bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effects of Glutamate on Oxytocin Release
Authors: Badmus Yetunde Awwah , Cantley Richard , Hill Jennifer W 
Published: November 2023

During pregnancy, weight gain creates a positive energy balance that serves the biological purpose of providing adequate energy stores for the upcoming extended period of lactation. However, excess adiposity is associated with a delay in the initiation of lactation and a reduced duration of breastfeeding. Glutamatergic neurons in the paraventricular nucleus (PVN) are implicated in the control of oxytocin release. Recent studies have also shown that glutamatergic target neurons in this nucleus mediate much of the ability of melanocortins to suppress feeding. Based on novel preliminary data, we hypothesize that glutamatergic neurons of the PVN influence prenatal and postnatal hyperphagia and modify the activity of oxytocin neurons involved in lactation. To test this hypothesis, we have created vglut2/sim1‐cre female mouse, in which the gene for the vesicular glutamate transporter VGLUT2 has been deleted in the PVN. To examine dysfunctional lactation in this model we evaluated multiple parameters including neonatal survival and growth, and analysis of mammary tissue and ovary tissue. In addition, circulating oxytocin, prolactin, and other hormone levels were measured. The number of pups born to homozygous vglut2/sim1 dams that survive until weaning was dramatically down compared to controls; 0% survival was observed when fostering did not occur compared to approximately 100% survival when fostering did occur. Results to date suggest that homozygous vglut2/sim1 mice show a consistent and complete deficit in milk release and a buildup of milk protein and lipids within the mammary glands. In addition, we have observed a potential subfertility phenotype observed in the vglut2/sim1 females. These results highlight a potential pathway whereby obesity and lactational deficiency may develop concurrently. Additional studies will be needed to test whether the glutamatergic neuronal populations in the PVN controlling body weight and lactation overlap.Support or Funding InformationSupported by a Michigan Diabetes Research and Training Center Pilot & Feasibility Study Grant (P30DK092926:5556) to JWH.
Short‐term high‐fat diet induces sympathoexcitation and increases blood pressure in Wistar rats
Authors: Garcia Michelle L , Nishi Erika E , Oliveira Tales L , Sato Alex Y Simões , Oyama Lila M , Campos Ruy R , Bergamaschi Cassia T 
Published: November 2023

The present study aimed to investigate the effects of short‐term high‐fat diet (HFD) on blood pressure and sympathetic vasomotor nerve activity. Furthermore, the influence of white adipose tissue (WAT) innervation on HFD‐induced cardiovascular changes was assessed. Male Wistar rats (250–300g) were divided into 3 independent groups that were treated for 8 weeks with a control diet (CT) or High‐fat diet (HFD) and HFD + WAT denervation (HFD+DNX). At the end of the sixth week of treatment a bilateral retroperitoneal WAT (rWAT) depot denervation was performed in the HFD+DNX group. After this period the mean arterial pressure (MAP), heart rate (HR), renal sympathetic nerve activity (rSNA) and splanchnic sympathetic nerve activity (sSNA) were recorded directly. HFD animals presented a significant slightly increase in MAP (109± 1; n=7 vs 101± 1 mm Hg; n=7 p<0.05) and a greatly increase in sSNA (82±10; n= 5 vs 46±10 spikes/s; n=5, p< 0.05) compared with CT group. Bilateral rWAT denervation reduced MAP (104±7 mmHg; n=7) and sSNA (57±9 spikes/s, n=5). No changes were observed in baseline HR and rSNA among groups. The present study suggests that short‐term HFD induces preferential sympathoexcitation to splanchnic territory and increases in blood pressure. Whether afferents and/or efferents from WAT participate in these responses remains to be elucidated.Support or Funding InformationCAPES and Cnpq
Leptin Induces the Expression of the Leptin Receptor in the Hypothalamic Paraventricular Nucleus
Authors: Pelletier Nicole E. , Shi Zhigang , Levasseur Peter R. , Marks Daniel L. , Brooks Virginia L. 
Published: November 2023

