bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of Urinary Levels of Estrogens and Estrogen Metabolites with Mammographic Density in Postmenopausal Women
Authors: Samavat Hamed , Ursin Giske , Lee Eunjung , Wang Renwei , Yuan Jian‐Min , Emory Tim , Wu Anna , Kurzer Mindy
Published: June 2021

The association between urinary estrogen metabolites and mammographic density (MD) has not been well studied in postmenopausal women. In a cross‐sectional study of non‐current hormone users, we investigated the relationship between urinary estrogen metabolites and percent MD in 200 healthy postmenopausal women at high risk of breast cancer (age = 60.0 +/−5.1 years, body mass index (BMI) = 25.1 +/−4.0 kg/m2, percent MD= 32.3+/−16.8). MD was measured using a highly reproducible computer‐assisted Madena method, and the 12 urinary estrogens and estrogen metabolites were analyzed by liquid chromatography‐tandem mass spectrometry. Multivariate linear regression analyses adjusted for age, BMI, and past use of hormone therapy showed that when compared with women in the bottom quartile, women in the top quartile of the ratio of 2‐hydroxylated to parent estrogens showed a trend toward higher percent MD (+3.9%, p=0.07) and women in the top quartile of 4‐hydroxylated estrogens showed a trend toward lower percent MD (−5.6%, p=0.06). We found no associations for any other individual estrogen, or their metabolites or ratios with percent MD. In conclusion, these findings suggest that urinary excretion of estrogen metabolites in certain metabolic pathways may exert an impact on MD, an established risk marker of breast cancer. This work was funded by NIH/NCI and the Department of Defense.
Prostaglandin E2 in tick saliva regulates host cell migration and cytokine profile
Authors: Poole Nina M , Mamidanna Gayatri , Smith Richard A , Coons Lewis , Cole Judith
Published: June 2021

Ticks are obligate ectoparasites that suppress the host's responses by secreting immunomodulatory and anti‐inflammatory molecules in their saliva. Previously, we have shown that tick salivary constituents from Dermacentor variabilis have distinctive effects on macrophage and fibroblast migration. Since tick saliva contains a high concentration of prostaglandin E2 (PGE2), we examined the effects of tick saliva on IC‐21 macrophage and NIH3T3‐L1 fibroblast migration in the absence and presence of a PGE2 antagonist. Assessment of macrophage and fibroblast migration showed the saliva‐induced changes in migration are reversed by the receptor antagonist AH 6809. Tick saliva induces macrophages to secrete copious amounts of PGE2, and conditioned medium from these cells caused a PGE2 antagonist‐sensitive inhibition on fibroblast migration. Using a cytokine antibody array, we showed tick saliva decreases the secretion of the pro‐inflammatory cytokines regulated and normal T cell expressed and secreted (RANTES/CCL5), tumor necrosis factor‐alpha (TNF‐α), and soluble TNF Receptor I (sTNFRI), through a PGE2‐dependent mechanism mediated by cyclic adenosine monophosphate (cAMP). Saliva also had similar effects on lipopolysaccharide (LPS) stimulated macrophages. Our data indicate ticks use PGE2 to regulate the acitivities of macrophages and fibroblast, cells important in the wound healing response.
Antidepressant‐like effects of lobeline in a chronic mild stress model
Authors: Roni Monzurul Amin , Rahman Shafiqur
Published: June 2021

Recently, we have demonstrated that lobeline, a neuronal nicotinic acetylcholine receptor (nAChR) ligand, has antidepressant‐like effects in mice. The objective of the present study was to determine the effects of lobeline in a chronic mild stress (CMS) model. Adult C57BL/6J mice were exposed to CMS for six weeks. Saline or lobeline (1 or 4 mg/kg, s.c.) were administered once daily during the last two weeks of CMS. Compared to unstressed group, mice exposed to CMS showed increased immobility time in forced swim test, a measure for depression‐like behavior, which was reversed by chronic lobeline treatment (unstressed: 256 ± 8, CMS: 385 ± 24, CMS + lobeline 1 mg/kg: 213 ± 39, CMS + lobeline 4 mg/kg: 266 ± 19 sec). Mice were sacrificed 24 h after chronic treatment to determine brain‐derived neurotrophic factor (BDNF) expression in hippocampus and prefrontal cortex. CMS significantly (p < 0.05) reduced BDNF expression in hippocampus which was reversed by chronic treatment with 1 mg/kg lobeline (CMS: 60 ± 13%, CMS + lobeline 1 mg/kg: 141 ± 12% of unstressed group). However, BDNF expression in prefrontal cortex was not changed by CMS or drug treatment. Overall, the results indicate that lobeline has antidepressant‐like effects likely involving nAChR signaling and regulation of BDNF expression in hippocampus. (Supported in part by SDSURF‐JRF)
The effect of transplanted adipose‐tissue derived stem cells (ADSCs) on the aging rat with erectile dysfunction
Authors: Yang Chun , Dai Jingxing , Yuan Lin
Published: June 2021

Objectives

To determine the protective effects and to identify the mechanism of action of transplanted ADSCs in D‐galactose ‐induced aging ED rat model.

Methods

Thirty male SD rats were randomly divided into normal control group (A), model group(B) and cell treatment group (C) . The aging model was induced by s.c. injection D‐galactose for 8 weeks. Each rat in group C underwent caudal vein injection of ADSCs. Two weeks later, harvest tissue and serum after the mating experiment for histology.

Results

D‐gal successfully produced aging rat model. ADSCs treatments improved the behavior of aging rats in mating experiment in group C, and resulted in significant recovery of erectile function. Also increased the level of SOD and testosterone, decreased the content of MDA in the serum. In addition, ADSCs decreased leydig cell degeneration and lowered AI in the rat testis in group C. Testosterone with significantly higher expression compared with C animals. BrdU‐labeled ADSCs were observed within corporal tissue of the treatment group. TUNEL staining was lower and 3β‐HSD expression were significantly higher within corporal tissue of B versus C animals. AI was significantly different between groups.

