bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of the hepatic stellate cell populations in carbon tetrachloride liver rat through Golgi‐Cox Method.
Authors: de Jesus Gómez Villalobos Ma , Giles Ruth , Carreon Idali , Vidrio Susana , De Sanchez Victoria Chagoya
Published: June 2021

Golgi‐Cox method was used to characterize the hepatic stellate cell (HSC) populations in CCl4 livers. In wistar rats, damage liver was induced by CCl4 administration during two months. After, rats were sacrifiezed and liver tissues were impregnated with the Golgi‐Cox stain, processed and analyzed by Sholl method under light microscopy adapted to a camera lucida. Location, soma cell size, and cytoplasmic processes from HSCs were analyzed. Damage tissue was evaluated with METAVIR score. HSCs were identified for their classical stellate form, and their cytoplasmic processes, making and extense network of reticular fibers. In accord with their soma cell size and location into the hepatic lobule, we identified periportal, perivenular and perisinusoidal hepatic stellate cells. Periportal and perivenular had the larger soma cells, whereas perisinusoidal had the smaller. The morphological changes of the HSCs in CCl4 livers consisted in an increase in the soma cell size, cut and frayly appearance of emerging cytoplasmic processes, and a significant decrease in the number of HSCs. All changes were less pronunciated in tissues with METAVIR score 1 and 2, particularly in the perisinusoidal hepatic stelate cells. HSC populations suffer morphological changes in CCl4 livers, however perisinusoidall cells are the last affected, suggesting that their preservation could be related to the regeneration liver.
Role of GLUT5 and ketohexokinase in fructose‐induced, acute increases in intestinal active Ca transport
Authors: Tharabenjasin Phuntila , Douard Veronique , Krishnamra Nateetip , Zuo Jian , Johnson Richard J. , Ferraris Ronaldo P.
Published: June 2021

Ketohexokinase (KHK) synthesizes fructose (F)‐1‐P and decreases enterocyte intracellular ATP concentrations. We hypothesized that absorption of F by GLUT5 should acutely reduce ATP‐dependent Ca transport. We stimulated Ca transport by chronically feeding mice a low Ca diet, then determined Ca transport in everted sacs incubated in glucose (G, control), F (±ATP donor glutamine), partly metabolizable GLUT5‐substrate 2‐deoxy‐D‐glucose (2‐DG), and nonmetabolizable SGLT1‐substrate 3‐O‐methylglucose (3OMG). In mice fed normal Ca, Ca transport was low and similar in sacs incubated in G or F, suggesting that baseline Ca transport is not acutely modulated by F. Activity and expression of active Ca transporters adaptively increased in all mice fed low Ca. Surprisingly, the adaptive increase in Ca transport was greater in sacs incubated in F‐ and 2‐DG than in G‐ or 3OMG. Glutamine did not modify Ca transport in G‐ or F‐incubated sacs. In KHK −/− and GLUT5−/− mice, Ca transport was also stimulated by a low Ca diet. However, adaptive Ca transport in these mice was similar in all everted sacs, regardless of incubation solution. Thus, F transport by GLUT5 and metabolism by KHK are required for acutely increasing the component of intestinal Ca transport stimulated by low Ca diets. This adaptive component seems insensitive to acute changes in intracellular ATP concentrations.
Involvement of Store‐operated cAMP signaling in the regulation of colonic secretory function
Authors: Nichols Jonathan Michael , Maiellaro Isabella , Abi‐Jaoude Joanne , Curci Silvana , Hofer Aldebaran M.
Published: June 2021

We recently described a new mode of intracellular cAMP production that is triggered by decreases in free Ca2+ within the ER lumen and requires the luminal ER Ca2+ sensor stromal interaction molecule (STIM1). We termed this process store‐operated cAMP signaling (SOcAMPS). Here we assessed the extent to which SOcAMPS participates in epithelial Cl− transport as measured by short‐circuit current (Isc) in polarized T84 monolayers. We found that in Ca2+‐free conditions the Ca2+ionophore ionomycin and the Ca2+‐mediated agonist carbachol stimulated Cl− secretion. The effect was enhanced by the phosphodiesterase inhibitor IBMX and inhibited by the CFTR inhibitor CFTRinh‐172. The response persisted after BAPTA‐AM treatment, and was unaffected by Ba2+ (inhibits Ca2+‐activated K+ channel), or flufenamic acid (inhibits Ca2+‐activated Cl− channels). Parallel imaging measurements using FRET‐based reporters for cAMP and PKA activity showed that depletion of Ca2+ stores caused increased cAMP and PKA activation. We propose that a discrete component of the Ca2+‐ activated secretory activity in the colon derives from SOcAMPS. This alternative mode of cAMP production could contribute to the actions of diverse xenobiotic agents that disrupt ER Ca2+ homeostasis, leading to diarrhea.

Support: Harvard Digestive Diseases Center, the NIDDK (1R21DK088197–01) and the Veteran's Administration (VA‐ORD 1 I01 BX000968‐01)
Mineralocorticoid receptor antagonism exhibits comparable BP lowering efficacy in Dahl salt sensitive rats with high vs. low renin and aldosterone tone
Authors: Ma Xiuying , Contino Lisa , Price Olga , Shuster Daniel , Xu Ling , Xue Jiyan , Metzger Joseph
Published: June 2021

