bluuebunny/crossref_metadata_2025 huggingface dataset:
Fiber capillary regression and endothelial cell apoptosis in the soleus muscle of hindlimb unloaded rats: role of angiogenic regulators
Authors: Fujino Hidemi , Kondo Hiroyo , Murakami Shinichiro , Nagatomo Fumiko , Takeda Isao , Ishihara Akihiko , Roy Roland R
Published: June 2021

The aim of present study was to determine the changes in the 3‐D architecture of the intramuscular endothelial networks and the responses of angiogenic and its inhibitory factors in atrophied soleus muscles. The hindlimbs of male Wistar rats were unloaded for 2 weeks by tail suspension. The endothelial network of soleus muscle was visualized by confocal microscopy. Apoptotic endothelial cells were identified by DNA fragmentation (TUNEL) using immunofluorescent staining. The mRNA levels of angiogenic factors (VEGF, KDR, Flt‐1, Ang‐1, Ang‐2, Tie‐2, HIF‐1 alpha) and inhibitory factors (TSP‐1 and caspase‐3) were determined by TaqMan probe‐based real‐time PCR. Chronic unloading resulted in a decrease in the number of anastomoses and tortuosity, appearance of TUNEL‐positive endothelial cells, a decrease in angiogenic factor mRNA, an increase in the Ang‐2‐to‐Ang‐1 ratio, and an increase in angiogenic inhibitor mRNA. The data suggest vasculature destabilization with chronic unloading and indicate that both a decrease in angiogenic factors and increase in angiogenic inhibitory factors play a role in this process.

Supported by Grants‐in‐Aid for Science Research from the Japanese Ministry of Education, Culture, Sports, Science and Technology, no. 19300196.
DDAH‐2 & eNOS in Mesenteric Vascular Remodeling : Role of Fenugreek
Authors: Munjal Charu , Falcone Jeff c , Qipshidze Natia , Mishra Paras , Tyagi Suresh C
Published: June 2021

Although mesenteric vessels played a crucial role in vascular remodeling, the mechanism was unclear. A critical factor, for the development of hypertension was increase in resistance in splanchnic blood flow by endothelial dysfunction. Increased homocysteine (Hcy) levels known as hyperhomocysteinimia(HHcy), causing vascular dysfunction. DDAH degrades ADMA, an endogenous inhibitor of nitric oxide synthetas (eNOS). Matrix metalloprotease (MMP) caused an increase in collagen/elastin ratio. Fenugreek (FG) primarily used as antidiabetic, also reported to have restoration of endothelial function. We hypothesized Hcy decreased mesentery blood flow in part by imbalancing the MMP/TIMP axis and decreasing the eNOS/DDAH activity. The treatment with FG mitigated blood flow and hypertension. To test this hypothesis we used WT(b) WT+ FG (c) WT+High Meth diet (d)WT+ High Meth diet+ FG, i.p. injection. The protein expression of MMPs, TIMPs and redox proteins were measured by Western blot. MMP‐2, 9 activities was measured by zymography. Tissue sections were used for to study elastin/collagen ratio. The data suggested Hcy decreased blood flow and matrix disruption by decreasing DDAH‐2, eNOS expression, FG ameliorated it. Therefore we concluded that FG migrate, decreased mesentery blood flow, MMP/TIMP axis distruption, decreasing the eNOS/DDAH activity by Hcy.
Nox inhibition in isolated rat mesenteric arteries via plasmid electroporation
Authors: Gruionu Gabriel , Obukhov Alexander G. , Bills Randall G. , Bohlen Glenn , Unthank Joseph L. , Miller Steven J.
Published: June 2021

Collateral growth (CG) is impaired with age. Previously, we have demonstrated that antioxidants, including a NAD(P)H oxidase (Nox) inhibitor, can reverse age‐related impairment in both flow‐mediated nitric oxide (NO) production and CG. The goal of the present study was to determine the optimal conditions for electroporation‐mediated delivery of siRNA to suppress Nox expression in rat mesenteric arteries. A plasmid containing shRNA to the Nox subunit p22phox, along with GFP DNA, was delivered into the arterial wall via square wave electroporation. We have designed a 4mm wide electroporation chamber to allow for both isolated fragment and in vivo electroporation of a 10–15 mm long mesenteric vascular bundle with minimal vector volume and mesenteric tissue manipulation. The results show optimal electroporation conditions of isolated vessels at 125V (312.5V/cm) with 8 pulses of 10msec duration as shown by comparative GFP fluorescence at 48hrs post electroporation. Superoxide production was assessed by monitoring DHE staining of the vessel fragments. Future studies will be focused on optimizing in vivo electroporation conditions and determining the Nox isoforms responsible for the observed flow‐mediated impaired collateral response. Sponsored by NIH HL092012‐S1.
Vasoprotective effects of caloric restriction in aging
Authors: Csiszar Anna , Pinto John , Ballabh Praveen , Pearson Kevin , de Cabo Rafael , Ungvari Zoltan
Published: June 2021

Endothelial‐dysfunction, oxidative stress and inflammation are associated with vascular aging and promote the development of cardiovascular disease. To determine whether caloric restriction (CR) exerts vasoprotective effects in aging, aortas of ad libitum (AL) fed young and aged and CR‐aged F344 rats were compared. Aging in AL‐rats was associated with impaired acetylcholine‐induced relaxation, vascular oxidative stress and increased NF‐êB‐activity. Lifelong CR significantly improved endothelial function, attenuated vascular ROS production, inhibited NF‐kB activity and down‐regulated inflammatory genes. In coronary‐arterial endothelial cells (CAECs) cultured in the presence of AL‐serum TNFá elicited oxidative‐stress, NF‐kB‐activation and inflammatory gene expression. By contrast, treatment of CAECs with CR‐serum attenuated TNFá‐induced ROS generation and prevented NF‐kB‐activation and induction of inflammatory genes. siRNA‐knockdown of SIRT1 mitigated the anti‐oxidant and anti‐inflammatory effects of CR‐serum. CR exerts anti‐oxidant and anti‐inflammatory vascular effects, which are likely mediated by circulating factors, in part, via a SIRT1‐dependent pathway.
The potential for localized translation and induction of plasminogen activator inhibitor‐1 at the myoendothelial junction in response to TNF‐alpha
Authors: Heberlein Katherine , Han Jenny , Zorn Gerlinde , Kaun Christoph , Straub Adam C. , Best Angela K. , Sharma Poonam , Wojta Johann , Isakson Brant E.
Published: June 2021