Conclusions

Autologous ADSCs injected into the caudal vein appear to survive and improve erectile function. The transplanted ADSCs have an anti‐aging activity in D‐gal induced ageing rats. Supported by National 973 Program (2007CB512705) and Guangdong province high and new technology industrialization project ‐ industrial research (2011 b010500004)
Effect of Cannabinoids and MethoxyPolyethylene Glycols on Aqueous Humor Outflow and Vascular Tone
Authors: Reddy Abhinav , Samudre Sandeep S
Published: June 2021

WIN, a cannabinoid, and MPDTE, a methoxy polyethylene glycol are novel drugs to mitigate the increase in intraocular pressure, a major risk factor for glaucoma. However, their mechanism of action is not well studied. We investigate whether WIN or MPDTE reduce IOP by targeting vascular tone or reduced aqueous humor (AH) production and if eNOS is involved. To document AH flow using fluorometry, eyes were treated topically with either 1.0% WIN, 1.0% MPDTE, 0.1% brimonidine or brinzolamide 10 min prior to applying fluorescein. To measure vascular tone, 4mm aortic rings were placed on a weighted hook system and equilibrated in Krebs solution before introducing either 1.0% WIN or 1.0% MPDTE (n=5/group). Changes in the length of the bands were measured with a micrometer. To control for eNOS contribution, endothelial lining on aortic rings was either removed or kept intact. The greatest reduction in fluorescein intensity was observed after WIN treatment (73±13%) followed by brimonidine (55±10%), MPDTE (42±7%) and brinzolamide (39±4%). WIN increased ring length by 15±3% and MPDTE by 6±4% (p=0.01, n=5). In aortic rings without endothelium, WIN increased ring length by 8±4% and MPDTE by 5±3%. Preliminary results suggest that WIN targets AH outflow with some eNOS involvement while MPDTE targets AH production without affecting vascular tone. Supported in part by E. VA Eye Inst. and E. VA Med Sch.
Angiotensin receptor type 2 mediates hypersensitivity and hyperinnervation in an inflammatory pain model
Authors: SMITH PETER G , LIAO ZHAOHUI , CHAKRABARTY ANURADHA
Published: June 2021

Abnormal sensory axon proliferation occurs in many pain syndromes. The objective of this study was to determine if the angiotensin type 2 receptor (AT2), a mediator of dorsal root ganglion axon sprouting, is required for increased innervation density and hypersensitivity in a rat hind paw model of inflammatory pain. Injection of complete Freund's adjuvant (CFA), but not saline, produced marked thermal and mechanical hypersensitivity through 7 days, accompanied by proliferation of cutaneous axons immunoreactive for the pan‐neuronal marker PGP9.5, calcitonin gene‐related peptide (a marker of heat‐sensitive nociceptors) and GFRα2 (a marker of mechanosensitive nociceptors). Continuous infusion of the AT2 antagonist PD123319 beginning with CFA injection completely prevented hyperinnervation and hypersensitivity. A single PD123319 injection 7 days after CFA also reversed thermal hypersensitivity and partially reversed mechanical hypersensitivity 3 hours later, without affecting cutaneous innervation. Angiotensin II‐synthesizing proteins renin and angiotensinogen were largely absent after saline but abundant in T‐cells and macrophages in CFA‐injected paws. We conclude that emigrant inflammatory cells establish a renin‐angiotensin system, which leads to AT2 activation required for nociceptor sprouting and heightened thermal and mechanical sensitivity. Supported by HD049615.
Anti‐cancer activity of protocatechualdehyde through HDAC2‐mediated downregulation of cyclin D1 in human colorectal cancer cells
Authors: Jeong Jin Boo , Lee Seong‐Ho
Published: June 2021

There are a few studies that protocatechualdehyde (PCA), a naturally occurring polyphenol in barley, induces cell growth arrest in breast and leukemia cancer cells. However, the underlying mechanisms are still poorly understood. Thus, we performed in vitro study to investigate whether PCA affects cell proliferation and apoptosis in human colorectal cancer cells and define potential mechanisms by which PCA induces growth arrest and apoptosis in human colorectal cancer cell lines, HCT116 and SW480. Exposure of PCA to HCT116 and SW480 cells suppressed cell growth and induced apoptosis in a dose‐dependent manner. PCA decreased cyclin D1 expression in protein and mRNA level and suppressed luciferase activity of cyclin D1 promoter, indicating a transcriptional downregulation of cyclin D1 gene by PCA. We also observed that PCA decreased enzyme activity of HDAC and reduced expression of HDAC2, but not HDAC1. These findings suggest that PCA results in cell growth inhibition and apoptosis via HDAC2‐mediated cyclin D1 suppression.

This work was supported by start‐up funds (University of Maryland) to S‐H Lee.
Compression of the lumbosacral trunk and S1 nerve root by calcific posterior branches of the internal iliac artery: A potential source of sciatic pain.
Authors: Cook Mark S.
Published: June 2021

The purpose of this study is to describe how lumbosacral nerve roots in the pelvis can be compressed by calcific branches of the internal iliac artery. Sciatic pain caused by nerve root compression can be painful and debilitating. Compression of nerve roots comprising the sciatic nerve can occur at their immediate exit from the spinal cord or anywhere along their length. Identifying the precise location of nerve root compression is critical for effective treatment of clinical signs and symptoms. This study of 38 cadaveric hemipelvis dissections provides evidence to support that calcific branches of the internal iliac artery may compress and deform underlying nerve roots. This deformation suggests nerve compression. Specificially, when the posterior division of the internal iliac artery or superior gluteal artery contains calcific plaque, they form a visible impression on the nerves they course over in approximately 85.7% of the time. In this study, the lumbosacral trunk is the most commonly compressed nerve root in the pelvis, but the S1 nerve root can be affected as well. When the blood vessels lacked calcific plaque, they did not produce visible deformation of the underlying nerves. Understanding this potential mechanism of nerve compression in the pelvis has clinical significance for patients with sciatic pain.
Propofol post‐conditioning confers ischemic cardioprotection via HO‐1/STAT3 signaling: role of peroxynitrite
Authors: Mao Xiaowen , Li Haobo , Irwin Michael , Wong Gordon , Xia Zhengyuan
Published: June 2021