Spironolactone (SPL), a mineralocorticoid receptor (MR) antagonist is used for the treatment of hypertension and heart failure, acting through competitive binding of aldosterone (aldo), which has been shown to induce sustained increases in plasma renin activity (PRA) and aldo concentration (PAC) in the treated patients. In the present study, our goal was to evaluate SPL effect on blood pressure (BP) and renal function in hypertensive rat models with high vs. low PRA/PAC. Plasma/urine chemistry and BP was monitored in Dahl salt sensitive rats fed with low vs. high salt diet (LSD vs. HSD) before and after administration of SPL (100mg/kg/day) or placebo premixed in feed for 4 weeks. Compared to LSD, HSD for 3 weeks reduced PRA and suppressed PAC to unmeasurable levels. Following the 4 week chronic administration of SPL, animals fed LSD showed acute increase in Na+ excretion (2 fold), decrease in K+ excretion (Δ0.05mmol/mg), and sustained elevation of PAC/urinary aldo (3 fold) with no significant effect on PRA; animals fed HSD only exhibited acute decrease in K+ excretion (Δ0.04mmol/mg) with no effect on Na+ excretion and PRA/PAC. Interestingly animals fed LSD vs. HSD exhibited equivalent BP lowering (LSD, 155±4 vs. 143±3mmHg; HSD, 193±9 vs. 180±5mmHg, P<0.05 placebo vs. SPL). In conclusion, MR antagonism with SPL at the tested dose exhibits comparable BP lowering efficacy in hypertensive rats regardless of PRA/PRC levels.
Evidence of donor epithelial type 2 cell engraftment in bleomycin‐injured murine lung after airway delivery
Authors: Wang Ping Ming , Martin William J
Published: June 2021

Alveolar epithelial type 2 cells (AT2) are the alveolar progenitor cells. We hypothesized that AT2 cells obtained from normal mice could function as donor repair cells with engraftment in injured lungs with new intercellular junction expression at the alveolar level. To address this, we harvested 106AT2 cells from adult male mice, labeled the cells with DiI and airway delivered them into the lungs of female mice at day 5 following bleomycin. Lungs were isolated at day 7 or 21 after bleomycin and cryostat sectioned. We identified donor AT2 engraftment, gap and adherens junctions by immunoflourescence of DiI, connexin 43 and E‐cadherin using confocal microscopy, respectively. We found that 28 of 94 and 64 of 76 randomly selected DiI‐labeled donor AT2 cells expressed connexin 43 in the lung at day 2 and 16 following airway delivery of donor cells, respectively. The connexin 43 expression between donor and recipient cells significantly increased from 2.1 ± 1.2 (mean ± SD, n=28) per donor AT2 cell at day 2 to 7.6 ± 4.3 (n=64) at day 16 (p<0.01), suggesting that gap junction formation increased as function of time. Also, the E‐cadherin expression in DiI‐labeled donor AT2 cells increased from at day 2 to 16 following airway delivery of donor AT2 cells. These results provide evidence that airway delivered donor AT2 cell successfully engraft within alveoli of bleomycin‐injured lungs and may facilitate alveolar repair.

(Funders: NICHD)
Differentiation of induced pluripotent stem cells into epithelial cells that express membrane transport proteins involved in transepithelial Na+ and Cl− transport
Authors: Zaidman Nathan A. , Dutton James R. , Mortari Angela , O'Grady Scott M.
Published: June 2021

Human iPS cells were grown in co‐culture with murine embryonic fibroblasts in media containing knockout serum. Differentiation was accomplished by transitioning iPS cells from stem cell media into serum free bronchial epithelial cell growth media over a 7 day period. During this time dramatic changes in cell morphology occurred as cells increased in size, became polygonal in shape and formed confluent cell monolayers over time. QRT‐PCR analysis revealed that differentiated cells expressed several epithelial specific mRNAs including cytokeratin 18, E‐cadherin and surfactant protein C (SPC). Additionally, QRT‐PCR showed expression of mRNA for proteins involved in transepithelial Na+, Cl− and fluid transport including the α1 and β1 subunits of the Na‐K ATPase, α, β and γ ENaC subunits, CFTR and aquaporin 5 (AQP5). Furthermore differentiated cells exhibited immunoreactivity to each of the proteins identified by QRT‐PCR. Moreover, SPC and AQP5 labeling was associated with cytoplasmic vesicles whereas the α1 subunit of the Na‐K ATPase was specifically localized to the basolateral membrane. In contrast, αENaC and CFTR appeared to be apically localized. These results suggest that differentiated cells express proteins necessary for transepithelial Na+ and Cl− transport and that they undergo polarization with respect to the membrane distribution of these transporters characteristic of epithelial cells.
Moxonidine as an Insulin Sensitizing Agent
Authors: Edwards Lincoln Paul , Cheema Meherali , Nunemaker Craig
Published: June 2021

Oral medications used to treat type 2 diabetes have important adverse effects. Novel agents with fewer risks are needed. Published studies indicate that moxonidine can have insulin sensitizing effects. The objective of this study is to provide insight into the mechanism(s) by which moxonidine acts as an insulin sensitizing agent. The acute and chronic effects of moxonidine on calcium handling by islet cells were determined in vitro using isolated mouse pancreatic islets. Time‐course and dose‐response studies were also carried out in cells, followed by Western blotting. Moxonidine lowered calcium levels in islet cells in a manner that was dose‐dependent up to 10nM, reversible and independent of the KATP channel. Moxonidine [1μM] caused an increased phosphorylation of both protein kinase B (PKB) and protein dependent kinase (PDK) by greater than 3 fold in HepG2 and HEK293 cells. The increased PKB phosphorylation could be blocked by efaroxan (10μM). Cells overexpressing the imidazoline receptor protein IRAS, showed greater phosphorylation of PKB compared to control, following moxonidine treatment. Moxonidine caused a time‐dependent increase in glucose uptake in HepG2 cells of up to 2.5 fold, and this could be blocked by efaroxan and by phosphatidyl inositol‐3‐ kinase inhibitor LY294002. These data suggests that moxonidine may regulate islet insulin release while sensitizing tissues to the action of insulin.