The myoendothelial junction (MEJ) is a signaling microdomain that integrates endothelial cells (EC) and vascular smooth muscle cells (VSMC). We have demonstrated that plasminogen activator inhibitor‐1 (PAI‐1) is enriched at the MEJ and functions to regulate MEJ formation, which suggests the localization of PAI‐1 at the MEJ is deliberate. To determine if PAI‐1 expression at the MEJ is inducible, we applied the inflammatory cytokine TNF‐α to our in vitro MEJ model (VCCC) and using qRT‐PCR show increased PAI‐1 mRNA at the MEJ. Transmission electron microscopy of MEJs from three microvascular beds demonstrates a large quantity of ribosomes, suggesting mRNA may target to the MEJ for localized translation. We next used PAI‐1 specific ELISAs and show a 4‐fold increase in total PAI‐1 and active PAI‐1 at the MEJ as compared to EC or VSMC, implying the PAI‐1 mRNA at the MEJ is maintained in a stable condition to allow for rapid translation. To elucidate the mechanism of PAI‐1 mRNA stabilization, we determined the expression of PAI‐1 RNA binding protein, serine binding protein‐1 (SERBP1) using immunoblotting and confocal microscopy of VCCC fractions, finding it to be expressed at the MEJ. Based on these data, we conclude that during an inflammatory response increased PAI‐1 expression at the MEJ may be due to stabilization of PAI‐1 mRNA by SERBP1. Supported by NIH RO1 088554 and an AHA SDG.
Blood pressure response during recovery after moderate leg cycling exercise: the role of carotid baroreflex control
Authors: Yamada Masako , Endo Masako Y , Fukuba Yoshiyuki
Published: June 2021

This study was to determine the characteristics of the carotid baroreflex (CBR) control of central and peripheral hemodynamics during the post‐exercise hypotension (PEH) using the neck chamber (NC) technique. 16 healthy young male subjects (age: 27+/−1 yr) undertook 60‐min moderate cycle ergometer exercise, followed by 30‐min of supine rest. Subjects remained at supine rest for a further 60‐min. During pre‐ and post‐exercise, the CBR control of the central (HR) and peripheral (vascular conductance, VC in popliteal and brachial arteries as the previously active and inactive muscles, respectively) circulations was evaluated using 5‐s periods of neck suction and pressure (−60, −40, 0, or +40 Torr). Eight subjects (responder (RE) group) showed substantial PEH during recovery from exercise (ΔBP, ~ −5 Torr; p<0.05). The other subjects (non‐RE group) did not exhibit the PEH but showed a significant post‐exercise CBR argumentation in HR, BP and VC, especially in response to −40, not +40 Torr. However, in RE group, pre‐ and post‐exercise CBR function was unchanged during PEH. Consequently, the subjects without PEH exhibit an augmented CBR control to central and peripheral hemodynamics following exercise ‐ especially to a high fluctuation of BP to the operating point. In conclusion, CBR control is not changed during PEH, while some normotensive individuals do not show the PEH.

(Support: JSPS‐KAKENHI, 20700526, 21370111)
Dietary fat‐specific adaptations of mitochondrial function in skeletal muscle and liver of C57Bl/6J mouse
Authors: Ciapaite Jolita , van den Berg Sjoerd A.A. , Nicolay Klaas , van Dijk Ko Willems , Jeneson Jeroen A.L.
Published: June 2021

The aim of this study was to asses the effects of high‐fat diets with different fatty acid composition on the function of skeletal muscle and liver mitochondria. 12 week old male C57Bl/6J mice were fed either low‐fat diet (LFD, 10 kcal% fat from palm oil) or one of three high‐fat diets (HFD, 45 kcal% fat from either lard (L), palm oil (PO) or palm oil supplemented with tristearin (POS) ad libitum for 5 weeks (n=8 per diet group)). The content of stearate was similar in HFD(L) and HFD(POS) (15.0% and 13.9%, respectively). Mitochondrial function was assessed using high‐resolution respirometry. After 5 weeks of diet body weight was ~20% higher (p<0.001) in all three HFD‐fed groups compared to LFD‐fed controls. The trend of HFD effects was comparable in skeletal muscle and liver mitochondria. Maximal ADP‐stimulated (state 3) oxygen consumption rates were similar in all diet groups when pyruvate plus malate or glutamate plus malate were used as the oxidizible substrates. HFD(L) feeding had no effect on palmitoyl‐L‐carnitine and stearoyl‐L‐carnitine‐driven oxygen consumption rate in state 3, while HFD(PO) and HFD(POS) feeding led to a significantly higher oxygen consumption rates compared to controls. This observation suggests that fatty acid composition of the dietary fat is important determinant in the HFD feeding‐induced mitochondrial adaptations.

This work was financed by the Netherlands Consortium for Systems Biology.
An improved nongenetic mouse model for type 2 diabetes
Authors: Gilbert Elizabeth Ruth , Fu Zhuo , Liu Dongmin
Published: June 2021

