bluuebunny/crossref_metadata_2025_split huggingface dataset:
HLA DQ/DR prevalence and microbiota disturbance in northwestern Mexican children with type 1 diabetes (1118.3)
Authors: Mejia‐Leon Maria , Petrosino Joseph , Ajami Nadim , Domínguez‐Bello Maria , Calderon de la Barca Ana 
Published: June 2021

Type 1 Diabetes (T1D) is a pro‐inflammatory autoimmune disorder leading to β‐cells destruction and insulin deficiency. Its prevalence of 1:300 is increasing and cannot be explained only by HLA DR4‐DQ8 and DR3‐DQ2 predisposition. Environmental factors seem to have a crucial role in its development through microbiota modulation. The aim of this study was to determine the HLA risk prevalence and to compare the fecal microbiota structure of Mexican children with T1D at onset and after treatment for more than 2 years. A case‐control study was conducted in Mexican mestizo children, aged 7‐18 years (8 newly diagnosed, 13 controlled T1D cases after 2 years treatment and 8 healthy controls). Predisposing haplotypes were typed and the fecal DNA was extracted; the V4 region of the 16S rRNA gene was amplified and pyrosequenced. All of the T1D cases had at least one HLA risk allele, principally the DQA1*0301. The newly diagnosed T1D cases had high levels of the genus Bacteroides (p<0.004), whereas the control group had a gut microbiota dominated by Prevotella. Children with T1D treated for 蠅2 years had levels of Bacteroides and Prevotella tending to those of the control group. The gut microbiota of newly diagnosed T1D cases is altered, but involving of causes or consequences remains unclear.Grant Funding Source: Partially Supported by CONACYT grant S0008‐2009‐01‐115212
High salt diet causes epigenetic modifications and suppresses endothelial progenitor cell function (1120.2)
Authors: Karcher Jamie , Hoffmann Brian , Liu Pengyuan , Greene Andrew 
Published: June 2021

Endothelial progenitor cells (EPCs) are bone‐marrow derived cells that exhibit endothelial cell properties, promote neovascularization, and contribute to vascular homeostasis through autocrine and paracrine mechanisms. We describe for the first time how dietary salt negatively affects EPC function. EPCs were significantly decreased in the bone marrow of rats on a high salt diet (HSD, 4% NaCl) as compared to normal salt diet (NSD, 0.4% NaCl) rats. CD34, CD133, VEFGR2, and c‐Kit expression was similar between NSD and HSD EPCs. HSD EPCs had suppressed in vitro tube formation and were unable to restore angiogenesis following transplantation into a rodent model of limited angiogenesis (Sprague Dawley rats on a HSD). To identify molecular candidates that were altered by dietary salt, we preformed reduced representative bisulfite sequencing to analyze DNA methylation and we preformed mass spectrometry to identify differentially expressed protein targets. Analyses revealed increased methylation and suppressed protein expression of RET (proto‐oncogene tyrosine‐protein kinase receptor Ret) in HSD EPCs. Loss of RET expression causes thyroid tumor suppression and increased cell death providing a mechanistic explanation for HSD EPC reduced angiogenic efficacy. Overall high salt inhibits EPC angiogenic function through DNA methylation causing proteomic changes on the membrane.Grant Funding Source: HL‐082798
Knockdown of tyrosine hydroxylase in the nucleus of the solitary tract prevents attenuated body weight gain and blunts neuronal activation in the hypothalamus following chronic intermittent hypoxia (1126.4)
Authors: Nedungadi T. Prashant , Bathina Chandra , Mifflin Steve 
Published: June 2021

