bluuebunny/crossref_metadata_2025 huggingface dataset:
Loss of function of CaV1.2 in cultured bovine coronary artery smooth muscle cells
Authors: Ochi Rikuo , Gupte Rakhee S , Abe Madoka , Murayama Takashi , Kurebayashi Nagomi , Gupte Sachin A
Published: June 2021

L‐type Ca2+ current (ICa,L) through Cav1.2 α subunit pore controls contraction and phenotype change between contractile and proliferative type in vascular smooth muscle cell (VSMC). ICa,L enhances the expression of proteins that are characteristic for contractile phenotype. ICa,L is small in proliferative VSMC. The phenotype change to proliferative type is involved in atherogenesis. To explore underlying mechanism of the reduction of ICa,L reduction in proliferative VSMC, we have compared (1) the density of ICa,L between freshly‐isolated and proliferative cultured bovine coronary artery smooth muscle cell (BCASMC) and (2) the effect of CaV1.2 α subunit transfection to cultured BCASMC and HEK293 cells. Whole cell ICa,L was recorded with 10 mM Ba2+ as the charge carrier. ICa,L was 3.0 ± 0.4 pA/pF (n=28) in freshly isolated BCASMC but was not detectable in cultured BCASMC (N=15). Significant expression of CaV1.2 α subunit was confirmed by western blot in cultured BCASMC. ICa,L density was 4.2±0.7 pA/PF (n=15) in HEK293 cells transfected with human cardiac CaV1.2α‐GFP. However, ICa,L was not detectable in cultured BCASMC with the same transfection (n=15). We conclude that loss of function of expressed CaV1.2 is responsible for the reduction of ICa,L in the proliferatative vascular smooth muscle cells. This study is supported by NIH grant#R01HL85352
Dietary calcium restriction does not exaggerate salt‐sensitive hypertension
Authors: Swenson Christopher D. , Beierwaltes William H.
Published: June 2021

Dietary Calcium (Ca) has been implicated as an anti‐hypertensive factor, especially in salt‐sensitive hypertension. We hypothesized that decreased dietary Ca would exaggerate salt‐sensitive hypertension in the Dahl Salt‐sensitive (DahlSS) hypertensive rat. Either DahlSS or normal Sprague Dawley (SD) rats (200‐260g bw) were fed a normal sodium (Na) diet (0.22%) with either normal (1.36%) or low (0.15%) Ca content over 3 weeks, then switched to a high Na diet (3.2%) maintaining Ca contents for four more weeks. Systolic blood pressure (SBP) was measured by tail cuff. All rats grew uniformly, regardless of diet. Overall, initial SBP in DahlSS was 163 ± 3 while SD were 128 ± 2 mmHg (p<0.001). Relative changes in SBP are shown in the Table.

Overall, SBP in DahlSS rats started higher, and while high Na intake increased SBP in all groups, it increased twice as much in DahlSS over the study period. Ca restriction had no effect in either strain during this time period. Our data do not support the hypothesis that dietary Ca intake exaggerates salt‐sensitive hypertension.

Source of Research Support

RO‐1 grant from the NIH; ID# HL076469
Effects of water temperature on hemodynamic responses to cold pressor test.
Authors: Garlich John M. , Willingham Laura A. , Langasek Julie E. , Knuepfer Mark M.
Published: June 2021

We have used the cold pressor test in Sprague Dawley rats to elicit behavioral stress. In this paradigm, ice‐cold water (1 cm deep) is rapidly added to a watertight cage while recording hemodynamic responses. The initial startle response (5 ‐ 10 sec) is characterized by a profound pressor response due to an increase in systemic vascular resistance (SVR). The sustained modest pressor response (15‐60 sec) is characterized by tachycardia. We hypothesized that the sustained response but not the initial startle response is dependent on water temperature. Rats instrumented for cardiac output, mean arterial pressure (MAP) and heart rate determination were acclimated then tested with each temperature in the following order: room temperature (22‐24 °C), warm (33‐36 °C), then cold (2‐4 °C) water. After acclimation, we rapidly added water and recorded the response for one minute. The initial startle response was independent of temperature since all rats responded by increasing MAP and SVR. The sustained responses were highly dependent on water temperature since the modest pressor response and tachycardia observed with cold water were smaller with room temperature water and not observed with warm water. Our results suggest the initial startle response is independent of water temperature whereas the sustained modest pressor response is dependent on cold water. This work was supported by USPHS DA0017371 and HL091440.
Estrogen attenuates food intake and perifornical orexinergic neuron′s activity during glucoprivation in ovariectomized rats
Authors: Takamata Akira , Miyake Kana , Morimoto Keiko
Published: June 2021

We examined the effect of estrogen (E2) replacement in ovariectomized rats on food intake and lateral hypothalamic neuron′s activity during glucoprivation induced by i.v. 2‐deoxy‐D‐glucose (2DG) administration. Rats were ovariectomized and implanted E2 or vehicle (cholesterol) subcutaneously. Two weeks after the replacement, rats were infused with 2DG (400 mg/kg) and food intake was measured for 3 hours. The same experiment was performed for immunohistochemical examination of c‐Fos, melanin concentrating hormone (MCH), and orexin A expression in the lateral hypothalamic area (LH) and arcuate nucleus (Arc). Glucoprivation induced c‐Fos expression in the orexin A neurons locating at the perifornical region of LH, but did not activate MCH neurons. Glucoprivation significantly induced food intake, and food intake in E2 replaced group was significantly lower than E2 deficit group. The number and fraction of c‐Fos expressed orexinergic neurons was significantly lower in E2 replaced group than E2 deficit group. The number of c‐Fos ir cells was less in E2 replaced group than E2 deficit rats. These data indicate that E2‐induced reduction of food intake induced by 2DG is possibly due to the reduced perifornical orexinergic neuron′s activity and to the reduced Arc neuron′s activity.
Selective inhibition of forebrain or hindbrain leptin receptors modifies the response to peripheral leptin
Authors: Berry Heather , Harris Ruth B.S.
Published: June 2021

