bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential protective effects of alginate and fucoidan from the edible algae on the ethanol‐induced liver damage
Authors: Namkoog Seung , Kim Ye-Jin , Kim Taeseong , Kim Jeung-eun , Lee Jimin , Ro Hyo-Lyun , Sohn Eun-Hwa
Published: June 2021

Alcohol‐induced liver injury progresses from fatty infiltration followed by a harmful cause of inflammation leading to an irreversible damage. In this study, two compounds (alginate and fucoidan) isolated from marine edible brown algae were examined for their protective effects against ethanol‐induced toxicity in vitro. Ethanol‐induced HepG2 cells were treated with the compounds at various concentrations, and the results showed that fucoidan at 50 μg/mL was decreased TGF‐β expression, a hallmark of liver fibrosis, and iNOS expression. The administration of 60 mg/kg of fucoidan resulted in the reduction of sGOT and sGPT levels caused by 25% ethanol exposure (2.0 g/kg/day, po) for 5 days in mice. However, alginate unexpectedly enhanced the iNOS and TGF‐β expression in HepG2 cells. These findings suggest that fucoidan could be a potential candidate for attenuated of ethanol induced liver damage.
Assessment of iron status and biomarkers of inflammation in schoolchildren with and without infection
Authors: Grijalva Maria Isabel , Garcia Karla Fabiola , Artalejo Elizabeth , Caire Graciela
Published: June 2021

Iron deficiency is the most prevalent nutritional disorder in the world and the leading cause of anemia in children; it often occurs in populations with a high prevalence of chronic and/or repeated acute infections associated with chronic inflammation.

Objetive

To evaluate the iron deficiency in schoolchildren by serum ferritin (SF), protoporphyrin and serum transferrin receptor (sTfR) in the presence or absence of infection.

Subjects and Methods

A crossectional study was performed in 195 children of 5 to 11 years old. Hemoglobin (Hb), SF, protoporphyrin and sTfR were measured, as well as the inflammation biomarkers á1‐acid glycoprotein (AGP) and C‐reactive protein (PCR), to associate iron‐status indicators with the inflammatory process.

Results

The prevalence of anemia (Hb <11.5 g/dL) was 5%. However, a 77% of iron deficiency was detected through serum ferritin. The values of RsTf and protoporphyrin were normal, indicating that the children were in the stage I of iron status. Despite this, SF correlated positively with PCR (r=0.178, p<0.05) but not with AGP (r=0.054, p=0.449). Correlations between RsTf and the markers of inflammation, AGP and PCR, were not statistically significant (P<0.05).

Conclusion

The markers of inflammation did not influence the analysis of ferritin for the detection of iron deficiency.
Epigenetic regulation of high glucose‐induced pro‐inflammatory cytokine production in monocytes by fisetin
Authors: Yun Jung-Mi , Kim Hye Joo
Published: June 2021

Diabetes is a pro‐inflammatory state. Recently, we have shown that high glucose induces pro‐inflammatory cytokines via epigenetic changes. Fisetin, a flavonoid compound commonly present in fruits and vegetables, can exert anti‐inflammation activities via inhibition of the NF‐κB‐signaling pathway. In this study, we tested the effect of fisetin on histone acetylation and pro‐inflammatory cytokine secretion under high‐glucose conditions in human monocytes. Human monocytic (THP‐1) cells were cultured in presence of normoglycemic (NG, 5.5 mmol/L glucose) or hyperglycemic (HG, 20 mmol/L glucose) conditions in absence or presence of fisetin (3–10μM) for 48 h. Cytokine level, nuclear factor κB (NF‐κB) transactivation, histone deacetylases (HDACs) activity, histone acetylases (HATs) activity were measured by western blot, ELISA, and real‐time PCR. HG activates HAT which in turn acetylates p65 and suppresses HDAC3 resulting in NF‐κB activation and increased transcription of IL‐6 and TNF‐α in monocytes. Fisetin induces HDAC3 and decreases HAT (p300) activity, thereby resulting in decreased NF‐κB activation and decreased inflammatory cytokine release (p<0.001) in HG conditions. These results indicate that fisetin decreases HG‐induced cytokine production in monocytes via epigenetic changes involving NF‐κB. In conclusion, fisetin supplementation may prevent diabetic complications by reducing vascular inflammation
Epigenetic regulation of microRNA‐192 by TGF‐beta through Akt/p300 pathway in the diabetic kidney
Authors: Kato Mitsuo , Wang Mei , Park JungTak , Putta Sumanth , Lanting Linda , Natarajan Rama
Published: June 2021

Evidence shows that microRNA‐192 (miR‐192) is upregulated by Transforming Growth Factor beta1 (TGF‐b) in a Smad3 and p53 dependent manner in early stages of diabetic nephropathy and plays a role in renal fibrosis. Although Ets‐1 binding sequences are present in the miR‐192 promoter region, the role of Ets‐1 and its effects on chromatin are not known. Promoter activities were examined by luciferase reporter assays, and binding of Ets‐1 and p300 and acetylation of histone H3 on the miR‐192 promoter by Chromatin‐immunoprecipitation assays. Luciferase assays showed that the Ets‐1 site is critical for the TGF‐b response. TGF‐b‐activated Akt kinase could lead to phosphorylation of p300 (phospho‐p300S1834) and subsequent acetylation of Ets‐1 and Histone H3K9/14/27 to upregulate miR‐192. Significant increase of phospho‐p300 levels was detected in glomeruli from diabetic mice. Basal miR‐192 levels were higher and TGF‐b‐induced increase in miR‐192 was lost in glomerular mesangial cells derived from Ets‐1 knockout mice and in mouse mesangial cells treated with Ets‐1 siRNA. These results demonstrate a novel negative regulatory role for Ets‐1 in miR‐192 expression and suggest that the dissociation of acetylated Ets‐1 (via TGF‐b‐activated Akt/p300 pathway) from the miR‐192 promoter and relaxation of chromatin (Histone acetylation) can lead to enhanced miR‐192 expression related to diabetic glomerular fibrosis.
Spermatogonium compartment in experimental administration of semicarbazide
Authors: Costa Eduardo Leitão , Marques Pedro , Marques Rodrigo Farinha , Cabrita Silvério
Published: June 2021

Lathyrism is a pathologic condition with deficient collagen synthesis, which can be induced in the lab animal by the administration of semicarbazide.