Propofol, an aesthetic with antioxidant and peroxynitrite (ONOO−) scavenging property, when given during reperfusion attenuates myocardial ischemia/reperfusion (MI/R) injury. Heme oxygenase‐1 (HO‐1) and STAT3 are key proteins in postconditioning (PC) cardioprotection. We explored if Propofol PC (PPC) confers cardioprotection by scavenging ONOO− and activating the HO‐1/STAT3 pathway. Rats were subjected to 30 min coronary artery occlusion and 120 min reperfusion in vivo. Rats (n=7/group) were respectively treated with Propofol (2mg/kg), IPC, ONOO− generator SIN‐1(1.5 mg/kg), ONOO− scavenger FeTPPS (10 mg/kg) during MI/R. Also, primarily cultured cardiomyocytes were subjected to hypoxia/re‐oxygenation in the absence or presence of SIN‐1 or FeTPPS. PPC conferred similar cardioprotection to IPC in reducing postischemic myocardial infarction compared to control. FeTPPS enhanced PPC cardioprotection while SIN‐1 abolished PPC cardioprotection. HO‐1 and p‐STAT3 protein expression was increased in PPC group compared to control and it was associated with decreased ONOO− production and increased antioxidant capacity. PPC also attenuated post‐hypoxic lactate dehydrogenase in vitro. However, HO‐1/STAT3 gene knockdown abolished protective effect of PPC. In conclusion, PPC confers cardioprotection by scavenging ONOO− and activating the HO‐1/STAT3 pathway.

Supported by RGC/GRF grant 782910M
Liver histone H3 phosphoacetylation (K9S10) by binge ethanol
Authors: Shukla Shivendra D , Restrepo Ricardo , Fish Philip , Lim Robert W
Published: June 2021

Binge ethanol drinking is on the rise worldwide and there is epidemiological evidence that it accelerates liver injury. However, the molecular mechanism(s) of binge ethanol induced liver injury are not understood. We have examined if dual site modifications of histone H3 in the liver are affected by binge ethanol in order to ascertain the role of this epigenetic process in the injury. We monitored the levels of phosphoacetylated (acetylated at lysine K9 and phosphorylated at serine S10) histone H3 (H3AcK9PS10) by western blotting. To this end both in vitro primary cultures of hepatocytes, and in vivo animal models were used. Data show that in rat hepatocytes ethanol treatment for 24 hr caused a 3 fold increase in the levels of H3AcK9PS10. In an in vivo model where binge ethanol (3.5g/kg) was given intraperitoneally in rats, the levels of H3AcK9PS10 increased about 4 fold 4 hr after treatment. When rats were chronically treated with ethanol in liquid diet for 4 weeks there was no change in the levels of H3AcK9PS10 compared to pair‐fed control. However, when ethanol binge (3 repeat binge at 5g/kg, at 12 hr intervals) was administered in these chronically exposed rats then about 1.4 fold increase (over control rats) in the levels of H3AcK9PS10 was noted. This was not different from similar binge ethanol effect in control rats. These data were also compared with the liver injury marker CYP2E1. Thus, binge ethanol elicits dual histone modifications in liver in distinctive manner and can be examined both in vitro and in vivo conditions. Such studies have the promise of offering newer targets for controlling binge ethanol induced alcoholic liver disease, a disease for which there is no FDA approved drug.
Effects of Reduced Physical Activity on Intracellular Nitric Oxide in Circulating Angiogenic Cells
Authors: Guhanarayan Gayatri , Jablonski Julianne , Witkowski Sarah
Published: June 2021

Physical inactivity, a risk factor for cardiovascular disease, promotes changes in the endothelium that may be influenced by circulating angiogenic cells (CACs). CACs have the capacity to replace and repair damaged vascular endothelium. Intracellular nitric oxide (NOi) is essential for CAC migration, motility, and proliferation and is therefore a key determinant of CAC health. The objective was to determine whether CAC number and NOi levels changed in response to ten‐days of reduced physical activity (rPA). Lipid profile, weight, and blood pressure (BP) were quantified before and after rPA. rPA was confirmed with accelerometry and caloric intake was reduced to match the reduced energy expenditure during rPA. CACs (CFU‐Hill, CD34+) were isolated from PBMCs prior to and following rPA. CD34+ cells were isolated via magnetic separation and quantified with a hemocytometer. CFU‐Hill were cultured and quantified via colony‐forming assay. NOi was determined using DAF‐FM diacetate. There were no significant changes in lipid profile, weight, or BP with rPA. CFU‐Hill colonies decreased by 44.7% and CD34+ cells increased by 34.8% (p=0.095, p=0.45, respectively). CFU‐Hill NOi was significantly decreased by 52.7% (p=0.023) and CD34+ cells had reduced NOi by 24% (p=0.37). The effect of rPA on CAC NOi is specific to the CAC population.

UMass, Amherst Faculty Research Grant and CHC Research Grant
Stimulation of ANP secretion by Angiotensin‐(1–9) via Angiotensin Type 2 Receptor
Authors: Cha Seung Ah , Park Byung Mun , Oh Young‐Bin , Gao Shan , Kim Suhn Hee
Published: June 2021

Renin‐angiotensin system (RAS) plays an essential role in cardiovascular homeostasis. The peptide hormone angiotensin II (Ang II), generated by angiotensin converting enzyme (ACE), mainly regulates cardiovascular system via its receptors. More recently, we have reported that Ang‐(1–7) stimulates ANP secretion via Mas receptor. However, Ang‐(1–9), converted from Ang I by ACE 2, is still unknown. The aim of the present study is to determine whether Ang‐(1–9) stimulates ANP secretion using isolated perfused beating atria and to find out its signaling pathway. Ang‐(1–9) augmented ANP secretion and concentration in a dose‐dependent manner. Ang‐(1–9)‐induced ANP secretion (about 60% increase by 3 uM) was attenuated by the pretreatment with Ang II type 2 receptor (AT2R) antagonist but not by AT1R or Mas receptor antagonist. In addition, pretreatment with inhibitors of phosphatidylinositol 3 kinase(PI3K), protein kinase B (Akt), endothelial nitric oxide synthase (eNOS) or guanylyl cyclase (GC), blocked the attenuation of ANP secretion by Ang‐(1–9). However, Ang‐(1–9) did not influence atrial contractility and ECF translocation. These results suggest that Ang‐(1–9) stimulates ANP secretion via AT2R, PI3K, Akt, eNOs, GC pathway. We try to do further study to find out the signaling mechanism involved these responses.

