bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phosphorylation of the electrogenic sodium/bicarbonate co‐transporter 1 (NBCe1) at Ser245 and Ser255‐257is linked to mTOR‐mediated transporter activity
Authors: Giannaki Marina , Heermann Stephan , Roussa Eleni 
Published: May 2022

The electrogenic sodium bicarbonate co‐transporter 1 (NBCe1, Slc4a4) is a key pH‐regulating membrane protein and is widely expressed in kidney, pancreas, cornea, heart and brain. Phosphorylation in several residues can affect the surface expression and the activity of the transporter. NBCe1 has been found to be phosphorylated in several residues among them in Ser65 where SPAK inhibits its activity and in Thr49required for regulation of NBCe1 by IRBIT and SPAK. Moreover, IRBIT regulates the activity of NBCe1 by controlling the phosphorylation status of Ser232, Ser233 and Ser235. The aim of this study is to identify novel phosphorylation sites and examine their putative contribution in the transport activity of NBCe1.Phosphoproteomic analysis in mouse cortical astrocytes revealed constitutively phosphorylated NBCe1 at Ser245 and Ser255‐257. Mutational analysis in Hela cells and intracellular H+ recordings using pH‐sensitive fluorescent dye (BCECF) showed that the activity of NBCe1 is regulated by the phosphorylation of these residues, phospho‐Ser245 significantly reduced the activity of NBCe1 whereas phospho‐Ser255‐257led to increased NBCe1 activity. Additionally, in the presence of the mTOR inhibitor rapamycin or the mTOR activator 3BDO our data demonstrated that mTOR signaling pathway regulates the phosphorylation of the Ser245 and Ser255‐257.Our findings reveal phosphorylation at Ser245 and Ser255‐257as novel regulators of NBCe1 transport activity. We suggest that mTOR pathway is capable to fine tune NBCe1 activity, an event with putative implications during pathophysiological conditions.
Correlation of Cardiovascular Function and Hemodynamic Parameters with Gender and BMI in Healthy Subjects
Authors: Zhang Yanfang , Sun Xinguo , Wang Jinan , Zhou Qingqing , Tai Wenqi 
Published: May 2022

ObjectiveTo observe and study the left heart function and hemodynamic parameters in young healthy normal subjects, and to analyze the correlation between gender and body mass index (BMI) and left heart function.MethodsWe selected thirty‐nine young healthy graduate students, advanced training doctors, and visiting scholars from Fuwai Hospital without any disease diagnosis and low daily exercise. Hemodynamic parameters were collected by using a non‐invasive synchronous ventricular function detector (N‐ISVFD). We calculated the abnormal rate of hemodynamic parameters and analyzed the correlation between gender and BMI and left heart function.ResultsIn this study,39 healthy young subjects (males 18, females 21), aged (30.1±5.6) years old, BMI(22.0±2.9) kg/m2,all participants signed the written informed consent. The abnormal rate of left ventricular jet pressure (LVJP), systolic mean pressure (SMP), diastolic mean pressure (DMP), left ventricular end diastolic volume (LVEDV), myocardial oxygen consumption (MOC), ejection fraction (EF), left cardiac index (LCI) were 39.2%±22.6%. LVJP, SMP, DMP, LVEDV and MOC were correlated with gender and BMI. EF and LCI were relatively independent of gender and BMI.ConclusionDue to the stress life, psychological and other aspects, there is no symptoms or various checks presented negative, hemodynamic parameters of young people has deviated from the normal range. We should take more exercise to prevent diseases from happening. Indicators in connection with myocardial contractility, left ventricular preload, left ventricular afterload and coronary circulation are related to gender and BMI, so the assessment of cardiovascular function of patients should take into account gender and BMI differences.
Ablation of PRAK exacerbates the mitochondria dysfunction in C2C12 myoblasts exposed to palmitate stress
Authors: Wang Jianguo , Zhao Thomas , Yano Naohiro , Zhao Ting C. 
Published: May 2022