The aim of this study is to evaluate the seminiferous tubules morphologic changes, measuring the area occupied by the spermatogonia, in the experimental administration of semicarbazide.

Thirty Wistar male rats, 8 weeks‐old were randomly distributed on two groups: the control group was kept without manipulation; the animals of test group were submitted to the administration of semicarbazide incorporated in the diet in the dose of 6g/kg, during 4 weeks. All the animals were sacrificed on the 30th day, by an overdose of anaesthetics and the complete necropsy was performed.

The fragments collected in the necropsy were studied under light microscopy, stained by Haematoxylin & Eosin. The testicle's slides were submitted to morphometric analysis to evaluate the area occupied by spermatogonium compartment.

The statistical analysis by frequencies distribution allows observing different distributions of the different cases. Comparing both groups, we observe more cases with medium area than on the test group. The graphic of the test group presents a peak of cases with greater areas than the control ones.

These results allow us to conclude that the spermatogenesis is changed on the administration of semicarbazide.
DELETIONS IN MITOCHONDRIAL DNA FROM LASER MICRODISSECTED BLOOD VESSELS OF ALZHEIMER BRAINS
Authors: trikamji bhavesh v , Miller Bradley Bryan
Published: June 2021

The role of neurovascular dysfunction has long been suggested to be of relevance in the disease pathology of Alzheimer's. However, a mitochondrial genetic cause for vascular dysfunction has yet to be investigated in depth. We examined the mtDNA of individual cerebral endothelial cells obtained by laser micro‐dissection from 9 Alzheimer disease brains in late Braak & Braak topographical stages of pathology. The objective of our study was to detect deletion‐type mutations in the mtDNA by scanning a region of the genome in which deletions have been most commonly detected. We detected 4 separate mtDNA mutations from a total of 18 endothelial cells isolated from 9 Alzheimer brains (2 cells from each). These mutations were characterized by sequence analysis. We suggest that the presence of mtDNA mutations in the small number of endothelial cells from Alzheimer brains indicates that the microvascular cell population may harbor a high aggregate level of such mutations, potentially underlying increasing vascular dysfunction in Alzheimer disease and, possibly, in aging.
RGS4 as a regulator of the antidepressant effects of SSRIs
Authors: Amos Mary Ellen , Binkey Amanda E. , Taylor Phillip N. , Rorabaugh Boyd R. , Neubig Richard R. , Traynor John R. , Talbot Jeffery N.
Published: June 2021

Previously, we showed that RGS‐insensitive Gαi2G184S (Gαi2GS) mice exhibit basal and serotonin‐dependent antidepressant (AD) phenotypes. Here we show that acute (3‐day) administration of the serotonin selective reuptake inhibitor (SSRI) fluoxetine (FLX) produced AD‐like responses in Gαi2GS mice in the novelty‐induced hypophagia test, which requires chronic (21‐day) FLX to produce AD effects in wild‐type (WT) animals. In contrast, acute desipramine, a norepinephrine‐based antidepressant, had no effect. The AD efficacy of FLX in acutely treated Gαi2GS mice was twice that of chronically treated WT littermates. Also, Gαi2GS mice exhibited basal and selective 4‐fold upregulation of cortical RGS4 vs. WT mice. mRNA expression of eleven RGS proteins in the cortex and hippocampus by RT‐PCR showed chronic FLX selectively upregulated cortical RGS4 in WT mice. Notably, vehicle‐treated Gαi2GS mice showed similar regional and RGS‐selective upregulation of cortical RGS4 mRNA and protein. These are the first studies of which we are aware to show altered expression of RGS proteins in response to SSRIs. Overall, these data suggest RGS insensitivity improves the efficacy and onset of action of SSRIs in animal models of mood. Moreover, upregulation of cortical RGS4 may contribute to the AD phenotype of Gαi2GS animals and to the therapeutic effects of SSRIs. Supported by DA04087 and the Bower Bennett Bennett Endowment.
MRP2 Transporter Reduces Renal Cisplatin Accumulation and Protects Against Nephrotoxicity
Authors: Aleksunes Lauren M , Wen Xia
Published: June 2021

Use of the chemotherapeutic drug cisplatin is limited in part by nephrotoxicity. The organic cation transporters OCT2 and MATE1 participate in the uptake and efflux of cisplatin in renal tubule cells, respectively. We hypothesized that the multidrug resistance‐associated protein 2 (MRP2) also effluxes cisplatin metabolites into urine thereby limiting renal toxicity. In the present study, cisplatin disposition and toxicity were assessed in MRP2‐, MATE1‐ and OCT2‐transfected HEK293 cells and in male wild‐type and Mrp2‐null mice. Cisplatin‐induced cytotoxicity was increased 72% in OCT2 cells and decreased in MATE1 and MRP2 cells by 260% and 485%, respectively. Serum and kidneys were collected from wild‐type and Mrp2‐null mice up to 4 days after cisplatin (20 mg/kg ip). More extensive proximal tubule injury was observed in Mrp2‐null mice, as assessed by BUN levels, histopathology, and mRNA profiling. Increased toxicity in Mrp2‐null mice correlated with a 33% increase in renal platinum AUC compared to wild‐types. Plasma clearance of cisplatin as well as Oct2 and Mate1 mRNA expression were similar between genotypes. Collectively, these data suggest that MRP2 is also responsible for the renal secretion of cisplatin and deficiency in Mrp2 increases platinum accumulation and susceptibility to cisplatin‐induced kidney injury in mice.
Deregulated Hepatic Metabolism Exacerbates Impaired Testosterone Production in Mrp4‐Deficient Mice
Authors: Morgan Jessica A , Cheepala Satish B , Wang Yao , Neale Geoff , Adachi Masashi , Nachagari Deepa , Leggas Mark , Boyd Kelli , Schuetz John D
Published: June 2021

