bluuebunny/crossref_metadata_2025_split huggingface dataset:
Autonomic Control of Thermogenic Capacity is Optimized in Deer Mice Native to High or Low Altitudes
Authors: Wearing Oliver H , Tate Kevin B , Scott Graham R 
Published: November 2023

The North American deer mouse (Peromyscus maniculatus) ranges from below sea level to above 4,300 m elevation. To survive the cold hypoxic conditions at altitude, highland populations must sustain high rates of aerobic thermogenesis in an oxygen scarce environment. Here, we investigated whether differences in autonomic control of the cardiovascular system contributes to the increased thermogenic capacity (V̇O2max) of deer mice native to high altitudes. We compared captive breeding colonies derived from wild populations at high and low altitudes, and measured V̇O2max in cold hypoxia following intraperitoneal (i.p.) injection of adrenergic agonists/antagonists. Following control saline injection, highland mice had higher mass‐specific V̇O2max than lowland mice. Both α‐adrenergic agonist and antagonist reduced V̇O2max by a similar magnitude in both populations, indicating that α‐adrenergic vascular tone is naturally optimized to enhance blood flow to tissues responsible for thermogenic V̇O2max, and that functional sympatholysis does not contribute to population differences in V̇O2max. β2‐adrenergic tone had no effects on V̇O2max, suggesting that these receptors are not required to achieve thermogenic V̇O2max. β1‐adrenergic tone appears to be maximized to achieve V̇O2max in both populations, because β1‐agonist (dobutamine) had no effect on V̇O2max whereas β1‐antagonist (metoprolol) reduced V̇O2max. Preliminary experiments in anaesthetized mice confirmed that pharmacological agents entered the circulation after i.p. injection and had predictable effects on heart rate and blood pressure. Our results therefore suggest that autonomic control of the cardiovascular system is optimized during thermogenesis in hypoxia, such that population differences in V̇O2max do not arise from evolved changes in autonomic control.Support or Funding InformationSupported by NSERC of Canada
Subconcussive Head Impact Results in a Unique Circulating Exosomal MicroRNA Signature
Authors: Caban Carolina T , Jackson Kelli , Pinson Catherine L , Dos Santos Fernando V , Jeka John J , Tierney Ryan T , Hudson Matthew B 
Published: November 2023

A large segment of the population participates in sports (e.g. football and soccer) and endure hundreds to thousands of low level head impacts over their lifetime. While a continuously growing body of evidence indicates concussive head injury can lead to long term medical problems, little is known about the effects of subconcussive head impact, that is mild head impact that does not result in a clinical indication of concussion. Recently our group has shown that subconcussive head impact results in acute vestibular dysfunction. Additional recent evidence indicates subconcussive head impact results in memory loss for up to 24 hours. Thus, the possibility exists that both high magnitude head impact like concussions as well as repetitive low levels of head impact lead to pathological changes. Recent research has shown that small circulating molecules termed exosomes contain cargo including microRNAs that may be indicative of pathological events and signaling occurring in the tissue from which they were released. Thus, the purpose of this study was to identify a unique circulating exosomal microRNA profile indicative of subconcussive head impact. We used a common soccer heading task as a controlled head impact model to elicit subconcussive head impact in college males (n=6), in which subjects headed a soccer ball 10 times at a set velocity from ~30 meters away. Pre, immediately post, and 24 hours post blood samples were collected. Exosomes were isolated from plasma, and total RNA, including microRNA, was isolated from exosomes. Small RNA Next generation sequencing (NGS) was performed on microRNAs isolated from exosomes in pre and 24 hour post plasma to unbiasedly identify alterations in levels of exosomal microRNAs. A unique microRNA signature in circulating exosomes was identified 24 hours following subconcussive head impact. Specifically, based on abundance and fold change a small unique panel was identified including three microRNAs that were increased four fold or more (miR‐92b‐3p, miR‐423‐5p, and miR‐24‐3p), and four microRNAs that were decreased three fold or more (miR‐7844‐5p, miR144‐5p, miR‐221‐5p, and miR‐22‐3p). To verify NGS results, quantitative real time polymerase chain reaction (qPCR) was performed on microRNAs at all time points. Further, to verify specificity of head impact exosomal microRNAs in the panel were measured via qPCR from a group the received soccer ball impact to the gastrocnemius muscle. Interestingly, several of the identified microRNAs are known to be involved in or associated with neurological dysfunction and disorders. In conclusion, subconcussive head impact leads to a unique circulating exosomal microRNAs signature that could potentially be indicative of head injury following repetitive subconcussive head impacts.Support or Funding InformationSupported by NIH GM087239
miR429: Potential regulator of PAK2 in Inflammatory Monocytes
Authors: Stull Lauren Christine , Amin M Asif , Rabquer Bradley James 
Published: November 2023