These studies were supported in part by NIH1R15DK084468–01 A1and the Center for Health Disparities at Loma Linda University
Effect of ER stress in Collagen 6A3 and ATF3 expression in adipocytes
Authors: Saraf Manish Kumar , Choudhary Sanjeev , Chandalia Manisha , Abate Nicola
Published: June 2021

Although increased expression of Collagen 6A3 (Col6A3) has been linked with elevated adipose tissue inflammation, mechanisms of Col6A3 regulation have not yet been identified. We identified ATF3 binding site in the promoter region of Col6A3. ATF3, a marker endoplasmic reticulum (ER) stress, is transcriptional repressor protein that binds to the promoter region and represses expression of adiponectin receptor‐1 and ‐2. In the present study, we investigated the regulation of Col6A3 expression by ATF3 in pre‐ and matured adipocytes using 3T3 cell model. Undifferentiated predipocyte treated with TNF‐α, Thapsigargin or DTT induced an increased expression of ATF3 with a concomitant suppression of Col6A3. Moreover, an inverse relationship between ATF3 expression and the expression ofadipocyte maturation markers, such as CEBPα and PPARγ was observed in undifferentiated cells treated with TNF‐α. Similar inverse relation between ATF3 and col6A3 expression was observed in the cells differentiated by insulin alone suggesting a physiological role of ATF3 in adipocyte differentiation and Col6a3 transcriptional regulation. These findings suggest a novel ATF3 mediated pathway regulating expression of Col6A3 expression which, in turn is known to affect adipose tissue inflammation.
The impact of long‐term methylphenidate exposure on neurogenesis in mouse hippocampus
Authors: Nguyen Claire , Carter Tracy , Carothers Chancey , Hanley Angela , Pond Brooks B
Published: June 2021

Methylphenidate (Ritalin®, MPH) is a psychostimulant that increases the levels of catecholamine neurotransmitters in the synaptic cleft by blocking reuptake through the dopamine transporter (DAT) and the norepinephrine transporter (NET). Although MPH is commonly used for the treatment of Attention Deficit Hyperactivity Disorder (ADHD), relatively little is known regarding the consequences of long‐term exposure to this drug. In this study, we investigated the effect of long‐term MPH exposure on the rate of neurogenesis in the hippocampus. Briefly, 25 day old male mice received intraperitoneal injections of saline, 1mg/kg, or 10mg/kg of MPH twice‐daily for 28 days. On day 29, the mice were injected with 5‐ethynyl‐2′‐deoxyuridine (EdU), a modified nucleoside used to identify newly generated cells. Brain tissue was collected 1 day post EdU injection to determine neurogenesis rate and 28 days post EdU injection to examine the survival of newly generated cells. Brain tissue was sectioned on a cryostat, and tissue sections were stained using a Click‐iT® EdU Imaging Kit and double‐labeled using immunohistochemistry for the neuronal marker, NeuN. Stained cells in the dentate gyrus were counted using an epifluorescence microscope, and the ratio of EdU positive cells to NeuN positive cells were compared between groups. Funded by the ETSU Research Development Committee and the Department of Pharmaceutical Sciences
Glucose metabolism and DNA methylation of offspring are altered by maternal sodium restriction
Authors: Siqueira Flavia Ramos , Nguyen PhuongSon , Kobzik Lester , de Oliveira Ivone Braga , Heimann Joel Claudio , Furukawa Luzia Naoko Shinohara
Published: June 2021

Objective

To evaluate glucose metabolism of adult offspring of dams fed low sodium diet during pregnancy.

Methods

Female Wistar rats (n= 6 – 8/group) were fed low (LS‐ 0.15%) or normal (NS‐1.3% NaCl) salt diet since the 1st day of gestation until delivery or LS during 1st (LS10) or 2 nd half of gestation (LS20). Body weight (BW), circulating glucose, insulin, leptin and C‐peptide levels, glucose (GTT) and insulin tolerance test (ITT) and leptin receptor (LR) methylation were measured in male (M) and female (F) offspring at 12 weeks of age.

Results (mean±SEM, p< 0.05):

BW, at birth (g, n=14 – 27/group) (M: NS = 6.5±0.1, LS = 5.5±0.1, LS10 = 6±0.1, LS20 = 4.8±0.1, F: NS = 6±0.2, LS = 5±0.1, LS10 = 6±0.1, LS20 = 4±0.1) was lower in LS, LS10 and LS20 than in NS, while at adulthood it was not different. Glucose was higher in LS (M=115±3; F=110±4) than in the other groups (M: NS=103±1; LS10=100±2; LS20=96±2; F:NS=101±2; LS10=100±2; 108±2). C‐peptide was higher in LS (M=1117±152; F=509±27) than in NS (M=375±41; F=233±63) and lower in LS20 (M=97±15; F=76±9) compared to LS10 (M=528±112; F=378±45).Glucose was higher in LS M and F at 5 minutes of the GTT compared to NS offspring. Leptin, insulin, and ITT were not different. But LR methylation was increased in LS20.

Conclusion

Sodium restriction during pregnancy leads to low birth weight and to modifications of glucose metabolism and LR methylation. Supported by FAPESP and CAPES.
Therapeutic Role of Caveolin‐3 in Mitochondrial Directed Cardioprotection during the Development of Diabetic Cardiomyopathy
Authors: Migita Michael Yoshimichi , Zemljic‐Harpf Alice E. , Finley J. Cameron , Kellerhals Sarah E. , Fridolfsson Heidi N. , Panneerselvam Mathivadhani , Niesman Ingrid R. , Ali Sameh S. , Roth David M. , Patel Hemal H.
Published: June 2021

Diabetes is a worldwide epidemic with cardiovascular disease being a major complication. Caveolins act as scaffolding molecules for regulating signaling. Overexpression of caveolin protects the heart from cardiovascular stress. We hypothesize that cardiac‐specific caveolin‐3 (Cav‐3) overexpression (OE) will protect the diabetic heart. Transgene negative (TGneg) or Cav‐3 OE mice were given a single dose of streptozotocin (75mg/kg) and then placed on a high fat diet to induce type II diabetes mellitus (T2DM). After 3 months, TGneg T2DM mice and Cav‐3 OE T2DM mice showed an increase in body weight, altered glucose tolerance response, and increased insulin levels compared to controls on normal diet. Cav‐3 OE T2DM mitochondria showed protection from calcium swelling and reactive oxygen species generation similar to controls, when compared to TGneg T2DM mitochondria. Cav‐3 OE controls and Cav‐3OE T2DM showed increased protein expression of OPA‐1 and Mitofusin 2, compared to TGneg controls and TGneg T2DM. Mitochondrial ultrastructure (i.e., mitochondrial swelling and clustering) was preserved in Cav‐3 OE T2DM hearts compared to TGneg T2DM. Our data suggest that Cav‐3 OE in the heart has the ability to limit injury in the setting of diabetes through regulation of mitochondrial structure and function.
Constraining effects the CFTR‐DeltaF508 mutation on myocyte calcium release, aortic tone and arterial blood pressure
Authors: Peotta Veronica , Volk Kenneth A , Guo Jinny , Roghair Robert D
Published: June 2021