Patients with sleep apnea (SA) are at a risk of developing metabolic syndrome. In the rat, 7 days of Chronic Intermittent hypoxia (CIH), a model of the arterial hypoxemia seen in SA patients, is associated with reduced body weight gain (p<0.005, n= 18), food intake (p<0.05, n=11), hyperinsulinemia (p<0.05, n=7), glucose intolerance and elevated fasting blood glucose levels (p<0.05, n=8). Brainstem melanocortins and other peptides has been well documented to be involved in metabolic homeostasis while tyrosine hydroxylase (TH) is known to be responsive to hypoxic stress; however the involvement of NTS TH neurons in regulating energy homeostasis following CIH has not yet been investigated. AAV‐TH shRNA virus was used to knockdown TH in the NTS of male rats, while virus with scrambled RNA was used as a control. Knockdown of TH in the NTS prevented the reduction in body weight following CIH (n=7) compared to scrambled virus injected rats and naïve rats subjected to CIH. Immunohistochemical staining for the neuronal activational marker FosB revealed elevated immunoreactivity following CIH (p<0.05, n=6) in the hypothalamic arcuate nucleus (ARH). Knockdown of TH resulted in reduced FosB staining in the ARH and dorsomedial hypothalamus while no change was observed in the lateral hypothalamic area. However, in the ventromedial hypothalamus, increased FosB staining was observed (p<0.05, n= 8). Our findings suggest that NTS TH neurons play an important role in regulating metabolic status during exposure to CIH and alter the neuronal activity in hypothalamic feeding centers, possibly via regulation of an anorexigenic signaling pathway.Grant Funding Source: P01 HL88052
Rheumatoid arthritis and autonomic function (1132.10)
Authors: Adlan Ahmed , Shantsila Alena , Kitas George , Paton Julian , Lip Gregory , Fisher James 
Published: June 2021

Rheumatoid arthritis (RA) is an inflammatory disorder associated with increased cardiovascular mortality. We sought to determine whether muscle sympathetic nerve activity (MSNA) is heightened, and cardiac baroreflex sensitivity (cBRS) is reduced in patients with RA. Whilst resting supine, blood pressure (BP; Portapres), heart rate (HR; ECG) and MSNA (microneurography) were continuously monitored in 7 chronic RA patients (5 men, 56±4 yr, 28±1 kg/m²; mean±SE), 7 healthy controls (HC: 5 men, 52±5 yr, 26±1 kg/m²) and 7 patients with hypertension as ‘disease’ controls (DC: 5 men, 54±5 yr, 28±1 kg/m²). MSNA burst frequency and spontaneous cardiac baroreflex sensitivity (sequence technique, systolic BP‐RR interval) were determined. Mean BP (p=0.001) and HR (p=0.014) were lower in HC group (88±5 mmHg, 55±2 bpm) than RA patients (106±2 mmHg, 70±3 bpm) and the DC group (116±6 mmHg, 63±4 bpm). MSNA burst frequency tended to be higher in RA patients and the DC group (34±4, 37±3 and 26±3 bursts/min in RA, DC, HC; P=0.066), whilst cBRS was reduced in RA (7.6±2.0, 10.0±3.1 and 16.7±2.1 ms/mmHg in RA, DC, HC; P<0.05 RA vs. HC and DC). These preliminary findings support the existence of an imbalance in autonomic neural control of the heart and peripheral vasculature in patients with RA.Grant Funding Source: Supported by Arthritis Research UK
Acute leptin exposure alters renal proximal tubule function in vitro via mTOR and AMPK (1133.3)
Authors: Hryciw Deanne , Briffa Jessica , Grinfeld Esther , McAinch Andrew 
Published: June 2021