Previously we showed that peripheral infusions of physiological doses of leptin increase body fat in chronically decerebrate rats, in which the forebrain is surgically dissociated from the hindbrain. This study tested whether inhibition of leptin receptors (ObR) in the vicinity of either the 3rd or the 4th ventricle modified changes in food intake and body weight caused by peripheral leptin injections. Rats were food deprived during the light cycle and received 3rd ventricle injections of 0, 1.5, 2.5, 3.0 or 3.5 ug of leptin mutein protein (mutein), an ObR antagonist, 30 minutes before an i.p. injection of either PBS or 2.5 mg leptin/kg. Leptin inhibited 36 hour food intake and weight gain in rats receiving 0, 1.5 or 2.5 ug mutein, whereas 3.0 and 3.5 ug mutein increased weight gain and prevented any effect of leptin on either intake or weight gain. In a second study of similar design rats received 4th ventricle injections of 0, 0.75 or 1.5 ug mutein 30 minutes before an i.p. injection of 2.5 mg leptin/kg. Leptin inhibited 24 hour, but not 36 hour, food intake of rats receiving 0 ug mutein. Both doses of mutein inhibited weight gain and food intake and these effects were exaggerated and prolonged by leptin. These observations support those made in decerebrate rats and suggest that ObR in the brainstem oppose the feeding and energy expenditure responses to activation of forebrain ObR. Supported by NIH grant DK053903.
Dabigatran inhibits thrombin's differentiation of lung fibroblasts to a myofibroblast phenotype
Authors: Bogatkevich Galina S , Silver Richard M
Published: June 2021

Myofibroblasts are the principal mesenchymal cells responsible for tissue remodeling, collagen deposition, and the restrictive nature of lung parenchyma associated with pulmonary fibrosis. We previously reported that thrombin activates protease‐activated receptor (PAR)‐1 and induces a myofibroblast phenotype in normal lung fibroblasts resembling the phenotype of scleroderma lung myofibroblasts. Here we demonstrate that in a dose‐dependant manner dabigatran effectively inhibits thrombin‐induced differentiation of normal lung fibroblasts to the myofibroblast phenotype. As an active site inhibitor of thrombin, dabigatran restrains cleavage of the extracellular N‐terminal domain of PAR‐1 and prevents activation of PAR‐1 by the tethered ligand SFLLRN; however, dabigatran does not affect the activation of PAR‐1 by the selective agonist PAR‐1 activating peptide (PAR1‐AP). In normal lung fibroblasts dabigatran inhibits thrombin‐induced cell proliferation, α‐smooth muscle actin (α‐SMA) expression and organization, and the production of collagen and connective tissue growth factor (CTGF). Moreover, when treated with dabigatran scleroderma lung myofibroblasts produce less CTGF, α‐SMA, and collagen type I. We conclude that dabigatran restrains important profibrotic events in lung fibroblasts and can be considered to be a potential anti‐fibrotic drug for the treatment of fibrosing lung diseases, e.g. scleroderma lung disease and idiopathic pulmonary fibrosis.
Nitric Oxide (NO) Induces Airway Smooth Muscle Relaxation by Inhibiting Ca2+ Oscillations
Authors: Perez‐Zoghbi Jose F. , Sanderson Michael J.
Published: June 2021

To investigate how nitric oxide (NO) induces airway smooth muscle cell (SMC) relaxation, we examined airway contraction, Ca2+ signalling, and Ca2+ sensitivity in mouse lung slices in response to agonists and an NO donor, NOC‐5. In airways contracted with 5‐HT or ACh, NOC‐5 induced a concentration‐dependent relaxation consisting of an initial relaxation followed by partial re‐contraction. Inhibition of cGMP‐specific phosphodiesterases (PDE‐5) with zaprinast increased NOC‐5‐induced relaxation. 8‐Br‐cGMP, a PDE‐resistant analog of cGMP, induced sustained airway relaxation. Agonist‐induced airway contraction was mediated by SMC Ca2+ oscillations and airway relaxation correlated with a NOC‐5‐induced reduction in the frequency of these Ca2+ oscillations. NOC‐5 inhibited the Ca2+ oscillations and contraction triggered by the photolytic release of IP3 in SMCs. However, in Ca2+ permeabilized SMCs, NO only induced a small airway relaxation when the [Ca2+]i was clamped at a high level. We conclude that NO relaxes airway SMCs by decreasing the frequency of Ca2+ oscillations by blocking Ca2+ release via IP3 receptors and not by a major change in Ca2+ sensitivity.
Inhibition of Cx43/ZO‐1 Interaction Improves Gap Junction Intercellular Communication and Reduces Connexon Activity
Authors: Rhett Joshua Matthew , Jourdan Jane , O'Quinn Michael , Gourdie Robert G
Published: June 2021