PurposeRheumatoid Arthritis is an inflammatory disease that leads to the eventual deterioration of joints. Monocytes are key players in its pathogenesis and migrate to the sites of inflammation. Micro (mi)RNAs regulate mRNAs and the synthesis of proteins and have the ability to silence specific mRNAs by preventing translation or aiding their degradation. Previous results from our lab have shown that specific microRNAs are elevated in monocytes from patients with Rheumatoid Arthritis. Using in silico analysis, we have also determined potential gene targets for these miRNAs in monocytes. miR429 is a differentially expressed miRNA in monocytes in response to inflammatory stimuli and has PAK2 as a theoretical gene target. miR429 has been shown to inhibit cancer cell migration by reducing the expression of its target genes. PAK2, which is highly expressed in leukocytes, including monocytes, is known to regulate inflammation. Therefore, we hypothesized that miR429 regulates inflammation by binding to PAK2 and mediating its degradation.Methods & ResultsIn order to assess the binding between miR429 and PAK2 we cloned the 3′ untranslated regions (UTR) of PAK2 into the pmirGLO dual luciferase vector. The vector was propagated, purified, and treated with the restriction enzymes SacI and SaclI, and cleavage was confirmed by PCR analysis. THP‐1 monocytes were grown and used as a source of mRNA. cDNA was prepared and primers specific to the miR429 predicted binding site on the 3′ UTR of PAK2 were used to produce a PCR product of 238 base pairs. Another double digest involving the same enzymes was performed on the PCR product, and the product was ligated into the vector and confirmed by gel electrophoresis. Sanger sequencing was used to determine the sequence of the resulting DNA, ensuring that the plasmid contains the 3′ UTR of PAK2 with the predicted miR429 binding site.ConclusionThe 3′ UTR of PAK2 was cloned into the pmirGLO vector for the assessment of miR429 binding.Support or Funding InformationThis work was supported by the Albion College Biology Department, Foundation for Undergraduate Research, Scholarship, and Creative Activity (FURSCA), Hewlett‐Mellon Fund for Faculty Development at Albion College, and the University of Michigan Division of Rheumatology.
Kidney‐specific Conditional Knockout of Klotho Gene Impairs Natriuresis and causes hypertension by upregulating Epithelial Sodium Channel alpha
Authors: Ali Quaisar , Lin Yi , Wang Shirley , Chen Kai , Chen Jianglei , Sun Zhongjie 
Published: November 2023

Background and PurposeExcessive reabsorption of sodium by the kidney tubules contributes to renal dysfunction and high blood pressure. Deletion of Klotho leads to hypertension. The purpose of this study is to investigate if renal epithelial sodium channel (ENaC) contributes to klotho deficiency‐induced hypertension.Methods and ResultsWe generated kidney‐specific conditional klotho null (KspKL−/−) mice and found out that renal alpha subunit of ENaC is significantly upregulated compared to wild type (WT) mice. Blood pressure measured by telemetry demonstrated systolic hypertension and elevated pulse pressure suggesting vascular dysfunction in KspKL−/−. Pulse wave velocity, a marker of arterial stiffening was significantly increased in KspKL−/− mice. Amiloride, an ENaC inhibitor, completely prevented systolic hypertension and arterial stiffening in KspKL−/− mice. Ex vivo vascular relaxing responses to acetylcholine were diminished in mesenteric arteries in KspKL−/− group, indicating that klotho deficiency causes vascular endothelial dysfunction. Interestingly, treatment with amiloride abolished Klotho deficiency‐induced vascular endothelial dysfunction. We found that urinary sodium excretion (UNaV) was significantly impaired in KspKL−/− group. Na retention was also associated with a decrease in glomerular filtration rate (GFR), suggesting impaired renal function in KspKL−/− mice. Treatment with amiloride prevented sodium retention and improved GFR in KspKL−/− mice. Total renal nitric oxide bioavailabililty and eNOS activity were significantly decreased in KspKl−/− mice which was ameliorated by amiloride treatment. Histological and morphometric analysis showed glomerular and tubular damage in KspKL−/−, which was improved by amiloride treatment. Western blotting analysis demonstrated a significant decrease in the αγ subunits of ENaC in the kidney cortex following treatment with amiloride.ConclusionThis study demonstrates for the first time that depletion of klotho causes impairment in Na‐excretion and hypertension by affecting ENaCα levels. ENaC may be a promising therapeutic target for klotho deficiency‐induced renal and vascular dysfunction and hypertension.
Feed Restriction and IGF‐1 Affect the Oocyte Maturation in Matrinxã Brycon amazonicus
Authors: Montrezor Luís H. , Urbinati Elisabeth C. 
Published: November 2023

