bluuebunny/crossref_metadata_2025 huggingface dataset:
Systemic and Cerebrovascular Function following Short Duration Intermittent and Continuous Hypoxia in Humans
Authors: Peebles Karen Clendon , Winsbury John , Montgomery James , Newby John , Sheehan Hugh , Yuansherng Aaron , Thomas Kate Nicole , Ainslie Philip Neil
Published: June 2021

Patients with obstructive sleep apnoea (OSA) have impairment in cerebral and systemic endothelial function. To examine to what extent these initial changes are caused by the repetitive hypoxic apnoeas, we randomly gave 10 healthy volunteers, two conditions: 1) short duration intermittent hypoxia (SDIH), which was designed to mimic moderate to severe OSA (i.e. 20s voluntary hypoxic breath‐holds, SpO2 = 85%, 30 times per h for 2 h); 2) short duration continuous hypoxia (SDCH) of similar intensity and duration (i.e. 20 min, SpO2 = 85%). Before (pre) and immediately after (post) each intervention we measured ventilation (VE), cerebral blood flow velocity (CBFV) and arterial blood pressure (BP) in conditions of eucapnia and during hyperoxic (PETO2 "d 150 mmHg) and hypoxic (PETO2 = 50 mmHg) rebreathing. Systemic endothelial function was assessed using flow‐mediated dilatation (FMD). All baseline variables (end‐tidal gases, VE , CBFV, BP, and FMD) were unchanged following both SDIH and SDCH. Whilst the slope of the CBFV‐CO2 relationship was higher during hypoxic rebreathing, exposure to SDIH and SDCH did not alter these relationships. These data indicate that the SDIH and SDCH protocols used in this study were not of sufficient duration to elicit any changes in cerebral or systemic vascular function. The duration of SDIH or SDCH required to impact on vascular health warrants further research.
Mapping long‐term transactivation of redox‐sensitive AP‐1 in the paraventricular nucleus (PVN) following myocardial infarction (MI) using in vivo bioluminescence
Authors: Stupinski John A , Infanger David W , Sharma Ram V , Davisson Robin L
Published: June 2021

Heart failure is characterized by sustained sympathoexcitation and deteriorating cardiac function. We have recently shown that excessive redox signaling in the PVN contributes to these changes, however the molecular mechanisms remain poorly understood. We hypothesized that chronic oxidative stress in the PVN causes activation of the redox‐sensitive transcription factor Activator Protein 1 (AP‐1) following MI. To test this, C57 mice were given bilateral PVN injections of adenoviruses encoding firefly luciferase downstream of AP‐1 (AdAP1‐Luc) in combination with either the ROS scavenger superoxide dismutase (AdSOD) or control (AdLacZ). Two wks after gene transfer, mice underwent MI (LAD ligation) or sham surgery and measurement of AP‐1 activation for 6 weeks by in vivo bioluminescence. MI caused a significant increase in AP‐1 activation in the PVN between 1 and 2 wks post‐ligation (AdLacZ 181018 ± 45474 vs. sham 73036 ± 12462 photons/sec; n=5, p<0.05). Interestingly, MI‐induced AP‐1 activation was abolished in MI mice treated with AdSOD (79314 ± 12375 photons/sec, p<0.05, n=5). Echocardiography at 2wks post‐MI showed significantly reduced ejection fractions in LacZ‐treated mice (23±3% vs 57±4%, p<0.05, n=5) which was markedly improved with AdSOD treatment (43±6%, p<0.05, n=5). These data suggest that ROS‐mediated activation of AP‐1 in the PVN may contribute to decreased cardiac function after MI.
Effect of milk and non dairy creamer on human bioavailability of coffee phenolic acids
Authors: Renouf Mathieu , Marmet Cynthia , Guy Philippe , Fraering Anne‐Lise , Moulin Julie , Enslen Marc , Cavin Christophe , Barron Denis , Dionisi Fabiola , Williamson Gary , Steiling Heike
Published: June 2021

Chlorogenic acids are antioxidants found in coffee. They are becoming of interest for their health promoting effects, but their human bioavailability is not well known.

We hypothesized that adding whole milk or non dairy creamer to instant coffee might alter the bioavailability of coffee phenolics. Nine healthy subjects were asked to drink in a cross‐over design instant coffee, instant coffee and 10% whole milk or instant coffee, non‐dairy creamer and sugar already pre‐mixed. Blood was collected for 12h after ingestion and plasma samples extracted via a liquid‐liquid method that included a full enzymatic cleavage to break down all chlorogenic acids into smaller phenolic acids. Hence, we focused our LC‐ESI‐MSMS detection and quantification on caffeic (CA), ferulic (FA) and isoferulic acid (iFA). Compared to a regular black cup, the addition of milk did not significantly alter the area under the curve (AUC), maximum plasma concentration (Cmax) or the time needed to reach Cmax (Tmax). Cmax of CA and iFA were significantly lower and T max of FA and iFA significantly longer for the non dairy creamer group compared to black coffee. However, the AUCs were not significantly different. As a conclusion, adding whole milk did not alter the overall bioavailability of coffee phenolic acids. Adding non dairy creamer affected the time and maximum concentration but not the overall plasmatic delivery of coffee phenolics.
Dietary Supplement Use Among Endurance Athletes
Authors: Talbott Shawn M , Talbott Julie A
Published: June 2021

Existing surveys of dietary supplement use among the general population suggest that 50‐75% of adult Americans are "regular users" of dietary supplements. Use among athletes is less clear, with some reports indicating 100% usage among bodybuilders, and other estimates indicating 30‐50% usage among endurance athletes.