The physiological role of multidrug resistance protein 4 (Mrp4, Abcc4) in the testes is unknown. We found that Mrp4 is expressed primarily in mouse and human Leydig cells; however, there is no evidence that Mrp4 regulates testosterone production. We investigated its role in the Leydig cells, where testosterone production is regulated by cAMP, an intracellular messenger formed when the luteinizing hormone (LH) receptor is activated. Because Mrp4 regulates cAMP, we compared testosterone levels in Mrp4−/− and Mrp4+/+ mice. Young Mrp4−/− mice had significantly impaired gametogenesis, reduced testicular testosterone, and disruption of Leydig‐cell cAMP homeostasis. Both young and adult mice had impaired testosterone production. In Mrp4−/− primary Leydig cells treated with LH, intracellular cAMP production was impaired and CREB phosphorylation was strongly attenuated. Notably, expression of CREB target genes that regulate testosterone biosynthesis was reduced in Mrp4−/− Leydig cells in vivo. Therefore, Mrp4 is required for normal Leydig‐cell testosterone production. However, adult Mrp4−/− mice are fertile with a normal circulating testosterone concentration. The difference is in 3‐wk Mrp4−/− mice, disruption of gonadal testosterone production upregulates hepatic Cyp2b10, a known testosterone‐metabolizing enzyme. Therefore, defective testicular testosterone production deregulates hepatic Cyp‐mediated testosterone metabolism to disrupt gametogenesis. These findings have important implications for understanding the side‐effects of therapeutics that disrupt Mrp4 function and are reported to alter androgen production. This work was supported by grants from the NIH and ALSAC.
Characterization of chronic desensitization of vanilloid receptor (TRPV1) in the rat
Authors: Czikora Ágnes , Rutkai Ibolya , Pasztor Eniko T. , Porszasz Robert , Edes Istvan , Papp Zoltan , Toth Attila
Published: June 2021

Desensitization of TRPV1 in sensory neurons by prolonged, high dose stimulation is used in clinical practice to achieve analgesia, but the effects of this treatment on the recently identified TRPV1 mediated vascular responses are not known. Newborn rats were injected with capsaicin to desensitize TRPV1. Sensory activation was measured by eye wiping tests and plasmaextravasation. Isolated, pressurized skeletal muscle (m. gracilis) arterioles were used to characterize TRPV1 mediated vascular responses, while expression of TRPV1 was detected by immunohistochemistry. Capsaicin evoked sensory responses, eye wiping or evans blue accumulation were reduced in desensitized rats. The number of TRPV1 positive sensory neurons in the dorsal root ganglia was also decreased. However, TRPV1 expression in smooth muscle cells was not affected. There were no differences in the diameter, endothelium mediated dilations, norepinephrine mediated constrictions, myogenic response and in the capsaicin evoked constrictions of arterioles. Systemic capsaicin treatment of juvenile rats evokes anatomical and functional disappearance of the TRPV1‐expressing neuronal cells but does not affect the TRPV1‐expressing cells of the arterioles, implicating a different regulation of TRPV1 responsiveness in these systems. Funding: TÁMOP‐4.2.1.B‐09/1/KONV‐2010‐0007
2me‐SATP activates P2X4R and induces a secondary increase of Na+ pump and Na+/Ca++ currents in cardiac myocytes of P2X4R overexpression transgenic mice
Authors: Shen Jian Bing , Pappano Achilles J , Liang Bruce T
Published: June 2021

2me‐SATP activates the P2X4 receptor (R) to induce an inward current at resting potentials, carried mostly by Na+ as well as some Ca++. This experiment tests if the Na+ pump current (Ip) or Na/Ca exchange current (Iex) would change after this increased Na+ entry caused by the activation of P2X4R. The whole cell voltage clamp was applied to myocytes from the P2X4R overexpressing transgenic mice at room temperature. Ip was measured at −20mV by rapidly switching the superfusing solution from 0 to 5.4mM K+ when the K+, Iex and ICa currents were blocked by CsCl and NiCl2 in pipette and superfusing solution. In 5 of 8 myocytes, 3 μM 2me‐ SATP induced an inward current (−1.20±0.28pA/pF) at −80mV. The average amplitude of Ip in these 5 cells increased from 0.12±0.03 in control to 0.14±0.03nA in 2me‐SATP (P=0.03). The integrated area of Ip also increased from 1371±379 to 1707±418 nA*ms (P=0.047). To measure Iex, 5μM ouabain instead of NiCl2 was used to block Ip. 10mM NiCl2 was applied to myocytes for 1 min by a rapid solution‐switching device and Ni‐sensitive current was taken as Iex. In 5 of 9 cells, 3 μM 2me‐SATP induced an inward current (−1.37±0.34pA/pF), the reversal potential of Iex shifted from −18 mV at control to −28 mV with ATP. Outward Iex increased significantly from 0.7±0.12 at control to 1.0±0.14 pA/pF after ATP at 50 mV (P=0.046), while the inward Iex changed little, from 0.98±0.07 at control to 1.03±0.03pA/pF with ATP at −80mV. These results indicate that 2me‐SATP, by activating P2X4R to increase the intracellular Na+ concentration, induces a secondary increase of Na pump activity and reverse‐mode Na+/Ca++ exchange.
Hypertension related alterations in α1‐adrenergic responsiveness of the rat seminal vesicle and vas deferens
Authors: Yono Makoto , Tanaka Takanori , Tsuji Shigeki , Irie Shin , Sakata Yukikuni , Otani Masayuki , Latifpour Jamshid
Published: June 2021