Supported by the National Research Foundation (2012–0009322 )
PARAVENTRICULAR NUCLEUS CONTRIBUTES TO ACUPUNCTURE MODULATION OF SYMPATHOEXCITATORY CARDIOVASCULAR REFLEXES
Authors: Tjen‐A‐Looi Stephanie C , Guo Zhi‐Ling , Longhurst John C
Published: June 2021

The paraventricular nucleus (PVN) regulates sympathetic outflow and blood pressure (BP). Somatic afferent stimulation activates PVN neurons that project directly to the rostral ventrolateral medulla (rVLM), but little is known about the physiological actions and regulation of its neural activity. Since electroacupuncture (EA) stimulates somatic nerves to modulate sympathoexcitatory reflex responses, we hypothesized that the PVN and its projections to the rVLM participate in the sympathoexcitatory cardiovascular actions of EA. Cats were anesthetized, ventilated, and heart rate and BP monitored. Bradykinin (BK) applied every 10 min to the gallbladder induced consistent pressor responses. EA at acupoints P5–6 reduced the pressor responses for 60 min. Naloxone microinjection into the PVN restored the change in BP during BK‐induced pressor responses. Retrograde tracing from the rVLM showed EA‐related c‐Fos PVN neurons juxtaposed to endorphinergic PVN fibers. EA decreased splanchnic nerve‐evoked cardiovascular PVN neurons with direct projections to the rVLM for 60 min. Responses of cardiovascular barosensitive sympathoexcitatory rVLM neurons receiving median nerve input was reduced by EA and restored by PVN naloxone blockade. Thus, sympathoexcitatory PVN responses and a naloxone sensitive PVN‐rVLM pathway contribute to central neural processing during EA. Supported by HL‐72125.
Activation of Spinal GABAB Receptors Normalizes N‐methyl‐D‐Aspartate Receptor in Diabetic Neuropathy
Authors: Wang Xiu‐Li , Zhao Xiaonan , Liu Peng , Li De‐Pei , Guo YueXian
Published: June 2021

N‐methyl‐D‐Aspartate receptor (NMDAR) is increased, while GABAB receptor is decreased in the spinal cord dorsal horn in diabetic neuropathy. In this study, we determined the interaction of NMDAR and GABAB receptors in streptozotocin (STZ)‐induced diabetic neuropathy. The paw withdrawal threshold (PWT) was significantly lower in STZ‐treated rats than in saline‐treated rats. Intrathecal baclofen significantly increased the PWT in STZ‐treated rats, an effect that is abolished by pre‐administration of GABAB receptor specific antagonist CGP55845. Spinal NR2B protein and mRNA expression levels were significantly higher in STZ‐treated rats than in saline‐treated rats. Intrathecal baclofen significantly reduced the NR2B protein and mRNA expression levels in STZ‐treated rats. Intrathecal administration of CGP55845 eliminated baclofen‐induced reduction of protein and mRNA levels in STZ‐treated rats. In addition, the phosphorylated cAMP response element‐binding (CREB) protein levels was significantly higher in spinal cord dorsal horn in STZ‐treated rats. Intrathecal baclofen significantly decreased phosphorylated CREB protein levels in STZ‐treated rats, an effect could be blocked by CGP55845. These data suggest that activation of GABAB receptors in the spinal cord dorsal horn suppresses NMDA receptor expression in diabetic neuropathic pain.
Downstream MMR processing contributes to GAA•TTC repeat expansion
Authors: Grabczyk Ed , Halabi Anasheh , Fitzgerald Claire
Published: June 2021

Friedreich ataxia (FRDA) is a progressive neurodegenerative disease caused by GAA•TTC repeat expansion. Understanding the mechanisms by which repeat expansion occurs may reveal therapeutic targets that will enable us to slow FRDA progression and delay or even prevent FRDA onset. We have previously shown that the mismatch repair (MMR) complex MutSbeta, plays an important role in the expansion process. However, it is not known if expansion results from an aberrant side reaction mediated by MutSbeta, or from an otherwise normal MMR response. Typically, in MMR, MutS heterodimers recognize a mismatch but a MutL heterodimer is required for the next step. In humans there are four identified MutL heterodimers, with MLH1 as the master subunit in all of them. Therefore, to determine if appropriate downstream MMR processing is involved in GAA•TTC repeat expansion we targeted MLH1 for knockdown in our system. We report here that MLH1 knockdown studies show a role for MLH1 in GAA•TTC expansion. Our data suggest that GAA•TTC repeat expansion may represent an unfortunate outcome of normally functioning MMR. Funded by grants from the NIH (F30AG042263 to AH), the Friedreich's Ataxia Research Alliance and the LSUHSC Research Enhancement Fund to EG.
Effect of melatonin combined with treadmill exercise on the cartilage regeneration of experimental osteoarthritic rats
Authors: Jin Yunho , Hong Yunkyung , Hong Yonggeun
Published: June 2021