We examined dietary supplement usage patterns among a sample of 326 triathletes ‐ 176 "Ironman" distance (IM, 71 females, 103 males) and 152 "Olympic" distance (OD, 63 females, 89 males) via a 50‐question survey.

Results showed that triathletes at both OD and IM distances are avid users of dietary supplements (d/wk usage = 6.1d IM / 4.5 OD), with IM using more supplements for "recovery" (+20%) and "endurance" (+22%) and also greater use "after" exercise (+35%), compared to OD. Primary sources of information about supplements comes from Friends and Training Partners (89% IM/83% OD), the Internet (92% IM/95% OD), and Coaches/Trainers (65% IM/53% OD). A high percentage of triathletes indicated difficulty finding accurate information (88‐90%) and wanting more information (89‐90%) about supplements.

These data show a high usage of dietary supplements among competitive triathletes, as well as a desire for additional information regarding their use. Future research is warranted to elucidate how to best educate endurance athletes about the pros and cons of dietary supplements usage.
Investigations of Iron, Hypoxia and Adipocyte Hypoxia on Hepcidin Promoter Activity
Authors: Hintze Korry Joseph , Nabor Darren , Timbimboo Hunter , Snow Dallin
Published: June 2021

Hepcidin plays a key role in regulating organismal iron metabolism by blocking iron efflux from enterocytes and macrophages. Hepcidin is synthesized in the liver and its expression is increased by iron overload and inflammation and decreased by hypoxia. To determine if iron, hypoxia or conditioned media from hypoxic adipocytes modulates hepcidin promoter activity; the human hepcidin promoter (1207 b.p. fragment upstream of the transcription start site) was cloned into a luciferase reporter construct. Constructs were transfected into Huh7 hepatocytes. Treatment of transfected cells with ferric ammonium citrate for 24h (50, 100 and 200 µM) modestly increased hepcidin promoter activity over controls (1.39‐fold ± 0.27, P=0.06; 1.46‐fold ± 0.16, P < 0.01 and 1.47‐fold ± 0.14, P < 0.01 respectively). Hemin (10 µm) increased hepcidin promoter activity 1.6‐fold ± 0.11 over controls, (P < 0.01). Cells cultured for 24h at 19% O2 had 2.6‐fold ± 0.15 higher (P < 0.01) promoter activity compared to cells cultured at 1% O2. Treatment of Huh7 cells with media from 3T3‐L1 adipocytes cultured at 1% O2 increased promoter activity 2.9‐fold ± 0.7 (P < 0.01) over cells treated with 3T3‐L1 media cultured at 19% O2. These data suggest that changes in hepcidin expression by iron or hypoxia may be partially mediated through the hepcidin promoter. Furthermore, adipocyte hypoxia (a feature of central obesity) may increase hepcidin expression.
Depression and Hardiness and their Association with Appetite in Older Adults
Authors: Engel Julia , Sahyoun Nadine , Jackson Robert , Siewerdt Frank
Published: June 2021

Background

Poor appetite leads to increased morbidity in older adults, and can be influenced by many factors, including chronic disease and depression. However, the direction of influence of depression on appetite is unclear in this population. Hardiness is believed to be another risk factor that may influence appetite in older adults, and is defined as an ability to manage stress and having a positive outlook on life.

Purpose

The aim of this research is to examine the associations of hardiness, depression, and emotional well‐being with appetite in older adults.

Methods

A survey evaluating hardiness, depression and appetite was administered to 292 adults (≥60 years) in assisted‐living facilities or attending senior centers in the Washington D.C. area.

Results

In univariate models, depression, hardiness, and emotional well‐being are associated with appetite. Fair/poor emotional well‐being increases risk for poor appetite (OR=5.13, 95% CI: 2.47‐10.67) whereas commitment (a dimension of hardiness which indicates an individual's involvement in life) is inversely associated with risk of poor appetite (OR=0.81, 95% CI: 0.68‐0.95). Both variables emerged as the strongest predictors of appetite in multivariate models.

Implications

These strong associations may further elucidate the components of mental health which contribute to poor appetite in this population. Funding provided by: ADA HADPG

Grant Funding Source

ADA HADPG Student Research Award
Protein intake, weight loss, and bone mineral density in postmenopausal women
Authors: Tang Minghua , Weaver Connie M. , Martin Berdine R. , Jackson George S. , Campbell Wayne W.
Published: June 2021

Background

Higher‐protein diets are promoted for effective weight loss. Striated tissues in omnivorous diets contain high‐quality protein, but there is a paucity of data regarding their effects on bone.

Objective

To examine the effects of weight loss and protein intake on bone mineral density (BMD) in overweight postmenopausal women.

Design

28 women consumed a 750 kcal/d energy deficit diet with either 18% of energy from protein via lacto‐ovo‐vegetarian sources (NP, n=16) or 30% of energy from protein with 40% of total protein from lean pork (HP, n=12, omnivorous) for 12 wk. Total body BMD was measured pre‐ and post‐intervention using DXA. Subsequently, one woman (case study) who was pre‐dosed with 41Ca consumed the NP and HP diets during randomized, sequential 8‐wk periods and BMD and bone resorption were assessed from DXA and urinary 41Ca/Ca ratio, respectively.

Results

With weight loss (NP ‐11.2%; HP ‐10.1%) BMD was not significantly changed (‐0.005 ± 0.003 g/cm2, ‐0.4%) in NP and decreased (‐0.016 ± 0.004 g/cm2, ‐1.3%) in HP (group‐by‐time P = 0.05). In the case study, BMD changed by 0.003 g/cm2 (0.2%) and ‐ 0.014 g/cm2 (‐1.1%) after the NP and HP periods, respectively. The 41Ca/Ca ratio was 15.5% higher during HP vs. NP (P = 0.05).