The objective of this study was to generate an improved non‐genetic mouse model of type 2 diabetes (T2D). Ninety‐six 6 mo.‐old C57BL/6N males were assigned to 1 of 12 groups including 1) low‐fat diet (LFD; low‐fat control; LFC), 2) LFD with 1 i.p. 40 mg/kg BW steptozotocin (STZ)‐injection, 3), 4), 5), 6) LFD with 2, 3, 4 or 5 STZ‐injections on consecutive days, respectively, 7) high‐fat diet (HFD; high‐fat control; HFC), 8) HFD with 1 STZ‐injection, 9), 10), 11), 12) HFD with 2, 3, 4 or 5 STZ‐injections on consecutive days, respectively. At 4 wk post‐STZ injection, serum insulin levels were reduced (P<0.02) in HFD‐mice administered at least 2 STZ‐injections as compared with HFC, but levels were not different among respective LFD groups. Glucose tolerance in mice that consumed HFD and received 2, 3 or 4 injections of STZ was greatly impaired as compared with respective LFD groups (P < 0.05). Insulin sensitivity in HFD‐fed mice was reduced (P < 0.05) compared to LFD‐fed mice, regardless of STZ treatment. Islet mass was not affected by diet but was reduced by 50 % in mice that received 3 STZ‐injections. Thus, the combination of HFD and three 40 mg/kg STZ‐injections was suitable for inducing a diabetic mouse model with metabolic characteristics of T2D, including peripheral insulin resistance and reduced β‐cell mass and function.
Exogenous long chain C14 ceramide prevents insulin‐stimulated glucose uptake in C2C12 muscle cells independent of Akt signaling
Authors: Kelly Karen R. , Hwang Calvin , Kasumov Takhar , Huang Hazel , Kirwan John P.
Published: June 2021

Plasma ceramides have been linked to peripheral insulin resistance, however the cellular mechanism is unclear. We investigated whether incubation with the long chain C14 ceramide would reduce insulin‐stimulated glucose uptake in muscle cells and if so, whether it acts via insulin signaling through Akt. C2C12 muscle cells were exposed to either C6 or C14 ceramide (50 uM), or vehicle, for 1 hour. Glucose uptake was measured using 3H‐2‐deoxyglucose. Parallel studies using non‐labeled glucose were used to determine Akt (Ser473) phosphorylation via ELISA, and cellular content of ceramide via electrospray ionization tandem mass spectrometry after separation with high‐performance liquid chromatography. Insulin‐stimulated glucose uptake was significantly reduced following treatment with both C6 and C14 compared to untreated cells (P=0.001). Akt phosphorylation was reduced in C6 treated cells; but was unaffected by C14 treatment. Further, there was an increase in C6 content in the cells following treatment with C6; however there was no change in C14 content following C14 treatment, suggesting that this long chain ceramide is not transported into the cell. These preliminary data suggest that C14 ceramide down‐regulates insulin‐stimulated glucose uptake via a different molecular mechanism than C6 ceramide, possibly a second messenger system, and is independent of insulin signaling through Akt.
Laminar Shear Stress Up‐regulates Endothelial CD73 Expression by Activating Calmodulin‐dependent Kinase Kinase
Authors: Li Weidong , Ohta Masanori , Nandedkar Sandhya , Fan Fan , Jo Hanjoong , Miura Hiroto
Published: June 2021

Endothelial cell (EC) surface CD73, ecto‐5′ nucleotidase, extracellularly metabolizes AMP to adenosine, a potent anti‐inflammatory molecule. Since athero‐protective high laminar shear stress (LS) rises intracellular calcium levels and induces the release of adenine nucleotides in ECs, we hypothesized that LS increases CD73 expression by activating calmodulin‐dependent kinase kinase (CaMKK), leading to the extracellular production of adenosine in ECs.

Cultured human coronary artery ECs were subjected to static, LS (15 dyne/cm2), or oscillatory shear (OS; ± 5 dyne/cm2) condition for 24 hours. Real‐time PCR showed that LS increased CD73 mRNA expression (2.1±0.3‐fold increase vs. static condition, p<0.05, n=10–17), whereas OS unchanged the mRNA expression (0.9±0.2 fold, p=ns, n=6). STO‐609 (a CaMKK inhibitor, 10μg/ml) suppressed LS‐induced increase in CD73 mRNA expression (1.1±0.2 fold, n=5). In contrast, U‐73122 (a phospholipase C inhibitor, 1μM) and KN‐62 (a calcium/calmodulin‐dependent kinase inhibitor, 10 μM) had no inhibitory effect (2.7±0.5 fold, n=3 and 2.1±0.3, n=8). HPLC analysis revealed that LS resulted in the accumulation of adenosine in the conditioned medium.

These results indicate that LS elicits the generation of extracellular adenosine from ECs by upregulating CD73 expression via activating CaMKK. Thus, CD73 might contribute to the athero‐protective effects of LS in ECs.
Human arterial endothelial cells develop a mesenchymal phenotype with aging
Authors: Fleenor Bradley S , Marshall Kurt D , Rippe Catarina , Seals Douglas R
Published: June 2021

Large elastic arteries stiffen with aging and this leads to multiple cardiovascular pathologies. Arterial endothelial cells are thought to contribute to this process possibly via age‐associated reductions in nitric oxide production and consequent increases in smooth muscle cell (SMC) tone. Here we test the novel hypothesis that these cells also may contribute by changing to a mesenchymal phenotype featuring development of fibroblast/SMC‐like migratory and secretory (synthetic) properties. Human aortic endothelial cells were studied at early (27.0 ± 0.54, mean±SE), intermediate (37.0 ± 0.59) and late (45.0 ± 1.18) population doublings (PDLs), representing “young” (Y), “middle‐aged” (MA) and “old” (O) cells, respectively. Smooth muscle alpha actin (SMαA) protein expression (western blots) was greater in MA and O cells compared with Y (MA: 1.30 ± 0.05, O: 1.28 ± 0.05 vs. Y: 1.00 ± 0.05 AU; P < 0.05). Moreover, mean expression of type I collagen increased progressively with aging (Y: 1.00 ± 0.31 vs. MA: 1.40 ± 0.30 vs. O: 2.70 ± 0.43 AU; Y vs. O and MA vs. O, P < 0.05). These preliminary data are consistent with the hypothesis that replicative aging induces a vascular endothelial to mesenchymal cell transition resulting in development of a synthetic, migratory phenotype that may contribute to intimal thickening and increases in stiffness of large elastic arteries.