Backgroundp38 regulated/activated protein kinase (PRAK) plays a crucial role in modulating survival and metabolism. However, the role of PRAK in the regulation of palmitate‐induced metabolic stress remains unknown. We examined whether deletion of PRAK would suppress cell survival and mitochondrial function and whether PRAK‐induced detrimental effect was mitigated by irisin in C2C12 myoblasts in response to palmitate (PA) stress.MethodsPRAK of C2C12 myoblasts was knocked out by using CRISPR/Cas‐9 genome editing technology. Both wild type and PRAK‐/‐ C2C12 cells were exposed to palmitate at the concentration of 200 mmol/L for 48 h to induce metabolic stress. The effect of irisin, an adipomyokine, on both wild type and PRAK‐/‐cells was determined to explore its relationship with RPAK in response to palmitate stress. Cell viability, ATP product, glucose uptake, mitochondrial membrane potential and mitochondrial swelling were assessed.ResultsPRAK knockout decreased C2C12 viability in response to PA stress as evident by MTT assay in association with the reduction of ATP and glucose uptake. PRAK knockout enhanced apoptosis of C2C12 myoblasts in response to PA treatment, consistent with an impairment in mitochondrial function, by decreasing mitochondrial membrane potential and increasing mitochondrial swelling. However, PRAK knockout induced an impairment of mitochondrial and cell damage in C2C12 cells exposed to PA stress were rescued by treatment of irisin (10ng/ml).ConclusionOur finding indicates a pivotal role of PRAK in preserving cellular survival, mitochondrial function and glucose uptake in C2C12 cells exposed to palmitate induced metabolic stress.
Enabling regeneration in a β‐catenin‐deficient liver: Unraveling a novel compensatory role of mTOR
Authors: Hu Shikai , Cao Catherine , Singh Sucha , Poddar Minakshi , Monga Satdarshan 
Published: May 2022

BackgroundsLiver can regenerate to maintain its essential functions upon injury. Several signaling pathways including the mTORC1 and Wnt/β‐catenin pathways have been shown to independently stimulate liver regeneration (LR) to promote repair. However, how one pathway could compensate during deficiency of another is less well understood. Here, we report discovery and characterization of a compensatory interplay between the mTORC1 and the Wnt/β‐catenin pathway that enables LR following liver injury when Wnt/β‐catenin pathway is interrupted genetically.MethodsWe generated hepatocyte‐specific β‐catenin knockout (β‐catenin∆HC) mice by delivering AAV8‐TBG‐Cre to 6‐week‐old Ctnnb1flox/flox mice. Two weeks after AAV8 injection, animals were either harvested at baseline, or subjected to partial hepatectomy (PH) for analysis at various time points to address changes and compensations during the process of LR. LR was also compared between β‐catenin∆HC and Albumin‐Cre‐driven β‐catenin knockouts from both hepatocytes and cholangiocytes (β‐catenin∆Liver).ResultsAt baseline, a small subset of β‐catenin∆HC mice had smaller liver size and mild fibrosis, but overall, there was no impact on body weight, liver size, and liver weight to body weight ratio (LW/BW). After PH, LR was more severely delayed in β‐catenin∆HC mice compared to β‐catenin∆Liver, likely due to chronic adaptive changes that only occur in the latter. After PH, 14‐day continuous BrdU labeling through drinking water showed only 31% positively labeled hepatocytes in β‐catenin∆HC mice versus 92% positively labeled hepatocytes in controls. The scant LR in β‐catenin∆HC mice started around the periportal region at 40h and increased at 72h and peaked at 96h seen by positive staining for Cyclin D1, Ki67, BrdU (5h labeling). Western blots using whole cell lysates showed a clear increase in p‐IGF1R β‐Y1135/1136 and p‐Insulin receptor (IR) β‐Y1150/1151 at 72h, and activation of mTORC1 activity seen as increased p‐mTORC1 (S2448), p‐p70S6K (T389), p‐S6 (S235/236) and p‐S6 (S240/244) at 72h and 96h. More importantly, careful quantification showed 97% of mitotic hepatocytes to be positive for p‐S6 (S235/236) in β‐catenin∆HC. Pharmacological inhibition of IGF1R and IR by linsitinib, or inhibition of mTORC1 by rapamycin completely blocked LR in β‐catenin∆HC, further confirming that IGFR/IR‐mTORC1 pathway drove LR to ensure liver repair in β‐catenin∆HC mice.ConclusionsOur data reaffirms an important role of β‐catenin in normal LR after PH. In the absence of β‐catenin in hepatocytes, there is spontaneous activation of IGFR/IR driven mTORC1 pathway, which in turn drives hepatocyte proliferation in β‐catenin∆HC mice. Our studies have discovered a novel axis of compensation, once again supporting existence of redundant mechanisms that enable LR when one pathway is inhibited.
A Preliminary Report on the Variation of Respiratory Blood Pressure during Sleep in Normal Subjects
Authors: Wang Jinan , Sun Xingguo , Tai Wenqi , Zhou Qingqing , Zhang Yanfang 
Published: May 2022