Conclusions

Consumption of a higher‐protein, omnivorous diet promoted decreased BMD, possibly due to increased bone resorption, after weight loss in overweight postmenopausal women.

Grant Funding Source

The National Pork Board
Dietary lipids and curcumin interact to affect gene expression in a mouse model of DSS induced chronic colitis
Authors: Jia Qian , Weeks Brad R , Goldsby Jennifer S , Lupton Joanne R , Chapkin Robert S , McMurray David N
Published: June 2021

Both fish oil (FO) and curcumin have potential as anti‐tumor and anti‐inflammatory agents. To explore their combined effects on dextran sodium sulphate (DSS) induced colitis, C57BL/6 mice were randomized to four diets (2x2 design) differing in the type of fat with or without curcumin supplementation (FO, FO+2% curcumin, corn oil (control, CO) or CO+2% curcumin). Following 2 cycle DSS exposure to induce chronic intestinal inflammation, addition of curcumin promoted mucosal injury/ulceration only in CO fed mice. Compared to other diets, interaction of FO and curcumin enhanced the resolution of chronic inflammation and suppressed (p<0.05) a key inflammatory mediator, NF‐kB, in colon mucosa. Examination of global gene expression profiles revealed that FO and curcumin combination blocked the expression of 38 genes induced by DSS treatment. Select genes represent non‐classical mediators of inflammation including ZBP1, PTHrP, Onecut2, Htra3, CCK, ZPF185, CSTAD and Syt15. These results suggest that dietary lipids and curcumin interact to regulate mucosal homeostasis to modulate chronic inflammation in the colon.

Grant Funding Source: NIH grants DK071707 and P30ES09106.
Antiobestic and antiinflammatory effect of doenjang (Korean fermented soy paste)
Authors: Park Kun‐Young , Chung Hae‐Young , Kwon Sun‐Hwa , Choi Jae‐Hoon , Kim Ji‐Young
Published: June 2021

Antiobestic effect of Korean fermented soy foods by using SD‐rats and C57BL/6 mice was studied. Doenjang and chungkukjang(short‐fermented soy paste) showed higher antiobestic activities when fed with high‐fat diet. Traditionally prepared doenjang especially exhibited highest antiobesity in the in vivo studies. The levels of serum cholesterol and triglycerides in the rats treated with doenjang diet significantly decreased to the levels of normal diet‐fed rats. Anthocyanins from the coat of black soybeans showed antiobestic effect. Doenjang prepared with A. oryzae and natural salt or bamboo salt for the fermentation increased antiobestic effect. Black soybean doenjang showed the highest antiobestic effect in C57BL/6 mice, expressing lower proteins of PPARγ and SREBP‐1 in the western blot analysis. Doenjang and chungkukjang significantly increased PPARα that suppressed inflammation in YPEN‐1 endothelial cells. The doenjang treated cells also decreased expressions of NF‐κB and COX‐2, but it increased adiponectin expression that caused lipid lysis. The expressions of PPARα and adiponectin increased, however, the NF‐κB, COX‐2 and iNOS protein levels considerably decreased in doenjang and chungkukjang treated SD‐rats.
Anti‐obesity and anti‐atherogenesis effects of Doenjang supplementation in overweight/obese Korean subjects: A randomized, double‐blind, placebo‐controlled clinical trial
Authors: Yang Jiae , Back Hyangim , Kim Sooran , Kim Mingul , Chae Soowan , Cha Youn‐Soo
Published: June 2021

To investigated the effects of Doenjang supplementation on anti‐obesity and anti‐atherogenesis in overweight/obese subjects. A total of 51 subjects (26 Doenjang group, 25 Placebo group, both BMI = 23 kg/m2 and WHR = 0.90 (men), WHR = 0.85 (women)) participated in a randomized, double‐blind, placebo‐controlled, oral Doenjang (26g/d)or placebo for 12 weeks. After 12 weeks, subjects in the Deonjang group showed a significant reduced in body weight, BMI, body fat mass, and body fat. CT scans revealed that total and subcutaneous fat areas were significantly reduced in the Doenjang group (p<0.001, p<0.005) and placebo group (p<0.05, p<0.05), but there were no significant differences between placebo and Doenjang group. Visceral fat area was significantly reduced in the Doenjang group (p<0.001) after the intervention, but the placebo group was not changed, thus it was significant difference between placebo and Doenjang group. In addition, total cholesterol level (p<0.05), LDL‐C (p<0.001), Apo B (p<0.001), Fasting plasma glucose and fructosamine concentration were significantly decreased in the Doenjang group and placebo group, but there were no significant differences between placebo and Doenjang group. The results suggested Doenjan supplementation that potential anti‐obesity and anti‐atherogenesis benefits might be more pronounced when combined with lifestyle modification.
Inhibition of Escherichia coli O157:H7 by lactic acid bacteria and organic acids
Authors: Kim Myunghee , Kim Wang June , Moon Gi‐Seong
Published: June 2021

Bacteriocin‐producing lactic acid bacteria (LAB) and their bacteriocins have been the subject of intensive study in the area of biopreservatives because they increase the shelf‐life of food. Major classes of bacteriocins produced by LAB are those bacteriocins that inhibit the organisms closely related to LAB and those bacteriocins that inhibit a broad spectrum of gram‐positive bacteria associated with food spoilage and food‐borne illnesses. It is known that few gram‐negative bacteria are sensitive to LAB bacteriocins because their outer membrane acts as a barrier and protects them from bacteriocins. We isolated a strain of bacteriocin‐producing LAB from kimchi and used it together with various organic acids for inhibiting Escherichia coli O157:H7 (E. coli O157:H7). As results, E. coli O157:H7 was reduced by 2.8‐log10‐unit in ground beef. It was found that combination of LAB and organic acids was useful for the inhibition of E. coli O157:H7 in food.
Assessment of serum 25‐hydroxyvitamin D [25(OH)D] status and its predictors in healthy toddlers aged 12‐20 months
Authors: Houghton Lisa A , Deng Xiaolan , Bailey Karl B , Heath Anne‐Louise M , Ferguson Elaine L , Szymlek‐Gay Ewa A , Skeaff C Murray
Published: June 2021

Background

Suboptimal vitamin D status is common in many populations worldwide, however, vitamin D status of young children remains poorly described.