NIH AG013038 and HL007822, Swedish Research Council
Acute shear stress does not increase phosphorylation of eNOS at S1179 in mouse mesenteric arteries
Authors: Todd Sarah E. , Looft‐Wilson Robin C.
Published: June 2021

Shear stress provokes vasodilation through activation of eNOS, which produces the vasodilator NO·, and is necessary for healthy endothelial function. In cultured endothelial cells, this activation involves increased phosphorylation of eNOS at S1179, and we hypothesized a similar response in intact arteries during shear stress‐induced dilation. Small mesenteric arteries from male mice (7–13 wks old) were cannulated, pressurized (75 mmHg), and one of four treatments was applied: no treatment, phenylephrine (PE, 10−5 M), PE followed by acetylcholine (ACh, 10−4 M), or PE followed by high luminal flow (60 μl/min, 15 min); then flash frozen for immunoblotting (4 arteries/group/blot, 2 separate blots). Arteries dilated 65% and 32% in response to ACh and flow, respectively (determined by video microscopy). 45% of the dilation to flow at 60 μl/min is due to NO·, as indicated in separate experiments +/− L‐NAME (n=4/group). eNOS phosphorylation at S1179/total eNOS was 3.85‐fold greater in the ACh group (vs. no treatment), but the high flow group was no greater than the PE group (2.4‐fold and 2.47‐fold, respectively, vs. no treatment), despite robust dilation with flow. These data indicate that PE alone induces phosphorylation of eNOS at S1179 (perhaps through myoendothelial gap junction communication), and increased phosphorylation at this site is not required for shear stress‐induced dilation. APS‐UGSRF and NHLBI‐R15
The Endothelial Glycocalyx In Vitro: Its Structure and The Role of Heparan Sulfate and Glypican‐1 in eNOS Activation by Flow
Authors: Ebong Eno Essien , Spray David C , Tarbell John M
Published: June 2021

The endothelial glycocalyx (GCX) mediates flow‐induced nitric oxide release via heparan sulfate (HS), but the GCX structure is unclear and the specific HS core protein(s) involved in this mechanotransduction is unknown. Our study tests the hypotheses that flow regulates GCX thickness and organization and that the HS glypican‐1 core protein mediates flow‐induced activation of endothelial nitric oxide synthase (eNOS). Monolayers of bovine aortic and rat fat pad endothelial cells with intact GCX, enzymatically degraded HS, or RNA‐silenced glypican‐1 were exposed to 15 dyne/cm2 uniform shear stress for 3 hr. Confocal immunocytochemistry and cryo‐transmission electron microscopy revealed a GCX that was 2.5 to 4.0 μm thick. Sheared GCX was well organized and aligned perpendicular to the cell surface, while unsheared GCX was disorganized. Western blot and confocal microscopy demonstrate that when the GCX is intact shear stress increases eNOS activation (ser1177 phosphorylation) and membrane localization, which are blocked by HS degradation. Baseline and flow‐induced levels of activated eNOS are attenuated when glypican‐1 is silenced. This work further elucidates GCX structure and role in endothelial cell mechanotransduction. Supported by NIH: 5T32HL007675, HL73732, HL57093.
Flow responses of human blood outgrowth endothelial cells adhered to bioartificial tissue
Authors: Tranquillo Robert T , Ahmann Katherine A
Published: June 2021

Blood outgrowth endothelial cells (BOECs) are isolated by outgrowth of circulating progenitor cells from a patient blood sample and thus could provide a source of autologous endothelial cells for tissue‐engineered vascular grafts. To examine the suitability of these cells for use in vascular tissue engineering, late outgrowth endothelial cells isolated from human peripheral blood were seeded on tissue constructs formed from fibrin remodeled by entrapped neonatal human dermal fibroblasts (NHDFs). BOECs adhered to this surface and remained adherent when exposed to laminar shear flow of cell culture medium, at shear stresses of 15 dynes/cm2.

We have examined shear stress effects on human BOEC activation state, by comparing VCAM‐1, ICAM‐1, and Thrombomodulin (TM) expression after activation with TNF‐α. These markers were chosen due to their reported response to changes in shear stress, as well as their implication in endothelial cell activation. BOECs seeded on collagen‐coated slides and tissue constructs were statically cultured or exposed to 5–15 dynes/cm2 shear stress for 24 hours. Expression of the activation markers was altered compared to static controls, while the cell densities did not vary significantly. TM expression was elevated by shear stress, while VCAM‐1 and ICAM‐1 showed decreased expression. These results illustrate the potential utility for BOECs in vascular tissue engineering, as not only do the cells adhere to fibrin‐based tissue constructs and remain adherent under physiological shear stress, they are also responsive to shear stress signaling. Funding from NIH R01 HL083880 (to RTT).
Effects of Panax notoginseng and aerobic exercise on acute glycemia in non‐diabetic men
Authors: Lau W.Y. Jamie , Liang Michael T.C. , Sokmen Bulent , Spalding Thomas W , Chuang William J
Published: June 2021

The purpose of this study was to determine whether an acute 3g‐dose of Panax Notoginseng (PNG) taken for 5 days and one 30‐min bout of exercise could have an effect on acute postprandial hyperglycemia with a 75‐mg oral glucose tolerance test (OGTT) in non‐diabetic adults, age 20–45 years. We assigned 53 men to: 1) ginseng (G) plus exercise (G+Ex, n=14), 2) ginseng (G, n=13), 3) placebo (C) plus exercise (C+Ex, n=12) and 4) placebo groups (C, n=13). The G and C groups took a daily 3g dose of PNG and cornstarch‐placebo supplement for 5 days, respectively. The G+Ex and C+Ex also performed 30 min of cycling exercise prior to the OGTT. Outcome measurements include: plasma glucose AUC from 0–90 min (PG‐AUC0‐90), plasma glucose (PG) and insulin (PI) concentrations at 0, 30, 60 and 90 min post‐OGTT. In the G group, PNG lowers (p<0.05) acute postprandial blood glucose level at 30 min post‐OGTT (G vs. C, 107±7.8 vs. 133±7.8 mg/dl) and PG‐AUC0‐90 (G vs. C, 72±22 vs. 169±33 mg/dl) compared with the C but not G+Ex and C+Ex. No significant differences were observed between the groups for PI at 0, 30, 60 and 90 min post‐OGTT. Conclusion. An acute 3g‐dose of PNG taken for 5 days, not a 30‐min bout of cycling exercise, lowers acute postprandial glycemia and PG‐AUC0‐90 with OGTT in non‐diabetic men.
Inaccuracies introduced by single width blood pressure cuffs
Authors: Andrews Jeffrey , DeWitt Blake , Czerwien Terry , Bijelic Miro , Latman Neal S.
Published: June 2021

Blood pressure (BP) cuff dimensions directly affects accuracy of BP measurements. For accurate BP measurements the width of the cuff must be proportional to arm circumference. A cuff that is too narrow results in falsely high BP values, and a cuff that is too wide results in falsely low values. Some BP standards permit a single cuff regardless of arm circumference.