The CFTR‐ΔF508 mutation is the most common cause of cystic fibrosis (CF). Epithelial cells expressing CFTR‐ΔF508 have reduced intracellular calcium mobilization, presumably due to retention of misfolded ΔF508 within the sarcoplasmic/endoplasmic reticulum (SR). We hypothesized the lower blood pressures reported in ΔF508 carriers may be due to impaired SR calcium release. By carotid telemetry, ΔF508 carrier mice had lower mean arterial pressures than wild‐type controls (102±3 vs.112±2 mmHg, N=6 and 10, p<0.05). By wire myography (N=4), thoracic aorta from ΔF508 mice had diminished contractile responses to KCl, and CFTR inhibition diminished the responsiveness of wild‐type (WT, −31+/−8%, p<0.05) but not ΔF508 aorta (−6+/−7%). Likewise aorta from neonatal ΔF508/ΔF508 piglets had diminished responses to KCl (3.8+/−0.3 vs. WT 5.1+/−0.4g, N=11–21, p<0.01), and this was replicated in WT piglets (3.5+/−0.5g) by combined inhibition of IP3 and ryanodine receptors with 2‐APB and ryanodine, respectively. Finally, by Fura‐2 imaging, aortic smooth muscle cells from ΔF508 piglets had significantly decreased angiotensin II‐stimulated calcium response (fold‐increase: WT/WT 5.4+/−0.6, ΔF508/WT 4.1+/−0.4, ΔF508/ΔF508 3.4+/−0.3, p=0.01). We conclude the CFTR‐ΔF508 mutation alters calcium handling, decreases aortic responsiveness and lowers arterial pressures.
Allelic Variability in the AGT M235Tand AT1 A1166C Single Nucleotide Polymorphisms from a Cohort of East Africans
Authors: Rice Nancy Ayers , Freeman Julia C , Lengube Brian M
Published: June 2021

Non‐communicable disease (NCD), in particular cardiovascular disease, is a significant problem in developing countries. Essential hypertension (EH) is a leading risk factor for vascular diseases and while managing EH in developing countries is considered a high global priority few studies exist from third world populations. From a cohort of Kenyans living in the Kasigau region, we have investigated the allele frequency of two different single nucleotide polymorphisms (SNPs) previously reported to correlate with salt‐sensitive EH. These include the angiotensinogen (AGT) M235T (rs699) and the angiotensin II receptor Type 1 (AT1) A1166C (rs5186) alleles, both part of the renin‐angiotensin system (RAS). Overall, the genotype distribution for AGT was 86% C/C, 11% C/T, and only 3% T/T. When evaluated as normotensive, pre‐hypertensive, Stage I, and Stage II categories, the allelic frequency for f(C) = 0.76, 0.86, 0.81, and 0.76, respectively and did not demonstrate Hardy‐Weinberg equilibrium as assessed by χ2, p < 0.005. The AT1 gene frequency was 95% A/A, 5% A/C, and 0% C/C. These results are the first to identify allelic frequencies in RAS which may be linked to the prevalence of EH in East Africans and suggest that nonrandom mating or genetic drift may be responsible for the evolutionary selective pressure. This work was supported by the National Institute of General Medical Sciences of the National Institutes of Health under award number 8 P20 GM103436–12.
Reduction of vasoconstriction by removing periarterial nerve in human gastroepiploic artery imply prevention of vasospasm
Authors: Yokoyama yasutaka , Matsushita Satoshi , Iesaki Takafumi , Amano Atsushi
Published: June 2021

Background

The right gastroepiploic artery (GEA) is used as an in‐situ arterial graft for coronary artery bypass grafting (CABG). However, the GEA is more likely to cause vasospasms compared to the internal thoracic artery. We hypothesized that the significant cause of GEA spasms is triggered by periarterial sympathetic nerve, since the GEA is classified as a muscular artery.

Materials and Methods

Unused parts of the GEA were obtained from patients who underwent CABG. The vessel was assigned to control (N+) and denervation (N−) group. For N− group, periarterial nerve was microscopically removed. These vessels were investigated by hematoxylin‐eosin (H‐E) and immunohistochemical staining. Then, each vessel was exposed to electrical field stimulation (EFS).

Results

Histological analysis revealed that the periarterial connective tissues including neuropeptide Y (NPY) were removed from lateral layer to external elastic membrane in the N−, whereas they were preserved in N+. The vasoconstriction by EFS with serial frequency was consistently lower in N− than N+ (p<0.05 at 20 and 50Hz; n=8 each). These vasoconstrictions were inhibited by tetrodotoxin. Moreover, endothelium dependent relaxation and vasoconstriction of the smooth muscle were similar in both groups.