As hypertension may impact ejaculatory function, we investigated effects of hypertension on α1‐adrenoceptors in the rat seminal vesicle and vas deferens. Spontaneous seminal emission was studied in male spontaneously hypertensive rats (SHRs) and normotensive Wistar‐Kyoto (WKY) rats. The characteristics of α1‐adrenoceptor in the seminal vesicle and vas deferens of the two strains were determined using an isolated muscle bath, radioligand receptor binding and real‐time RT‐PCR techniques. Although SHRs had significantly higher serum testosterone than WKY rats, the daily mean number of ejaculatory plugs emitted and their dry weight in SHRs were significantly lower than those in WKY rats. The maximum contractile responses to phenylephrine, total α1‐adrenoceptor density and expression of α1A‐adrenoceptor mRNA were significantly higher in the seminal vesicle and epididymal portion of vas deferens of SHRs vs WKY rats. Our data demonstrate the presence of hypertension related alterations in serum testosterone and in α1‐adrenergic responsiveness of the rat seminal vesicle and vas deferens and suggest that ejaculatory function in SHRs does not mirror these hypertension related alterations. Supported by KAKENHI 21791511, Grant‐in‐Aid for Young Scientists (B) provided by the Ministry of Education, Culture, Sports, Science and Technology of Japan.
Lifestyles of Physicians and Scientists: Balancing Careers and Family
Authors: Lorenz Robin G
Published: June 2021

This presentation will discuss the specific hurdles faced by physicians and scientists after finishing their MD, PhD or MD/PhD degrees. Included will be a discussion of lifestyle choices, establishing a lab or a practice, and balancing family with work.
Oxoguanine glycosylase 1 (OGG1) protects cells from DNA double‐strand break damage following methylmercury (MeHg) exposure
Authors: Ondovcik Stephanie Lee , Tamblyn Laura , McPherson John Peter , Wells Peter G
Published: June 2021

MeHg is a potent neurotoxin, teratogen and probable carcinogen, but the underlying mechanisms remain unclear. Although MeHg causes several types of DNA damage, the toxicological consequences of this macromolecular damage are unknown. MeHg also enhances oxidative stress, which can cause various oxidative DNA lesions that are primarily repaired by OGG1. Thus, we investigated the potential protective role of OGG1 in MeHg‐induced DNA damage using OGG1‐deficient (Ogg1−/−) murine embryonic fibroblasts (MEFs) with impaired capacity to repair oxidatively damaged DNA. The response of wild‐type (WT) and Ogg1−/− MEFs to low micromolar concentrations of MeHg was compared by measuring clonogenic efficiency, cell cycle arrest and generation of DNA double‐strand breaks. Ogg1−/− cells exhibited greater sensitivity to MeHg than WT controls as measured by the clonogenic assay. Both WT and Ogg1−/− cells underwent cell cycle arrest when exposed to MeHg; however, double‐strand break induction was exacerbated in Ogg1−/− cells compared to WT controls. Thus, impaired DNA repair capacity enhances cellular sensitivity to MeHg, indicating that the genotoxic properties of MeHg may contribute to its neurotoxic effects, and that an individual's response to DNA damage may be a determinant of risk. Support: CIHR doctoral scholarship (SLO); Cancer Research Society & Province of Ontario Early Researcher Award (JPM); CIHR (PGW).
Vascular Signaling Pathways for Bisphenol A
Authors: Omorebokhae Joanne Izevbua , Munyu Sarah , Oyekan Adebayo O , Yakubu Momoh A
Published: June 2021

Bisphenol A (BPA has been implicated in varied toxic effects but with limited understanding of the mode of actions leading to cellular and vascular dysfunction. Using the whole rat and cerebral micovascular endothelial cells (EC), we investigated the possible signaling pathways for BPA. The effects of BPA (160 mg/kg in feed8 weeks) were determined on blood glucose, tissue perfusion, plasma, and urine NO and bilirubin. Signaling pathways for BPA was determined in EC derived from piglet's brain. Confluent cells received BPA (10−8 − 10−4M) in the presence or absence of calphostin C (10−5M), tyrphostin (10−5M), Apocynin (10−4M); NO and ET‐1 levels were determined in the media and cells analyzed for protein expression. In the animal studies, BPA elevated blood glucose from 81 ± 6 to 92 ± 4 mg/dL, urinary bilirubin from 599±30 to 1047±154 μM/mL as well as urinary excretion of NO. Tissue eNOS, pphox22 and NF‐kB protein expression were elevated in BPA‐treated rats. In EC, BPA increased NO levels none dose‐dependently which was enhanced by pretreatment with tyrphostin but not with apocynin at 12 hrs but longer BPA (24 hrs) in the presence of apocyinin increased NO level. BPA increased ET‐1 production as well as eNOS protein expression. These results inconclusively indicate that BPA could adversely affect diverse vascular signaling pathways possibly involving eNOS, ROS, protein tyrosine kinase and NF‐kB in EC. The effects of these changes on adverse vascular functions are yet to be fully linked and would require a longer treatment time.
Enhanced Nitric Oxide Synthase‐Nitric Oxide (NOS‐NO) signaling underlies sildenafil amelioration of cyclosporine‐induced nephrotoxicity in rats
Authors: El-Moselhy Mohamed Ahmed Mohamed , Morsy Mohamed Ali , Abdel-latif Rania Galal , Khalifa Mohamed Montaser
Published: June 2021

Studies have demonstrated that the potent immunosuppressive effect of cyclosporine A (CsA) is associated with severe nephrotoxicity. However, the mechanism(s) of CsA‐mediated nephrotoxicity are understudied. This study aimed to investigate the possible protective effect of sildenafil on CsA‐induced nephrotoxicity and whether this effect is mediated via enhanced NOS‐NO signaling. Wistar rats were administered sildenafil (5 mg/kg, p.o) for 21 days alone or in combination with CsA 20 mg/kg, s.c. or with the non‐selective NOS inhibitor L‐NAME; 10 mg/kg, i.p. or both. Control groups were treated with either vehicle, CsA or L‐NAME. Renal functions (serum urea and creatinine, creatinine clearance and albumin‐creatinine ratio), indices of antioxidant activities (catalase, reduced glutathione and malondialdehyde), total nitrate/nitrite (NOx) were measured. Apoptotic and inflammatory markers (caspase‐3 and TNF‐alpha) were measured by. CsA administration for 21 days resulted in significant renal oxidative stress, deterioration of renal functions, reduction of NOx levels, marked apoptotic effect and elevation of nephritic TNF‐alpha expression. Concomitant treatment with sildenafil significantly improved CsA‐renal dysfunction, elevated NOx levels and reduced nephritic oxidative stress. Furthermore, sildenafil attenuated CsA‐evoked apoptosis and TNF‐alpha expression. Interestingly, L‐NAME reversed sildenafil protective effects against CsA‐mediated nephrotoxicity. Taken together, the current study highlights the clinically significant sildenafil protective effects against CsA‐induced nephrotoxicity that might be mediated via enhanced NOS‐NO signaling.
Endothelium targeted anti‐complement therapy protects renal allografts by modulating T cell response
Authors: Maldonado Claudio , Pushpakumar Sathnur , Soni Chirag V. , Perez-Abadia Gustavo
Published: June 2021