Objective

The aim of the study was to measure serum 25(OH)D status and its predictors in toddlers aged 12‐20 mo.

Design

Serum 25(OH)D concentrations were measured in 193 toddlers living in the South Island of New Zealand (45°S). Sociodemographic, anthropometric and dietary intake data were collected. Multivariate linear regression analysis was used to determine the predictors of serum 25(OH)D concentrations.

Results

The median concentration of 25(OH)D was 55 nmol/L (interquartile range: 40 to 71 nmol/L) ranging from 42 nmol/L during the winter months to 69 nmol/L during the summer. Eighty‐seven of 193 participants (45%) had 25(OH)D concentrations less than 50 nmol/L and the majority of participants [151 of 193 (78%)] had levels below 75 nmol/L. Winter [Ratio of Means (RoM) 0.57, P < 0.001] and spring (RoM 0.77, P = 0.01) compared with summer, female sex (RoM 0.87, P = 0.01) and current breastfeeding (RoM 0.84, P < 0.05) were independently associated with decreased 25(OH)D concentrations. Ethnicity and body mass index were not associated with vitamin D status.

Conclusions

A high prevalence of serum 25(OH)D concentrations below 50 nmol/L was observed in this group of healthy toddlers. Significant predicators of vitamin D status were season, sex and breastfeeding.

Supported by Otago Medical Research Foundation [Laurenson Award]
Assessing the status of vitamin D in a family medicine clinic in the fall
Authors: Khandalavala Birgit
Published: June 2021

Objective

To determine the status of Vitamin D in patients presenting to a suburban family medicine clinic among life‐stage groups in the fall.

Background

Vitamin D deficiency has been reportedly low in most of the US population with the majority, up to 78% of the population having inadequate levels due to low dietary intake and limited sun exposure. Depending on the cutoffs, the low status is found to vary and 25 ‐hydroxyvitamin D levels of 35‐40 ng/ml are hence considered adequate and a reasonable goal.

Methods

Retrospective review of 73 ambulatory patients presenting to a suburban family medicine clinic in a Midwest city at latitude 41° were evaluated for their vitamin D status using the 25‐hydroxyvitamin D concentration and were grouped into 3 lifestages of 20‐49, 50‐69 and greater than 70 years of age. The Vitamin D levels were recorded in the fall when the level after the summer sun exposure should be at their highest. The results of Vitamin D levels were delineated as 0‐11 ng/mL, 12‐19 ng/mL, 20‐31 ng/mL, and above 32 ng/mL. None of the patients were housebound or incapacitated.

Results

A majority of the patients were found to have Vitamin D levels that were low‐ only 14 out of the 73 or 19.17%, had a level of optimum Vitamin D of greater than 32 ng/mL, with the large majority, 80.93%, being low.

Conclusion

Vitamin D deficiency was confirmed to be endemic and universal across the life‐stages with the older cohort having less deficiency, probably as a result of more supplementation with increasing age and/or time for sun exposure. Younger cohorts had surprisingly the most severe deficiency probably as a result of limited sun exposure. The prevalence of low levels in the fall, following usual maximum sun exposure over the summer months indicates that the prevalence probably can be suspected to be more pronounced and that programs for widespread supplementation will be required across all age groups to optimize vitamin D status.
Effects of dairy foods on angiotensin II and intracellular magnesium
Authors: West Sheila , Hilpert Kirsten , Bagshaw Deborah , Lefevre Michael , Most Marlene , Hinderliter Alan , Poupin Nathalie , Kris‐Etherton Penny
Published: June 2021

The goal of this study was to examine the contribution of dairy foods to the vascular effects of a DASH diet. In 23 adults with untreated hypertension, we measured flow mediated dilation (FMD), angiotensin II concentrations, and intracellular levels of calcium and magnesium. Participants were fed 3 experimental diets (5 wk each) in a randomized crossover study design. Diets included a dairy‐rich, high in fruits and vegetables diet (D‐F&V; 30% fat, 7% saturated fat [SFA], 3.4 servings/d dairy), a high fruits and vegetables diet (F&V; 30% fat, 7% SFA, 0.4 servings/d dairy), and an average Western diet (control; 36% fat, 15% SFA, 0.4 servings/d dairy). There was no significant effect of treatment on FMD. The D‐F&V diet significantly reduced intracellular calcium and significantly increased in intracellular magnesium vs. the other two diets (P<0.01). Furthermore, FMD scores on the two intervention diets were positively correlated with intracellular magnesium concentrations (r's = 0.51 to 0.77, p's< 0.02). Most importantly, our study validated a report from an in vitro study showing that dairy foods suppress angiotensin II concentrations. We found that angiotensin II concentrations decreased by 42% on the D‐F&V diet vs. the control diet. Taken together, these results confirm that dairy foods can alter intracellular cation concentrations and these changes may have beneficial effects on vascular tone.
Endothelial and smooth muscle cell deletion of Jagged1 independently reconstitute the cardiac and hepatic defects of Alagille Syndrome
Authors: Hofmann Jennifer J , Zovein Ann C , Iruela‐Arispe Luisa
Published: June 2021