The feeding and nutrition of breeders are crucial aspects in the reproductive process. During the maturation period, metabolic changes occur aiming at mobilizing energy for growth and follicular development. The involvement of IGF‐1 in metabolic and reproductive events is important. The aim of this work was to evaluate if alternate feed restriction and re‐feeding have permissive effects on in vitro actions of IGF‐1 on oocytes development of matrinxã. In vivo experiments were performed during vitellogenesis period. Females (n = 60) were fed with a commercial feed (2% of biomass) and they were divided into two treatments: fish receiving food daily (control ‐ fed), and fish submitted to cycles of three days of feed restriction and two days of re‐feeding (no fed group). The ovaries removed at the end of in vivo experiment were maintained in phosphate‐buffered saline (PBS) and the oocytes were mechanically dissected. The collected oocytes (n = 20) were cultured in 24 well plates (20 oocytes/well/mL) in Leibowitz medium supplemented with 20nM HEPES, antibiotics (1000U/mL penicillin and 100 μg/mL streptomycin) and 0,1% bovine serum albumin (BSA), in a final volume of 1,0mL, pH 7,5. The oocytes were divided into four treatments: a) fed ‐ IGF‐1; b) fed + IGF‐1 (0; 1; 10 and 50nM); c) no fed ‐ IGF‐1; d) no fed + IGF‐1 (0; 1; 10 and 50nM). The assays were performed in triplicate and the plates were incubated at 26° C for 3 hours. Fish under restriction had lower body weight, decreased plasma glucose, increased triglycerides levels, and their final maturation and mature oocyte were reduced and the atresic ones were in higher number. Moreover, the IGF‐1, in vitro, increased the percentage of mature oocytes in fed females and decreased the atresic ones. In no fed females, IGF‐1 increased the final maturation and mature oocytes and reduced the atresic ones. This study demonstrates the importance of the feeding management of female breeders of matrinxã during the vitellogenesis period. The feeding management affects oocyte development, food restriction impairs and IGF‐1 restores the negative effects on oocyte development induced by feeding management.Support or Funding InformationCNPq
A Cellular Mechanism of Leptin Mediated Responses in Mouse NTS Neurons
Authors: Do Jeehaeh , Kowal Anthony , Floreani Lavinia , McCrimmon Donald R , Martina Marco 
Published: November 2023