Complement activation and its components are pathogenic mediators of reperfusion injury and cell‐mediated organ rejection. Complement‐mediated endothelial cell activation and T cell interactions lead to the production of bioactive substances that enhance cell‐mediated immune response. The objective was to determine whether an endothelium‐targeted anti‐complement therapy would reduce the acute rejection response in allografts. We hypothesized that bolstering complement defenses on the endothelial barrier prior to transplantation reduces: inflammation, immune cell infiltration, and the severity of acute rejection. Fisher to Lewis kidney transplants were performed with a warm ischemia of 60 min. Allograft endothelium was decorated with an anti‐complement protein, vaccinia virus complement control protein (VCP), using a liposome‐based delivery system placed in an organ preservation solution. Animals were followed for 12 days. Assessment included renal function, histology and flow cytometry to quantify lymphocyte and T cell populations in allografts. Allografts decorated with VCP had reduced: renal dysfunction, antigen presenting cells and activated T cells. We conclude that complement blockade at the allograft's endothelial barrier reduces infiltration of immune cells during acute rejection and improves allograft outcome. Support provided by NIH grant 1R42HL079855 and EndoProtech, Inc.
Rutin Supplementation on Cholesterol Metabolism in Female Albino Wistar Rats Using High‐Cholesterol‐Diet Model: Possible Renal Protection
Authors: AL-REJAIE SALIM S. , Abuohashish Hatem M. , Alroujayee Abdulaziz S. , Aleisa Abdulaziz M. , Alkhamees Osama
Published: June 2021

This study was designed to investigate the effects of rutin (RT) and ascorbic acid (AA) combination on oxidative stress‐induced by high‐cholesterol‐diet (HCD) supplementation in the kidney of female Wistar albino rats. Feeding cholesterol increased serum total cholesterol (TC), triglycerides (TG), LDL and decreased HDL levels as compared to control diet. Treatments with RT, AA and their combination significantly decreased the TC, TG and LDL levels while increasing HDL levels. Nucleic acids (DNA and RNA), total protein and GSH concentrations were significantly decreased while TC, TG and TBARs levels were increased in kidney tissues of hypercholesterolaemic diet‐fed rats. The supplementation of RT and AA combination brought back the changes‐induced by the HCD to normal level. However, the correction of changes in all parameters showed more significant in RT and AA combined therapy than the individual treatments. These results suggest that the supplementation of RT (vitamin‐P) and AA (vitamin‐C) promoted the excretion of fecal sterols, thereby leading to a decreased absorption of dietary cholesterol as well as lower plasma and tissues cholesterol.
Influence Of Chronic Nicotine On Acetylcholine‐Evoked Renal Vasodilations In Female Rats: Dose Dependency And Ovarian Hormonal Modulation
Authors: El-Mas Mahmoud M , El-gowilly Sahar M , Gohar Eman Y , El-Gowelli Hanan M
Published: June 2021

In this study we report on the interaction of chronic nicotine with cholinergically‐mediated renal vasodilations in female rats and its modulation by ovarian hormones. Dose‐vasodilatory response curves to cumulative bolus doses of acetylcholine (ACh, 0.01–2.43 nmol) were established in phenylephrine‐preconstricted isolated perfused kidneys obtained from sham‐operated (SO) rats treated with or without nicotine (0.5–4.0 mg/kg/day for 2 weeks). The interaction was also evaluated in OVX rats in the absence or presence of progesterone (P), estrogen (E2), or their combination. The vasodilatory effects of ACh were potentiated in a dose‐dependent fashion by the low‐dose range of nicotine (0.5 and 1 mg/kg/day). By contrast, higher nicotine doses (2 and 4 mg/kg/day) failed to alter Ach responses. The co‐existence of both gonadal hormones, P and E2, seems imperative for the display of the potentiating effect of nicotine on ACh vasodilations because: (i) the increase in ACh responses by nicotine was lost in OVX kidneys, and (ii) combined supplementation with P and E2, but not individual treatments, restored the nicotine‐evoked potentiation of ACh vasodilation. Together, the data suggests that nicotine elicits dose‐ and gonadal hormonal‐dependent facilitation of ACh renal vasodilations in female rats.

This project was supported financially by the Science and Technology Development Fund (STDF), Egypt, Grant No. 502.
Dronedarone effects on atrial and ventricular electrophysiology in conscious dogs
Authors: Neves Liomar A. A. , Buening James , Huang Jinbao , Senese Peter B. , Gralinski Michael R.
Published: June 2021