Mutations in the human Notch ligand Jagged1 (Jag1) result in a multisystem autosomal dominant disorder called Alagille Syndrome. The most frequent abnormalities associated with this syndrome include paucity of bile ducts in the liver, which often requires liver transplant, and a wide range of cardiac defects. Minor skeletal and ocular anomalies can also be present with varying degrees of penetration. To gain a more thorough understanding of the function of this ligand during development, we employed a strategy involving cell‐specific deletion of Jag1 in mice. We found that inactivation of Jag1 in smooth muscle cell progenitors leads selectively to the hepatic defects associated with Alagille Syndrome, without any observed cardiac defects. Jag1 expression in vascular smooth muscle precursors is required for the morphogenesis of the biliary ducts, revealing the instructive and essential role of the vasculature in liver morphogenesis. In contrast, the deletion of Jag1 in the endothelium led to a wide spectrum of cardiac anomalies but lacked any hepatic defects. Together, these findings uncover the cellular basis for the hepatic and cardiac abnormalities associated with Alagille Syndrome and provide mechanistic information as to the essential role of Jag1 in biliary duct morphogenesis and cardiac outflow tract development.
Hep Par 1 antigen (CPS1) expression in liver cancer is regulated by DNA methylation
Authors: Liu Hongyan , Dong Jane (Huijia) , Zhang Lucy , Robertson Keith , Liu Chen
Published: June 2021

Hep Par 1 antibody is widely used in surgical pathology practice. We have previously identified the antigen of this antibody as " carbamoyl phosphate synthetase 1 (CPS1), a liver‐specific, rate‐limiting enzyme in the Urea Cycle. Expression of CPS1 appears to be related to the differentiation state of hepatocellular carcinoma (HCC). The objective of our study is to determine the expression profile of CPS1 in liver cancer and to elucidate the molecular mechanism of the gene expression control in carcinogenesis. Using human liver cancer tissues, primary hepatocyte culture, and liver cancer cell lines, we found that HCC cell lines and poorly differentiated HCC did not express CPS1, and all twenty HCC tissues examined expressed low levels of CPS. Primary hepatocyte culture had overt CPS1 expression. We also found that 5‐azacytidine (AZA) treatment restored CPS1 expression in the three cancer cell lines, Huh7, Huh7.5, and LH86, indicating the role of DNA methylation in CPS1 expression control. We then examined the DNA methylation status of CpG regions in the CPS1 promoter. Our data clearly show that the CpG regions are hypermethylated in liver cancer cells. Our study indicates that CPS1 is suppressed by DNA methylation in cancer cells, a reflection of aberrant DNA methylation in liver cancer. We suggest that CPS1 may play a role in carcinogenesis, and its methylation status may be a useful biomarker for liver cancer.
The role of cyclooxygenase‐2 in the development of steatohepatitis
Authors: Li Guiying , Han Chang , Xu Lihong , Wu Tong
Published: June 2021

This study was designed to investigate the role of cyclooxygenase‐2 (COX‐2) in the pathogenesis of steatohepatitis by using COX‐2 transgenic and knockout mice fed methionine‐and choline‐deficient (MCD) diet. We generated transgenic (Tg) mice with targeted expression of COX‐2 in the liver by using the albumin promoter‐enhancer driven vector. The COX‐2 transgenic (Tg), COX‐2 knockout (KO) and wild type mice were fed with MCD diet or normal diet for 3 weeks. Liver injury was assessed by histopathological examination and measurement of serum ALT and AST levels. Liver tissues were obtained for Western blot analysis. Hepatic triglycerides and lipid peroxide levels were determined. Our data showed that with the MCD diet, the COX‐2 Tg mice exhibited significantly elevated serum ALT and AST, higher levels of hepatic triglycerides and lipid peroxide, and more prominent hepatic steatosis and inflammation when compared to wild type mice (p<0.01). The COX‐2 KO mice showed significantly less liver injury than the COX‐2 Tg or wild type mice when these animals were placed on MCD diet. Western blot analysis revealed that transgenic expression of COX‐2 increases the accumulation of PPAR (peroxisome proliferator‐activated receptor)‐γ and cannabinoid CB1 receptor in the liver tissue. These findings suggest that hepatocyte COX‐2 facilitates the development of steatohepatitis and this effect may involve PPARγ and CB1.
Mice lacking transcription cofactor PRIC285 reveal attenuation of liver regeneration but are viable and develop normally
Authors: Viswakarma Navin , Matsumoto Kojiro , Jia Yuzhi , Rao M Sambasiva , Reddy Janardan K
Published: June 2021

PRIC285 was identified as a nuclear receptor transcription coactivator. To assess the biological significance of PRIC285, we developed whole‐body knock out mice using two‐loxP and two‐frt system and characterized them for peroxisome proliferator‐activated receptor α(PPARα)‐mediated transcriptional activation. Homozygous PRIC285 null (PRIC285−/−) mice appeared to develop normally and showed no consistent phenotypic differences from their wild‐type floxed littermates (PRIC285fl/fl). Treatment with PPARα ligands, such as Wy‐14,643 or ciprofibrate, resulted in the development of classical pleiotropic response, which includes hepatomegaly, peroxisome proliferation in hepatocytes, and increased levels of PPARα target genes. Although the PRIC285−/− phenotype does not result in gross abnormalities in the mouse, our data suggest that it may play an important role in liver regeneration after partial hepatectomy as assessed by BrdU labeling. Western blot analysis revealed reduction of several cell cycle associated proteins in PRIC285−/− mouse liver after partial hepatectomy as compared to wild type controls. These data indicates that although PRIC285 is not essential for PPARα‐mediated transcriptional activation in vivo it appears to affect hepatocellular proliferation. (This work was supported by NIH Grant DK083163).
Cellular Cartography…Mapping Protein Dynamics in Living Cells with novel Image Correlation Techniques
Authors: Wiseman Paul W.
Published: June 2021