Conclusions

The removal of periarterial nerves from human GEA can prevent graft spasms without disturbance of endothelial and smooth muscle functions.
Regulation of SERCA2a by Akt in alcoholic cardiomyopathy
Authors: Jeffress Miara Akiel , Umoh Nsini , Walker Robin , Alrubaiee Mustafa , Haddad George
Published: June 2021

Alcoholic cardiomyopathy is one of the leading causes of non‐ischemic dilated cardiomyopathy. Approximately one in three alcoholics develops this disease. Prior studies from our lab have demonstrated the up‐regulation of intracellular calcium in dilated cardiomyopathy by Akt. SERCA2a has shown to be reduced in heart failure. Thus, we hypothesize that alcohol regulates the SERCA2a activity via the Akt pathway, affecting Ca2+ handling in cardiocytes. Thus, parallel measures of intracellular Ca2+ and sarcomere/cellular contractions were assessed (Ionoptix) with the expression level (western blot) of primary Ca2+ handling proteins (SERCA2a, phospholamban, ryanodine receptors, Na/Ca exchanger and L‐type Ca2+ channels) from control, low (LA: 0.02%), moderate (MA: 0.11%) and high (HA: 0.45%) alcoholic rat hearts with and without Ad. EGFP, Ad. Akt and Ad.Akt(K179M) transfection. Our studies indicate that SERCA2a levels are decreased in MA and HA hearts as well as those transfected with Ad.Akt. This suggests that elevated alcohol exposure induces cardiac dysfunction partly through reduction of SERCA2a activity in an Akt‐dependent manner.

This work was supported in part by grants NIH/NIAAA/1R15AAA019816–01A1 and 2G12 RR003048

RCMI/NCRR/NIH.
Cardio‐and cerebrovascular control in men and women with furosemide‐induced hypovolemia during artificial gravity exposure by short radius centrifuge
Authors: Zhang Qingguang , Evans Joyce M , Knapp Charles F , Falvo Michael J , Moore Fritz B , Patwardhan Abhijit R , Serrador Jorge M
Published: June 2021

We tested cardio‐and cerebrovascular regulation in nine men and eight women during artificial gravity (AG) exposure using a short radius centrifuge while hypovolemic. ECG, beat‐by‐beat blood pressure, middle cerebral artery blood velocity (MCAv), and end‐tidal carbon dioxide (ETCO2) were measured in supine position during ~90‐min AG exposure. Dynamic cerebral autoregulation and arterial baroreflex sensitivity (BRS) were obtained with cross‐spectral analysis during 5‐min rest pre and post AG exposure, and during maximal AG. Plasma volume was reduced by 8.6% following furosemide infusion and a subsequent 5.7% with AG exposure. From pre AG rest to maximal AG, mean arterial pressure (MAP) increased, while mean MCAv, ETCO2 and BRS decreased significantly; oscillations in MAP and mean MCAv, and coherence between MAP and mean MCAv augmented significantly within the frequency range (0.07–0.20 Hz) while gain and phase remained unchanged. In post AG rest, MAP, BRS, and oscillations in MAP returned to control values, while mean MCAv and coherence between MAP and mean MCAv were significantly lower than pre AG rest. Similarly gain remained unchanged but phase was reduced significantly. We conclude that enhanced coherence suggests that autoregulation remained intact during AG exposure; MCAv and phase were reduced suggesting autoregulation may have been affected following AG.

Supported by KY NASA EPSCoR Grant #NNX07AT58A, KY State Matching Grants, the NASA Johnson Space Center Human Research Program and the NASA Ames Research Center.
Regulation of adipogenesis and key adipogenic gene expression by nutritional molecules in 3T3 L1 preadipocytes
Authors: Ji Shuhan , Cheguru Pallavi , Acharya Suresh , Hill Rodney A.
Published: June 2021

To investigate the function of nutrient molecules (1, 25‐dihydroxyvitamin D (1, 25‐(OH)2D3) and retinoic acid (RA)) in regulation of adipogenesis, adipocyte differentiation and key adipogenic gene expression were studied in 3T3‐L1 preadipocytes. Lipid accumulation was measured by Oil Red O staining and expression of key adipogenic genes was quantified using quantitative real‐time PCR. Adipogenic responses to 1, 25‐(OH)2D3 or RA were determined on days 2–10 after induction of adipogenesis with the traditional hormonal cocktail ± 1, 25‐(OH)2D3 or RA. In response to 1, 25‐(OH)2D3 (10−7, 10−8, 10−9 M), lipid accumulation and the expression of PPARγ, C/EBPα, FABP4 and SCD‐1 were inhibited through day 10. In response to RA (10−6, 10−7 M), lipid accumulation and the expression of these genes were inhibited through day 8, rebounding to control levels by day 10. The greatest inhibitory effect was upon expression of FABP4. However, expression of SREBP‐1c was not affected. The lowest concentrations of 1, 25‐(OH)2D3 or RA tested did not affect adipocyte differentiation or expression of adipogenic genes. These results indicate that 1, 25‐(OH)2D3 and RA inhibited adipogenesis via suppressing adipogenic specific genes, especially FABP4, and suggest that the roles of these nutrient factors in regulating adipogenesis will be informed by further studies of adipogenic specific gene promoter activity.
Ventral respiratory column neuron interactions and discharge patterns during expression of low‐frequency or very low‐frequency brainstem network oscillations
Authors: O'Connor Russell E , Nuding Sarah C , Segers Lauren S , Ott Mackenzie M , Lindsey Bruce G , Morris Kendall F
Published: June 2021

Mayer and Lundberg (B) waves are oscillations of arterial pressure occurring spontaneously at a frequency lower than breathing (~0.1 Hz and ~0.04 Hz respectively). Each has been attributed to a central oscillator or an effect of baroreceptor‐mediated dynamic arterial pressure control (Julien 2006, Lescot et al. 2004). Previously we have shown that Mayer wave related oscillations (MWROs) intrinsic to the pontine and raphé networks are coupled with breathing (Morris et al. 2010). We used multi‐electrode arrays to record from neurons in the ventral respiratory column (VRC) and rostral ventro‐lateral medulla (RVLM) in decerebrate, adult cats. Results include (i) detection of neurons active only during discrete segments of MWROs, (ii) evidence for impulse synchrony of RVLM and VRC neurons with multiple coupled rhythms, and (iii) long lasting rhythm changes with central chemoreceptor stimulation. Time series analyses of spike trains informed the development of network models. Computer simulations predicted pulmonary stretch receptor‐mediated modulation of MWROs and replicated in vivo results: (i) resetting of MWRO:breathing coupling with no‐inflation cycles; (ii) change in coupling ratio with “vagotomy”. Coupling of multiple time‐scale cardio‐respiratory rhythms may assist in the matching of ventilation and perfusion and underpin the beneficial effects of slow, deep breathing. Support: NS19814
The effectiveness of health services interventions to promote and support breastfeeding initiation and exclusivity
Authors: Akik Chaza , Safieddine Batoul , Ghattas Hala , Knai Cecile , Filteau Suzanne
Published: June 2021