Atrial and ventricular electrophysiological assessments in conscious dogs are relevant models to interrogate the selectivity of potential antiarrhythmic drugs. We investigate the selective effects of dronedarone (DRO) on atrial and ventricular effective refractoriness using a conscious dog model. Male beagle dogs (n=5, 8–11Kg) were surgically instrumented with telemetry devices and two sets of bipolar electrodes placed on the right atrium and the right ventricular outflow tract to determine the atrial and ventricular effective refractory periods (AERP and VERP). One week after surgery, dogs received vehicle (β‐cyclodextrin/mannitol 0.033 mL/kg/min) and DRO (0.033, 0.067 and 0.167 mg/kg/min) every 30 minutes. Dose dependent prolongation of AERP, but not VERP, was observed with DRO administration. At 300 msec cycle length, AERP was significantly increased by 19%, 31% and 46% with 1, 2 and 5 mg/kg of DRO respectively, compared to vehicle. At 400 msec cycle length, a significant increase of 44% in AERP was observed only with 5mg/kg DRO as compared to vehicle. Arterial blood pressure, heart rate, P‐wave duration, and QTc interval values were unchanged throughout the experiment. Both vehicle and DRO (1, 2 and 5 mg/kg) had no significant effect on any of these cardiovascular parameters except P‐wave duration which was significantly increased by 5% with 5mg/kg DRO as compared to vehicle. In summary, dose‐dependent prolongations of AERP, but not VERP, were observed with DRO. This model possesses utility as a paradigm to determine the differential efficacy of test articles on atrial and ventricular refractoriness.
Inhibition of Small‐Conductance Ca2+‐activated K+ Channels Protects Against Ventricular Fibrillation (VF) In Rats With Acute Myocardial Infarction (AMI)
Authors: Gui Le , Qin Xiaotong , Pan Min , Cheng Zixi , Zhu Jianhua , Chen Qing-Hui
Published: June 2021

In vitro study has shown that up‐regulation of SK channels in the ventricular epicardial myocytes is responsible for the spontaneous VF in failing ventricle. The present study determined the role of SK channels in regulating VF in AMI rats. AMI was induced by coronary artery ligation and ventricular programmed stimulation was used to evaluate ventricular vulnerable period (VVP), VF threshold (VFT) and ventricular effective refractory period (VERP) in anesthetized rats. In AMI animals, VVP was prolonged and VERP was shortened (p<0.05, n=6). Pre‐treatment in the AMI group with the SK channel blocker UCL1684 significantly shortened VVP and prolonged VERP (p<0.05, n=6). No effects were observed in sham‐operated controls (n=9). Additionally, VT was reduced in the AMI group, and UCL1684 increased VFT in the AMI group (p<0.05, n=6), but, again, was without effect in sham‐operated controls (n=9). Finally, monophasic action potential duration (MAPD90) was examined using an electrode placed on the left ventricular epicardium. The data showed that MAPD90 was shortened in AMI group (p<0.05, n=7), and UCL1684 significantly prolonged the MAPD90 (p<0.05, n=5), but was without effect in sham‐operated controls (n=9). We conclude that activation of SK channels may underlie the mechanisms of VF. Inhibition of SK channels reduced shorting of MAPD90, which may be responsible for the inhibitory effect on VF in AMI rats. Support: NNSF‐30971223 (JHZ); AHA 10SDG2640130 (QHC).
Differences in ionic currents between myocardial and Purkinje cells of canine heart
Authors: Vassalle Mario , Bocchi Leonardo
Published: June 2021

Canine single ventricular muscle (VM) and Purkinje (P) cells were studied by means of whole cell patch clamp technique. In VM cells, slope conductance is greater and IK1 peak is less negative. In both P and VM cells, quick decay of step current with more negative depolarizing steps is blocked by Ba2+ and disappears at less negative potentials. In VM cells, sodium currents INa3 and INa1 have less negative threshold potential. In both types of cells, INa3 and INa1 activations occur at IK1 peak, but in VM cells INa1 is smaller. Slowly inactivating INa2 is present in P cells and absent in VM cells, although a small short tail may follow INa1 in some VM cells. IK1 peak is followed by early and late negative slope (NS) regions. In P cells, the early NS disappears with less negative holding potential (Vh). In VM cells, the late NS region is larger, peaks at positive potentials and persists with slow ramps or less negative Vh. The NS region increases in size with faster ramps. In Vm cells, the NS early component is blocked by Ba2+ and the late component by Ni2+. ICa is greater in VM cells and Ito in P cells. During repolarizing ramps, in VM cells the smaller outward current decreases less and in both M and P cells decreases more during faster ramps. A positive slope region is greater in VM cells and may be missing in some P cells. The many differences found are consistent with the different functions of P and VM cells in situ. Supported in part by NIH grant HL56092.
Longitudinal assessment of type I diabetes mellitus using conventional echocardiography and speckle‐tracking based strain imaging
Authors: Shepherd Danielle , Croston Tara L. , McLaughlin Sarah L. , Baseler Walter A. , Nichols Cody E. , Thapa Dharendra , Lewis Sara E. , Hollander John M
Published: June 2021

Cardiac complications, such as cardiomyopathy, are the leading cause of mortality among diabetic patients. Sensitive in vivo imaging is essential for assessment of cardiovascular function within small animal models. Echocardiographic speckle‐tracking based strain analysis has been suggested as a way to noninvasively evaluate cardiac performance in small animal models of acute pathological insult. The goal of this study was to provide a comparative longitudinal analysis of conventional echocardiographic and speckle‐tracking based strain imaging analyses in a small animal model of diabetes mellitus. Six week old male FVB mice were made diabetic through multiple low‐dose streptozotocin injections. M‐mode and B‐mode echocardiographic analyses revealed no differences in ejection fraction and fractional shortening in diabetic animals relative to control until approximately 5 weeks post diabetes onset (P<0.05). Diabetic mice showed changes in average time‐to‐peak analysis using speckle‐tracking 1 week post diabetes onset and radial strain alterations at 4 weeks post diabetes onset relative to control (P<0.05 for both). These findings indicate that assessment of myocardial strain may efficiently detect early contractile changes which may precede functional alterations observed with conventional M‐mode and B‐mode echocardiography. (Support: NIH DP2DK083095, NIH T32HL090610, AHA 10PRE3420006)
Protein quality control disruption by PKCbetaII in heart failure
Authors: Ferreira Julio C.B. , Mochly-Rosen Daria , Brum Patricia Chakur
Published: June 2021