Exposure to elevated leptin reduces the metabolic activity in proximal tubule cells (PTC), leading to apoptosis. Currently there is limited knowledge of the molecular pathways involved. Mammalian target of rapamycin (mTOR) and AMP‐activated protein kinase (AMPK) regulate cell growth and differentiation, and in the obese kidney, phosphorylated AMPK is decreased and phosphorylated mTOR is increased. Therefore we hypothesize that in PTCs acute elevated leptin exposure will alter tubular function via AMPK and mTOR.We used the established Opossum kidney (OK) PTCs cell line model, that were exposed to leptin (0.05 ‐ 0.50 µg/mL) for 2 hrs. We have previously demonstrated that leptin acts via megalin and not the leptin receptor in this model. We then investigated the effect leptin has on signalling mediated expression, metabolic activity, TGF‐β1 secretion and albumin uptake and degradation.Leptin decreased the PTC metabolic activity via mTOR activation. Leptin increased TGF‐β1 secretion, decreased megalin expression and upregulated phosphorylated AMPK‐α. Interestingly, elevated levels of leptin decreased albumin uptake and degradation. This suggests that leptin activates fibrotic pathways via mTOR, AMPK and TGF‐β1.Therefore we have identified for the first time that leptin alters the function of PTCs and that leptin alters PTC signalling mediated expression via a megalin mediated pathway.
Dopamine D1 and D5 receptors differentially regulate paraoxonase 2 (1134.6)
Authors: Yang Sufei , Yu Peiying , Yang Yu , Jose Pedro A , Zeng Chu‐Yu 
Published: June 2021

We have previously reported that dopamine D1‐like receptors (D1R and D5R) negatively regulate NADPH oxidase isoform expression and activity in renal proximal tubule (RPT) cells from rodents and humans. We tested the hypothesis that D1‐like dopamine receptors (D1R and D5R) differentially regulate the anti‐oxidant enzyme paraoxonase2 (PON2) in HEK‐293 cells heterologously expressing human D1R and D5R. Fenoldopam (1µM, 15 min), an agonist for both D1R and D5R, increased PON2 co‐immunoprecipitation with D1R (160±4% vs. control, 101±1%) and D5R (132±0.1% vs. control, 102±1%) in both cell lines. Short‐term (15, 30, and 60min) stimulation of D1R and D5R with fenoldopam (1µM) did not alter total PON2 protein. However, in D1R cells, at 15min, fenoldopam increased PON2 protein in both lipid rafts (LRs) (144±3% vs. control, 100±3%) and non‐LRs (163±25% vs. control, 100±21%) (P<0.05, n=6/group, ANOVA). In contrast, in D5R cells, fenoldopam increased PON2 protein only in non‐LRs (132±5% vs. control, 100±1.6%, n=3). Long‐term (2, 4, 8, and 24h) fenoldopam (1µM) stimulation increased PON2 protein in a time dependent manner (146% ±7/8h, and 162% ±10/24h vs. control, 100±9%) (P<0.05, n=4, ANOVA) in D5R but not D1R cells. Fenoldopam also increased PON2 mRNA (1.25‐fold) (n=3, P<0.05, t‐test) at 24h in D5R but not D1R cells. Silencing PON2 gene with PON2‐siRNA (10nM/48h) in D5R cells decreased PON2 protein (‐40±4% vs. mock‐siRNA, 100±17%, n=3) and mRNA (‐17±4% vs. mock‐siRNA, 100±2%, P<0.05, n=3, t‐test) and increased basal ROS production by 1.36‐fold, relative to mock‐siRNA. PON2 protein was decreased in D5R‐/‐ mice (‐44±13%) relative to D5R+/+ mice (100±8%, n=4‐6/group). We conclude that short‐term stimulation of either D1R or D5R leads to PON2 protein recruitment to non‐LRs and also to LRs in the case of D1R. However, long‐term stimulation of PON2 and negative ROS regulation are mainly due to D5R.Grant Funding Source: HL023081, HL074940, DK039308
microRNA‐mediated actions of unliganded estrogen receptor beta in breast cancer (1138.1)
Authors: Nassa Giovanni , Tarallo Roberta , Bruno Giuseppina , Giurato Giorgio , Hashim Adnan , Ravo Maria , Rinaldi Antonio , Rizzo Francesca , Salvati Annamaria , Stellato Claudia , Nyman Tuula A. , Weisz Alessandro 
Published: June 2021