The purpose of this study was to evaluate whether 12 cm single width cuffs currently permitted by the British Hypertension Society (BHS) standard are sufficiently accurate.

Each of 101 subjects was tested sequentially with both a single and a proportional width cuff in random order. Auscultatory BP was determined by 2 observers using a double binaural stethoscope.

The single width cuff BP failed the Association for the Advancement of Medical Instrumentation and BHS standards for clinically acceptable accuracy. The magnitude of failures ranged from a mean of 6.6 to 11.3 mmHg.

In conclusion, this could result in a significant number of people being misdiagnosed and mistreated for hypertension. Therefore, to avoid “cuff hypertension” and “cuff hypotension”, the cuff width should be proportional to arm circumference.
The Effect of 28 days Administration of Betaine on Blood Pressure and Arteriolar Contractility in Normal and Spontaneously Hypertensive Rats.
Authors: Al‐Husseini Isehaq Saif , Albarwani Sulayma , Ali Baderldin H , Tanira Musbah O
Published: June 2021

Homocysteine, a possible risk factor of cardiovascular disease, may play a role in the pathogenesis of essential hypertension. Betaine serves as a methyl donor in a reaction converting homocysteine to methaionine. Previous studies showed, equivocally, that betaine could reduce blood pressure (bp) and blood homocysteine level. The aim of this study was to examine the effect of administering betaine on normal and spontaneously‐hypertensive rats (SHR) bp and aretiolar contractility. Male SHR and WKY rats weighing 180–230 g were used. They were divided into 7 groups and treated (i.p.) for 28 days as follows: control (normal saline) or betaine (0.4, 2, 10, 50, 100, 250mg/kg/day). Non invasive blood pressure measurement was taken weekly and small mesenteric arteries were used for the isometric study in which KCl, acetylcholine 5HT and phenylephrine were used as reference drugs. Betaine did not show any significant changes on bp or on the isometric studies. It may be concluded that under our experimental condition, betaine had no significant beneficial effect on tested parameters.
Na+/H+ Exchanger NHE3 is differentially regulated in renal proximal tubules of pre‐hypertensive and hypertensive spontaneously hypertensive rats
Authors: Crajoinas Renato Oliveira , Lessa Lucilia Maria , Carraro‐Lacroix Luciene Regina , Malnic Gerhard , Girardi Adriana Castello Costa
Published: June 2021

The present work aimed to measure NHE3 in vivo transport activity and to define the mechanisms underlying NHE3 regulation in young pre‐hypertensive (5‐week‐old, systolic blood pressure (SBP) = 92 ± 2 mmHg) and adult hypertensive spontaneously hypertensive rats (SHR) (14‐week‐old, SBP = 187 ± 4 mmHg). NHE3 function was measured as the rate of bicarbonate reabsorption by means of in vivo microperfusion. NHE3‐mediated bicarbonate reabsorption was stimulated in 5‐week‐old SHR (44 ± 5%, P<0.01) and reduced in 14‐week‐old SHR (57 ± 4%, P<0.001) compared to Wistar Kyoto (WKY) rats at corresponding age. Stimulated NHE3 transport activity in young pre‐hypertensive SHR was associated with enhanced NHE3 microvillus expression, lower levels of phosphorylation at Ser552 and increased association with the enzyme dipeptidyl peptidase IV (DPPIV). Conversely, adult hypertensive SHR showed decreased NHE3 microvillus membrane content, higher relative ratio of phosphorylated Ser552, and lower amount of the NHE3‐DPPIV complex. No differences on renal cortical NHE3 protein content and mRNA levels were found between SHR and its WKY counterpart. We conclude that NHE3 is differentially regulated before and after development of hypertension in SHR by mechanisms that involve post‐translational modifications, subcellular redistribution and assembly with interacting proteins. Supported by FAPESP and CNPq
Hyperactivity and Associated Memory Deficit in Hyper‐ and Hypo‐tensive Mice
Authors: Stewart John Michael , Kamper Joel , Hartman Richard E , Goyal Ravi , Longo Lawrence D
Published: June 2021

Objective

The development of hypertension can lead to a vast array of physiological and behavioral complications. In mice, we tested the hypothesis that hyper‐ and hypo‐tension is associated with significant alterations in anxiety, activity, motor coordination, and spatial learning.

Methods

To test activity levels we used the open field test, anxiety levels using the standard elevated zero maze, motor coordination using a standard Rotarod testing setup, and spatial learning with the Morris water maze.

Results

We found hypertensive mice had significantly increased activity levels compared to controls. Females showed statistically more evidence of anxiety than males on the elevated zero maze; however, there was no significant difference between blood pressure groups. When tested on the rotarod, hypotensive mice fell off much quicker than the other groups. In the water maze, both hypo‐ and hypertensive mice had deficits in spatial learning/memory performance, with hypotensive mice performing the worst.