The nucleus of the solitary tract (NTS) in the medulla is the site of first synapse for sensory afferents of the vagal and glosspharyngeal nerves. A dense termination of sensory input reflects a key function of the NTS as an integrative center for a number of vitally important homeostatic reflexes such as cardiovascular, respiratory and visceral reflexes. Little is known concerning the cellular rules of information integration in the NTS, especially how the metabolic state influences respiratory output. Leptin is an anorexigenic cytokine acting through activation of specific G‐protein‐coupled receptors (GPCRs). Leptin receptors are expressed in the NTS, but the mechanism of action following their activation remains unclear. Moreover, the precise identity of the cells expressing the leptin receptor in the NTS is also elusive.Our study has two main goals: 1‐ to uncover the expression of individual genes that identify neuronal subpopulations of cells expressing the leptin receptor; and 2‐ to identify the ion channel(s) mediating the action of leptin in these different cellular populations. To pursue these goals we combine genetic tagging of leptin receptor expressing neurons, electrophysiological recordings and single cell RT‐PCR to test the expression of candidate channels and neuropeptides. Our data show that NTS leptin receptor expressing neurons belong to two distinct populations characterized by different firing patterns (bursting vs. regular firing). Further, we found that leptin receptor activation leads to membrane depolarization that is mediated by a cationic conductance. This mechanism appears to be the same in both the cell populations. The PCR data suggest that the conductance activated by leptin is, at least in part, mediated by NALCN channels.Support or Funding InformationThis study was supported by NIH grant HL122921
The Vagus Nerve in Development of Lung Tumor
Authors: Liu Jun , Song Nana , Guardiola Juan , Yu Jerry 
Published: November 2023

ObjectiveLung cancer is the leading cause of cancer death worldwide. Its treatment remains largely unsatisfactory, because our knowledge of its underlying mechanisms is limited. In addition to genetic factors, the initiation, development and progression of lung tumors result from a network of interaction among mediators, cytokines, and growth factors derived from various cells. The vagus nerve is closely related to each of these network components, thus must influence the outcome. Here we tested the hypothesis that the vagus nerve protectes the lung from tumor formation and explored its underlying mechanism.MethodsTumors were assessed microscopically by HE staining and macroscopically by directly counting tumor numbers and measuring their sizes in the two lungs in unilaterally vagotomized AJ mice following urethane treatment. Tumors were also dissected from the lung tissue and grinded for FACS analysis to assess myeloid‐derived suppressor cells.ResultsMorphologically, hyperplasia lesions and nodules were similar in the two lungs. However, tumor numbers and sizes (normalized with lung surface area) 20 weeks after urethane treatment were greater in vagotomized (0.068 /mm2 and 21.6 area%) than intact lungs (0.052 /mm2 and 16.0 area%) (n = 13 and n = 8; p < 0.05 and p < 0.01). Similar results were observed at 10 weeks after urethane treatment. In addition, CD11b+Ly6− C++Ly6G− suppressor cells were more in the vagotomized lung than in the intact lung.ConclusionOur data support that the vagus nerve may protect the lung from tumor formation by modulating immune cell expression.Support or Funding InformationFunded by the Pulmonary Fibrosis Foundation
Multipotent Myoepithelial Progenitor Cells Are Born Early During Airway Submucosal Gland Development
Authors: Anderson Preston , Lynch Tom , Engelhardt John 
Published: November 2023

Airway submucosal glands (SMGs) are facultative stem cell niches for the surface epithelium, but the phenotype of the SMG‐derived progenitor cells remains unclear. In other organs, glandular myoepithelial cells (MECs) have been proposed to be multipotent progenitors for luminal cells. We sought to determine the developmental phase during which mouse tracheal glandular MECs are born and whether these primordial MECs are progenitors for other cell phenotypes during SMG morphogenesis. To approach this question, we localized two MEC protein markers (α‐smooth muscle actin [αSMA/ACTA2] and smooth muscle myosin heavy chain 11 [SMMHC]) during various stages of SMG development (placode, elongation, branching, and differentiation) and used ACTA2‐CreERT2 transgenic mice to fate map MEC‐derived lineages during SMG morphogenesis. Protein localization ontogeny studies demonstrated that both αSMA‐ and SMMHC‐expressing cells emerged early following placode formation and during the elongation phase of SMG development. Tamoxifeninduction of newborn ACTA2‐CreERT2 mice led to lineage‐tracing of ~50% of αSMA+ MECs at the tips of invading tubules during the elongation phase and these cells contributed to ~25% of αSMA+ MECs in the fully formed gland by 21 days. During the differentiation phase of gland development, ~33% MEC derived cells that were lineage‐marked at birth gave rise to αSMA‐negative glandular cell types by 21 days, including serous, mucous, and duct cells. By contrast, lineage‐traced MECs did not contribute to cell types in the surface airway epithelium. These findings demonstrate that primordial MECs born early during SMG morphogenesis are multipotent progenitors with the capacity to differentiate into other glandular cell types.Support or Funding InformationThis work was supported by NIH grants DK047967 (to J.F.E), the University of Iowa Center for Gene Therapy (DK54759) (to J.F.E), and the Carver Chair in Molecular Medicine (to J.F.E).
Modulation of the lung inflammatory response to ozone by the estrous cycle
Authors: Silveyra Patricia , Cabello Noe , DiAngelo Susan 
Published: November 2023

