bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dysregulation of Insulin receptor expression affects proximal tubule gluconeogenesis
Authors: Pandey Gaurav , Mandhani Anil , Srivastava Anssesh , Ecelbarger Carolyn , Agnihotri Kripa S , Gaikwad Anil , Tiwari Swasti 
Published: November 2023

Reduced insulin receptor protein levels have been reported in the kidney cortex from diabetic human and animals. We have recently reported that targeted deletion of insulin receptor (IR) from proximal tubules (PT) resulted in hyperglycemia in non‐obese mice. To understand the mechanism, we studied human proximal tubule cells (hPTC) and C57bl/c mice fed with high fat diet (HFD, 60% fat for 20 weeks). Immunoblotting revealed a significantly lower expression of IR and blunted rise in p‐AKT levels in the kidney cortex of HFD mice in response to acute insulin (2 unit/kg body weight, i.p) relative to normal chow diet (NCD) n=8/group, p<0.04). Moreover, we found significantly higher transcript levels of phosphoenolpyruvate carboxykinase (PEPCK, rate‐limiting gluconeogenic enzyme) in the kidney cortex from HFD, relative to mice on NCD, (n=8, p<0.05). The higher level of PEPCK in HFD was confirmed by immnoblotting. However, no significant difference was observed in G6Pase and FBPase enzyme transcript levels in the renal cortex of HFD relative to NCD. Furthermore, an in vitro study using primary human PT cells (hPTC) showed insulin's inhibitory effect on cAMP/DEXA –induced gluconeogenesis in these cells. In addition, transcript levels of gluconeogenic enzymes G6Pase and PEPCK were significantly increased in cAMP/DEXA‐stimulated hPTC cells (n=5, p=0.05). However, these effects of insulin on cAMP/DEXA–induced gluconeogenesis and gluconeogenic enzyme induction were blunted in IR silenced hPTC (n=3, p<0.05). Taken together the above data indicate a direct role of insulin receptor in PT‐gluconeogenesis regulation. Thus reduced insulin sensitivity of the proximal tubule could, itself, contribute to hyperglycemia via elevated gluconeogenesis. (BT/HRD/35/02/17/2008)Support or Funding InformationThe work was supported by the Department of Biotechnology, government of India, Ramalingaswami grant (BT/HRD/35/02/17/2008 to S.T). G.P. was supported by Research Fellowship from University Grant Commission.
Engineered FGF21 variant, LY2405319, can protect nonalcoholic fatty liver disease through enhancing hepatic mitochondrial function
Authors: CHUNG HYO KYUN , Kang Yea Eun , Hwang Jin Hee , Kim Koon Soon , Shong Minho 
Published: November 2023

ObjectiveNonalcoholic fatty liver disease (NAFLD) is one of the causes of fatty liver, linked to insulin resistance, metabolic syndrome, liver fibrosis and cirrhosis. Traditionally, NAFLD has been recognized as a result of excess nutrient intake. However, the molecular target of NAFLD has not been fully addressed. The increased ROS/RNS and mitochondrial dysfunction of hepatocyte can play critical roles in the development of NAFLD and nonalcoholic fatty liver (NASH) through chronic inflammation and insulin resistance. We here show that the beneficial effects of LY2405319, an Engineered FGF21 Variant (lilly, USA), on NAFND using ob/ob mice model.MethodsThe 6‐week‐old male ob/+ control and ob/ob C57BL/6J Lep(−/−) mice were divided into three groups, including ob/+ control, vehicle‐treated (ob/ob‐vehicle) and LY2405319‐treated group (ob/ob‐LY). The vehicle and LY2405319 (5mg/kg) were administered oral gavage for 3 weeks. Body weight was recorded every 2 days. Intraperitoneal glucose tolerance test and energy expenditure were performed after LY2405319 treatment for 3 weeks. The effects of LY2405319 on NAFLD progression were evaluated using biochemical, hitological and molecular markers. Oxygen consumption rate (OCR) and mitochondrial gene expressions were measured to determine the effects on mitochondria in ob/ob mouse and primary hepatocyte.ResultsLY2405319 treated ob/ob mice revealed decreased body weight and serum glucose levels and markedly decrease of serum AST, serum ALT and hepatic triglycerides compared to control group. And also, hepatic steatosis and lipid peroxidation significantly improved compared to control group. Interestingly, LY2405319 treatment mice group showed increased energy expenditures and significantly increased in mitochondrial transcriptional‐, and translational gene expression than control group. Furthermore, LY2405319 increased OCR by dose dependent manner in primary hepatocytes.Support or Funding InformationThis work was supported from the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT, and Future Planning, Korea (NRF‐2015R1A2A1A13000951). H.K.C. and J.H.H were supported by NTF grant, the Ministry of Education (MOE), Korea (NRF‐2013R1A1A2058889).
The Role of P2X7R in Priming the NLRP3 Inflammasome after Mechanical Strain
Authors: Albalawi Farraj , Lu Wennan , Lim Jason , Mitchell Claire H 
Published: November 2023