Conclusions

Spatial learning ability was significantly reduced with changes in blood pressure, especially with hypotension. Hypertension was associated with hyperactivity. We speculate that alterations in cerebral hemodynamics may be an underlying cause.
High dietary fat promotes a normal metabolic phenotype in the infarcted rat heart
Authors: Berthiaume Jessica Marie , Chen Xiaoqin , McElfresh Tracy A , Chandler Margaret P
Published: June 2021

Lipid accumulation is suspected to induce & exacerbate cardiac dysfunction. However, work in our lab has shown high dietary fat (SAT) subsequent to myocardial infarction results in less dysfunction as compared to a standard diet despite increased tissue lipids. This is accompanied by improved mitochondrial function suggesting SAT protection involves energy metabolism. This study sought to evaluate whether SAT alters the energy substrate utilization profile after cardiac infarction. Coronary ligated (HF) or sham (SH) rats were fed SAT or normal chow (NC) for 8 weeks. Working heart perfusions were performed to evaluate function (output, heart rate, & oxygen uptake) & metabolism (glucose & fatty acid oxidation) at low & high workloads. At low workload, cardiac output & oxygen uptake were decreased & glucose oxidation was increased in HF‐NC, but not in HF‐SAT. High workload data suggest a similar trend, but the protective effects were diminished. Lower oxygen use & increased glucose reliance implies a switch from fatty acids in the HF‐NC hearts, a hallmark of heart failure. However, the lack of these differences in the HF‐SAT at low workload suggests SAT does indeed modulate energy metabolism of the infarcted heart. This work supports the hypothesis that high dietary fat after infarction promotes a normal metabolic phenotype & is part of the mechanism by which high fat is protective of cardiac function.
Low carbohydrate diet modifies cardiac oxidative metabolism under normoxia and ischemia/reperfusion conditions
Authors: Wang Peipei , Douglas Sam , Lloyd Steven
Published: June 2021

The effects of Low carbohydrate diets (LCD) on the heart have not been well investigated. We showed that LCD increases ischemic myocardial injury. Here we investigated the effect of LCD on cardiac metabolism, a contributor to cardiac function, during normoxia (NOR) and ischemia/reperfusion (I/R) in the isolated rat heart. Adult rats were fed LCD (60% kcal fat/30% protein/10% CHO) or control diet (CONT; 16%/19%/65%) for 2 weeks. Hearts were isolated and subject to NOR or I/R (60 min global low flow ischemia, 0.3ml/min, followed by 60 min reperfusion) with insulin (15 or 30 ƒÝU/ml) and 3‐hydroxybutyrate (3‐HB, 0.6 or 1.2 mM; N=18 to 19 at each level). After perfusion with 13C‐labeled substrates, TCA cycle entry was measured by 13C‐NMR. Analysis was conducted using a general linear model examining effect of diet, perfusion condition (NOR or I/R), and perfusion buffer (with 4 levels of insulin and 3‐HB). The model demonstrated a strong effect of diet (P<0.01) and perfusion condition (P<0.001) on substrate oxidation, with palmitate oxidation higher with LCD and I/R. There was no effect of perfusion buffer within the ranges studied. Functional recovery in I/R was lower in LCD (P < 0.05), consistent with earlier findings. These results suggest that the LCD‐induced increase of myocardial injury following ischemia‐reperfusion described in previous reports might be due to alteration of cardiac metabolism.
Chronic ingestion of a western diet alters O‐linked‐β‐N‐acetylglucosamine (O‐GlcNAc) protein modification in the heart
Authors: Medford Heidi M , Chatham John C , Marsh Susan A
Published: June 2021

We recently demonstrated that myocardial fibrosis was increased in young rats fed a diet high in saturated fat and simple carbohydrate (“western” diet, WD) for 2 weeks, which was sustained at 14 weeks. To determine the chronic effects of such a diet, we fed male Sprague‐Dawley rats either control diet (n=9) or WD (n=10) for 12 months. Blood chemistry analyses exhibited numerous abnormalities in the WD group, indicative of liver, kidney, and metabolic dysfunction. Surprisingly, left ventricular function was not different between diets. In myocardial tissue, there were no differences between diets in fibronectin, endoplasmic reticulum stress (GRP78, phosphorylated IRE1), or advanced glycation end‐products. Increased levels of O‐linked‐β‐N‐acetylglucosamine (O‐GlcNAc) on serine and threonine residues has been linked to metabolic disease, and is elevated in the heart in response to diabetes. We found that O‐GlcNAc levels increased in some but not all protein bands in the WD group; at least one protein band exhibited decreased intensity with WD. These data suggest that aging attenuates the differences in fibrosis observed between diets in younger animals, but that chronic ingestion of a WD alters the pattern of O‐GlcNAc protein modification in the heart in the absence of overt cellular stress.
Mitochondrial Overexpression of Phospholipid Hydroperoxide Glutathione Peroxidase 4 (mPHGPx) Provides Cardioprotection From Type 1 Diabetes Mellitus Insult
Authors: Dabkowski Erinne R , Baseler Walt A , Croston Tara L , Williamson Courtney L , Hollander John M
Published: June 2021

Evidence suggests that the inner mitochondria membrane (IMM) is a target for the deleterious effects of type 1 diabetes mellitus (DM). Maintenance of IMM integrity represents a specific locus for testing directed prophylactic intervention. We previously reported that type 1 DM imparts differential effects on spatially distinct mitochondrial subpopulations, subsarcolemmal (SSM) and interfibrillar (IFM). The goal of this study was to determine whether overexpression of a mitochondrially‐targeted antioxidant enzyme, mPHGPx, could elicit protection to mitochondria during type 1 DM. MPHGPx transgenic mice and littermate controls were made diabetic through low dose injections of streptozotocin. Five weeks post hyperglycemia onset, ejection fraction and fractional shortening were decreased in the diabetic heart (*P<0.05), and were reversed with mPHGPx overexpression (*P<0.05). MPHGPx overexpression in the diabetic heart was associated with increased electron transport chain complex activities in IFM as compared to diabetic controls (*P<0.05), with no differences on SSM. Hydrogen peroxide and lipid peroxidation were attenuated in the mPHGPx diabetic IFM as compared to diabetic controls (*P<0.05), with no changes in the SSM. These results indicate that mPHGPx overexpression provides cardioprotection to the diabetic heart, which is associated with mitochondrial subpopulation‐specific protection.
Risk factors for dvt of the lower extremities
Authors: Leci‐Tahiri Laura O , Bajraktari Sadri , Tahiri Afrim
Published: June 2021

Background

DVT and her two complications, pulmonary emboli and post‐thrombotic syndrome are the main cause of intrahospital mortality and chronic morbidity. Studies says that there are around 100 to 160 new cases on 100 thousand habitans per year. For Kosova it means 2000 to 3000 new cases per year.