BackgroundStudies have shown that women are at increased risk of adverse health outcomes from air pollution (e.g. ozone) than men. Emerging data indicate that hormones could play a role in the regulation of lung innate immunity and inflammation in response to environmental challenges, but the molecular mechanisms involved in these responses remain unknown. The goal of this project was to investigate whether fluctuations in circulating hormone levels during the estrous cycle could modulate the inflammatory response to ambient ozone.MethodsAdult female C57BL/6 mice, in different stages of the estrous cycle, were exposed to ozone (2ppm) or filtered air (FA) for 3 hours (n=6/group). The estrous cycle stage was determined by vaginal smear, and cyclicity was confirmed for at least 3 cycles. Four hours after exposure, lungs were harvested and RNA was extracted using Trizol. The mRNA expression of inflammatory cytokines and chemokines was analyzed by Real Time PCR (mouse genes: Ccl2, Ccl3, Cxcl2, Ccl20, Il1b, Il6, Tnf, and RANTES) using TaqMan probes, and normalized to 18S. Serum levels of LH, estradiol, and progesterone were also measured by ELISA to confirm the estrous cycle stage.ResultsExposure to ozone significantly increased expression of Cxcl2, Ccl20, and Il6 genes in female mice exposed in all estrous cycle stages, with higher expression levels in proestrus vs. other stages (p<0.05). In contrast, the expression of both Ccl2 and Ccl3 was only increased in mice exposed to ozone at the proestrus stage (p<0.05), but not in animals exposed in diestrus/estrus. Ozone exposure did not affect the expression of Il1a, Tnf or RANTES, when compared to females exposed to FA. Serum hormone levels confirmed proper estrus cycle stage in all animals.ConclusionsOur results confirmed differences in lung inflammatory gene expression in response to ozone in female mice exposed at different stages of the estrous cycle. Our observations suggest that the negative effects of air pollution in women's lung health may be affected by their hormonal status. Future studies investigating adverse health effects of ozone in women should consider their menstrual cycle phase, and/or circulating hormone levels.Support or Funding InformationSupported by NIH HL‐133520
Activation of Bitter Taste Receptors Has Distinct Modulatory Effects on Different Lung Afferent Signaling in Rats
Authors: Gu Qihai (David) , Gilbert Carolyn , McLaurin Hugh 
Published: November 2023

We have reported recently that activation of bitter taste receptors (T2Rs) in lung nociceptors significantly augments capsaicin‐evoked TRPV1 responses, likely through PLC and PKC intracellular signaling pathway. Using whole‐cell patch‐clamp recordings, the present study was carried out to investigate how T2Rs activation may affect lung sensory neurons responding to different airway stimulations. Three airway irritants that are known to stimulate different pulmonary sensory receptors are selected: zinc, an agonist for TRPA1; low pH or acid, an activator for both acid‐sensing ion channels (ASICs) and TRPV1; and ATP, an agonist for P2X purinoceptors. Our results showed that pretreatment with T2Rs activator chloroquine (0.01, 0.1 and 1 mM, 90 s) concentration‐dependently potentiated zinc (30 μM, 3–16 s)‐evoked TRPA1 currents, and markedly inhibited ATP (0.3 or 1 μM, 4–6 s)‐evoked P2X currents, whereas affected acid (pH 5.5 and pH 6.5, 4–16 s)‐evoked inward currents differently: an inhibition for the slow inactivation ASIC‐like current, and a potentiation for the TRPV1‐like current as well as the fast‐activation and fast‐inactivation ASIC current. Surprisingly, our results also showed that none of the above modulations was completely abolished by the inhibition of PLC, PKC or PKA transduction pathway. In summary, our results demonstrated that T2Rs activation in lung afferents has distinct regulatory effects on various ion channels that are sensitive to different airway irritants.Support or Funding InformationSupported by funds from Navicent Health Foundation and MUSM