The NLRP3 inflammasome is a cytosolic multiprotein complex whose activation results in the maturation and release of cytokine IL‐1β. There are two steps in inflammasome involvement; first the relevant proteins must be primed and upregulated on a transcriptional and translational level. Second, the proteins must be activated to assemble and process the maturation of caspase 1 and IL‐1β. The P2X7 receptor (P2X7R) is known to activate the NLRP3 inflammasome. However, it is currently unclear whether the P2X7R also plays a role in priming the inflammasome components. Rat optic nerve head astrocytes were swollen by 30% hypotonic solution for 4 hours then RNA was extracted. For in vivo experiments, we elevated intraocular pressure (IOP) moderately to 50–60 mmHg for 4 hours, with RNA extracted 24 hrs later. qPCR analysis was used to measure the expression of inflammasome related genes. Rat optic nerve head astrocytes release ATP when swollen. Swelling these cells for 4 hours upregulated mRNA for NLRP3 and IL‐1β but not caspase 1. This upregulation was inhibited by 4 μM Bay11‐7082 (NFκB inhibitor), implicating NFκB. Inhibiting the P2X7R with 10 μM Brilliant blue G (BBG), 50 nM A839977, or 5 μM A740003 prevented the swelling‐induced upregulation of IL‐1β but not NLRP3. In vivo, the expression of IL‐1β, NLRP3 and caspase 1 were all increased at the mRNA level in optic nerve head astrocytes of eyes subjected to moderate elevation of IOP. Intraocular injection of BBG prevented the rise in IL‐1β but not NLRP3. In conclusion, mechanical strain upregulates NLRP3 and IL‐1β mRNA via NFκB; but only the upregulation of IL‐1β required P2X7R stimulation.Support or Funding InformationNIH Grants EY013434, EY015537
Contribution of Endogenous Hydrogen Sulfide to Hypoxic Inhibition of Sodium Transport by Lung Epithelial Cells
Authors: Althaus Mike , Krause Nicole Catherine , Pott Jennifer , Münch Lena Katharina , Olson Kenneth R 
Published: November 2023

In lung epithelial cells, hypoxia decreases the expression and activity of sodium transporting molecules, thereby reducing the rate of transepithelial sodium absorption. The mechanisms underlying the sensing of hypoxia and subsequent coupling to sodium transporting molecules remain unclear. Hydrogen sulfide (H2S) has recently been recognized as a cellular signaling molecule whose intracellular concentrations critically depend on oxygen levels. Therefore it was questioned whether endogenously produced H2S contributes to hypoxic inhibition of sodium transport. H2S is generated by multiple pathways involving cystathionine‐γ‐lyase (CSE), cystathionine‐β‐synthase (CBS) and 3‐mercaptopyruvate sulfurtransferase (3‐MST). RT‐PCR and immunoblotting experiments revealed the presence of all of these enzymes in human H441 lung epithelial cells. Using an amperometric H2S‐sensitive electrode, H2S‐production by H441 lysates was detected. H2S‐production inversely correlated with oxygen concentrations. In electrophysiological Ussing chamber experiments, exogenous application of H2S by the sulfur salt Na2S inhibited amiloride‐sensitive sodium transport by cultured H441 monolayers. Furthermore, acute hypoxia which was established by decreasing oxygen concentrations from 10 % to 0.1 % for 30 min decreased amiloride‐sensitive sodium transport by these cells. Pretreatment with the CSE‐inhibitor D/L‐propargylglycine (PAG) decreased hypoxic inhibition of sodium transport, whereas inhibition of CBS (with aminooxy‐acetic acid; AOAA) or 3‐MST (with aspartate) had no effect. Inhibition of all H2S‐generating enzymes with a combination of AOAA, PAG and aspartate abrogated the hypoxic inhibition of sodium transport. By contrast, increasing the concentrations of L‐cysteine, pyridoxalphosphate and α‐ketoglutarate, precursors of H2S production, did not enhance the effect of hypoxia. These data indicate that H441 lung epithelial cells endogenously produce H2S during hypoxia and this might contribute to hypoxic inhibition of sodium absorption.Support or Funding InformationThis work was funded by the German Research Foundation (AL‐1453/1‐2).
Effect of Age on Sexually Dimorphic Expression of X‐linked Genes in the Developing Mouse Cortex and Hippocampus
Authors: Moreira Debbie , Armoskus Chris , Rath Faviolanny , Reyes Rosa , Tsai Houng‐Wei 
Published: November 2023