Estrogen Receptor β (ERβ) exerts oncosuppressive functions in breast cancer (BC) also in the absence of physiological ligands. Ligand‐independent actions of ERβ were investigated by expressing it in MCF‐7 and ZR75.1 BC cells. Interaction proteomics revealed >300 nuclear interacting partners, comprising proteins involved in transcriptional gene silencing by miRNAs. miRNA profiling (smallRNA‐Seq) and quantitative proteomics (iTRAQ) of ligand‐free ERβ+ vs ERβ‐ BC cells showed >100 miRNAs and >700 proteins whose expression is modulated by ERβ. Interestingly, these results combined with transcriptome analysis revealed post‐transcriptional regulation of protein expression by unliganded ERβ mediated by miRNAs. Forced expression of a mimic of ERβ‐responsive miR‐30a‐5p led to the identification of several transcripts targeted by this small RNA in BC cells, including 11 encoding regulatory proteins whose intracellular concentration was strongly affected by unliganded ERβ. These results suggest that regulation of BC cell functions by ligand‐free ERβ via miRNAs may exert a key role in the control of the biological and clinical phenotype of BC.Grant Funding Source: Supported by: FIRC (fellowship to GN) and AIRC (Grant IG‐13176 to AW and fellowship to MR)
Expression of plasma membrane (PMCA) and sarco/endoplasmic reticulum (SERCA) Ca2+‐ATPase pumps in cellular model of Huntington disease (1138.8)
Authors: Cesca Federica , Dubsky de Wittenau Giorgia , Curcio Francesco , Lonigro Renata 
Published: June 2021

Deregulation of calcium homeostasis is involved in the etiology of Huntington’s disease (HD). We investigated the expression level of calcium pumps in cellular models of HD derived from murine embryonic striatum. We compared the steady‐state level of PMCA1‐4 and SERCA2,3 pumps in wild‐type and mutant cell lines, both in undifferentiated and in glial differentiated conditions.Comparison between mutant and wild‐type cell lines in the undifferentiated condition show that: i. the level of PMCA1‐4 RNA and protein is comparable except for a reduction of PMCA3 RNA.ii. SERCA2 protein level is significantly reduced while SERCA3 protein level is significantly increased, suggesting a role for these pumps in calcium homeostasis deregulation in HD.There is no correspondence between SERCA proteins and their respective RNA, probably due to post‐transcriptional regulatory mechanism/s. In a rat striatal‐derived cellular model of HD in which huntingtin expression is inducible by doxycicline, we confirmed the reduction of SERCA2 protein level as a huntingtin expression‐dependent event. These data suggest that the reduction of SERCA2 pump could be an early event occurring in HD.Comparison between mutant and wild‐type cell lines in the glial differentiated condition show that PMCA1 and PMCA2 protein levels are reduced, while their respective RNA are increased suggesting a post‐transcriptional regulatory mechanism/s for calcium homeostasis deregulation also in glial differentiated cells.Grant Funding Source: SNO ‐ Gobessi Fund
Protein kinase C affects transport function of organic anion transporting polypeptide 1B1 (1141.7)
Authors: Hong Mei , Hong Weifang , Yu Xuan , Huang Jiujiu 
Published: June 2021

Objective: Organic anion transporting polypeptides (OATPs) are a family of important uptake transporters. It was demonstrated previously that OATP uptake function is regulated by protein kinase C (PKC). However, the phosphorylation site(s) modified involved in PKC regulation remains unknown. Methods: HEK293 cells stably expressing organic anion transporting polypeptides 1B1 (OATP1B1) were treated by PKC modulators to investigate its regulatory effect on OATP1B1. In addition, site‐directed mutagenesis was used to identify the possible PKC regulation sites within OATP1B1. Results: We found out that OATP1B1 uptake function is regulated by PKC modulators. Further studies indicated that PKC may affect OATP1B1 activity through its regulation of the protein expression on the cell surface. Moreover, we found out that PKC activator PMA not only affect the internalization of OATP1B1 but its recycling as well. Mutagenesis studies revealed that several amino acids located at intracellular loops and the carboxyl terminus of OATP1B1 are involved in the phosphorylation regulation process. Conclusions: OATP1B1 transport function is regulated by PKC, the action of which leads to accelerated internalization and reduced recycling of the transporter protein.Grant Funding Source: Supported by National Natural Science Foundation of China Grant #81373473 and #U1332124
A live‐cell reporter that differentiates between quiescent and cycling cells (1148.14)
Authors: Henderson Lindsay , Lim Curtis , Zambon Alexander 
Published: June 2021

