated by 45 min. One week later the subjects returned to repeat MS. All experiments were conducted in the supine posture during the morning hours. To maintain neutral skin temperature, each subject wore a custom suit (34–35°C). Skin blood flow and sweat rate were measured on the dorsal foot. MS elicited a marked increase in SSNA within the first 10 s (184±42%; P<0.01) in all subjects, which was less during the remaining period of MS but remained elevated (87±20; P<0.01). The pattern of responses to MS was unchanged during the second bout (10 s, 247±55%; 3 min avg., 133±29%) and during the retest 1 week later (10 s, 196±55%; 3 min avg., 117±36%). MS did not significantly affect cutaneous vascular conductance and sweat rate during any trial. In summary, MS elicits robust and reproducible increases in SSNA in humans. Thus unlike MS effect on MSNA, the pattern of SSNA is consistent during repeated trials on the same day and when performed 1 week later.

Supported by NIH (HL109952)
Immunohistochemistry confirms the functional evidence that the cardiopulmonary chemoreflex (CCR) pathways in the caudal nucleus of the solitary tract (cNTS) are directly inhibited by A1 adenosine receptors and indirectly inhibited by A2a receptors via GABA release
Authors: Minic Zeljka , O'Leary Donal S. , Goshgarian Harry G. , Scislo Tadeusz J.
Published: June 2021

The CCR may elicit severe hypotension which can release adenosine within the cNTS. Adenosine may serve there as a central negative feedback regulator for this reflex. We have shown that CCR‐evoked sympathoinhibition was markedly attenuated after stimulation of both A1 and A2a adenosine receptors in the cNTS (Am J Physiol 303: R539–R550, 2012; FASEB J 24: 624.11, 2010). Furthermore, A2a mediated attenuation of the CCR was virtually abolished by GABAergic blockade (FASEB J 25: 844.3, 2011) and cNTS GABAergic neurons express A2a receptors (FASEB J 26: 1091.28, 2012). We hypothesized that A1 but not A2a receptors are localized on CCR vagal afferents whereas A1 receptors may be located on cNTS non‐GABAergic neurons. Therefore, we used double immunofluorescent staining for: 1) A1 or A2a receptors and cholera toxin B microinjected into the vagus nerve or 2) A1 receptors and GAD67, the GABA synthetic enzyme. We found that GABAergic fibers project to cNTS neurons expressing A1 receptors; no colocalization of A2a or A1 receptors was seen on vagal afferents. These data support our functional findings that A1 receptors directly inhibit CCR whereas A2a adenosine receptors inhibit CCR via GABAergic mechanism. HL‐67814
Diminished baroreflex function following ovariectomy is a consequence of the reduced excitability of a sex specific population of low threshold myelinated baroreceptor afferents in the rat
Authors: Chavez Grace Corina Santa Cruz , Li Baiyan , Schild John H.
Published: June 2021

Concomitant with menopause there is a significant reduction in the capacity of the baroreflex (BRx). Loss of so‐called sex hormones is but one factor. Our previous in situ BRx studies have validated and quantified the contribution of a sex specific subpopulation of low‐threshold myelinated aortic baroreceptor afferents (Ah‐type) in eliciting depressor dynamics not observed in male rats. Ovariectomy greatly reduces the excitability of these Ah‐type afferents while the excitability of low threshold myelinated A‐type and high threshold unmyelinated C‐type afferents is unchanged.

OBJECTIVE

Determine if the ovariectomy‐mediated loss in excitability of Ah‐type afferents alters the depressor response evoked by this sex specific baroreceptor afferent pathway. Age‐matched, normal (NF) and ovariectomized (OVX) female rats were prepared for selective, bipolar electrical stimulation of the left aortic depressor nerve. The OVX (n = 9) presented with a significantly diminished parasympathetic mediated reduction in mean arterial pressure in comparison to the NF (n = 16). Interestingly, the most significant changes in depressor dynamics occurs at electrical thresholds and frequencies most closely aligned with Ah‐type baroreceptor fibers. We conclude that these sex specific afferents may provide a neuromodulatory pathway uniquely associated with the hormonal regulation of BRx function. HL072012, HL081819
Sympatho‐inhibition in an Ovine Model of Septic Shock: Cardiovascular and Renal Effects
Authors: May Clive , Bellomo Rinaldo , Calzavacca Paolo
Published: June 2021

There is evidence that inhibition of the increased sympathetic outflow in sepsis is beneficial, but the mechanisms are unclear. In conscious sheep, at 24 hours of septic shock induced by intravenous infusion of live E. coli, the effect of intravenous infusion of clonidine for 8 hours on cardiovascular and renal function was examined. Administration of E. coli caused hyperdynamic septic shock: hypotension, tachycardia, increased cardiac output, increased renal blood flow, oliguria and decreased glomerular filtration rate. During sepsis, clonidine (1.0 μg/kg/h) reduced cardiac index (from 7.5±0.8 to 5.9±0.5 L/min), heart rate (from 146±9 to 124±8 b/min), but mean arterial pressure did not significantly fall (79±4 vs. 73±5 mmHg). Clonidine reduced renal blood flow (363±9 to 312±30 mL/min) and increased urine output (22±5 to 46±19 mL/h), but did not improve creatinine clearance (42±4 to 29±9 mL/min). In hyperdynamic sepsis, clonidine treatment did not increase the degree of hypotension despite a fall in cardiac output, it increased urine output but did not improve glomerular filtration rate.

This research was supported by the NHMRC, Australia.
Cerebrovascular Reactivity to Carbon Dioxide: A Theoretical Examination
Authors: Pucci Olivia , Battisti‐Charbonney Anne , Fierstra Jorn , Poublanc Julien , Crawley Adrian , Mandell Daniel M , Mikulis David , Fisher Joseph , Duffin James
Published: June 2021

Cerebrovascular reactivity (CVR) is the ratio of cerebral blood flow (CBF) response to a vasoactive stimulus increase. Current measurement of CVR uses the BOLD MRI signal as an indicator of CBF in response to standardized changes in CO2. A step increase in PCO2 is applied and the resulting changes in CBF are assumed to be linearly related. However, this assumption of linearity may be incorrect, and the resulting CVR may be prone to errors. We therefore investigated the differential effects of gradual versus step changes in PCO2 on CVR. Two gas provocations were applied in 15 patients and 18 healthy subjects: 1) a step change from 40 to 50 mmHg and 2) a steady 4‐min ramp increase from 30 to 50 mmHg. CVR was defined on a voxel‐wise basis as %ΔBOLD MR signal/Δ PETCO2. The total brain % BOLD response to a ramp showed a sigmoidal pattern globally and in some individual voxels. CVRs calculated from the step change in PCO2 did not represent the steepest part of the sigmoidal curve in individuals whose sigmoidal inflection point was at a PCO2 less than 50 mmHg. Voxels with negative CVR values showed abrupt onset signal declines at PCO2 levels exceeding a threshold value. A more sophisticated interpretation of high resolution CVR must take into account the range of PCO2, the position and shape of the BOLD‐PCO2 sigmoidal curve, and the vasodilatory and constrictor reserve in various vascular beds.