Among different brain regions, the cortex and hippocampus are responsible for regulating cognitive and social behaviors, and considerable evidence suggests that these functions are sexually dimorphic. However, little is known about the molecular and genetic mechanisms underlying sexual dimorphism in these two brain regions. An earlier study observed higher mRNA expression of six X‐linked genes, Ddx3x, Eif2s3x, Kdm5c, Kdm6a, Uba1, and Usp9x, in the female mouse brain than the male during early development and adulthood, suggesting that sex chromosomes may act directly in brain to cause sex differences in development and function. Recently, we have identified eight candidate genes located on X chromosome differentially expressed in the neonatal mouse cortex/hippocampus between the sexes, including Ebp, Eif2s3x, Ftsj1, Kdm6a, Psmd10, and Xist as well as two pseudoautosomal genes, Erdr1 and Mid1. We hypothesized that similar to those observed in neonates, dimorphic expression of these genes along with Ddx3x, Kdm5c, Uba1, and Usp9x, might be persistently present in the mouse cortex/hippocampus during early development, responsible for establishing distinct structures and circuits underlying sex‐biased cortical and hippocampal function. To test this hypothesis, we employed RT‐qPCR to measure mRNA levels of Ddx3x, Ebp, Eif2s3x, Erdr1, Kdm5c, Kdm6a, Mid1, Psmd10, Uba1, Usp9x, and Xist in the male and female cortex/hippocampus of C57BL/6J mice collected on the day of birth (PN0), and 7 (PN7), 14 (PN14), and 21(PN21) days after birth (n=7–9 per group). We found that among the 11 genes tested, female mice expressed higher mRNA levels of Eif2s3x, Erdr1, Kdm5c, Kdm6a, and Xist than males. Interestingly, the female‐biased expression Erdr1 and Kdm6a was only observed at PN21 and PN0 & PN21, respectively. As compared to PN0, Eif2s3x and Xist showed a decrease in expression at PN7 and PN14 while reduced Kdm5c levels were found at PN7 only. Based on our data, we concluded that during early development, sexually dimorphic expression of selected X‐linked genes in the mouse cortex/hippocampus is dynamically altered with age, suggesting that these genes might participate in brain feminization at different developmental stages.Support or Funding InformationThis research project was supported by the National Institute of General Medical Sciences Grant SC3‐GM102051.
Regulation of the Sexually Dimorphic Gene, Rora, in the Developing Mouse Cerebellum Is Independent of Sex Steroids
Authors: Mota Thomas , Tsai Houng‐Wei 
Published: November 2023

The cerebellum is important for motor coordination and non‐motor functions, such as cognition, language, and social function. Furthermore, there is mounting evidence of cerebellar involvement in gender‐biased neurological disorders and mental illness. For example, decreased cerebellar expression of retinoic acid receptor‐related orphan receptor α (Rora) is observed in autism, a male‐biased neurodevelopmental disorder characterized by deficits in social behavior and interpersonal communication. In addition, Rora expression is up‐regulated and downregulated in vitro by estrogen receptor α (ERα) and androgen receptor (AR), respectively. Since a perinatal rise in testosterone secreted by the developing testes acts directly on AR or indirectly on ERα via estradiol synthesized locally by aromatase to masculinize brain structures and behaviors, we hypothesized that Rora expression in the mouse cerebellum during early development might be sexually dimorphic, which is regulated by the activation of AR and/or ERα. To test our hypothesis, we measured mRNA levels of Rora in male and female mouse cerebella collected on the day of birth (PN0), 7 (PN7), 14 (PN14), and 21 days (PN21) after birth by quantitative RT‐PCR. While Rora levels significantly increased with age (p<0.001), they were male‐biased on PN0 (p=0.006), but female‐biased at PN14 (p=0.02). We next determined if the male‐biased expression of Rora in the neonatal cerebellum was regulated by AR and/or ERα by treating pregnant female mice daily with vehicle, testosterone propionate (TP), or estradiol benzoate (EB) starting on embryonic day 16 until PN0. The cerebellum was collected from vehicle‐, TP‐, and EB‐treated, male and female neonatal pups. As compared to vehicle‐treated controls, there was no effect of TP (p=0.812) or EB (p=0.624) on Rora expression, suggesting that sex steroids might not be required for the control of Rora expression. In summary, sexual dimorphism in Rora expression in the neonatal mouse cerebellum is transient, followed by a robust change with age during early development. Although the Rora gene in the neonatal cerebellum does not seem to be regulated by sex steroids and their receptors, sex‐ and age‐specific expression of the Rora gene might still be involved in the control of cognitive behaviors between the sexes and the etiology of sex‐biased neurological disorders and mental illnesses.Support or Funding InformationThis research was supported by the National Institute of General Medical Sciences Grant SC3‐GM102051.
Loss of Cdk5 Function May Mediate Age‐Related Decline in Voluntary Physical Activity
Authors: Ruegsegger Gregory , Toedebusch Ryan , Booth Frank 
Published: November 2023