ObjectiveBased on the new theory of holistic integrative physiology and medicine, we hypothesize that respiration is the origin of the variability of circulatory parameters, and initially verify this view by analyzing the relationship between blood pressure variability and respiration.MethodsThis study analyzed 8 normal subjects (NS) with no disease diagnosis who performed cardiopulmonary exercise testing (CPET), polysomnography (PSG), continuous fingertip pulse wave and electrocardiogram (ECG), and analyzed the correlation between the respiratory cycle of nasal airflow and blood pressure variation cycle during sleep. The respiratory cycle included complete inhalation and subsequent exhalation. Analysis and calculation of the number of breathing cycles (B‐n), average breathing cycle time (Bn‐T) and other parameters. Blood pressure variability is calculated using two different methods: fingertip pulse wave waveform and pulse transit time (PTT). The peak of the fingertip pulse wave represents the systolic blood pressure (SBP), and the end point represents the diastolic blood pressure (DBP). The values of the peak and end points are extracted separately and sorted separately. Continuous blood pressure rises from lowest to highest at a time, then dropped from highest to lowest, as a blood pressure variation cycle, calculation of blood pressure variation cycle (BPV‐n), and other parameters. PTT can directly calculate the blood pressure value, and it calculates the blood pressure variability in the same way as the fingertip pulse wave. To compare the relationship between respiratory and blood pressure variability parameters and the similarities and differences between the two methods, independent‐sample t test and paired‐sample t test were used for statistical test.ResultsThe subject's apnea hypopnea index was 1.71±1.30 events/hour. Pulse wave waveform calculation Bn (6581.63±1411.90), SBPV‐n (6629.88±1479.84) and DBPV‐n (6628.38±1396.37) are highly consistent during sleep. Bn/SBPV‐n (1.00±0.03) and Bn/DBPV‐n (0.99±0.02) is close to 1 (P>0.05); Bn‐T (4.19±0.57 s), average systolic blood pressure variation cycle time (4.17±0.63 s) and average diastolic blood pressure variation cycle time (4.16±0.60 s) basically the same (P>0.05). SBPV‐n (3988.38±1701.93) and DBPV‐n (886.63±176.86) calculated by PTT during sleep were significantly lower than the calculated values of pulse wave waveform (P<0.01).ConclusionNormal subjects’ blood pressure variability during sleep is very similar to respiration, and the initiating factor of blood pressure variability is respiration.
The role of SCFAs on microbiota composition in a mouse model of NTG‐induced migraine
Authors: Lanza Marika , Scuderi Sarah Adriana , Filippone Alessia , Casili Giovanna , Campolo Michela , Paterniti Irene , Cuzzocrea Salvatore , Esposito Emanuela 
Published: May 2022

BackgroundBased on global burden of headache reports, migraine is a prevalent disorder that affect approximately 15% of the adult population. Generally migraine attacks are sporadic, however, some individuals develop a chronic disease form. To date, several researches have shown that migraine is associated with some gastrointestinal disorders such as Helicobacter pylori (HP) infection, irritable bowel syndrome (IBS), and celiac disease (CD). However, the mechanisms explaining how the gut and the brain may interact in patients with migraine are not entirely clear. In this study, we aimed to evaluate the role of the short‐chain fatty acids (SCFAs), such as sodium propionate (SP) and sodium butyrate (SB) as mediators and modulators of host intestinal microbial ecology, in regulating the pathophysiology of migraine in a mouse model induced by nitroglycerine (NTG).MethodsMice were orally administered with SB and SP at the dose of 10, 30 and 100 mg/kg, 5 min after NTG intraperitoneal injections. Histological and molecular analysis were performed on the whole brain and small intestine and behavioral tests after 4 h from migraine induction. The composition of the intestinal microbiota was extracted from frozen fecal samples and prepared for sequencing according to the protocol for Illumina Miseq System. However, the expression of inflammatory and oxidative markers were detected by Western blot. Tail flick, hot plate, orofacial formalin and photophobia tests were used to evaluate migraine‐like pain and migraine‐related light sensitivity.ResultsSP and SB treatment notably reduced histological damage in whole brain and small intestine in NTG‐injected mice. Treatments with both SCFAs decreased the markers of inflammation and increased the protective antioxidant enzymes, suggesting an important role of SCFAs to exercise neuromodulatory action. Moreover, SCFAs reduced the headache modifying the intestinal microbiota.ConclusionsThese results provided the evidence that SCFAs exerts a protective effect on central sensitization induced by NTG through a modulation of intestinal microbiota, suggesting a new insight into the potential application of SCFAs as novel supportive therapies for migraine.
Kidney Injury Stimulates Apical Translocation of NHERF1
Authors: Gagnon Kenneth B. , Bushau‐Sprinkle Adrienne , Hu Ming‐Chang , Chang Audrey N. , Miller R T. , Lederer Eleanor D. 
Published: May 2022