Image correlation methods provide a new window of analysis for measurement of protein‐protein interactions and macromolecular transport properties from fluorescence images of living cells. We recently introduced spatio‐temporal image correlation spectroscopy (STICS) which measures vectors of protein flux in cells based on the calculation of a spatial correlation function as a function of time from an image time series. Here we will describe the application of STICS for measuring transport maps of adhesion related macromolecules such as integrin, alpha‐actinin, paxillin, talin, etc. within, or associated with the basal membrane in living fibroblast and CHO cells. These measurements have allowed us to propose a model for the molecular clutch that regulates connections between the extracellular matrix, integrins in the membrane and the cytoskeleton during cell protrusion and migration. We will also highlight recent advances we have made with a new form of reciprocal space ICS, called kICS, that allows us to measure unbiased transport coefficients and clustering of fluorescently labeled membrane proteins even if there is complex photophysics (such as nanoparticle emission blinking) of the probe.
C‐Jun N‐terminal kinase is involved in disassembly of apical junctions in model intestinal epithelia
Authors: Ivanov Andrei I , Naydenov Nayden
Published: June 2021

Pathogens and other external stressors disrupt integrity of epithelial barriers by disassembling tight junctions (TJ) and adherens junctions (AJ), however the role of stress‐related signaling in junctional disassembly remains poorly understood. The aim of this study was to investigate the role of a stress‐activated c‐Jun N‐terminal kinase (JNK) in disruption of apical junctions in model intestinal epithelia. A rapid AJ/TJ disassembly triggered by extracellular calcium depletion in T84 and SK‐CO15 cell monolayers was accompanied by activation (phosphorylation) of JNK and prevented by different pharmacological inhibitors of JNK. JNK‐1 but not JNK‐2 colocalized with mature apical junctions and siRNA‐mediated down‐regulation of JNK‐1 attenuated disruption of AJ and TJ in calcium‐depleted SK‐CO15 cells. Correspondingly, reassembly of apical junctions was accelerated by a JNK inhibitor, SP600125, and suppressed by JNK activator, anisomycin. In calcium‐depleted epithelial cells, inhibition of JNK blocked formation of contractile F‐actin rings suggesting that JNK regulates junctions by reorganizing the actin cytoskeleton. Furthermore, pharmacological analysis has shown that JNK signals downstream of Rho‐dependent kinase (ROCK). These finding suggest a novel role for JNK in the signaling pathway that links ROCK and F‐actin remodeling and leads to disassembly of epithelial apical junctions.
How did the bat get its wings?
Authors: Cretekos Chris Jack , Rasweiler John J , Behringer Richard R
Published: June 2021

The question of how bats evolved wings highly adapted for powered flight from limbs equally well adapted for walking has been a topic of fascination for centuries. In On the Origin of Species, Charles Darwin proposed how divergent limb morphologies evolved through "successive slight modifications" of a conserved pattern, stating "there will be little or no tendency to alter the original pattern" and that "The bones of a webbed foot might have all its bones, or certain bones, lengthened and the membrane connecting them increased so as to serve as a wing". One hypothesis fitting well with Darwin's ideas and with comparative molecular data is that divergence in form arises primarily from changes in the dynamics of gene expression during development. We are testing this hypothesis using a functional genetic approach comparing limb morphogenesis between mouse and bat. We initially focused on Prx1, a homeobox gene required for developing limb skeleton elongation. A limb‐specific Prx1 enhancer was identified using a LacZ reporter assay in transgenic mice. The endogenous limb enhancer of the mouse Prx1 gene was then replaced with that of the bat by gene targeting in mouse ES cells. Targeted mice express the mouse Prx1 gene under the control of the bat limb enhancer, develop forelimbs that are significantly, albeit slightly, lengthened and display elevated levels of Prx1 mRNA in limb bones during development.
Clinical Application of aCGH for Prenatal Diagnosis: Experience with >350 Cases
Authors: Cheung Sau Wai
Published: June 2021

We report our experience in using a targeted clinical aCGH for prenatal diagnosis including assessment of variants of uncertain significance and the ability to detect abnormalities not detected by karyotype.

Women who underwent amniocentesis or chorionic villus sampling (CVS) were offered aCGH as an adjunct test. Fetal DNA was analyzed on targeted BAC or oligonucleotide arrays, optimized for detection of genomic disorders with reduced detection of polymorphic copy number variants (CNV).

We analyzed 350 samples, most were amniotic fluid (82 %) and CVS (17%). The most common indications were advanced maternal age (N=123) and abnormal ultrasound findings (N=84). We detected 58 CNVs (19.3 %). Of these, 40 (13.3 %) were interpreted as likely benign, fifteen (5.0%) were of defined pathological significance while three (1.0 %) were of uncertain clinical significance. For seven (~2.3% or 1/43), aCGH contributed important new information. For two of these (1 % or ~1/150), the abnormality would not have been detected without aCGH analysis. We conclude that aCGH is an important new diagnostic tool for prenatal diagnosis of submicroscopic and larger unbalanced genomic rearrangements and for identification of the genomic content of marker chromosomes. Although aCGH detected benign inherited variants in 13% of cases, these did not present major counseling difficulties.
Single Cell Cytogenetics
Authors: Weier Jingly F , Weier Heinz‐Ulrich G , Fisher Susan , Munne Santiago
Published: June 2021