The transition of a proliferating cell into a state of cell quiescence is a key step in organogenesis and tissue homeostasis. It is currently difficult to distinguish between quiescent cells and those that have entered the cell cycle. This study’s objective was to generate a fluorescent‐based genetically encoded reporter capable of differentiating between arrested and actively cycling cells. The Ki67 promoter (Ki67p) was previously shown in our lab to selectively label cells that have entered the cell cycle. However, using Ki67p to drive GFP as a reporter gene results in fluorescent daughter cells due to GFP’s long half‐life (~26h). We hypothesized using the Ki67p to drive expression of the Fluorescent Ubiquitination‐based Cell Cycle Indicator (FUCCI) reporters would enable indirect detection of quiescent (G0) cells and cells in G1/S and S/G2/M. The existing FUCCI reporters employ a constitutively active promoter, thereby preventing discrimination between cells in G0 and cells in G1. To overcome both reporters’ limitations we generated two lentiviral vector constructs with Ki67p upstream of mcherry‐hCdt1(30‐120) and mAG‐hGem(1‐110). We then generated stable double transgenic cell lines (HT1080 and COS cells) that express mCherry‐hCdt1(30‐120) and mAG‐hGem(1‐110) under control of Ki67p. Fluorescence time‐lapse imaging of Ki67p‐FUCCI cells indicates that low‐density plating induces G0 cell cycle withdrawal and concurrent attenuation of Ki67‐FUCCI reporter activity. Low density compared to high density plating increased the number of Ki67p‐FUCCI− HT1080 cells (44% vs. 5%, P<0.05) indicating G0 entry. Moreover, serum starvation induced G1 arrest (91% Ki67p‐mCherry+ without serum vs. 47% with serum, P<0.01). These reporters will enable studies designed to segregate between quiescent and actively proliferating cells in each of the major phases of the cell cycle in living tissue and in real‐time, facilitating studies in stem cell and cancer biology.Grant Funding Source: NIGMS 2‐R25‐GM‐083275, AHA 10SDG2630130
Matrix metalloproteinase‐2 mediate oncostatin‐M induced cardiomyocyte dedifferentiation (1151.2)
Authors: Fan Frank , Ali Mohammad , Hughes Bryan , Launier Katherine , Schulz Richard 
Published: June 2021

Dedifferentiated cardiomyocytes are an important source of cardiac progenitor cells facilitating cardiac repair. Cardiomyocyte dedifferentiation induced by oncostatin‐M (OSM) is characterized by progressive sarcomere degeneration. However, the mechanism regarding the execution of sarcomere degeneration remains unclear. Matrix metalloproteinase‐2 (MMP‐2) is a key intracellular protease abundantly expressed in cardiomyocytes. We hypothesized that MMP‐2 may be involved in cardiomyocyte dedifferentiation. We performed confocal immunofluorescence and biochemical studies to explore the role of MMP‐2 in OSM‐induced dedifferentiation of neonatal rat ventricular myocytes (NRVM). Cells treated with OSM (10‐200 ng/ml for 1‐5 days) showed a dose and time‐dependent loss of sarcomeric α‐actinin and troponin‐I. The mature sarcomere transformed to a pattern resembling a less developed sarcomere (Z‐disks transformed into Z‐bodies usually found in immature myofibrils). Western blots and gelatin zymography showed that OSM treatment dose‐dependently increased MMP‐2 activity. Both selective MMP‐2 inhibitor (ARP100, 100 µM) and pan‐MMP inhibitors (GM6001, 5 µM) rescued OSM‐induced sarcomere degeneration. These results suggest that intracellular MMP‐2 mediates sarcomere degeneration in OSM‐induced cardiomyocyte dedifferentiation and potentially contributes to cardiomyocyte regeneration.Grant Funding Source: The Canadian Institutes of Health Research (CIHR)
Nicotinamide adenine dinucleotide hydrate (NAD+) regulates glucose deprivation‐induced activation of protein O‐GlcNAcylation, ER stress and autophagy (1154.2)
Authors: Zou Luyun , Chatham John 
Published: June 2021