BackgroundNHERF1 (Na+‐hydrogen exchanger regulatory factor isoform 1), recognized as a scaffold protein that regulates proximal tubule phosphate transport, also has a role in regulation of cell metabolism and survival. Our laboratory previously demonstrated more severe cisplatin‐induced acute kidney injury (AKI) in the global NHERF1 knock out (KO) mouse compared to the cisplatin‐treated wild type (WT) mouse. In the present study, we tested the hypothesis that kidney injury results in decreased NHERF1 expression by examining NHERF1 expression in two models of AKI (cisplatin and bilateral renal ischemia‐reperfusion) and two models of chronic kidney disease or CKD (adenine diet and Col4a3‐/‐) by immunofluorescent microscopy and western blot analysis.MethodsCisplatin‐induced AKI:Two‐month‐old male and female C57BL/6J WT mice received a single intraperitoneal injection of saline (vehicle) or 20 mg/kg cisplatin. Vehicle‐ and cisplatin‐treated mice were euthanized after 72 hours. Bilateral renal ischemia‐reperfusion injury AKI: Two‐month‐old male and female C57Bl/6J WT mice underwent bilateral renal artery clamp for 30 minutes followed by release. Sham and IRI surgery treated mice were euthanized at 2, 4, and 14 days post‐surgery. Adenine‐induced CKD: Two‐month‐old male and female C57Bl/6J WT mice received either regular or adenine‐supplemented chow for 20 weeks followed by euthanasia. Col4a3‐/‐ CKD: Two‐month‐old male and female C57Bl/6J heterozygous and homozygous KO mice for the collagenase type IV alpha 3 chain were followed for up to 7 months followed by euthanasia. In all four mouse models, the kidneys were removed, de‐capsulated, immersed in 3.7% formaldehyde in phosphate‐buffered saline for 24 hours, then transferred to 70% ethanol for paraffin embedding and immunofluorescent microscopy. Western blots of kidney lysates from each kidney injury model were electrophoresed in 4‐12% Bis‐Tris gradient gels and immunoblotted for NHERF1.ResultsImmunofluorescent microscopy revealed increased staining for NHERF1 at or near the apical membrane of proximal tubule epithelial cells in all four mouse injury models. For the IRI model, longitudinal immunohistochemistry demonstrated a progressive increase in the apical NHERF1 signal from baseline through day 4 post‐surgery followed by a decrease to baseline levels by day 14. Western blot analysis of lysates from all four kidney injury models showed no change in total expression of NHERF1.ConclusionsWe conclude that kidney injury results in translocation of NHERF1 to the apical membrane. These findings suggest that NHERF1 plays a significant role in the response to kidney injury, though at this time, neither the mechanism for translocation nor the specific role of NHERF1 in the response to injury is clear.
N‐methyl‐D‐aspartate Receptor Antagonist Agmatine Prevents Oxycodone Self‐Administration
Authors: Barajas Cecilia , Peterson Cristina , Wilcox George , Fairbanks Carolyn 
Published: May 2022