Intercellular communication is important in many processes including conduction in the heart. Cytoplasmic coupling between cells is achieved by an aggregate of intercellular channels called the gap junction (GJ). Intercellular channels are composed of half‐channels, called connexons, one each contributed by the membrane of adjacent cells. The main subunit of cardiac GJs, Connexin 43 (Cx43), is bound by zonula occludens‐1 (ZO‐1). Work in our lab has shown that disrupting this interaction by a peptide ‐ termed Alpha‐Connexin C‐terminal peptide‐1 (ACT‐1) ‐ results in larger GJs. We hypothesize that ZO‐1/Cx43 binding limits the rate of connexon accretion into GJs. The objective of this study was to test the functional implications of this: ZO‐1/Cx43 binding negatively regulates GJ intercellular communication (GJIC); ZO‐1/Cx43 interaction enhances connexon activity. GJIC was assayed by scrape‐loading; ACT‐1 treatment of cultured cells showed an increase in GJIC. Connexon function was assayed by live imaging of dye uptake in cultured cells. We found that coupled cells − and not non‐contacting cells − treated with ACT‐1 had reduced connexon activity. Current work in our lab shows that ACT‐1 reduces the propensity for arrhythmia in cryoinfarcted hearts implying roles for connexon/GJ aggregate transitions in the pathology and treatment of heart failure. Funded by the South Carolina Space Grant Consortium.
Epidermal Growth Factor Inducing Differentiation of Rat Adipose‐Derived Stem Cells into Fibroblast in Vitro
Authors: Jin Huan , Liu Jian , Deng Juan , Ouyang Jingping
Published: June 2021

Objective

To investigate the induction of EGF(Epidermal growth factor)in the differentiation of rat adipose‐derived stem cells(ADSCs) into fibroblasts in vitro for potential seeding cell of ligament tissue engineering.

Methods

After inducing and culturing with EGF,ADSCs were determined by the utilization of morphological observation,MTT assay and immunohistochemistry.

Results

7 or 14 days after induction,the group with EGF developed a more homogeneous fibroblast‐like,spindle‐shaped morphology with long cell processes,and reached higher cell densities.The group with EGF had higher rate in proliferation.10 days after induction.EGF group and control group were positively stained with an antibodies for type I and III collagen,but the staining densities type I and III collagen of the EGF group were higher.The EGF group and the control group were negatively stained with antibodies for type lI collagen.

Conclusion

These data suggest that EGF has the capacity to stimulate cell proliferation and expression of extracellular matrix proteins for the tissue engineering of tendons and ligaments.
Factors released from TGF beta2 Primed ES cells inhibit Apoptosis and Necrosis in the Cell Culture System and Improve Infarcted Heart Function Following Transplantation
Authors: Singla Dinender K , Singla Reetu D , Fatma Sumbul
Published: June 2021

We reported that ES‐conditioned medium (CM) contains anti‐apoptotic factors that inhibit H2O2 induced apoptosis in H9c2 cells. However, whether ES‐CM prepared with the treatment of pro‐cardiac and anti‐apoptotic cytokine TGF beta 2 will demonstrate enhanced inhibition of apoptosis and necrosis in the cell culture is unknown. We provide evidence that TGFbeta 2 released factors enhanced inhibition of iodoacetic acid (IAA)‐induced apoptosis and necrosis in H9c2 cells. Conditioned medium (CM) from growing mouse ES cells treated with and without TGFbeta 2 was generated. Apoptosis and necrosis was induced after exposure to IAA in H9c2 cells for 1h followed by replacement with fresh cell culture or ES‐CMs. After 24 h, H9c2 cells treated with both ES‐CMs demonstrated significantly decreased apoptosis, as determined by TUNEL staining, apoptotic ELISA and caspase‐3 activity. Next, necrosis was also decreased as determined by flow cytometry and the release of lactate dehydrogenase (LDH). Importantly, TGF beta2‐ES‐CM significantly enhanced inhibition of apoptosis and necrosis compared with untreated ES‐CM. Furthermore, whether TGF beta 2 primed ES cells following transplantation in the infarcted mouse hearts will contribute to the improved cardiac function remains elusive. Using our standard myocardial infarction model, we transplanted with and without TGF beta2 primed ES cells (50,000 ES cells in 10‐20 μl of medium) in the infarcted heart. Echocardiography was performed at day 7 and 14. Cardiac function was significantly improved following TGF beta 2 primed ES‐cells transplantation compared with unprimed ES cells. In conclusions, we suggest that factors released from TGF beta2 primed ES cells enhances the inhibition of apoptosis and necrosis as well as improve cardiac function.
Adenosine A2a/b receptor‐mediated vasodilation is antagonized by adenosine A1 receptor in coronary circulation of healthy Ossabaw swine
Authors: Neeb Zachary Paul , Long Xin , Mokelke Eric , Edwards Jason , Alloosh Mouhamad , Sturek Michael
Published: June 2021

Adenosine clearly plays a role in mediating coronary blood flow. However, contributions of specific adenosine receptor subtypes A1, A2a, and A2b (A1R, A2aR, and A2bR) to changes in coronary flow in swine have not been elucidated. Adenosine receptors (AR) are G‐protein coupled, and inhibit (A1R, Gi) or stimulate (A2a/bR, Gs) adenylyl cyclase.

HYPOTHESIS

A1R antagonizes vasodilatory effects of A2a/bR on coronary circulation. The left main coronary artery of Ossabaw miniature swine was accessed with a guiding catheter allowing intracoronary (IC) infusions. Following placement of a flow‐wire into the left anterior descending coronary artery the responses to IC bolus infusions of 0.167, 0.333, 1, and 3 μg/kg adenosine were obtained. Steady‐state infusion of other adenosine receptor agents utilized a small catheter fed over the flow‐wire. Baseline flow was increased by the A2a/bR agonist CV1808 in a dose‐dependent manner, but not changed by other AR subtype‐specific agents. The A2a/bR antagonist DMPX and the A1R‐selective agonist CCPA decreased adenosine‐mediated vasodilation.