Some genetic forms of human cardiomyopathy result from accumulation of damaged proteins. However, it is not known whether damaged proteins contribute to other forms of cardiomyopathies and heart failure (HF). We found that failing human hearts from two different etiologies displayed three fold increases in misfolded proteins, an ~50% decrease in proteasomal activity (the machinery that disposes of them) and an ~5 fold increase in levels and ~2.5 fold increased activity in cardiac protein kinase C betaII (PKCbetaII) relative to control hearts. Myocardial infarction‐induced and hypertension‐induced heart failure models in rats also exhibited a 50% reduction in cardiac proteasomal activity, an ~3 fold increase in damaged and misfolded proteins, as well as an ~3 fold increased PKCbetaII activity. PKCbetaII directly phosphorylated the proteasome and inhibited its activity, in vitro. Finally, we showed that sustained and selective PKCbetaII inhibition with betaIIV5‐3 (but not the selective inhibition of PKCbetaI, delta or epsilon) re‐established cardiac protein quality control and reversed HF in both models. Therefore, accumulation of abnormal proteins, disruption of protein quality control and increased activity of PKCbetaII appear to contribute to the pathophysiology of heart failure, suggesting that PKCbetaII inhibition may benefit patients with heart failure.
Development of a Fluorescent Molecular Rotor‐Based Approach for Concurrent Measurement of Blood Viscosity and Hemodynamics
Authors: Craig Michael P , Haidekker Mark , Hove Jay
Published: June 2021

Shear stress measurements are routinely calculated using local fluid velocity gradients and estimated static viscosity values. However, since blood viscosity is dependent on local hematocrit and is affected by non‐Newtonian shear‐thinning, a methodology allowing concurrent blood velocity and viscosity measurement should improve intracardiac shear mapping accuracy. Our objective was to develop such a methodology using viscosity‐sensitive fluorescent molecular rotors coupled to inert microspheres and validate the approach in a zebrafish model. Microinjection parameters have been optimized for effective delivery of rotors into the zebrafish vascular bed. Age‐dependent injection targets have been identified to facilitate reproducible bolus delivery. Finally, FCVJ reflect local hemodynamic profiles demonstrating a functionality consistent with their in vitro performance. Taken together, our data indicate that fluorescent molecular rotors provide the spatial and temporal resolution required for use in planar and volumetric digital defocusing particle image velocimetry (DDPIV) technology to facilitate real‐time 3‐dimensional in vivo shear mapping. (This work funded by AHA 10IRG4020025.)
Left ventricular longitudinal strain and strain rate are preload dependent
Authors: Gao Zhaohui , Drew Rachel C. , Momen Afsana , Ndukwu Ifesinachi , Muller Matthew D. , Mast Jessica , Blaha Cheryl , Leuenberger Urs A. , Sinoway Lawrence I.
Published: June 2021

2D‐speckle tracking echocardiography (STE) derived strain and strain rate measurements have been proposed as potential non‐invasive measures of myocardial deformation and function. However, the effects of left ventricular (LV) loading conditions on 2D‐STE derived LV longitudinal strain and strain rate have not been elucidated. The aim of this study was to determine whether acute preload reduction by Lower Body Negative Pressure (LBNP) would alter 2D‐STE derived LV longitudinal strain and strain rate. LBNP varied between 0, −10, −20, −30, −40 and −50 mmHg (3 min/level) as strain and strain rate were assessed in 12 healthy individuals (26±1 yrs, 6 females and 6 males). Systolic peak strain (%), systolic (S‐Sr), early and late diastolic strain rate (E‐Sr and A‐Sr) were measured from standard LV apical views at each LBNP level. Compared to baseline, LBNP caused significant decreases in LV end‐diastolic volume (P<0.05) and stroke volume (P<0.01) while heart rate increased (P<0.01). LV longitudinal strain and strain rate decreased at LBNP ≥ −40 mmHg. Our results indicate that 2D STE‐derived longitudinal strain and strain rate are sensitive to acute preload changes. Thus, the effects of preload should be considered when strain and strain rate are used as indices of systolic and diastolic function.

Supported by P01 HL096570 (LIS); UL1 RR033184 (LIS).
Small left heart syndrome and post‐coronary artery ligation outcomes in mice
Authors: Haskell Sarah , Peotta Veronica , Hermann Gregory , Reinking Benjamin , Roghair Robert
Published: June 2021

OBJECTIVE

Test the hypothesis that neonatal SSRI exposed mice will have worsened cardiac function and mortality following myocardial infarctions.

METHODS

C57BL/6 pups received saline (10 ml/kg IP) or sertraline (5 mg/kg IP) on postnatal days 1–14. At 5 months, pups were implanted with telemeters. Mice then underwent left coronary artery ligation and were monitored by telemetry until death or 4 weeks post‐ligation. Echocardiograms were obtained at baseline and weekly following infarctions. Infarct area was measured on immersion‐fixed left ventricular sections.

RESULTS

At baseline, sertraline exposed mice had increased heart rates, decreased left ventricular volumes, and decreased stroke volumes. Following coronary artery ligation, sertraline exposed mice had increased heart rates compared to control mice (control 470 ± 15 bpm, sertraline 516 ± 13 bpm, p<0.05). Post‐MI echocardiography showed decreased ejection fraction in control mice (baseline 60 ± 4%, post‐MI 41 ± 2%, p <0.01) but not SSRI exposed mice. There were no differences in mortality or infarct size between the groups.

CONCLUSIONS

We speculate SSRI‐induced cardiac growth restriction may provide partial protection from post‐MI dilated cardiomyopathy. With 10% of pregnancies affected by maternal depression, it is crucial to determine the long term adverse effects from early SSRI exposure.
High fructose intake induces cardiac diastolic dysfunction in rats
Authors: Araujo Iara Cristina , Mostarda Cristiano , de Souza Lima Polyana , Yamane Larissa Naomi , de Souza Marina Soares , Fonteles Manasses , Fiorino Patricia , Farah Vera
Published: June 2021

High fructose intake has metabolic impacts and induces cardiovascular alterations. The aim of this study was to evaluate morphometric and cardiac function induced by fructose intake in rats during 8 weeks. Weaned male Wistar rats with 21 days old (50–60g) were divided into 2 groups: Control (CG) and Fructose (FG, 10% in drinking water). Arterial pressure (AP) and heart rate (HR) were directly recorded using a data acquisition system (Windaq, 2KHz). Morphometric and cardiac function was evaluated under anesthesia (xilazin, 12mg/Kg and ketamin,80mg/Kg) by transthoracic echocardiography (Sequoia 512 machine, Acuson, Mountain View, CA). AP showed an increase of 17% in FG when compared to CG with no change in HR. There were no differences in systolic function and myocardial performance index between groups. However, a reduced normalized isovolumetric relaxation time and an increased E/A ratio were found in FG suggesting diastolic impairment of left ventricle. Taken together, these data suggest that high fructose intake found in western diet, increases blood pressure and determined left ventricular hypertrophy and diastolic dysfunction. These results provide support for the relationship between high fructose intake and the increased incidence of cardiovascular diseases observed in industrialized countries.