Opioid use disorder (OUD) can be defined as the continued use of opioids despite the negative physical, psychological, and social consequences that result from its use. Since the 1970s, several strategies have been approved by the Food and Drug Administration (FDA) to treat OUD and reverse opioid overdose. Despite their implementation and other exhaustive efforts and resources expended by the scientific and public health communities, the increase in opioid use disorder (OUD) in the United States continues to have staggering economic and quality of life impacts. Decades of research has established that chronic activation of the N‐methyl‐D‐aspartate (NMDA) receptor is a major driving force of the neuroplastic pathology that underlies opioid use disorder. The therapeutic potential of antagonism of the NMDA receptor has been explored, however due to the ubiquity of the receptor, several off‐site side‐effects have hindered development. In recent years, the endogenous NMDA receptor antagonist agmatine has come under consideration for its therapeutic potential in combatting CNS disorders such as neuropathic chronic pain as well as OUD, without producing unwanted side‐effects.Female ICR mice (21‐30g) were separated into dosing groups and oriented to self‐administration operant chambers in which they were able to press either for oral oxycodone reward (30 mg/L, 200 mg/L, or 1,000 mg/L) or inactive control (H2O + quinine) over 12 hours. Animals were sacrificed and perfused with tissue fixative for later molecular analysis of reward pathways. Animals with the 30 mg/L and 200 mg/L dose option showed consistently higher responding compared to animals pressing for 1,000 mg/L and control. Notably, animals in the 200 mg/L group showed an almost immediate increase in lever presses while the animals in the 30 mg/L group showed a slow increase in responding over time when compared to inactive control. We next sought to characterize agmatine’s ability to prevent oxycodone self‐administration, with 200 mg/L of oral oxycodone selected as the reward dose based on the previous data. Mice were given daily i.p. injections of either agmatine or saline immediately prior to self‐administration sessions. Mice who received agmatine pre‐treatment demonstrated significantly reduced drug‐seeking compared to animals who received saline pre‐treatment. Following completion of the experiment, animals were sacrificed and perfused for molecular analysis.These data support that agmatine may have therapeutic potential in preventing opioid use disorder. Future studies will focus on comparative molecular analysis between oxycodone‐exposed mice with or without agmatine.
Single‐Cell Proteomic Profiling of Hepatocytes Reveals Heterogeneous Responses to Hepatotoxic Drugs Nevirapine, Efavirenz, and Acetaminophen
Authors: Yuan Yuting , Orsburn Benjamin , Bumpus Namandjé 
Published: May 2022

Drug‐induced hepatotoxicity remains a leading cause of the withdrawal of drugs from the global market. Changes in the proteomic profile of hepatocytes following exposure to known hepatotoxic drugs could provide insight into the mechanisms underlying drug‐induced hepatotoxicity. Thus, we aimed to employ mass spectrometry (MS)‐based proteomics to investigate the impact of a subset of known hepatotoxic drugs, namely, efavirenz (EFV), nevirapine (NVP), and acetaminophen (APAP) on the human hepatocyte proteome in vitro. In addition, to add further granularity to the analysis and to understand potential cell‐to‐cell variability in the proteomic response to the above‐mentioned drugs, single‐cell proteomics was employed.Cultured cryoplateable hepatocytes were incubated with each drug individually at their IC50 or IC90 values to induce hepatotoxicity. For single‐cell proteomic analysis, after 40‐hour treatment individual hepatocytes were sorted using fluorescence‐activated cell sorting (FACS) and protein lysates were digested with trypsin, labeled with unique tandem mass tags (TMT), and pooled together for multiplex analysis using a timsTOF Flex mass analyzer.Preliminary single‐cell proteomic results were obtained from 385 cells analyzed at a depth of approximately 350 proteins per cell, and an approximate 1,700 proteins per treatment could be readily quantified using reporter ion‐based quantification with SequestHT with Percolator validation. A principal component analysis (PCA) separated the hepatotoxic drug‐treated cells and DMSO control‐treated cells into two mostly discrete clusters thereby confirming the hepatocytes’ proteome change upon hepatotoxic drug treatment. Further, these data revealed a heterogeneous response to hepatotoxic across single hepatocytes. From proteomic analysis on bulk hepatocytes, we found that the abundance of 36 proteins was significantly increased following exposure of cultured hepatocytes to IC50 and IC90 concentrations of NVP, EFV, and APAP (p‐value < 0.05, Log2 fold change >1). These proteins included calnexin, an endoplasmic reticulum (ER) stress‐induced protein. Interestingly, single‐cell proteomic analysis also showed that the abundance of calnexin was significantly increased following treatment of NVP, EFV, and APAP at IC90; however, the levels of calnexin were divergent across the single cells with certain cells exhibiting no increase in calnexin following drug treatment. These data demonstrate hepatocyte‐to‐hepatocyte heterogeneity in the response to hepatotoxic drugs and suggest that proteomics performed on bulk/total hepatocytes may not fully shed light on hepatoxicity mechanisms.