Worldwide breastfeeding (BF) rates fall short of recommendations. Health services initiatives exist to provide a supportive environment, yet challenges remain. Thus, we set out to systematically review the evidence on health services interventions to promote and support BF initiation and exclusivity. As numerous systematic reviews (SR) have been conducted to assess the effectiveness of interventions on BF outcomes, a review of SR was undertaken. Seven key databases were searched using combinations of search terms including SR, BF, health promotion, health education and health policy. After applying inclusion and exclusion criteria and quality assessment, the search yielded 19 papers published between 1992 and 2012. Commonly cited limitations included diversity in definitions of BF outcomes and heterogeneity of interventions. Preliminary findings show that multi‐component interventions targeting women from the prenatal through to postnatal periods were most effective at improving initiation and exclusivity of BF as compared to single‐component and single‐contact interventions. There is also evidence that a combination of professional and lay support is more effective than professional support alone at increasing exclusive BF rates. Policy implications include the need to invest in multi‐component interventions that follow women up rather than invest in one‐time interventions.
The N‐Formyl peptide receptor 1 (FPR1) is required for enteric commensal mediated mucosal homeostasis and restitution
Authors: Alam Ashfaqul , Leoni Giovanna , Wentworth Christy , Kwal Jaclyn , Jones Rheinallt , Ardita Courtney , Swanson Phillip , Nusrat Asma , Neish Andrew
Published: June 2021

Mucosal homeostasis and restitution of injury depends on epithelial proliferation and migration. The commensal microbiota of the gut lumen is essential for normal intestinal development, renewal and restitution. N‐formyl peptide receptors (FPRs) are seven membrane‐pass G protein coupled receptors that represent a family of mammalian pattern recognition receptors. FPR ligands include an array of peptides, lipids and small molecules derived from bacteria and the host. FPRs modulate phagocyte chemotaxis and oxidative burst. Intestinal epithelial cells (IECs) also express functional FPRs on the apical surface that can stimulate migration of cultured IECs in response to bacterial formyl peptides and endogenous ligands. Herein we report that a specific member of the gut microbiota requires FPR1 to stimulate reactive oxygen species (ROS) generation in IECs adjoining wounds resulting in phosphorylation of focal adhesion kinase (FAK) and ERK MAPK signaling in an intestinal epithelial NADPH oxidase Nox1 dependent manner. Moreover, we show that enteric microbiota requires FPR1 and Nox1 to stimulate redox dependent proliferation and migration of IECs, and to enhance recovery of mechanical or chemically induced mucosal injury in mouse distal colon. Taken together, these findings demonstrate a novel role for FPR1 in perceiving enteric microbiota to regulate homeostasis and restitution of the intestinal mucosa.
Forkhead (Fox) transcription factors open a new dimension in understanding the epigenetic control of replication origins in S. cerevisiae
Authors: Aparicio Oscar , Knott Simon R. V. , Ostrow Zachary A. , Peace Jared M. , Gan Yan , Kalhor Reza , Chen Lin , Tavaré Simon
Published: June 2021

As a group, eukaryotic replication origins are subject to strict cell cycle regulation of their activity to ensure complete and accurate replication of the genome. Individually, however, through mechanisms that have remained obscure, replication origins are subject to epigenetic regulation that determines their time of activation during S‐phase, or may silence their activity entirely. The significance of this phenomenon is unclear but has been proposed to play a role in gene regulation, particularly in the inheritance of epigenetic patterns. We have now identified the Forkhead transcription factors, Fkh1 and Fkh2 (Fkh1/2), yeast homologues of mammalian Fox proteins, as global regulators of replication origin timing. Our studies indicate that Fkh1/2 play a role in organizing replication origins spatially into clusters in G1‐ phase that will become replication factories in S‐phase. Our current studies are examining the regulation of Fkh1/2 binding to replication origins, which appears to be cell cycle regulated. In addition, new evidence suggests that Fkh1/2 dimerize, which affects their DNA binding specificity. Regulation of Fkh1/2 dimerization has the potential to regulate the three‐dimensional organization of replication origins, and hence, that of chromosomes. These findings provide new insights into the epigenetic regulation of replication origin function and genome organization.
Gamma‐tocotrienol antagonizes adipogenesis through activation of AMPK/autophagy axis in primary human adipocytes
Authors: Zhao Lu , Ha Jung‐Heun , Kang Inhae , Okla Meshail , Chung* Soonkyu
Published: June 2021

Tocotrienols are a subclass of vitamin E, exerting stronger biological activity than tocopherols. In particular, gamma tocotrienol (γT3) possesses potent anti‐inflammatory and anticancer properties by modifying multiple signaling pathways. However, little is known about the effects of T3 on adipogenesis. The aim of this study was to investigate the anti‐adipogenic effects of γT3 in primary human adipose‐derived stem cells (hASCs). Here, we showed that γT3 specifically inhibits early stage adipocyte differentiation by acting on downstream of C/EBPβ, but upstream of C/EBPα Inhibition of adipogenesis by γT3 was confirmed by dramatic decreases in adipogenic gene, protein and TG accumulation. Interestingly, γT3 reduced anabolic signaling of Akt/mTOR, but activated catabolic signaling of AMPK. Inhibition of AMPK via adenoviral delivery of the mutant form of AMPK partly restored the adipogenic gene and adipocyte morphology. Unexpectedly, γT3 promoted an abnormal increase in LC3II formation, suggesting that AMPK activation may subsequently induce autophagy. Continuous exposure of γT3 eventually led to an apoptotic cell death by increasing PARP cleavage and caspase‐3 activation. Collectively, our work demonstrated that γT3 antagonizes adipogenesis in hASCs by triggering multiple signaling pathways of growth inhibition, including activated AMPK/autophagy axis and apoptosis.