CONCLUSIONS

A1R negatively regulates A2a/bR‐mediated adenosine vasodilation and adenosine is not involved in regulation of basal flow in the coronary circulation of healthy Ossabaw miniature swine.
Role of light in the estrogen deficiency‐induced changes in diurnal SCN neural activity and food intake
Authors: Miyake Kana , Morimoto Keiko , Takamata Akira
Published: June 2021

To test the hypothesis that light exposure plays an important role in estrogen (E2) deficiency‐induced decrease in neuronal activity of the suprachiasmatic nucleus (SCN) and increase in food intake during light phase, we examined the effect of E2 replacement in ovariectomized rats on food intake, body temperature, and c‐Fos expression under different light exposure schedule. Rats were ovariectomized and implanted subcutaneously either with 17β‐estradiol or vehicle (cholesterol), and experiments were conducted 2 weeks after the implantation. Rats were maintained under 12h/12h‐light/dark condition (LD), followed by exposed to dark/dark condition (DD), and food intake and body temperature were measured throughout the experiments. Exposure to DD increased body temperature and food intake during daytime in E2‐replaced rats, but not in E2 deficit rats. The number of c‐Fos immunoreactive cells was significantly decreased in daytime with DD only in E2‐replaced rats. The data indicate that E2 elevates sensitivity of SCN neurons to light, resulting in enhancement of the amplitude of circadian variations of food intake and body temperature.
The effect of mannooligosaccharide supplementation on food intake, body weight and body composition in C57Bl/6 mice
Authors: Smith Daniel Larry , Nagy Tim R. , Wilson Landon S. , Barnes Stephen , Allison David B.
Published: June 2021

Objective

Prior research suggests that mannooligosaccharide (MOS or Mannan) supplementation might act as a potential calorie restriction mimetic. This study determined the effect of MOS supplementation on food intake, body weight and body composition in a mouse model.

Methods

C57Bl/6 male mice were fed a 45% by calories high fat (HF) "western" type diet with or without 1% MOS (by weight) supplementation (n=24/group) from 10 to 22 weeks of age. Animals were housed individually and provided 95% of ad libitum food intake for the duration of the study. Body weight was measured weekly and body composition (lean and fat mass) measured by QMR noninvasively every 3 weeks.

Results

Supplementation of a HF diet with 1% MOS, consisting of n=4‐13 oligomers by MALDI‐TOF mass spectrometry, tended to reduce total food intake (mean±s.d.; CON: 293.69±10.53g, MOS: 288.10±11.82g; p=0.09) during the study. However, MOS supplementation had no significant effect on final body weight (CON: 25.21±2.31g, MOS: 25.28±1.49g; p=0.91), body weight gain (CON: 5.04±1.49g, MOS: 5.09±0.80g; p=0.90) or total fat (CON: 4.72±0.90g, MOS: 4.82±0.83g; p=0.69).

Conclusion

In contrast with previous research, MOS supplementation had no effect on body weight gain or fat accrual during this 12 week study. This research is supported by Purdue‐UAB Botanicals Center for Age‐Related Disease Pilot Grant (P50AT00477) and the UAB CNRU (P30DK56336).
Food Insecurity and Cost‐related Medication Non‐adherence in Low‐income Older Adults in Northeast Georgia
Authors: Bengle Rebecca Anne , Johnson Tommy , Johnson Mary Ann , Lee Jung Sun
Published: June 2021

Low‐income older adults are at increased risk of cutting back on basic needs, including food and medication. This study examined food insecurity and cost‐related medication non‐adherence (CRN) in a randomly selected sample of senior center participants in northeast Georgia (n=137, age 77.3±8.8 years, 82.5%women, 44.8% black). Food insecurity was assessed using the 10‐item USDA Household Food Security Survey Module. Practice of 5 CRN behaviors (e.g. splitting pills, skipping doses) and 9 other prescription cost‐cutting (PCC) behaviors (e.g. seeking free samples, importing prescriptions) over the last month were evaluated. About 8% of participants were food insecure, while 9% and 32% had utilized one or more CRN and cost‐cutting strategies, respectively. Food insecure participants were more likely to be black, less educated, and at nutritional risk. Those who practiced CRN were more likely to be at nutritional risk and to practice PCC strategies. Food insecure participants were about 14 times more likely to practice one or more CRN behaviors than their counterparts even after controlling for potential confounders. Food insecure older adults were unable to meet not only basic food needs but also basic prescription needs. Improving food security is important for low‐income older adults in order to promote adherence to recommended medication management. Funding: ADA Healthy Aging DPG Student Research Award
Green tea extract inhibits CXC chemokine production, but enhances CXC chemokine receptor expression in RA synovial fibroblasts
Authors: Ahmed Salahuddin , Marotte Hubert , Koch Alisa E
Published: June 2021

Rheumatoid arthritis (RA) is a chronic inflammatory disease in which chemokines produced by the activated synovial fibroblasts promote joint destruction. In this study, we tested the efficacy of the polyphenol‐rich green tea extract (GTE) in regulating the CXC chemokine production and CXC chemokine receptor expression in RA synovial fibroblasts in vitro. The preincubation of RA synovial fibroblasts with GTE inhibited interleukin‐1β (IL‐1β 10 ng/ml)‐induced CXC chemokines growth regulated oncogene (GROα) and IL‐8 production in a dose‐dependent manner (IC50 values ~6.7 and ~16.5 μg/ml, respectively). However, the quantitative RT‐PCR analysis showed that GTE (10‐20 μg/ml) inhibits GROα, but enhances IL‐8, mRNA synthesis in RA synovial fibroblasts. Evaluation of the signaling pathways revealed that the PKCδ inhibitor, Rottlerin (10 μM), completely abrogated the IL‐1β‐induced RA synovial fibroblast GROα and IL‐8 production. We also found that GTE enhances the constitutive and IL‐1β‐induced expression of CXCR1 and CXCR2, the receptors utilized by GROα and IL‐8. To our surprise, a similar increase in the CXCR1/CXCR2 expression was mimicked by Rottlerin. Since RA synovial fibroblasts attract inflammatory cells by releasing chemokines, CXCR1/CXCR2 overexpression with reduced chemokine production by GTE may be a potential way of limiting the overall inflammation and joint destruction in RA.
Temporal and Spatial Activation of Angiogenesis and Expression of VEGF/VEGF Receptors in the Infarcted Heart
Authors: Zhao Tieqiang , Zhao Wenyuan , Chen Yuanjian , Sun Yao
Published: June 2021