We recently reported that nanoinjection of leptin into the hypothalamic paraventricular nucleus (PVN) elicits a slowly developing increase in sympathetic nerve activity (SNA), despite a well‐documented paucity of leptin receptors (LepR). This result suggests that leptin may induce the expression of its own receptor. To test this hypothesis, male SD rats (n=4) were anesthetized with α‐chloralose and were instrumented with electrodes for recordings of lumbar SNA (LSNA) and with femoral catheters for infusions and recordings of mean arterial pressure (MAP) and heart rate (HR). After collecting baseline data, leptin (60 ng in 60 nL) was injected into one side of the PVN, and the artificial cerebrospinal fluid (aCSF; 60 nL) vehicle was injected into the other side. Measurements of LSNA, MAP, and HR were continued for the following 6 hr. The animals were then deeply anesthetized, and brains were collected, flash frozen, sectioned (20 μm), and stored for subsequent in situ hybridization (ISH) assay of the LepR in PVN using antisense 33P‐labeled LepR (corresponding to bases 10–407 of rat LepR). Levels of LepR in each side of the PVN were assessed in three sections by counting the total number of silver grains using custom‐designed software that subtracts background signal from selected regions. Unilateral injections of leptin into the PVN increased LSNA to 136±18 % control, MAP from 123±9 to 134±4 mmHg, and HR from 350±22 to 392±28 bpm (all P<0.05). LepR ISH revealed LepR signal on both sides of the PVN; however, the total number of silver grains was greater in the leptin‐treated side (2628±204) compared to the aCSF‐treated side (1996±47) (P<0.05). In conclusion, leptin induces the expression of its own receptor in the PVN.Support or Funding InformationNIH HL128181, AHA 12GRNT11550018 and 15POST23040042.
Transient receptor potential vanilloid type 1 (TRPV1) activation in the Nucleus of the Solitary tract inhibits brown adipose tissue sympathetic nerve activity
Authors: Madden Christopher J 
Published: November 2023

Stimulation of vagal afferent fibers or activation of neurons in the NTS (the site of vagal afferent terminals) inhibits sympathetic outflow to BAT. TRPV1 which is densely expressed in visceral vagal afferents can be directly activated by endogenous lipids to increase visceral afferent activation of neurons in the NTS. The current study investigated whether activation of TRPV1 receptors in the NTS inhibits BAT SNA and compared the level of endogenous activation of TRPV1 in rats maintained on a control chow diet or a high fat diet. In urethane/chloralose anesthetized rats maintained on a control chow diet, nanoinjection of the highly potent and selective TRPV1 receptor agonist resiniferatoxin (RTX) completely inhibited cold‐evoked BAT SNA. In rats on a control chow diet blockade of TRPV‐1 receptors in the NTS by pretreatment with the TRPV1 antagonist capsazepine (CPZ) had no effect on basal or cold‐evoked BAT SNA but prevented the RTX evoked inhibition of BAT SNA. In contrast, in rats maintained on a high fat diet for at least 8 weeks BAT SNA failed to increase during cold exposure. Nanoinjection of CPZ in the NTS reversed the HFD‐induced impairment of cooling‐evoked BAT SNA. These data demonstrate that activation of TRPV1 receptors in the NTS inhibits cold‐evoked increases in BAT SNA and suggest that in rats maintained on a high fat diet there is an elevated endogenous activation of the TRPV1 receptors in the NTS that is necessary for the high fat diet‐induced impairment of BAT activation.Support or Funding InformationSupported by American Diabetes Association Basic Science grant #1‐13‐BS‐120.
Sphingolipid chaperone proteins modulate signal transduction and pathophysiology
Authors: Hla Timothy 
Published: November 2023

Although originally thought as an intracellular second messenger, work over the past two decades have shown that sphingosine 1‐phosphate (S1P) acts primarily as an extracellular lipid mediator. Our laboratory cloned the first S1P receptor as an orphan G protein‐coupled receptor (GPCR) from vascular endothelial cells in 1990 and de‐orphaned in 1998. Some of the well‐studied actions of S1P include its essential roles in vascular development, immune cell trafficking and neuronal development. Inhibition of GPCR‐dependent S1P signaling results in therapeutic efficacy in the autoimmune disease of remitting, relapsing multiple sclerosis (RRMS). We recently discovered that the majority (~65%) of plasma S1P is chaperoned by HDL‐bound Apolipoprotein M. Plasma S1P is essential for lymphocyte trafficking. This talk will discuss the role of chaperone‐dependent signaling of HDL‐bound Apolipoprotein M. Our recent studies suggest that HDL‐bound S1P acts as a biased agonist to suppress vascular inflammation and restore endothelial function. In the immune system, HDL‐bound S1P is dispensable for immune cell trafficking but suppresses lymphopoiesis and neuroinflammation in mouse models. In the liver, ApoM‐bound S1P is critical for liver regeneration and suppression of fibrosis. Better understanding of fundamental biochemical principles involved in S1P signaling may aid in the development of novel therapeutic principles in vascular and immunological diseases.Support or Funding InformationThe work was supported by grants from the NIH and the Fondation Leducq transatlantic network program.
Tonic Glycinergic Inhibition of brown adipose tissue (BAT) Sympathetic Premotor Neurons in Rostral Raphe Pallidus (rRPa)
Authors: Conceicao Ellen Santos 
Published: November 2023