Grant Funding Source: NIH NCRR
Plasma and liver lipids of iron‐deficient rats with excessive dietary manganese
Authors: Yokoi Katsuhiko , Konomi Aki , Tachibana Itsuki , Uchida Yuka
Published: June 2021

Recently, manganese (Mn) toxicity in a child with iron (Fe) deficiency was reported. Since there is a possibility that effect of Fe deficiency is augmented by excessive Mn, plasma and liver lipids in rats were analyzed. Thirty‐two 3‐week‐old male Wistar rats were randomly assigned in a 2×2 factorial design (eight rats each): FeA/MnA group fed AIN‐93G diet, FeA/MnE group fed a high Mn diet (1000 ppm), FeD/MnA group fed a low‐Fe diet (no supplemental Fe), and FeD/MnE group fed a low Fe/high Mn diet. Rats were fed ad libitum for six weeks and then fasted overnight. Plasma and liver lipids were measured enzymatically. Data were analyzed by two‐way ANOVA and P values less than 0.05 was considered significant. The low Fe diet increased plasma triglycerides, phospholipids and free fatty acids. The low Fe diet decreased plasma glucose and HDL cholesterol, and concomitant high Mn augmented their reduction. The low Fe diet increased liver triglycerides. Both the low Fe and high Mn diets increased liver phospholipids. The low Fe diet increased liver cholesterol, and concomitant high Mn attenuated its rise. These results suggest that concomitant high dietary Mn modulates changes in plasma and liver lipids induced by Fe deficiency. Partly supported by Japan Society for the Promotion of Science Grants‐in‐Aid for Scientific Research (C) (22500772).
Associations among body mass index, waist circumference, dietary factors and cardiometabolic risks in 10th grade students: The NEXT Generation Health Study
Authors: Pratt Charlotte A , Iannotti Ronald J , Li Kaigang , D'Elio MaryAnn , Olson Sarah , Lipsky Leah , Simons‐Morton Bruce , Fan Ruzong
Published: June 2021

Objective

To identify associations among body mass index (BMI), waist circumference (WC), dietary factors and cardiometabolic indicators in US adolescents.

Approach

A random sample of overweight (N=282) and normal‐weight (N=278) 10th‐grade students at baseline of the NEXT Generation Health Study.

Results

Low density lipoprotein cholesterol (LDL‐C), high density lipoprotein cholesterol (HDL‐C), triglycerides (TG), total cholesterol (TC), diastolic blood pressure (DBP), mean arterial pressure (MAP), WC, hemoglobin A1C, C‐reactive protein (CRP), uric acid and serum fructose were significantly higher in overweight 10th graders than in normal weight. Overweight youth had 2.4 unit higher DBP than normal weight. Controlling for covariates, BMI percentile was significantly associated with WC (B=0.03, p<.001), DBP (= 0.06, p<.01), MAP (B=0.06, p<.001), TC(B = 0.01, p<.01), LDL‐C (B = 0.01, p<.01), HDL‐C (B=− 0.002, p<.001), CRP (B=0.02, p<.01), and uric acid (B=0.01, p<.01). Tenth graders with WC ≥90th percentile had significantly higher metabolic indicators. SBP was associated with intake of added sugar (B=0.09, p<.03) but not with sodium or solid fats.

Conclusion

These findings underscore the role of obesity in increasing cardiovascular disease (CVD) risk factors and a need for interventions that target high school students to prevent further CVD risks.

Grant Funding Source: This research was supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Developmentand the National Heart, Lung, and Blood Institute (Contract #HHSN2672008000009c).
Amino Acid Metabolite Infusion Enhances Muscle Protein Synthesis without Altering Degradation in Neonates
Authors: Wheatley Scott Michael , El‐Kadi Samer , Suryawan Agus , Boutry Claire , Orellana Renan , Nguyen Hanh , Davis Steve , Davis Teresa
Published: June 2021

Many low‐birth‐weight infants experience failure to thrive. The amino acid, leucine, stimulates protein synthesis in skeletal muscle of the neonate but less is known about the effects of amino acid metabolites on neonatal muscle protein synthesis. The study objective was to determine the effect of an amino acid metabolite (AAM) on fractional protein synthesis, translation initiation, and regulation of the degradation pathway. Overnight fasted neonatal pigs were infused with AAM at 0, 20, 100, or 400 μmol·kg−1·hr−1 (AAM 0, AAM 20, AAM 100, and AAM 400) for 1 h. Blood AAM concentrations increased with AAM infusion (P<0.05) and were 10, 98, 316, and 1400 nmol·ml−1. Fractional protein synthesis rates in the longissimus dorsi (LD), gastrocnemius, soleus, and diaphragm muscles increased in response to AAM 20 (P<0.05) but AAM 100 affected only the LD while AAM 400 had no effect. Infusion of 20 and 100 AAM increased (P<0.05) formation of the active eIF4E · eIF4G complex as well as phosphorylation of S6K1 and 4EBP1 in the LD, gastrocnemius, and soleus. Infusion of 20, but not 100, AAM increased (P<0.05) the activation of these mTORC1 indices in the diaphragm. Expression of Atrogin‐1, MURF1, and LC3‐ II, markers of protein degradation were unchanged. Results suggest that supplemental AAM enhances protein synthesis in skeletal muscle of the neonate by stimulating translation initiation.
Imaging neurovascular interactions in the cerebral cortex in vivo
Authors: Devor Anna
Published: June 2021