Supported by: FAPESP(2009/52556‐7) and PIBIC/Mackpesquisa
PAR‐1 induced AMPK‐p38 MAPK signaling axis mediates STIM1 phosphorylation to prevent calcium entry through TRPC channels in endothelial cells
Authors: Sundivakkam Premanand , Natarajan Viswanathan , Malik Asrar B , Tiruppathi Chinnaswamy
Published: June 2021

Objective

To investigate the possible role of Ca2+ entry through TRPC channels in the signaling mechanism of STIM1 phosphorylation and thereby preventing Ca2+ entry through TRPC channels.

Results

Here we show that knockdown of TRPC1 in human endothelial cells (hECs) or deletion of TRPC4 in mouse endothelial cells (mECs), abolished thrombin‐induced Ca2+ entry, AMP‐activated protein kinase (AMPK) activation, p38 mitogen‐activated protein kinase (p38 MAPK) activation, and STIM1 phosphorylation in ECs. Pharmacological inhibition of either AMPK or its downstream target p38 MAPK, prevented PAR‐1‐ mediated STIM1 phosphorylation at Serine residues in ECs. Pretreatment of ECs with AMPK activator AICAR, enhanced basal STIM1 phosphorylation and markedly reduced PAR‐1‐induced Ca2+ entry in ECs. Interestingly, infecting ECs with adenovirus encoding wild type‐p38 MAPK increased basal STIM1 phosphorylation and blocked PAR‐1‐induced Ca2+ entry and permeability response. In contrast, expression of dominant negative‐p38 MAPK in ECs augmented PAR‐1‐mediated Ca2+ entry and permeability response.

Conclusion

Our findings demonstrate that PAR‐1‐induced Ca2+ entry through TRPC channels activates AMPK and p38 MAPK signaling pathway to reverse the Ca2+ entry and permeability response in ECs.
Unitary TRPA1‐Mediated Ca2+ Influx Events in Primary Cerebral Artery Endothelial Cells
Authors: Sullivan Michelle N , Francis Michael , Taylor Mark S , Earley Scott
Published: June 2021

The sole member of the ankyrin subfamily of transient receptor potential channels, TRPA1, is a Ca2+ permeable, non‐selective cation channel involved in endothelium‐dependent cerebral artery vasodilation. Total Internal Reflection Fluorescence microscopy (TIRFM) was utilized to investigate the biophysical properties and regulation of TRPA1‐mediated Ca2+ influx in primary cerebral artery endothelial cells (EC). Rat basilar arteries were cut open and placed intima side down on Matrigel‐coated plates. EC were allowed to proliferate (≤14 days), loaded with Fluo 4‐AM, and imaged in situ using TIRFM. Localized, transient Ca2+ influx events (mean amplitude (F‐F0) of 0.17±0.02, duration of 0.21±0.03 s, and spatial spread of 2.09±0.29 μm2) were detected at a whole‐cell frequency of 0.04±0.02 Hz (n = 24) under basal conditions. Mean event frequency and duration greatly increased with addition of the TRPA1 agonist allyl isothiocyanate (AITC) (0.23±0.08 Hz, 1.64±0.10 s, n = 25). These increases were attenuated in the presence of the selective TRPA1 antagonist HC‐030031 (0.03±0.02 Hz, 0.65±0.16 s, n = 10 cells). Histogram analysis of AITC‐invoked event amplitudes indicates that these Ca2+ signals display quantal separation. Similar events were recorded from HEK 293 cells overexpressing TRPA1. Together, these data suggest that quantal, TRPA1‐mediated Ca2+ influx can be recorded from EC using TIRFM. RO1HL091905.
Novel Role of the ATP7A Copper‐transporting ATPase and Extracellular SOD in Endothelial Dysfunction in Type I Diabetes Mellitus
Authors: Varadarajan Sudhahar , Urao Norifumi , Oshikawa Jin , Llanos Roxana M , Mckinney Ronald D , Ushio-Fukai Masuko , Fukai Tohru
Published: June 2021

Oxidative stress and endothelial dysfunction contribute to diabetes mellitus (DM). Extracellular superoxide dismutase (ecSOD), a secretory copper enzyme, preserves endothelial function by modulating extracellular superoxide (O2•−) and its full activity requires Cu transporter ATP7A. The present study examines the role of ecSOD and ATP7A in endothelial dysfunction in type 1 DM with hypoinsulinemia. Here we show that specific activity of ecSOD, but not Cu/Zn SOD, is decreased, which is associated with increased O2•− production and decrease in ATP7A expression in aortas of streptozotocin induced DM mice. Exogenous copper partially rescued ecSOD activity in isolated DM aortas. Functionally, acetylcholine‐induced NO‐mediated vasorelaxation is impaired in mesenteric arteries of DM, which is rescued by SOD mimetic tempol or adenovirus mediated gene transfer of ecSOD. Mechanistically, insulin application increases activity of ecSOD in hypoinsulinemic DM aortas and also increases ATP7A protein expression in VSMC. Moreover, DM‐induced impaired endothelial function and ecSOD activity are rescued in ATP7A overexpressing transgenic mice. In summary, ATP7A plays an important role in protecting DM induced endothelial dysfunction by regulating ecSOD activity and vascular O2•−. Thus, ATP7A is a potential therapeutic target for oxidant stress‐dependent cardiovascular and metabolic diseases. (NIH and AHA).