The aim

It is the aim of the paper to analyse the epidemiology of the DVT, etiology and risk factors among the patients hospitalized at the Vascular Surgery Department.

Results

During two years study period, september 2002‐september 2004, at the Vascular Surgery Department of the University Clinical Center of Kosova due to DVT of the lower extremities were 194 patients or 45.64%. There was no difference between sex. The mean age was 49.92 years. From 204 extremities, DVT was localized on 85 extremities to the right (41.67%) and 119 extremities to the left (58.33%). Risk factors were presented at 145 patients. Surgery was often presented as risk factor, at 25 patients (12.89%); post‐partal state at 13 patients (6.70%), pregnancy 10 patients (5.15%), malignancy 10 patients (5.15%). Mean age of patients with DVT and malignancy was 54.4 years.

Conclusion

DVT is disease that is very hard to diagnose. First step is always to determine risk factors. Second step is to determine rate of clinical probability for DVT.
A monoclonal antibody raised against nanoparticles isolated from human kidney stones detects structures in atherosclerotic plaques
Authors: Schwartz Maria K. , Lieske John C. , Miller Virginia M.
Published: June 2021

Calcifying nanoparticles (NPs) have been implicated in many diseases including kidney stones and vascular calcification. The chemical composition of these NPs is unknown and advances in understanding their contribution to disease etiology has been hampered by the lack of specific antibodies. Therefore, a monoclonal antibody (MoAb) was developed using decalcified NPs isolated from a human kidney stone as an antigen. After clone screening, a monoclonal antibody was produced that recognized an approximately 125kDa band in the kidney stone NP isolate. Immunoprecipitation of NP lysate followed by proteomics was used to further characterize the protein(s) recognized by the antibody. Consecutive tissue sections from a human atherosclerotic plaque were also stained with the MoAb, which recognized punctuate structures at the media/plaque border and around cholesterol clefts. The staining pattern was similar to that observed with a commercially available antibody in our previous studies. Therefore, we have developed a monoclonal antibody against human kidney stone‐derived NPs that recognizes structures in human atherosclerotic plaques. This MoAB has great potential for use in NP detection in other diverse human tissues and in experimental protocols. Supported by NIH HL88988 and Division of Experimental Surgery, Mayo Clinic.
Slingshot‐isoform specific regulation of cofilin activation during VSMC migration and neointima formation following vascular injury
Authors: Torres Rebecca A. , Drake Douglas A. , Solodushko Viktoryia , Jadhav Rashmi , Smith Erika S. , Rocic Petra , Weber David S.
Published: June 2021

Vascular smooth muscle cell (VSMC) migration is a vital component of neointima formation following vascular injury. Our findings demonstrate that cofilin is critical for VSMC migration. Cofilin activation (dephosphorylation) at Ser3 is regulated by the Slingshot (SSH) phosphatase family. Each of the three SSH isoforms (1, −2, −3) is expressed in both cultured VSMCs and carotid artery tissue. In vitro studies examining SSH isoform regulation of cofilin activation during migration revealed that only SSH1 regulates of PDGF‐induced VSMC migration. Thus, we hypothesized that SSH1‐dependent cofilin activation is a key mechanism regulating VSMC migration during neointima formation following vascular injury. To test this, rat carotid arteries were injured with a Fogarty 2F catheter. The degree of vascular injury was quantified 14 days post injury by comparing wall thickness, cross‐sectional wall area and media/intima ratio in H&E stained cross sections. Immunoblot analysis revealed that both cofilin and SSH1 expression were elevated at 4, 7 and 14 days post injury (vs. non‐injured). Moreover, IHC staining of injured arteries confirmed that localization of both cofilin and SSH1 expression was primarily in the neointima. Taken together, our studies suggest that SSH1‐dependent cofilin activation during VSMC migration potentially contributes to neointima formation following vascular injury in vivo. NIH HL084159
Progressive Coronary Artery Remodeling in Diabetic db/db Mice
Authors: Katz Paige Shattuck , Trask Aaron J. , Lucchesi Pamela A.
Published: June 2021

Type 2 diabetes is associated with vascular dysfunction and remodeling. The aim of this study was to determine the progression of coronary artery remodeling in Type 2 diabetes. Septal coronary arteries from 12, 16, and 20‐wk‐old heterozygous Db/db and Type 2 diabetic db/db mice were isolated and mounted on a pressure myograph containing Ca2+‐free physiological saline solution, EGTA and sodium nitroprusside. Passive structural measurements across a range of pressures revealed no changes in coronary structure in 12‐wk db/db mice, a time at which endothelial dysfunction is reported. However, wall thickness in diabetic arteries at 16 and 20‐wks was augmented (Db/db‐16: 6.9±0.6 μm vs. db/db‐16: 9.7±0.5 μm and Db/db‐20 6.7±0.8 μm vs. db/db‐20 9.2±0.7 μm at 100 mmHg, p < 0.05, respectively) while internal lumen diameters tended to be reduced (Db/db‐16: 117.6±4.6 μm vs. db/db‐16: 102.9±4.3 μm and Db/db‐20 112.3±9.1 μm vs. db/db‐20 106.2±6.7 μm at 100 mmHg). The wall/lumen ratio at the same ages was augmented in diabetic coronary arteries (Db/db‐16: 6.0±0.6 μm vs. db/db‐16: 9.5±0.4 μm and Db/db‐20 6.1±0.6 μm vs. db/db‐20 8.9±0.7 μm at 100 mmHg, p < 0.01). Despite these structural changes, no change in compliance was observed between control and diabetic groups. These data indicate that diabetic coronary arteries undergo progressive inward remodeling that may lead to impaired cardiac perfusion and coronary flow reserve. Supported by NIH RO1‐HL056046 (PAL).
CaMKII Phosphorylation of RyR2 Mediates Heart Failure Development
Authors: van Oort Ralph Jeroen , Respress Jonathan L , De Almeida Angela C , Sarma Satyam , Li Na , Skapura Darlene G , Wehrens Xander H
Published: June 2021