Aneuploidy contributes significantly to pregnancy losses and implantation failures. Preimplantation Genetic Diagnosis (PGD) of single cells for selection of diploid embryos has been shown to increase implantation and reduce spontaneous abortion rates. A major challenge in blastomere analysis is the fact that most cells are in interphase. We screened 12 chromosomes on interphase cells (X,Y,8,13,14,15,16,17,18,21,22) for PGD and allowed us to detect ~63% of the aneuploidies in spontaneous abortions. To complement FISH karyotyping of single cells, we developed comparative genome hybridization (CGH) on polar bodies and blastocysts. Results from 60 cases of polar body and 28 cases of blastocyst analysis showed 34% and 57% of normal cells, respectively. The most common aneuploidy seen via CGH involved chromosomes 22, 21, 15, 16, 20, 13, 9, X and Y. Preliminary clinical results showed that PGD combined with CGH leads to a significantly higher implantation rate than controls (61% vs. 28%, p<0.005). PGD is routinely followed by amniocentesis and CVS. We found that aneuploidy plays an important role at the fetal‐maternal interface, and results from interphase FISH studies need to be interpreted with caution; human cytotrophoblasts gain extra copies of chromosomes 2, 3, 5, 7, 13, 14, 15, 19, 21, 22, and X as they differentiate along the invasive pathway. Research support: HD45736 and UC Discovery.
Transcriptional Regulation of Self‐Renewal in Embryonic & Hematopoietic Stem Cells
Authors: Reizis Boris
Published: June 2021

Stem cells manifest a unique capacity to differentiate into various cell types while maintaining their own number in an undifferentiated state. The unique property of continuous self‐renewal is shared among different stem cell types, including pluripotent embryonic stem cells (ESC) and adult tissue‐specific stem cells such as hematopoietic stem cells (HSC). However, embryonic and adult stem cells are drastically different in their cell biology and genetic makeup, making their common regulation elusive. We have found that transcription factor Zfx is essential for the self‐renewal of both ESC in vitro and of adult HSC in vivo; moreover, Zfx overexpression facilitates ESC self‐renewal by opposing differentiation. In contrast, Zfx is dispensable for the differentiation capacity of stem cells and for the growth of their differentiated progeny. These studies have identified Zfx as a shared transcriptional regulator of ESC and HSC, revealing a common genetic basis of self‐renewal in embryonic and adult stem cells. Our current studies will be presented, which include the overexpression of Zfx in HSC and the dissection of Zfx target genes and mechanism of action in normal and leukemia‐propagating stem cells. The implications of these findings for the generation of HSC from embryonic stem cells in vitro will be discussed.
Anatomy of Human Life: Moving Ahead From Considering An Embalmed Cadaver As Your First Patient
Authors: Gannon Patrick John , Metzger Keith A , Moser Eileen M , Kheck Nancy , Wallach Paul M , Stagnaro‐Green Alex
Published: June 2021

First exposure to a deceased person for many medical students is the cadaver in gross anatomy. This can give rise to a myriad of anxiety provoking experiences from confronting mortality to humanistic concerns. Further, students know they are likely expected to dissect and dismember the body. To assuage these concerns it is commonly suggested "consider this body your first patient". Since anxieties might persist, does this approach really engender comfort and promote clinical skills? Here we present a new approach in a new school that might help bridge any gaps.

Students can be exposed to surface anatomy of the body before they meet the face of death in lab. We propose students become familiar with body surface phenomena such as pulses, reflexes, bony & muscular landmarks and auscultation. Experiences serve as living links to systems and deep structures. The "first patients" will be themselves, their peers and live simulation models. Further, the nature of a living individual's body is welcoming, realistic and distinct.

We conclude that our new approach will have students initiate their lifelong journey of learning human anatomy as physicians with fond memories of an unforgettable founding experience.
Designing and Implementing Neurosciences Curricula in New Medical Schools
Authors: Guttmann Geoffrey D , Stefan Cristian
Published: June 2021

As we are well into the new millennium, 22 new medical schools are or will be ready to serve the need for physicians within the US healthcare system as well as 3 new branches of existing medical schools and one new medical school in Canada. This situation presents faculty involved in designing, teaching and administration of courses an exciting opportunity to develop curricula that can be unique, learner friendly, and clinically relevant. In order to develop the curricula, one must know the mission, vision, and values of the new medical school. Each of these variables and other factors will govern what type of curriculum and approach to learning one should take. Due to its complex nature and the various settings that have evolved at different institutions over the years, Neuroscience presents special opportunities and challenges in maintaining its identity yet harmoniously blending into the integrative curriculum. We summarize the main principles in building a robust clinically oriented Neuroscience component in their new curricula including the appropriate coverage of material; time factors; selecting the active pedagogical modalities in teaching and assessing; ensuring the continuity of information across the curriculum; and the links with other disciplines. We also discuss how we independently applied and intertwined these principles to the courses and programs we are involved in at The Commonwealth Medical College in PA and Touro University College of Medicine in NJ.
Midbrain Neurons Integrate Information From Different Senses To Produce Adaptive Behaviors
Authors: Stein Barry Edward
Published: June 2021

Midbrain Neurons Integrate Information From Different Senses To Produce Adaptive Behaviors. Barry E. Stein. Department of Neurobiology & Anatomy, Wake Forest University, School of Medicine, Winston‐Salem, North Carolina, 27157, USA