The rRPa contains BAT sympathetic premotor neurons controlling BAT sympathetic nerve activity (SNA) and BAT thermogenesis. We report here the contribution of a tonic activation of glycineA receptors in the rRPa at the inhibitory regulation of BAT SNA and BAT thermogenesis, as well as cardiovascular parameters, in urethane/chloralose anesthetized, artificially‐ventilated rats. Under warm conditions, nanoinjection of strychnine (STR) into the rRPa increased BAT SNA (peak: +495% of control), BAT temperature (TBAT, + 1.1 °C), expired CO2, (+ 0.4 %), core body temperature (TCORE, + 0.2 °C), mean arterial pressure (MAP, + 4 mmHg) and heart rate (HR, + 57 bpm). Glycine (GLY) injection into the rRPa evoked a potent, 74 % inhibition of cooling‐evoked BAT SNA, and reductions in TBAT (−0.2 °C), TCORE (−0.2 °C), expired CO2 (−0.2 %), MAP (−8 mmHg), and HR (−22 bpm), but did not reduce any of these parameters after STR nanoinjection into rRPa. Nanoinjection of STR into the rRPa had no effect on the ability of nanoinjection of GABA into the rRPa to inhibit BAT SNA (−86 % of the cold‐evoked BAT SNA), and expired CO2 (−0.4 %). Blockade of glutamate receptors with AP5/CNQX into rRPa markedly inhibited the STR‐evoked increases in BAT SNA (−56 %), TBAT (−0.4 °C), expired CO2 (−0.8 %), MAP (−8 mmHg) and HR (−34 bpm). Regarding the synaptic integration occurring at the BAT sympathetic premotor neurons in the rRPa, we conclude that a tonically‐active, glycinergic inhibitory input contributes to reductions in their discharge probabilities that compete with their excitatory inputs from the DMH and brainstem sites to determine the level of BAT thermogenesis and energy expenditure.Support or Funding InformationThis work was supported by NIH R01‐NS091066 (S.F.M.).
Lactic acid bacteria isolated from Korean kimchi modulate the vitamin D receptor‐autophagy signaling pathways
Authors: Shang Mei , Zhang Yong‐Guo , Lu Rong , Jiao Yang , Xia Yinglin , Kim Cheol‐Hyun , Kang Sang‐Moo , Sun Jun 
Published: November 2023

PurposeVitamin D receptor (VDR) plays an essential role in pathogenesis of various human diseases, including inflammatory bowel disease (IBD). Our recent study (Wang, et al, Nature Genetics, 2016) has demonstrated that human VDR is a key host factor to shape gut microbiome. Further, our study has demonstrated that intestinal epithelial VDR conditional knockout (VDRΔIEC) leads to dysbiosis. Low expressions of VDR is associated with impaired autophagy, accompanied by a reduction of ATG16L1 and LC3B (Wu, et al, Gut, 2015). Patients with IBD usually present low expression of VDR and an impaired vitamin D status. Probiotics have been used in the anti‐inflammation process of IBD. The purpose of this study is to investigate the potential effects and mechanism of probiotics in modulating the VDR‐autophagy pathways.MethodsWe tested five probiotics Lactobacillus strains (Lactobacillus plantarum PS128, Lactobacillus plantarum DK119, Lactobacillus acidophilus La5, Lactobacillus 109 and Lactobacillus reuteri 121), which were isolated from Korean Kimchi. Conditional medium (CM) was used to treat human intestinal epithelial HCT116 cells and measured the expression of VDR. Expressions of autophagy markers LC3B and regulator Beclin1 were evaluated by Western blot. Mouse embryonic fibroblast (MEF) cells with or without VDR were also used to test the change of the VDR signaling and VDR dependence of the autophagy signaling. To test the role of probiotics in anti‐inflammation, HCT116 and Caco‐2 cells were treated with 121‐ CM prior to infection with Salmonella Enteritidis. In vivo, the role of probiotic in regulating VDR‐autophagy‐apoptosis signaling was tested, using 121‐CM orally administrating to VDRloxp and VDRΔIEC mice.FindingsProbiotics‐treated groups showed higher mRNA expression of the VDR and its target genes cathelicidin, compared to the control group, In addition, probiotic treatment could enhance beclin 1 and change the ratio of LC3B 1 and 2, indicating the activation of autophagy. Furthermore, 121‐CM treatment prior to Salmonella infection dramatically inhibited the apoptosis and inactivated NF‐kB pathway. Administration of 121CM to VDRloxp and VDRΔIEC mice for 12 and 24 hours resulted in an increase of VDR, p62 and Beclin1 expression and a decrease of Bcl‐2, Bax, phospho‐IkBα, and TLR4 expression.ImplicationsWe highlight the beneficial effects of these five probiotics in upregulating VDR signaling and autophagic responses and suppressing inflammation. Furthermore, these effects are associated with the VDR‐autophagy pathway. Our data indicate novel therapeutic and beneficial roles of probiotics Lactobacillus strains, isolated from Korean Kimchi, in inhibiting inflammation and infection.Support or Funding InformationThis work was supported by the NIDDK1R01DK105118‐01 to Jun Sun. Mei Shang was partially supported by International Program for Ph.D. Candidates, Sun Yat‐Sen University
Mitophagy regulation after diet and exercise in non‐alcoholic fatty liver disease
Authors: Rosa‐Caldwell Megan E. , Harris Matthew , Brown Jacob L , Lee David E. , Poole Kaylee , Seija Andrew , Brown Lemuel A. , Perry Richard A. , Washington Tyrone A. , Wooten Joshua S. , Greene Nicholas P. 
Published: November 2023