Abnormal regulation of cardiac ryanodine receptor RyR2 by Ca2+/calmodulin‐dependent protein kinase 2 (CaMKII) has been identified as a potential cause of Ca2+ leakage and contractile dysfunction in heart failure. To test the hypothesis that CaMKII phosphorylation of RyR2 is crucial for heart failure development, we generated RyR2 knockin mice in which the CaMKII phosphorylation site S2814 is either mutated into aspartate (SD) to mimic CaMKII phosphorylation, or into alanine (SA) to prevent phosphorylation. Echocardiography revealed a decrease in cardiac function in SD mice at 12 months of age. Both WT and SA mice were subjected to transverse aortic constriction (TAC) to induce pressure overload. At 8 weeks after TAC, SA mice displayed a similar hypertrophic response as WT TAC mice. At 16 weeks after TAC, however, ejection fraction was significantly higher in SA mice compared to WT TAC mice, indicating an inhibition of heart failure development. This rescue effect was further verified by a lower lung‐weight‐to‐tibia‐length ratio and a decrease in expression levels of cardiac stress genes in SA mice. Furthermore, Ca2+ imaging in isolated cardiomyocytes demonstrated a decreased SR Ca2+ leak in SA TAC mice. Our results demonstrate that CaMKII phosphorylation of RyR2 is both sufficient and necessary for heart failure development.

R.J.v.O. is recipient of the APS Postdoctoral Fellowship in Physiological Genomics
Brain stem heme oxygenase 1 (HO‐1) mRNA expression in inbred rat strains after severe hemorrhage
Authors: Oh Taesung , Calderon M. L. , Klemcke H. G.
Published: June 2021

Previously Klemcke et al. showed 8‐fold difference in survival time among inbred rat strains after severe hemorrhage (Shock 29:748, 2008). For Brown Norway (BN/Mcwi) rats we also found a 2.7‐fold increase in cardiac HO‐1 mRNA expression in catheterized plus hemorrhaged rats (Bled) compared to unmanipulated controls (CN; FASEB J. 23:801.2, 2009). To further examine HO‐1 as a possible intermediary of cellular responses to hemorrhage, in the same study we measured HO‐1 mRNA expression in brain stem of DA, Fawn Hooded Hypertensive (FHH), and BN/Mcwi strains. Using real time PCR, the relative quantity (RQ) of HO‐1 mRNA was measured with multiple housekeeping genes (Genome Biology 8:R19, 2007). Across all treatments (CN, catheterized only, and Bled) RQs were greater (P<0.05) in BN/Mcwi (0.47 ± 0.02; mean ± SEM) and FHH (0.48 ± 0.02) than in DA rats (0.41 ± 0.02). When considering all strains, HO‐1 mRNA RQ increased 12% (P<.05) in Bled rats compared with CN. Within strains and treatments, BN/Mcwi CN rats had greater (P<.05) RQs (0.46 ± 0.01) than did DA control rats (0.38 ± 0.03). The data imply that rat brain stem has minor strain‐dependent differences in HO‐1 mRNA expression, and that basal expression is modestly increased after the combined stressors of catheterization and hemorrhage.
Genetic B Lymphocyte Deficiency Attenuates Cold‐induced Hypertension
Authors: Wang Xiuqing , Stormont Ryan , Liu Xiaocan , Brock Amanda , Stewart Matthew , Sun Zhongjie
Published: June 2021

The major function of B lymphocytes is to produce antibodies and cytokines. The purpose of this study was to determine if B cells play a role in the pathogenesis of cold‐induced hypertension. Two groups of wild type (WT) mice and two groups of B cell‐deficient mice were used (all males, 5 mice/group). After blood pressure stabilized and no difference of BP was found between groups, 1 group of WT and 1 group of B cell‐deficient mice were exposed to cold intermittently (5°C, 7 hours/day). The remaining groups were kept at room temperature (RT, 25°C) and served as controls. Systolic, diastolic and mean BPs of the WT group began to increase at 9 weeks after intermittent exposure to cold. BP of this group reached a maximal level (mean BP = 140±4 mmHg) by week 14. In contrast, BP of the B cell‐deficient group did not increase during intermittent exposure to cold and maintained at the control level (mean BP = 91±3 mmHg, RT‐WT). Thus, B cell deficiency abolished the cold‐induced elevation of BP. Interestingly, intermittent exposure to cold increased macrophage infiltration, ET1 production, and in situ superoxide production in kidneyS of WT mice. Notably, B cell deficiency abolished the cold‐induced increases in these parameters. Conclusion: B lymphocytes play a critical role in the development of cold‐induced hypertension probably via the inflammation‐ET1‐superoxide pathway.
Progesterone inhibits trophoblast TNF alpha production.
Authors: Frazier Krystal , Wallace Kedra , LaMarca Babbette
Published: June 2021

Shallow trophoblast invasion contributes to inadequate vascular remodeling leading to the development preeclampsia. Preeclampasia is associated with increase inflammatory mediators such as TNF‐α. Progesterone, a steroid hormone with anti‐inflammatory properties, is markedly elevated during gestation, however, evidence suggests that plasma progesterone is decreased in preeclamptic patients. Therefore the purpose of this study was to determine the direct anti‐inflammatory effects of progesterone on human trophoblast cells. To achieve this objective Bewo cells, were cultured to confluence with or without progesterone (0.1μM, 1μM or 10μM) in DMEM with L‐glutamine and sodium pyruvate, 1% Pen./Strep., 0.5% Essential and non‐Essential AA, and 10% FBS under normal gaseous conditions. Cells were collected, RNA extracted and cDNA synthesized and TNF‐αgene expression determined utilizing SABiosciences primers and amplified using iQ SYBR Green Supermix. Results are expressed as fold induction over basal TNF‐α/b‐Actin. The addition of progesterone caused a concentration dependent decrease in TNF‐α expression reaching a 3‐fold reduction at 10 uM progesterone compared to baseline. Although these data indicate that progesterone inhibits trophoblast TNF‐α production, the effects of progesterone on trophoblast invasion are still unknown and therefore remains an important area of preeclamptic research.