Osteoarthritis (OA) is a complex degenerative joint disease causing disability in the general population of world wide. The purpose of the study is to elucidate the effect of combined treatment of exercise (Ex) on melatonin (MT)‐induced cartilage regeneration in the experimental OA rats. OA in the 8‐week‐old Sprague‐Dawley rats was induced by intra‐articular collagenase injection. Then starting 1 day after OA induction, rats were injected subcutaneously with MT at doses of 10 mg/kg body weight, twice a day (07:00, 19:00), and Ex was conducted for 1‐hr/day. There was a significant reduction of not the joint width but the thickness in MT and/or Ex. Serum TNFa level was decreased by MT and/or Ex, whereas IL‐6 was increased by co‐intervention. Chondrocyte hypertrophic marker, Runx2, was attenuated in MT and/or Ex. LC3 II as well as MMP13 expression was down‐regulated by MT combined with Ex. Arrangement as well as morphology of chondrocyte improved in the cartilage of MT+Ex rats, which led to attenuation of stride width during gait (P<.05). Finally, it was shown in MT and Ex that no significance of the trabecular parameters between the damaged and undamaged joint. Therefore, we suggest that cartilage regeneration is induced by MT and Ex and that therapeutic effect is greater in the co‐intervention group than solely MT treated group.
Different neurotransmitters are included the exercise fatigue in different humidity and heat environments
Authors: Zhao Jiexiu , Lai Lili , Cheung Stephen S. , Cui Shuqiang , An Nan , Feng Wenping , Lorenzo Santiago , Lianshi Feng
Published: June 2021

This study examined whether different neurotransmitters are presented at exercise fatigue in different temperature and relative humidity (RH) environments in athletes. Eight trained male athletes performed exercise in five different environmental conditions: 21°C/20% RH (Normal); 33°C/20 % RH (Hot 20%), 33°C/40% RH (Hot 40%), 33°C/60% RH (Hot 60%), and 33°C/80% RH (Hot 80%). Exercise group performed VO2max test in five conditions. Blood samples were taken pre‐ and post‐exercise and analyzed for noradrenaline (NA), adrenaline (Ad), dopamine (DA), serontonin (5‐HT), 5‐hydroxyindoleacetic acid (5‐HIAA), prolactin (PRL). Compare to Normal condition, Hot 20%, Hot 40% and Hot 80% have lower VO2max (P < 0.05). A comparison between the means indicated that in Hot 20%, Hot 40%, Hot 60% and Hot 80% conditions the RPEmax was higher than the Normal condition (P < 0.01 or P < 0.05). There was a significant effect for time in NE (P < 0.0001), PRL (P < 0.0001), 5‐HT (P = 0.002), 5‐HIAA (P = 0.029), DA (P = 0.016) during exercise in different conditions. However, Ad did not show any significant effect between pre and post exercise (P >; 0.05). In different humidity and heat environments, exercise fatigue is determined by the collaboration of the different neurotransmitter systems, with the most important role possibly being for the NE, 5‐HT and DA.

This work was supported by Grants from Ministry of Science and Technology of the People's Republic of China (2010–05).
GSK3Beta and LEF1 in regenerating young skeletal muscle following downhill running
Authors: Arthur Susan Tsivitse , Amin Hiral , Vachris Judy , Hamilton Alicia , Howden Reuben , Steuerwald Nury
Published: June 2021

The role of Wnt signaling during skeletal muscle repair has been studied using artificial models of muscle injury. Downhill running (DHR) is a physiological muscle injury model that involves a systems approach and is ideal when investigating sources of muscle repair.

Purpose

The objective of this study was to determine if DHR affects Wnt signaling.

Methods

C57BL/J6 male mice (3 mo) were exposed to either DHR or normal cage activity. The gastrocnemius was excised at 1, 2, 3, 4, 5, or 6 days post‐DHR. Gene (qRT‐PCR) and protein (western blot) expression of Wnt signaling components and GSK3□ (total and active) were measured.

Results

Muscle injury increased from baseline 0.4% to 1.4% at 3D, and 5D, and to 2.2% at 6D post‐DHR. M‐Cadherin protein increased from baseline (20.1%) to 54.7% at 3D through 5D (67.2%) post‐DHR. Total GSK3β protein decreased from baseline to 2D (3 fold), 3D (6 fold), 4D (3 fold) and 6D (3 fold) post‐DHR. GSK3βpY216 protein decreased from baseline to 2D (2.2 fold), 3D (3.7 fold), 4D (1.8 fold) and 6D (2.2 fold) post‐DHR. LEF1 protein increased from baseline to 5D and 6D (5 fold) post‐DHR.

Conclusions

In this study, DHR induced Wnt signaling activation. This physiological model provides insight into the complex role of Wnt signaling in skeletal muscle regeneration, which could be clinically important in treating skeletal muscle dysfunctions.
Comparison of rectangular and sine waveforms on electrical stimulation to atrophy of rat soleus muscle
Authors: Tanaka Minoru , Tanaka Masayuki , Kanazashi Miho , Kondo Hiroyo , Murakami Shinichiro , Fujita Naoto , Fujino Hidemi
Published: June 2021

PURPOSE

We focused on the difference between rectangular and sine waves, investigated the effect of electrical stimulation on muscle atrophy.

METHODS

The rats were randomly divided into hindlimb unloading (HU), hindlimb unloading plus electrical stimulation with rectangular waves (HU+RS), hindlimb unloading plus electrical stimulation with sine waves (HU+SS), and weightmatched control (Cont) groups. In the HU+RS and HU+SS groups, the stimulation was percutaneously provided to calf muscles. After 14 days, the soleus muscle located in deep layer of calf was removed.

RESULTS

The value of muscle fiber cross‐sectional area was significantly less in the HU group than in the Cont group. Although there were no significant differences between the HU and HU+RS groups, the value in the HU+SS group was significantly larger than that in the HU and HU+RS groups. The expression level of ubiquitinated proteins was significantly higher in the HU group than in the Cont group, whereas the expression level was significantly less in the HU+SS group than in the HU and HU+RS groups.