We sought to determine temporal and spatial expression of VEGF/VEGF receptors and their relation to angiogenesis in the infarcted heart. Hearts were collected at hour 3, 6, 12, day 1, 3, 5, 7, 14, 21 and 28 postMI. Normal rats served as controls. Cardiac VEGF gene and protein expression, VEGFR and angiogenesis were examined. After MI, existing vessels were lost in the infarcted myocardium at day 1 postMI. Newly formed vessels first appeared at the border zone as early as day 3, followed by the infarcted myocardium. Vascular density peaked at day 7 and 14, and gradually declined at day 21 and 28. VEGF gene expression was largely increased in the border zone from hour 6 to day 4, but not in the later stage, while it was markedly reduced within the infarcted myocardium at all time points. VEGF protein expression was evident at the border zone, while it was largely decreased in the infarcted myocardium at all time points. VEGF receptor binding was significantly lowered in the infarcted myocardium in the first week and gradually increased thereafter. The expression of VEGF and VEGF receptors remained unchanged in noninfarcted myocardium. Thus, angiogenesis is activated in the infarcted myocardium in the early stage of MI and becomes quiescent thereafter. VEGF expression is elevated soon after MI at the border zone, but not in the late stage of MI. The early rise in VEGF in the border zone may trigger cardiac angiogenesis following MI.
Shedding a new light on the circuit HIF‐1 alfa/CA IX/uPAR and other neovascularization related genes by means of post‐transcriptional gene modulators in proliferative retinopathies
Authors: Capaccioli Sergio , Papucci Laura , Witort Ewa , Lapucci Andrea , Quaglierini Paolo , Specogna Rebecca , Lulli Matteo , Donnini Martino
Published: June 2021

Hypoxia‐induced retinal neovascularization underlies three retinal pathogeneses (diabetic retinopathy, AMD and neovascular glaucoma) as the main causes of blindness. Although different growth factors are involved in this process, efficient inhibition of urokinase receptor (uPAR) by specific antibodies suppressing neovascularization suggests, that interaction between uPAR and its ligand uPA plays a major role. In turn, uPAR is transactivated by HIF‐1 alfa, while expression both uPAR and HIF is also controlled at post‐transcriptional level by interactions between AU‐rich cis‐acting elements (ARE) and relevant AU‐Binding Proteins (AUBPs). Despite HIF/uPAR interactions at post‐transcriptional level could serve as optimal therapeutic targets in the management of proliferative retinopathies, this topic has been scarcely investigated so far. Therefore, we aimed to shed a new light on the mechanism underlying these interactions. Preliminary results obtained by modulating HIF, uPAR and other hypoxia‐induced gene expression through peculiar antisense strategies indicated their co‐regulation at post‐transcriptional level as an optimal therapeutic target in proliferative retinopathies
Role of the bradykinin receptor (B2R) in differentiation, migration, and proliferation of endothelial progenitor cells (EPC)
Authors: Bakdash Nadia , Wu Yi , Colman Robert W.
Published: June 2021

As a potent activator of endothelial cells, bradykinin is known to induce vasodilation, vascular permeability, and nitric oxide production. Bradykinin signaling is initiated by binding to the G protein‐coupled receptor B1R and/or B2R. B2R is constitutively expressed in endothelial cells. Endothelial Progenitor Cells (EPCs) are bone‐marrow derived cells that have the potential to differentiate into mature endothelial cells. We now report that EPCs undergo differentiation, migration, and proliferation without addition of exogenous growth factors. Moreover, EPCs stimulated with bradykinin (250 nM) potentiated differentiation (tube formation), migration, and proliferation by 1.4, 1.6, and 1.7‐fold, respectively. Pre‐incubation of the EPCs with HOE‐140 (1 μM or 10 μM), a B2R selective antagonist, reduced differentiation by 70% (p<0.001), modulated migration by 40% (p<0.001), and inhibited proliferation by 20% (p<0.05), indicating that EPCs utilize the BR2 receptor in these three responses. In addition, we demonstrate that EPCs stimulated with the selective B2R peptidomimetic agonist FR190997 (50 nM) enhanced migration. Furthermore, when pre‐incubated with the B2R antagonist, the migration of EPCs was inhibited by 40% (p<0.05). Thus, we conclude that EPCs utilize the B2 receptor for potentiation of migration, differentiation, and proliferation.