Mammalian sirtuins are important regulators of metabolism and cell survival including autophagy and ER stress. The post‐translational modification of proteins by O‐linked‐N‐acetylglucosamine (O‐GlcNAc) is also metabolically regulated and regulates cell survival responses. We have previously reported that glucose deprivation (GD), which induces autophagy and ER stress is also a potent stimulus for increasing cellular O‐GlcNAc levels. Therefore, the goal of this study, therefore, was to determine whether NAD+, which activates sirtuins, alters the response of GD on protein O‐GlcNAcylation, ER stress, and autophagy. AC16 cardiomyocytes were subjected to GD for up to 24hrs with and without NAD+ (0.25mM). 24hrs after GD there was a significantly increase in O‐GlcNAc levels as well as CHOP, Bip, P‐PERK/T‐PERK and LC3‐II/LC3‐I, consistent with both increased ER stress and activation of autophagy. Treatment with NAD prevented the GD induced increase in O‐GlcNAc and also significantly attenuated both ER stress and autophagic responses. Interestingly GD resulted in a decrease in protein acetylation, which was prevented by NAD, suggesting that the effects of NAD+ may not be mediated via activation of sirtuins, which catalyze deacetylation. Therefore these data indicate that while NAD+ contributes to the regulation of protein O‐GlcNAcylation, ER stress and autophagy this appears to be sirtuin independent. These results also demonstrate for the first time potential cross‐talk between cytosolic redox state and regulation of O‐GlcNAc cycling.Grant Funding Source: Supported by NIH grants HL101192 and HL110366
Endothelial‐dependent dilation is lower in males compared to females on a controlled sodium diet (1156.6)
Authors: Lennon‐Edwards Shannon , Matthews Evan , Ramick Meghan , Brian Michael , Edwards David , Farquhar William 
Published: June 2021

Excess dietary sodium has been linked to the development of high blood pressure (BP) and other cardiovascular diseases (CVD) and recently shown to effect endothelial function independently of BP. However, it is unknown whether sodium consumption impacts endothelial function differently in males (M) and females (F). Given the varying habitual intake of sodium, we sought to fix sodium using a controlled diet study. Therefore, the aim of this study was to test the hypothesis that endothelial‐dependent dilation (EDD) would be lower in M as compared to F on a controlled sodium diet set at the recommended intake for Americans. 16 M (29±2 y; BMI 23.8±0.7 kg/m2) and 12 F (31±3 y; 24.3±0.7 kg/m2) completed the study. All subjects were apparently healthy and free of CVD. Subjects consumed a eucaloric diet providing 100 mmol/d of sodium for 7 days. On day 7 of the diet, 24‐hr mean arterial pressure (MAP) was recorded, and blood and urine were collected. EDD was assessed by brachial artery flow‐mediated dilation. Urinary sodium excretion was not different between M and F (81.4±7.7 vs. 93.9±22.8 mmol/24hr, p > 0.05) while 24‐hr MAP was higher in M (88±1 vs. 82±1.3; p<0.05). EDD was significantly lower in M than F (7.0±0.8% vs. 10.4±1.2%; p < 0.05). These data demonstrate that M have a lower EDD than F at the recommended intake of sodium. Future research should focus on exploring the mechanisms underlying this difference.Grant Funding Source: Supported by R01 HL 104106