CONCLUSION

The effect of electrical stimulation on muscle atrophy was depended on the waveform, and sine wave was effective in deep muscle. Supported by Grants‐in‐Aid for Science Research from the Japanese Ministry of Education, Culture, Sports, Science and Technology.
An anterograde transport study of the descending projections of the central nucleus of the inferior colliculus
Authors: Polson Jaimie W , Bekric Lejla , Garnsey Miles , Dissanayake Hasthi , Dampney Roger AL
Published: June 2021

The deep layers of the inferior (IC) and superior colliculus (SC) play a role in mediating escape behavior to a perceived threat (1). We recently showed that disinhibition of neurons in a discrete region of the IC and SC, centered on the central nucleus, evokes large synchronized bursts in renal sympathetic and phrenic nerve activity, as well as increases in blood pressure, heart rate and respiratory rate (2). However, the anatomical substrate underlying these responses is unclear. The purpose of this study, therefore, was to investigate the efferent projections of neurons in the IC with special reference to the cardiovascular and respiratory control sites of the medulla and pons. In anesthetized rats (ketamine, 100mg/kg; medetomidine 400μg/kg) 100nl of the anterograde tracer Dextran TMR (3000 MW) was injected stereotaxically into the central nucleus of the IC. After 5–7 days recovery, rats were anesthetized and perfused with 4% paraformaldehyde. Brainstem sections were examined under the fluorescent microscope for anterograde labeling. We found dense terminal labeling in the rostral ventromedial medulla (RVMM) and the medullary raphe, while there was sparse label in the rostral ventrolateral medulla (RVLM), parabrachial complex and A5 region. Labeling in the RVLM appeared to be dorsal to the presympathetic neurons. Our results indicate the cardiovascular responses from the IC may be mediated via a direct projection to medullary raphe and/or RVMM.
Intracerebroventricular injection of liposome‐entrapped GABA attenuates the renal sympathetic nerve activity response evoked by central administration of bicuculline in spontaneously hypertensive rats
Authors: Vaz Gisele Cristiane , Custódio Carlos Henrique Xavier , Bahia Ana Paula Oliveira , Santos Robson Augusto Souza , Frezard Frederic , Fontes Marco Antonio Peliky
Published: June 2021

Liposomes are lipid vesicles that allow a sustained release of entrapped substances. GABA is the most prevalent inhibitory neurotransmitter in the central nervous system. In this study we tested the efficacy of liposome‐entrapped GABA (GL) in attenuating the cardiovascular response evoked by intracerebroventricular (icv) administration of GABAA antagonist bicuculline methiodide (BMI). Liposomes were prepared by the freeze‐thawing method followed by extrusion (200‐nm final vesicle diameter). Under tribromoethanol anesthesia (250 mg/Kg i.p.), guide cannula was implanted into the lateral ventricle of spontaneously hypertensive rats (SHR). In two groups of animals (n=5–6), GL or empty liposomes (EL, 0.9% NaCl) were injected icv 48 hours before the GABAA antagonist (BMI, 0.5 nmol/2μL). The icv injection of BMI increased the renal sympathetic nerve activity in EL group, this effect was greatly attenuated in GL group (22 ± 6 vs. 0.8 ± 6 %, P = 0.032). Conversely, BMI injection did not change HR and MAP in both groups. Current data extends our previous findings suggesting that liposome‐entrapped GABA is a promising tool for long‐term intervention in central nervous system. Support: INCT NanoBiofar/CNPq/FAPEMIG
Aldosterone (aldo) and epithelial Na channel (ENaC)‐ dependent K secretion by BK‐α/β4 in the distal nephron (DN)
Authors: Cornelius Ryan J , Wen Donghai , Sansom Steve C
Published: June 2021

Aldo enhances K secretion by increasing ENaC‐mediated Na reabsorption, which generates the electronegative lumen potential that drives K secretion via ROMK in the principal cells (PC) of the DN. The present studies were conducted to determine the aldo and ENaC‐dependency of K secretion by the BK‐α/β4 channel, which resides in intercalated cells (IC) of the DN and mediates K secretion in mice on high K, alkaline diet (HK). Spironolactone, an aldo receptor blocker, decreased K excretion significantly in wild type (WT), but not BK‐β4 knock out (β4KO) mice on HK. Mice were then given a low Na, high K diet (LNaHK) for 7 days followed by administration of amiloride, an ENaC blocker, for 24 hr to determine the Na‐dependency of BK‐α/β4‐mediated K excretion. K clearance (ml/day/kg) of LNaHK WT mice increased by 13‐fold, compared with control diet mice; however, K clearance of LNaHK β4KO mice was attenuated by 31%. When treated with amiloride, WT mice exhibited a large increase in Na and decrease in K excretion, which yielded an ENaC‐sensitive K secretion to Na reabsorption ratio (K‐s/Na‐r) of 1.5; however, β4KO exhibited a large increase in Na excretion but modest decrease in K excretion, yielding a K‐s/Na‐r of 0.3. In conclusion, for HK mice, aldo‐enhanced and ENaC‐mediated K secretion accounts for a much greater K‐s/Na‐r than can be achieved by the 2:3 ratio of the Na/K ATPase pump‐mediated K for Na exchange in PC and involves BK‐α/β4 of IC.
Distribution of Electrical Activation to Parasternal Intercostal Muscles during High Frequency Spinal Cord Stimulation (HF‐SCS)
Authors: DiMarco Anthony F. , Kowalski Krzysztof E.
Published: June 2021

Objective

HF‐SCS is a novel technique of inspiratory muscle activation involving stimulation of spinal cord pathways. The purpose of the present study was to compare the spatial distribution of motor drive to the parasternal intercostal (PS) muscles during spontaneous breathing with that occurring during HF‐SCS.

Methods

In 6 anesthetized dogs, HF‐SCS was applied at the T2 spinal level. Fine wire recording electrodes were used to assess single motor unit (SMU) pattern of activation in the medial portions of the 2nd (PS‐2M) and 4th (PS‐4M) and lateral portion of the 2nd (PS‐2L) interspaces during spontaneous breathing and HF‐SCS following C1 spinal section.