NIH 2T32HL007777.
Events contributing to rat liver vascularization following partial hepatectomy
Authors: Stolz Donna Beer , Ross Mark A , Tomiyama Koji , Toyokawa Hideyoshi , Li Luyuan , Murase Noriko
Published: June 2021

Vascularization during liver regeneration following 70% partial hepatectomy (PHx) occurs via spatial and temporal cues. The liver sinusoidal endothelium (LSEC) proliferate only after hepatocytes complete their rounds of replication, suggesting both positive and negative effectors play roles in regulating LSEC growth. Of the positive signals examined, hepatocyte EphB3 signal increased 1‐7 d following PHx, prior to and beyond LSEC EphrinB1 upregulation, which was seen 2‐4 d post‐PHx. Another positive modulator, neuropilin‐1, increased on LSEC 2‐6 d after PHx. Vascular endothelial growth inhibitor (VEGI), an autocrine inhibitor of endothelial growth, was observed to increase on LSEC 24‐72 hr post‐PHx, when cells are not proliferating, and was absent or reduced on LSEC 4d after PHx, when LSEC are actively proliferating. Thrombospondin signals increased on LSEC membranes only after 7 d post‐PHx. These results indicate VEGI may override the early VEGF signals keeping LSEC growth in check, while thrombospondin appears to inhibit later LSEC growth events. Using GFP bone marrow radiation chimeras, we observed 1‐5% engraftment of GFP+ bone marrow derived LSEC that colocalized with the rat LSEC marker SE‐1. These results indicate that liver vascularization occurs via both angiogenesis and vasculogenesis.
Cellular automaton modeling of biological pattern formation
Authors: Deutsch Andreas
Published: June 2021

Examples of biological pattern formation are life cycles of bacteria and social amoebae, embryonic tissue formation, wound healing or tumour growth. Thereby, development of a particular spatio‐temporal "multi‐cellular" pattern may be interpreted as cooperative phenomenon emerging from an intricate interplay of local (e.g. by adhesion) and non‐local (e.g. via diffusing signals) cell interactions. Mathematical models are required for the analysis of cooperative phenomena. Typical modeling attempts focus on a macroscopic perspective, i.e. the models (e.g. partial differential equations) describe the spatio‐temporal dynamics of cell concentrations. More recently, cell‐based models have been suggested in which the fate of each individual cell can be tracked. Cellular automata are discrete dynamical systems and may be utilized as cell‐based models. Here, we analyze spatio‐temporal pattern formation in cellular automaton models of interacting discrete cells. In particular, we introduce lattice‐gas cellular automata. In the same spirit as cellular automata, lattice‐gas cellular automaton (LGCA) and lattice Boltzmann (LB) models are promising tools for studying transport and interaction processes in biological systems. In these models the update rule is split into two parts which are called collision (interaction) and propagation, respectively. The collision rule of LGCA can be compared with the update rule for CA in that it assigns new states to each cell based on the states of the sites in a local neighborhood. After the collision step the state of each node is propagated to a neighboring node. This split of the update rule guarantees propagation of quantities while keeping the rules simple. The desired behaviour, e.g. spatio‐temporal pattern formation of a LGCA shows up in the macroscopic limit which can be derived from a theory of statistical mechanics on a lattice. Instead of discrete particles, LB models deal with continuous distribution functions which interact locally and which propagate after "collision" to the next neighbour node. LB models can be interpreted as mean‐field approximations of LGCA. Model applications are bacterial pattern formation and tumour growth.

Ref.:

A. Deutsch, S. Dormann (2005) Cellular automaton modelling of biological pattern formation, Birkhauser, Boston
PKCalpha‐mediated signaling in regulating adherens junction integrity
Authors: Vandenbroucke Emily Elizabeth , Komarova Yulia , Gao Xiao‐Pei , Vogel Steven , Malik Asrar
Published: June 2021

The aim of this study was to determine the mechanism of protein kinase C‐α (PKCα)‐mediated disruption of adherens junctions (AJs). We have shown that depletion of PKCα in human microvascular endothelial cells reduces the thrombin‐induced permeability increase by 50%, as assessed by change in transendothelial resistance. PKCα‐depleted endothelial cells formed fewer interendothelial gaps and retained more vascular endothelial (VE)‐cadherin at AJs after thrombin stimulation compared to control cells. VE‐cadherin stability at AJs has been shown to be dependent on p120‐catenin (p120) binding. Dissociation of p120 from VE‐cadherin results in VE‐cadherin internalization and disassembly of AJs. Since activation of PKCα after thrombin stimulation leads to changes in phosphorylation of p120 in endothelial cells, we tested the hypothesis that PKCα‐mediated phosphorylation of p120 causes dissociation of p120 from VE‐cadherin, subsequent disassembly of AJs and increased permeability of the endothelial barrier. Our data demonstrate that thrombin stimulation of endothelial cells results in translocation of PKCα to AJs and interaction with p120. Furthermore, the level of p120 remains unchanged at AJs in PKCα‐depleted cells after thrombin stimulation, supporting our hypothesis that PKCα may induce p120 dissociation from VE‐cadherin, resulting in AJ disassembly.

Supported by NIH Grants HL045638 and HL007829
Regulation of urothelial cell function by corticotrophin peptides
Authors: Hanna‐Mitchell Ann T , Buffington Tony , Birder Lori A
Published: June 2021

Feline interstitial cystitis (FIC), a chronic idiopathic cystitis in cats, exhibits similarities to humans diagnosed with bladder pain syndrome/IC. In both syndromes, alterations in urothelial (UT) signaling/barrier may contribute to the associated pathophysiology. Corticotrophin peptides are involved in a number of functional pain syndromes and are now known to be expressed by peripheral tissues.