The ability to descend to the single‐cell and single‐capillary levels in vivo and observe firing of individual neurons, vasodilation, glucose uptake, and infusion of O2 into the tissue ‐ all while directly controlling neuronal activity ‐ has long been a dream of scientists interested in understanding the complex regulation of blood flow and metabolism as related to neuronal activity. However, in contrast to the detailed and elegant mechanistic studies in isolated tissue, in vivo reports have, in the main, focused simply on correlations between the “observables”, limited by the available methods. This “too hard to do” status quo for mechanistic studies in vivo is starting to change, due to rapid developments in optical microscopy. In fact, already today, a versatile suite of optical tools is available for high‐resolution, high‐sensitivity measurements of vascular, metabolic, and neuronal parameters in deep tissue and local, cell‐type specific manipulations of neuronal activity. In this talk, we will review examples where the use of novel optical technologies has been instrumental for central discoveries in basic mechanisms of neurovascular regulation.
Adult hippocampal neurogenesis: Another target of scylloinositol treatment?
Authors: Thomason Lynsie Alexandra Marie , McLaurin JoAnne
Published: June 2021

The aim of this study is to determine the effect of scyllo‐inositol, an anti‐amyloid‐beta peptide aggregation compound, on adult hippocampal neurogenesis in the TgCRND8 model of Alzheimers disease. Bromodeoxyuridine was used to label dividing cells in the hippocampus of adult TgCRND8 mice. The phenotype of newly dividing cells was assessed by staining for bromodeoxyuridine, doublecortin (an early neuron marker) and glial fibrillary acidic protein (an astrocyte marker). The survival of the newborn hippocampal cells was assessed 21 days later by staining for bromodeoxyuridine, neuronal nuclei (a mature neuron marker) and glial fibrillary acidic protein. scyllo‐Inositol increased the percentage of newborn cells in the hippocampus of TgCRND8 mice expressing doublecortin compared to non‐treated TgCRND8 mice. Further, scyllo‐inositol increased the survival of newborn hippocampal neurons in TgCRND8 mice compared to non‐treated TgCRND8 mice. These findings provide an alternative mechanism for the previously observed improved cognition in scyllo‐inositol treated TgCRND8 mice; therefore highlighting adult hippocampal neurogenesis as a potential target for Alzheimers disease therapy.
The developmental basis for jaw size variation in evolution and disease
Authors: Fish Jennifer L , Sklar Rachel S , Woronowicz Katherine C , Schneider Richard A
Published: June 2021

Variation in jaw size was critical for the adaptive evolution of vertebrates, yet variation during development is often associated with disease. To test the hypothesis that NC progenitor number and proliferation rates contribute to variation in jaw size, we compared NC development in two birds with distinct jaw size, duck and quail. At stage HH10, duck and quail embryos have substantial differences in brain shape and expression of the brain regionalization genes, Pax6, Otx2, Fgf8, and Krox20. There is no significant difference in Pax7‐postive NC precursors in HH8 duck and quail embryos. But by HH13, duck embryos have nearly twice as many Dlx2‐positive NC in their jaw primordia as do quail, a ratio which is maintained in HH20 embryos. At HH20, quail NC divide 1.4 times faster than duck NC, however, quail embryos also develop 1.6 times faster during this developmental window. After reduction of NC precursors, post‐migratory NC compensate within the jaw primordia to produce a symmetric and relatively normally sized jaw. Importantly, while chick undergo complete compensation, ablated duck embryos form slightly smaller than normal jaws. Our results suggest that modification of multiple aspects of NC cell biology was important to the evolution of large jaw size. Further, our finding of compensatory mechanisms opens avenues for treatment of disease associated with NC progenitors loss.

Grant Funding Source: none
Post‐transcriptional regulation of Lunatic fringe provides a critical mechanism to control Notch pathway signaling during somitogenesis
Authors: Cole Susan E. , Riley Maurisa F. , Williams Dustin R. , Shifley Emily T.
Published: June 2021

Somites are the embryonic precursors of the vertebrae, ribs, and skeletal muscles. They form from the presomitic mesoderm (PSM) by a periodic segmentation process called somitogenesis. This process is controlled in part by a segmentation clock that utilizes oscillatory expression of genes such as Lunatic fringe (Lfng) to track temporal information. Lfng activity levels in the mouse or chick PSM oscillate with a period that matches the rate of somite formation, regulating the timing of somitogenesis. Lfng encodes a fucose‐specific beta1,3 N‐acetylglucosaminyltransferase that modifies the extracellular domain of Notch receptors. This modification affects Notch activation, suggesting that oscillatory LFNG activity could regulate cyclic Notch pathway activity in the PSM. Thus, many models suggest that the oscillation of the Lfng glycosyltransferase activity underlies the coordinated, cyclic activation of the Notch pathway during somitogenesis. For such rapid oscillations to play a functional role during development, stable clock function requires that tight transcriptional control of Lfng expression be coupled with mechanisms that confer short half‐lives to the Lfng RNA transcript, and to the LFNG protein activity. We have examined post‐transcriptional mechanisms that may regulate Lfng activity within the segmentation clock. We will discuss miRNA‐based mechanisms that regulate mRNA transcript stability, as well as post‐translational mechanisms that control protein activity turnover.
Novel enzymatic transformations in secondary metabolism and tRNA modification
Authors: Bandarian Vahe
Published: June 2021

Deazapurine‐containing secondary metabolites comprise a broad range of structurally diverse nucleoside analogs found throughout biology including various antibiotics produced by species of Streptomyces bacteria and the hypermodified tRNA bases queuosine and archaeosine. Despite early interest in deazapurines as antibiotic, antiviral, and antineoplastic agents, the biosynthetic route toward deazapurine production had remained largely elusive for more than 40 years. We have utilized genomic and biochemical studies to identify a paradigm for the biosynthesis of deazapurine‐containing compounds. This presentation will discuss our most recent efforts towards molecular level understanding of the reactions catalyzed by enzymes in the deazapurine biosynthesis pathways. (Support from GM72623 is gratefully acknowledged)