Increases in age are associated with declining levels of physical activity in multiple species, including humans, which in turn promotes the development of numerous chronic diseases. However, the neuro‐molecular mechanisms that regulate physical activity motivation at various ages are poorly understood. Our lab has previously observed that, in female Wistar rats, lifetime voluntary wheel running behavior is greatest at 8 wks of age.ObjectiveWe aimed to assess differences in the nucleus accumbens (NAc), a specific brain nucleus postulated to influence rewarding behavior, of wheel running and sedentary female Wistar rats at 8 and 14 weeks (wks) of age (n= 5–8).MethodsWheel running rats were introduced to wheels at 5 wks of age. RNA‐seq, qRT‐PCR and Western blotting were used to assess molecular changes between 8‐ and 14‐wk‐old wheel running and sedentary rats.ResultsVoluntary wheel running was greatest at 8 wks (17.7± 1.0 km/d) and had significantly decreased by 14 wks (11.1± 1.2 km/d). From 619 differentially expressed genes, bioinformatics suggested that cAMP‐mediated signaling, DARPP‐32 feedback, PKA signaling, and synaptic plasticity were increased at 8‐ compared to 14‐wk in wheel running rats. While analyzing transcripts specific to these functions, we observed significant (~20–30%; p< 0.05) decreases in Cadm4, Cdk5, and p39 (Cdk5 activator) mRNAs and proteins from 8 to 14 wks of age in voluntary running rats. Further, Cadm4 (r= 0.84), Cdk5 (r= 0.57), and p39 (r= 0.71) mRNAs were significantly correlated with voluntary running distance during the week of sacrifice. Follow‐up analysis of sedentary 8‐ and 14‐wk‐old rats (n= 5–8) by qRT‐PCR found similar decreases in Cadm4 and p39 mRNAs and proteins from 8 to 14 wks of age (p< 0.05), suggesting an age‐dependent reduction in synaptic function and Cdk5 activity may mediate decreases in wheel running. In light of these transcriptomic and protein changes, we assessed wheel‐running distance following NAc injection of the Cdk5 inhibitor roscovitine (ROS) (80 nmol/0.5μg) (n= 7) or vehicle (n= 5). Compared to vehicle, ROS significantly decreased wheel running distance 0–30 and 30–60 min post‐injection (p< 0.001), and 60–90 min post‐injection (p< 0.01). These effects were present after both 1 day and 5 days of daily injections.ConclusionCollectively, these experiments suggest that an age‐dependent loss in synaptic function and Cdk5/p39 activity in the NAc may mediate the age‐related decline in voluntary running behavior.SignificanceGiven the epidemic levels of physical inactivity and its associated consequences, these data may foster the development of therapies targeted to reduce age‐dependent increases sedentary behavior.Support or Funding InformationResearch was supported by an MU Life Sciences pre‐doctoral fellowship (GNR) and MU development funds (FWB).
Angiotensin‐(1‐7) Delays Onset of Dilated Cardiomyopathy in Mice with Muscular Dystrophy
Authors: Sabharwal Rasna , Yang Liping 
Published: November 2023