Along with the increase in obesity, there has been a concurrent increase in the diagnosis of non‐alcoholic fatty liver disease (NAFLD). NAFLD may begin with fat accumulation in the liver, but can progress to non‐alcoholic steatohepatitis (NASH), fibrosis, and eventual cirrhosis. Current recommendations include weight loss strategies such as caloric restriction and exercise. Aberrant mitochondrial content/quality and mitochondrial autophagy (mitophagy) are common in NAFLD. Exercise is known to improve hepatic mitochondrial health and mitophagy thus mitophagy may be a mediator in the treatment of obesity induced‐NAFLD.PURPOSEThe purpose of the study was to examine how weight loss from diet or diet combined with physical activity impacts hepatic mitochondrial content, autophagy and mitophagy in NAFLD.METHODS48 Male C57BL/6J mice were divided into 1 of 4 groups: low fat diet (LFD, 10% fat, for 18 wks), high fat diet (HFD, 60% fat diet, for 8 wks.), weight loss by diet (D, 60% fat diet for 10 wks then 10% fat diet for 8 wks) or weight loss by diet and physical activity (D/PA, 60% fat diet for 10 wks, then 10% fat diet plus a running wheel for 8 wks). After interventions, livers were collected and analyzed via Western blot for markers of mitophagy. Results were analyzed by one‐way ANOVA with α set at 0.05.RESULTSMitochondrial content and biogenesis markers COX‐IV and PGC‐1α protein contents were approximately 50% less in HFD compared to LFD. COX‐IV content was restored and PGC‐1α content increased 50% with D/PA. Mitophagy marker BNIP3 content was 45% lower in HFD compared to LFD; D/PA had 50% more BNIP3 compared to LFD controls. PINK1 content was 40% higher in D and D/PA animals compared to LFD. P‐PARKIN/PARKIN levels were 40% lower in HFD, D, and D/PA compared to LFD. Whereas, p‐UbSer65 was 3‐fold higher in HFD animals. Autophagome marker LC3II/I ratio was 2‐fold greater in HFD and D/PA animals, yet autophagy flux marker p62 content was 2.5 fold higher in HFD animals compared to LFD, D, and D/PA, with no further differences observed.CONCLUSIONObesity‐induced NAFLD causes disruptions in hepatic mitochondrial content, mitophagy, and macroautophagy. While diet appears to restore some of these derangements, diet combined with physical activity ameliorates most of these derangements.
Production of Bioactive Peptides by Neutrophil Elastase Cleavage of E‐cadherin
Authors: Gordon Marilyn , MacNaughton Wallace K 
Published: November 2023