Results

During HF‐SCS mean peak SMU firing frequency was highest in the PS‐2M (13.3±0.4Hz) and significantly lower in the PS‐2L (8.8±0.2Hz) and PS‐4M (11.4±0.3Hz) (p<0.05 for each comparison). Similar rostrocaudal and dorsoventral gradients of activity were observed during spontaneous breathing prior to C1 section.

Conclusion

This study demonstrates that: a) the topographic pattern of electrical activation of the parasternal intercostal muscles during HF‐SCS is similar to that occurring during spontaneous breathing and b) differential descending synaptic input from supraspinal centers is not a required component of the differential spatial distribution of parasternal intercostal activation.

Support: NIH‐NINDS (R01NS064157)
Learning of Human Anatomy: Man versus Machine
Authors: Ang Eng Tat , Yip George , Lim Erle , Sugand Kapil
Published: June 2021

Objectives

The primary focus of the project is to investigate if learning human anatomy is achieved best using 1) Cadaveric prosections, or 2) Multimedia interactive programs.

Materials and Methods

A total of 62 first year medical (M1) and 15 first year Life science students (LSM) were recruited for this study. All students learnt anatomy from cadaveric prosections weekly but were also given access to web‐based programs ad libitum. The approaches were not mutually exclusive so as not to disadvantage either group. A questionnaire was distributed to collate their opinions of the pedagogies at the end of the academic year.

Results

There were different learning habits between the 2 cohorts of students. M1 students reported favorable results with the cadaveric prosections approach compared to the multimedia with the exception of 3D appreciation (p < 0.05). LSM students reported that they appreciated learning with the multimedia program more than cadaveric prosections. To understand physiology, these students voted in favor of multimedia (73%) versus cadaveric prosections (69%)(p < 0.05). However, when it came to organs and tissue recognition, they voted in favor of cadaveric prosections (94%) versus multimedia (75%)(p < 0.05).

Conclusion

Student perception on optimal modality for learning gross human anatomy depends on the structure of expected summative assessments. Overall, cadaveric pedagogy was preferred for organ and tissue recognition whereas multimedia programs and interactive animations were favored in appreciating physiology. There will be more revelation with further research.
Characterization of snoRNA 3’‐end formation in Saccharomyces cerevisiae reveals a broad role for the Paf1 complex and locus‐specific roles for histone post‐translational modifications
Authors: Tomson Brett N , Crisucci Elia M , Heisler Lawrence , Gebbia Marinella , Nislow Corey , Arndt Karen M
Published: June 2021

One eukaryotic protein complex involved in regulating RNA polymerase II transcription is the Paf1 complex (Paf1C), which has well‐characterized roles in promoting histone modifications and transcription elongation. Beyond these roles, the human and yeast Paf1 complexes also interact with RNA 3’‐end processing components to affect RNA formation. Specifically, the S. cerevisiae Paf1C is known to promote the proper 3’‐end formation of at least two small nucleolar RNAs (snoRNAs). To determine how Paf1C‐dependent functions regulate formation of these non‐coding RNAs, we used high‐density tiling arrays to analyze transcripts in cells lacking PAF1 and uncover new snoRNA targets of Paf1. Increased levels of RNA polymerase II seen downstream of snoRNA genes in the absence of PAF1 suggest that these snoRNA 3’‐end defects reflect impaired transcription termination. Examination of Paf1‐regulated snoRNA genes revealed locus‐specific requirements for post‐translational histone modifications and for other transcriptional regulators. Cumulatively, our work reveals a broad requirement for Paf1C in snoRNA 3’‐end formation and suggests that Paf1C contributes to the fine‐tuning of transcriptional regulation at individual loci.
MicroRNA‐451 Protects against Atherosclerotic Plaque Formation by directly targeting Ras‐associated Protein 5a in Vascular Smooth Muscle Cells
Authors: Chen Li‐Jing , Chuang Li , Huang Yi‐Hsuan , Chien Shu , Chiu Jeng‐Jiann
Published: June 2021

MicroRNA‐451 (miR‐451) modulates erythroid differentiation and human malignancy. However, its role in the regulation of vascular smooth muscle cell (VSMC) function in health and disease remains unclear. Using a combination of in vitro system and in vivo investigations on experimental animals and human clinical specimens to clarify the function of miR‐451 in VSMCs. In situ hybridization showed that miR‐451 was significantly expressed in VSMCs of the medial layer in diseased human coronary arteries. In vitro study, culturing VSMCs on fibrillar collagen increased miR‐451 level and led to low proliferative and anti‐inflammatory responses; these effects were diminished by anti‐miR‐451. We identified that Rab5a was targeted by miR‐451 to modulate VSMC proliferation and inflammation. In rat studies, overexpression of miR‐451 and lentivirus‐mediated Rab5a silencing markedly suppressed the neointima formation induced by balloon injury. The level of circulating miR‐451 of blood plasma in patients with coronary artery disease and apolipoprotein E knockout mice (ApoE‐/‐) fed with a high‐cholesterol diet was significantly lower than control group. Increase of circulating miR‐451 by tail vein injection with agomir‐451 in ApoE‐/‐ mice fed with a high‐cholesterol diet for three months decreased atherosclerotic lesion formation. Our findings indicate that miR‐451, by targeting Rab5a, inhibits VSMC proliferation and inflammation in cultured VSMCs in vitro and suppresses neointima formation in injured arteries in vivo.
Human Milk Leptin, Insulin and N6/N3 Fatty Acids are associated with Early Differences in Gut Microbiome of Infants Born to Normal Weight and Obese Mothers
Authors: Lemas Dominick , Young Bridget , Tomczik Angela , Hernandez Teri , DeLaHoussaye Becky , Robertson Charles , Rudolph Michael , Krebs Nancy , Santorico Stephanie , Barbour Linda , Frank Daniel , Friedman Jacob
Published: June 2021

BACKGROUND

Obese mothers deliver offspring with greater risk of developing childhood obesity and the gut microbiome may be an important factor mediating this relationship during infancy.

OBJECTIVE

Determine how exposure to human milk (HM) components are associated with the structure and function of infants' gut microbiome delivered to mothers with high vs. low pre‐pregnancy BMI.