Using time‐lapse fluorescence microscopy, we investigated a role for corticotrophin releasing factor (CRF), urocortin3 (UCN3), and receptors CRF‐1,‐2, in UT physiology. UT cells isolated from normal and FIC cat bladders were incubated with a membrane‐impermeant fluorescent dye (FM 1‐43; 5µM) and exposed to CRF (0.01µM), which has a greater affinity for CRF1. Normal UT exhibited a substantial membrane trafficking response (approximately 3 fold increase over basal/unstimulated) compared with FIC UT (1.5 fold increase over basal) .Both groups showed a low magnitude of trafficking in response to the selective CRF2 agonist, UCN3 (0.1µM).Astressin 2‐B alone (selective CRF2 antagonist; 1µM) evoked membrane trafficking in both groups; indicating cellular release of an autocrine factor, now free to act through CRF1 only. We also report a 'dis‐inhibition' of UT cell ATP release by astressin 2‐B and CRF mRNA expression by these cells. Our findings indicate a potential for CRF to play an important role in UT cell function.

Funded by

NIH R01 DK57284 and P50 DK64539
Development and evolution of facial bone shape
Authors: Kimmel Charles
Published: June 2021

Skeletal morphology underlies its function, and genetic studies in vertebrates like mouse and zebrafish reveal that a rich network of regulatory genes is used pattern to the very precise and complex assembly of facial bones that comprises the cranial skeleton. Understanding this gene network, and how the network directs cellular behaviors during development is essential for learning about skeletal evolution and what goes wrong in human disorders such as cleft palate. The signaling protein, Endothelin1, and its downstream target genes, including in zebrafish mef2ca, is a part of this network essential for the pharyngeal skeleton and jaw, as this talk will review. Endothelin1 functions to direct earliest skeletal patterning, and the early bones undergo a highly stereotyped and intricate allometric process of growth in the larva to arrive at the adult morphologies. These morphologies can vary tremendously, as evidenced by the diversity of bones shapes and sizes among the approximately 30,000 species of teleosts. Comparative quantitative shape analyses of one of these bones, the opercle, suggests that there exists very little limit to morphological evolution of the teleost skull. The data contrast with notions in the literature that phenotypic space is generally highly unoccupied. Sophisticated and evolutionarily plastic development might underlie a highly evolvable cranial skeleton, accounting for the seemingly unconstrained array of observable morphologies.
A shortened, case‐based anatomy course promotes long‐term recall and life‐long learning among medical and physician associate students.
Authors: Rizzolo Lawrence J , Rando William , O'Brien Michael , Haims Andrew , Abrahams James , Garino Alexandria , Stewart William B
Published: June 2021

Across the country, anatomy courses are becoming shorter, even as residency programs report that entering trainees are poorly trained in anatomy. In response, clinicians, anatomists and education specialists collaborated to design a course that emphasized clinical approaches to problem‐solving. Common clinical cases formed the basis for course content. Traditional dissection labs were replaced with classical, open‐surgical procedures that required students to prepare by scrutinizing actual clinical cases. To explore the anatomy behind the patient's history and physical exam, imaging studies and surgical or medical resolution, we provided students with a highly interactive, web‐based dissector Results include a dramatic improvement in student preparation and participation. Survey and focus group data indicated that students appreciated the clinical approach, but struggled with the demands of a more professional approach to learning. The success of the medical school course led to its adaptation to a course for physician associate students. A test of long‐term recall was administered prior to clerkship training (1.5 years after the medical course; 8 months after the physician associate course). Both groups showed improvement compared to classically taught students. When the same test was administered 1.75 years later, after clerkship training, the improvement of the medical students was even more marked. The data show that a course that uses a functional‐anatomy design can be more effective than a classical anatomy course, despite the fact that it is shortened by a third.
Guiding medical student behavior to become self‐directed learners
Authors: DiLullo Camille , Kriebel Richard M
Published: June 2021

Ongoing efforts to improve student learning outcomes have included many curricular initiatives to change the processes of content delivery. Generally overlooked is the preparation of students to learn in the revised curricula. This study addresses improving learning outcomes by providing guidance to students to develop a self‐directed learning mindset prior to their engagement in the learning process. Initially access of optional self‐directed case tutorials was monitored. The tutorial format used 1) videos to relate patient data and professional patient/physician interactions and 2) questions to direct student focus to the clinical context of basic science knowledge. Few students selected the optional tutorials. The next study iteration used required formative assessments for half of the tutorials and increased to 40% student selection of the optional tutorials. The current iteration added pre‐matriculation exercises to guide students to recognize the relevance of basic science information in patient treatment. Exercises were reviewed in small group discussions at the start of the formal academic program. The exercises/group discussions did not increase access of the optional tutorials however faculty reported student presentations of assigned anatomically based cases were more clinically oriented. Increased guidance will be necessary to improve student proficiency in self‐directed learning.
The embodied nature of primate communication: some phylogenetic, ontogenetic & neurobiological evidence
Authors: Ghazanfar Asif
Published: June 2021

Our work focuses on the neurobiology of facial and vocal signals that mediate communication between conspecifics. As a monkey agent's behavior is the result of the interplay between its evolutionary history, individual development and experience, and current context, we are studying primate communication on three time scales. First, a short time scale which relates to actual mechanisms (perceptual or neural) operating in real time guiding the agent's behavior. On this level, we are examining the functional interactions between cortical areas and how the might mediate the integration of faces and voices. Second, an intermediate time scale which incorporates the development and/or experience of the agent over its lifetime. On this intermediate level, we are studying the development of face/voice integration in monkeys, as well as the roles of sensory experience in forming face‐voice associations. Finally, a very long time scale, which focuses on the evolution of an agent's behavior, is slowly revealed when we make explicit comparisons between what know about humans versus other extant primate species.
Stem cells and the lung
Authors: Aliotta Jason M , Pereira Mandy , Lee David , Johnson Kevin , Dooner Gerri , Dooner Mark , DelTatto Michael , Papa Elaine , Liu Liansheng , Colvin Gerald A , Quesenberry Peter J
Published: June 2021