BACKGROUNDThe inflammatory microenvironment in the gut contains a variety of proteases from numerous sources including inflammatory cells. We have been studying the ability of proteases to induce a switch in the colonic epithelium from a barrier to a repair phenotype (epithelial to mesenchymal transition [EMT]) characterized by increased migration and disrupted homeostasis. EMT involves the degradation of junctional proteins such as E‐cadherin [Ecad], but the functional consequences of Ecad loss remain incompletely understood.AIMTo test the hypothesis that inflammatory proteases cleave Ecad to produce peptides that alter epithelial homeostasis by altering cell migration, proliferation, or cell death.METHODSRecombinant Ecad was incubated with neutrophil elastase [NE] in a minimized cell‐free system and 24 peptides identified by mass spectrometry were chosen for high‐throughput screening based on frequency, p‐value scoring, and accessibility of peptide cleavage site. Synthesized peptides were tested for biological activities including proliferation, cell death, and cell migration. Murine CMT‐93 intestinal epithelial cells were cultured in 96 well plates and wounded 5 days post‐confluency using the EssenBio WoundMaker™ tool. Plates were imaged with the IncuCyte™ live‐cell imaging system for 24–48 hours following exposure to 1, 10, and 100 mg/mL concentrations of peptides. Cells were transfected with a GFP marker for automated cell counting to measure proliferation. Cytotoxicity was determined using Cytotox dye entering cells undergoing membrane degradation. All analysis was done using the IncuCyte™ ZOOM platform in conjunction with ImageJ software.RESULTSBasolateral stimulation of human Caco2 and murine CMT93 cells with NE confirmed the ability of NE to produce C‐ and N‐terminal Ecad fragments in vitro. From our synthesized peptides, we identified 10 Ecad peptides that significantly influenced wound closure rates, both positively and negatively. Two peptides (100 mg/mL) significantly inhibited wound healing rate by 13–26% compared to vehicle controls. Six peptides (100 μg/mL) significantly increased wound healing rates by 7–11% and three peptides (10 μg/mL) significantly increased wound healing rates by 6–13% compared to vehicle controls. Preliminary results suggest that several of these peptides also have cytostatic or pro‐proliferative activity.CONCLUSIONSOur results suggest that degradation of cell junction proteins by inflammatory proteases can create bioactive peptides that alter epithelial homeostasis and alter cell migration. Our data reveal a novel and complex pathway whereby epithelia respond to inflammatory tissue damage at the cellular level to alter a barrier phenotype to a more dynamic epithelium.Support or Funding InformationFunding: Supported by the Canadian Institutes of Health Research (CIHR)
ER stress antagonizes metabolic stress‐induced loss of epithelial barrier function to commensal bacteria via xenophagy
Authors: Lopes Fernando , Keita Åsa , Saxena Alpana , Reys Jose Luiz , Mancini Nicole , Rajabi Ala , Arthur Wang , Baggio Cristiane , Dicay Michael , van Dalen Robert , Ahn Younghee , Rho Jong , MacNaughton Wallace , Jijon Humberto , Söderholm Johan , Philpott Dana , McKay Derek M. 
Published: November 2023

BackgroundPatients with IBD commonly present deregulated barrier function of the intestinal epithelium. We have shown that treatment with dinitrophenol (DNP: uncouples oxidative phosphorylation) dramatically impairs the barrier function of cultured epithelial monolayers, particularly internalization of non‐invasive commensal E. coli. Mitochondria do not function in isolation and are linked to the endoplasmic reticulum (ER). We hypothesized that interaction of mitochondrial dysfunction and ER stress is a key determinant of epithelial‐bacterial interaction, specifically the fate of commensal bacteria that gain access to the intracellular compartment as a consequence of metabolic stress.MethodsHuman colonic biopsies were mounted in Ussing chambers and human colon‐derived epithelial cell lines were cultured on transwell filters or on plasticware. Bacteria were added to the luminal buffer and the cells treated with DNP ± the ER stressor, tunicamycin (TM), and bacterial internalization and translocation assessed. Mechanistic studies involved measuring ATP production, assessment of autophagy (i.e. LC3 activation) and gene knock‐down (KD) by siRNA and CRISPR/cas9.ResultsDNP promoted the translocation and internalization of E. coli in colon tissue and epithelial monolayers: TM reduced this barrier defect, but did not prevent the DNP‐evoked drop in ATP or the rate of epithelial update of inert beads. E. coli, DNP + TM‐treated cells had increased autophagy. The TM antagonist of the DNP effect was lost in cells lacking the autophagy protein, ATG16L1, suggesting that the ER‐stress promoted killing of the internalized bacteria. Of the 3 major arms of the ER stress response, only KD of ATF6 ablated the TM antagonism of the DNP‐evoked barrier effect; the increase in autophagy evoked by TM was absent in ATF6 KD epithelia.ConclusionAn effective ER stress response, via mobilization of xenophagic response, can ameliorate epithelial barrier function in terms of enhanced killing of bacteria that gain access to the cell as a consequence of mitochondrial dysfunction. We suggest that target induction of ATF6 activity could be beneficial in treating disease characterized by bacterial ‘invasion’ of epithelial cells.Support or Funding InformationCIHR AIHS HPI NSERC