METHODS

Microbiota was determined from vaginally delivered exclusively breastfed full‐term infant stool samples using targeted 16S gene and whole‐genome shotgun sequencing. Insulin, leptin, total n‐6 and n‐3 fatty acids in fasting mid‐feed HM was measured by GC‐MS.

RESULTS

Taxa and metagenomes of the infant microbiome did not differ based on maternal BMI. HM insulin, leptin and n‐6/n‐3 fatty acid ratio were positively associated (p<0.01) with maternal BMI. Adjusting for maternal BMI, HM leptin was associated with Firmicutes (p=0.03) and Flavin adenine dinucleotide biosynthesis pathway (p=0.04). HM insulin was associated with Actinobacteria (p=0.02), leucine biosynthesis, lipid transport and metabolism (p<0.05). HM n‐6/n‐3 negatively associated with FAD (p=0.007) and Riboflavin biosynthesis (p=0.007).

CONCLUSIONS

Infant exposures to HM leptin, insulin, and n‐6/n‐3, all higher in mothers with high BMI, may influence the structure and function of the infant gut microbiota.
Whey‐Based Supplement Added to a Plant‐Based Diet Increases Total Zinc Absorption, but not Total Iron in Mexican Children.
Authors: Pérez‐Pérez Ana , Garcia Olga , Camacho Mariela , Westcott Jamie , Hambidge K Michael , Krebs Nancy , Rosado Jorge
Published: June 2021

The objective of the present study was to determine the effect of a whey‐based nutritional supplement (WPS) on zinc and iron absorption from a plant‐based diet (PBD) in Mexican children. Study 1 evaluated zinc absorption in a cross‐over design. Children (n=16) were randomly assigned to receive the PBD with and without WPS on days 1 and 2 and urine samples were collected on days 1 and 6 to 9 to measure zinc absorption. Study 2 evaluated iron absorption in a parallel study. Children were randomly assigned to one of two experimental groups. Group 1 consumed the PBD during 2 days (n=16) and group 2 consumed the PBD + WPS during 2 days (n=16). A reference dose of iron was consumed with 25 mg of ascorbic acid the first day. Blood samples were collected at baseline and 14 d after the last dose was given. Zinc and iron absorption were measured using 70Zn, 68Zn, 58Fe and 57Fe isotopes. Fractional absorption of zinc was similar in both the PBD and the PBD+WPS groups (0.09±0.03 vs 0.09±0.04 mg). Because total dietary zinc was significantly higher when receiving WPS, the total amount of zinc absorbed was higher compared to PBD alone (5.2±1.1 vs2.8±0.9 mg; p<0.05). No differences were observed between groups in fractional absorption of iron, adjusted iron absorption or total absorbed iron between groups. With the simultaneous intake of WPS, fractional absorption of zinc and iron from a PBD is maintained and total absorption of zinc was increased. Partially supported by IAEA.
Ceramide Mediated Lethal Mitophagy: A Novel Cell Death Mechanism in FLT3 Targeted Therapy for Acute Myeloid Leukemia
Authors: Dany Mohammed , Ogretmen Besim
Published: June 2021

Mutations in FLT3 receptor tyrosine kinase are common in Acute Myeloid Leukemia (AML) and confer a worse prognosis. Ceramide, a bioactive sphingolipid, is synthesized de novo by Ceramide Synthases (CerS) and mediates cancer cell death in response to various chemotherapeutic agents. This study investigates the biological role of ceramide lipid in FLT3‐positive AML pathogenesis. We show that AML cell lines and patient samples expressing FLT3 have suppressed CerS1 expression and lower levels of its product C18‐ceramide compared with FLT3 negative AML cells. Silenced FLT3 expression or its pharmacological inhibition increased CerS1 and C18‐ceramide levels while FLT3 overexpression suppressed them. The increase in C18‐ceramide after FLT3 inhibition is required for cell death as silencing CerS1 expression or inhibiting its enzymatic activity protected from FLT3 inhibitors‐induced cell death. Targeting FLT3 resulted in C18‐ceramide dependent mitophagy, as determined by increased LC3B‐II levels and formation of autophagosomes around mitochondria. Mechanistically, C18‐ceramide accumulated in the mitochondria to bind directly to LC3B‐II recruiting autophagosomal membranes for the execution of mitophagy. This process was accompanied by mitochondrial depolarization, decreased ATP generation, and DRP‐1 oligomerization. In summary, our novel study is the first to highlight the importance of ceramide metabolism in AML oncogenesis by showing that FLT3 suppresses CerS1 expression and ceramide generation while its inhibition reactivates CerS1/C18‐ceramide axis leading to lethal mitophagy and AML cell death.
MMPs as Regulators of Tumor Microenvironment
Authors: Werb Zena
Published: June 2021

Matrix metalloproteinases (MMPs) are a family of zinc‐dependent endopeptidases with important functions in development, tissue injury and repair and cancer. In cancer MMPs pave the way for tumor cell invasion and metastasis through extracellular matrix degradation as well as with non‐protelytic functions. Due to their ability to cleave, degrade and rearrange ECM molecules, MMPs can modulate a variety of stem cell niches both normal and in neoplastic progression. Indeed, changes in the microenvironment such as overexpression of an MMP can alter the propensity of signaling pathways that promote stem cell expansion and alter neoplastic risk. The abilities of MMPs to influence differentiation processes may be hijacked in cancer. There are also several ways by which MMPs may be influence proliferation during development and also in the tumor microenvironment, since they can alter the bioavailability or functionality of multiple important growth regulating factors. MMPs contribute to tissue invasion based on their ability to cleave ECM and basement membrane components proteolytically, and thereby pave the way through the interstitium for invading tissues or cancer cells. However, not all MMP functions are pro‐cancer. MMP8 may protect from tumor progression. Thus use of inhibitors tthat are specific for particular MMPs, e.g,, antibodies may have promise in the long run therapeutically.

Supported by grants from NCI