Investigators have shown that transplanted murine marrow cells contribute to the cellular component of various non‐hematopoietic organs, including the lung. The mechanism responsible for this remains unknown. We wished to determine if marrow cell phenotype is influenced by lung‐derived factors by co‐culturing (separated by a cell‐impermeable membrane) murine whole bone marrow (WBM) cells with lung cells. Co‐cultured WBM expressed high levels of lung cell‐specific genes and protein, which was further augmented by radiation injury to the lung. Cell‐free lung conditioned media (LCM) had a similar effect on co‐cultured WBM, suggesting that factors smaller than the membrane pore were responsible for these changes. Co‐cultured WBM treated with transcriptional blocking agents had lung cell‐specific gene expression that was either up regulated or down regulated, implying transfer of a transcriptional agent. Microvesicles (MV) containing lung‐derived RNA and protein were isolated from LCM and found to enter WBM in culture which subsequently expressed lung‐specific genes. These data suggest that MV transfer may be an important mediator of cellular communication in the context of marrow cell plasticity.
Regulation of histone acetylation and turnover by histone chaperones
Authors: Kaufman Paul D.
Published: June 2021

Acetylation of histone H3 on lysine 56 occurs on newly synthesized histones in fungal species, and the absence of this modification is associated with extreme sensitivity to genotoxic agents. H3‐K56 acetylation is catalyzed when Rtt109, a distant homolog of p300/CBP acetyltransferases, is stimulated by either of two different histone‐binding proteins, Asf1 or the Nap/Set family member Vps75. However, these histone chaperone proteins are functionally distinct, because Asf1 and Vps75 simulate distinct substrate specificities for Rtt109 and confer different degrees of resistance to genotoxic agents. We will present new biophysical, biochemical, genetic and genomic data on the function and regulation of the activity of these complexes. Specifically, genomic analysis of H3K56ac across the budding yeast cell cycle suggests that Vps75 and Asf1 differentially alter histone exchange at loci where there is rapid nucleosome turnover.
Functions of Chromodomains in Epigenetic Regulations
Authors: Khorasanizadeh Sepideh
Published: June 2021

Chromodomains are 50‐90 residues that form independent modules in many chromatin‐ associated proteins. A chromodomain typically assembles an aromatic cage to recognize a lysine‐methylated target peptide using pi‐cation interactions. Chromodomains help establish physical interactions with chromatin to keep a rein on epigenetic processes for both activation and repression of genes. Proteins with chromodomains have diverse roles as molecular adapters, scaffolding factors in multi‐subunit complexes or enzymes critical for epigenetic signaling. While some chromodomains only target prominent methyllysines along the absolutely conserved histone tails others target DNA or unmodified peptides. A great majority of the targets of chromodomains in the human genome as well as the genomes of various human pathogens remain elusive. We have delineated the structure, stoichiometry and thermodynamic basis for chromodomain interactions with peptides and DNA in a series of proteins derived from yeast, Drosophila, Arabidopsis and human. Our studies have revealed unexpected differences in mechanisms of chromatin regulation in different species.
Global analysis of mRNA localization reveals a prominent role in the organization of cellular architecture and function
Authors: Krause Henry
Published: June 2021

The localization of mRNA molecules is an important regulatory mechanism for targeting proteins to specific cellular compartments, although the overall prevalence and variety of transcript localization events remains unknown. To characterize subcellular mRNA localization dynamics during early Drosophila embryogenesis, we conducted a high‐throughput Fluorescent In Situ Hybridization (FISH) screen of over 4,000 distinct mRNAs, and found that the majority of expressed mRNAs (71%) are subcellularly localized. Many novel varieties of subcellular localization patterns were identified, implicating localized mRNAs in the assembly and regulation of diverse cellular modules and processes. Analysis of the localization data, which has been organized within a publicly available database (http://fly‐fish.ccbr.utoronto.ca), reveals that transcripts with similar localization dynamics are enriched for specific gene functions and putative regulatory elements. This work establishes mRNA localization as a widespread gene regulatory mechanism and underscores the predictive value of transcript localization phenotypes in assigning gene functions. We have begun dissecting the localization mechanisms and biological functions of various classes of mRNAs and the results of these ongoing studies will be presented.

Funding provided by the Canadian Institutes of Health Research
Identification of barriers and strategies to meet Fresh Fruit and Vegetable Program (FFVP) goals: A qualitative analysis from the foodservice perspective
Authors: Shertzer Julie Kennel , King Mindy Hightower , Middlestadt Susan E. , Fly Alyce D.
Published: June 2021

The FFVP is a federal program that provides free fruits and vegetables (FV) at schools. FV availability through the FFVP has shown to improve only fruit (not vegetable) consumption and preferences. Other determinants underlying the behaviors of eating FV remain mostly unchanged. This study identified implementation methods in 6 of 25 participating Indiana schools. Guided by a logic model framework, evaluation consisted of individual, semi‐structured interviews (n=9) with school staff who coordinated implementation. Interviews were recorded, transcribed, and coded; themes were extracted using thematic content analysis. Nine themes (barriers) emerged. The first 5 themes revealed policy and vendor limitations to purchasing and preparing a variety of FV, especially vegetables. Strategies to expand variety were purchasing varietals of commonly available FV and using dips to increase palatability. The last 4 themes related to gaps in program support and communication for enhancing teacher modeling and auxiliary nutrition education. Strategies to overcome these barriers were: using broadcast announcements and asking teachers to voluntarily incorporate information into curricula. Resolving barriers through policy change and applying strategies to facilitate implementation may enhance the success of the FFVP. Supported by Indiana University Graduate School Grant in Aid