We have demonstrated that angiotensin II‐induced autonomic and skeletal muscle dysfunction precedes and predicts development of dilated cardiomyopathy (DCM) and premature mortality in sarcoglycan‐delta deficient mice, i.e. murine model of muscular dystrophy [Exp Physiol 2015]. In addition, we have shown that ang‐(1‐7) administered for 8 weeks markedly improves autonomic function and locomotor activity in young (>15 weeks of age) Sgcd−/− mice by attenuating levels of circulating and skeletal muscle Ang‐II [Clin Sci 2014]. In this study, our goals were – (i) to determine whether Ang‐(1‐7) infusion delays onset of DCM in older mice (>50 weeks of age); and (ii) to evaluate the performance of the recently released SMP‐300 iPRECIO Infusion Pumps (Primetech Corporation®, Japan) in delivering 500 ng of Ang‐(1‐7) at a rate 0.1 ml/hour for 49 days. Blood pressure (BP), heart rate (HR) and sympathovagal tone were measured by telemetry (PA‐C10, DSI®) in older control C57BL6 (untreated n=3) and Sgcd−/− (untreated n=4; treated n=4) mice. Compared to untreated control mice, untreated Sgcd−/− mice exhibit increased sympathetic tone (HR response to propranolol), reduced HR variability (parasympathetic tone), increased cardiac fibrosis (Masson's staining), and cardiac dysfunction (echocardiography) (all variables P<0.05). Ang‐(1‐7) effectively restored autonomic function, reduced cardiac fibrosis by 44%, increased ejection fraction by 21%, and reduced end‐diastolic volume/mass by 57% (P<0.05 vs. untreated Sgcd−/− mice). We conclude: 1) Ang‐(1‐7) treatment restores sympathovagal balance, reduces fibrosis and delays onset of DCM in older aged mice with muscular dystrophy. 2) iPRECIO infusion pumps are refillable, reprogrammable, and delivers drugs easily and successfully. 3) Albeit the combined weights of iPRECIO pump (3.3 g) and DSI transmitter (1.4 g) do not interfere with data collection, it is recommended to use mice not smaller than 25 g of body weight.Support or Funding InformationTarix Pharmaceuticals, Primetech, DSI
Developing manganese‐enhanced MRI as a non‐invasive measure of in vivo neuronal activity in the rostral ventrolateral medulla (RVLM) of sedentary and physically active rats
Authors: Huereca Daniel J , Holt Avril G , Berkowitz Bruce A , Mueller Patrick J 
Published: November 2023

Elevated sympathetic nerve activity (SNA) is implicated as a major risk factor for cardiovascular disease (CVD). We have previously demonstrated greater SNA in sedentary versus physically active rats following direct and indirect activation of the RVLM, the primary regulator of SNA. We have also reported changes in structure among spinally projecting neurons in the RVLM, including greater dendritic branching in sedentary versus physically active rats. These studies indicate that sedentary conditions promote structural and functional changes within the RVLM linked with increased SNA. The aim of the present study was to develop a new method, manganese‐enhanced magnetic resonance imaging (MEMRI), to compare changes in RVLM activity over time in sedentary versus physically active rats. MEMRI utilizes both the paramagnetic properties of manganese (Mn2+) as well as its uptake by active neurons. Mn2+ is a T1 MRI contrast agent that enters active neurons via calcium channels, thus, greater manganese uptake indicates greater neuronal activity. We hypothesized that the enhanced SNA in sedentary versus physically active rats is due to greater activity of bulbospinal RVLM neurons. To evaluate the influence of sedentary and physically active conditions on in vivo neuronal activity of the RVLM longitudinally, five week old male Sprague Dawley rats (n=4) were anesthetized (2% isoflurane) and RVLMs were imaged on a 7T small animal MRI (Bruker ClinScan). One week later, changes in T1 were evaluated 24 hours after an i.p. injection of manganese (66mg/kg MnCl2). Two rats were then each assigned randomly to a sedentary or physically active group (spontaneous wheel running). After five weeks (24 hours after a 2nd injection of MnCl2), Mn2+ uptake was greater in the RVLM of sedentary versus physically active rats, regardless of the method used for collection and analysis of the MRI data; T1 weighted (+16.3% vs +6.8% signal increase) or T1 mapping (1/T1=0.81 vs 0.69). Furthermore, physically active rats had similar or decreased Mn2+ uptake after versus before wheel running (6.8 vs 11.0% change), while sedentary rats appeared to have enhanced Mn2+ uptake after versus before five weeks of sedentary conditions (16.3 vs 7.4% change). These initial findings support our hypothesis that sedentary conditions promote exaggerated neuronal activity in the RVLM, as indicated by greater Mn2+ accumulation in sedentary versus physically active rats. Enhanced RVLM activity due to sedentary conditions may contribute to greater SNA and contribute to the mechanisms by which a sedentary lifestyle increases the risk of developing CVD in humans.Support or Funding InformationDJH AHA 15PRE25700308; PJM NIH HL096787‐05A1, AHA 25810010; AGH USDVA 1I01RX001095‐011Rx; BAB NEI EY021619