Midbrain neurons in the superior colliculus (SC) are able to synthesize information from different senses, thereby substantially altering their responses to external stimuli (visual, auditory and somatosensory) and the behaviors that depend on them. Cross‐modal stimuli whose spatial and temporal properties make them likely to be associated with common events enhance physiological responses, and also enhance behavioral performance on orientation and localization tasks. Often, these performance benefits are quite striking, substantially increasing the probability of responding appropriately to biologically relevant events. In contrast, cross‐modal stimuli that are more likely to be associated with different external events either yield no multisensory integration or degrade physiological responses and overt behavior. Using the cat and monkey SC as models, we have found that neither these properties of SC neurons nor their behavioral benefits are present in the neonatal brain. Their maturation was studied in cat and found to be gradual and to be dependent on two factors: the development of a cooperative interaction between the descending projections to the SC from different sensory subdivisions of association cortex (e.g., visual and auditory), and the acquisition of extensive postnatal experience with the relevant cross‐modal cues. The biological significance of this circuit for underlying adaptive behavior, its developmental antecedents, and the likely component of the circuit that acquires the relevant cross‐modal experience will be discussed. This research was supported by NIH grants EY016716 and NS36916.
Chaperone‐assisted protein folding in health and disease
Authors: Hartl F. Ulrich
Published: June 2021

Within the crowded environment of the cell many proteins depend on molecular chaperones for efficient folding. Assistance of protein folding is provided by several types of chaperone which act to prevent misfolding and aggregation, often in an ATP‐dependent mechanism. In the cytosol, nascent chain‐binding chaperones, including trigger factor and Hsp70, stabilize elongating chains on ribosomes in a non‐aggregated state. Folding is then achieved either on controlled chain release from these factors or following polypeptide transfer to downstream chaperones, such as the chaperonin GroEL, which provides a compartment for single protein molecules to fold in isolation. Recent work indicates that these chaperonin nano‐cages not only function to prevent aggregation but also to modulate the energy landscape of the folding process, thereby accelerating folding for certain proteins. The cytosolic chaperone machinery also has an important role in controlling protein misfolding and aggregation in the context of neurodegenerative disorders such as Parkinson's and Huntington's disease (HD). Specifically, Hsp70 and chaperonins can cooperate to prevent the formation of toxic protein oligomers. A reduction in the general capacity of the chaperone system during aging may be critical in the manifestation of these late‐onset diseases, suggesting up‐regulation of chaperones as a possible therapeutic strategy.
Coordinated Regulation by Shp2 Tyrosine Phosphatase of Signaling events Controlling Insulin Biosynthesis in β‐cells
Authors: Zhang Sharon S. , Hao Ergeng , Yu Jianxiu , Liu Wen , Levine Fred , Feng Gen‐Sheng
Published: June 2021

Pancreatic β‐cell dysfunction contributes to the development of all forms of diabetes. However, molecular signaling defects underlying β cell failure are not fully understood. Shp2 is a widely expressed protein tyrosine phosphatase (PTP) with two SH2 domains. Shp2 is implicated in pathways activated by receptor tyrosine kinases (RTKs) or cytokine receptors. In particular, Shp2 binds to tyrosine‐phosphorylated IRS proteins and functions in insulin‐regulated glucose metabolism in insulin‐responsive tissues. However, whether Shp2 plays a biological role in insulin‐producing pancreatic β cells is unclear. We generated conditional mutant mice in which Shp2 is selectively deleted in the pancreas (Shp2Panc‐/−). Shp2Panc‐/− mice exhibit reduced glucose‐stimulated insulin secretion and progressively impaired glucose tolerance. Shp2‐deficient β‐cells show attenuated insulin gene expression and reduced insulin content. Consistently, siRNA‐mediated Shp2 knockdown in rat insulinoma INS‐1 832/13 cells resulted in significantly decreased insulin secretion and disrupted expression profile of several β‐cell specific genes. Biochemical analyses revealed defects in the Akt/FoxO1 and Erk pathways, leading to decreased Pdx1 expression/activity and insulin biosynthesis in Shp2‐deficient β‐cells. Therefore, this study identifies Shp2 as a signal coordinator in β‐cells, which orchestrates multiple pathways controlling insulin biosynthesis to maintain glucose homeostasis.
Tyrosine Kinase Mechanisms and Pathways
Authors: Cole Philip
Published: June 2021

Protein tyrosine kinases (PTKs) are critical signaling enzymes and their dysregulation in disease states has made them attractive targets for pharmacologic inhibition. We will highlight several of the chemical approaches that we have taken to analyze PTK catalytic mechanisms, substrate selection, and regulation. In particular we will describe how designed bisubstrate analog inhibitors of PTKs and chemical rescue of mutation have both been useful when combined with crystallographic and mass spec analysis. Representative tyrosine kinase examples to be discussed include: Src, Abl, and EGFR.
Initiation at the human Fragile X (FMR1) origin of chromosomal replication
Authors: Fanning Ellen , Gerhardt Jeannine , Gray Steven J , Guler Gulfem D
Published: June 2021

Eukaryotic chromosomal DNA replication begins at origins marked by pre‐replication complexes (pre‐RCs) containing ORC, MCM2‐7, and other proteins. However, understanding of mammalian origins and their possible role in maintenance of genomic stability remains incomplete. We have mapped a replication origin 5' of the FMR1 gene, a heritable fragile site on the human X chromosome. As expected, the FMR1 origin binds to pre‐RC proteins in vivo. FMR1 alleles with heritable CGG repeat expansions suffer chromosome breaks and gaps when cells experience folate deficiency, but how the expansion leads to chromosome fragility is not clear.

Recent clues from the human DNA helicase HDHB may lead to one answer for this question. In late M/G1, HDHB assembles in pre‐RCs at the laminB2, MCM4, and FMR1 origins, but not in flanking sequences. Based on siRNA and dominant negative approaches, HDHB is important for initiation. At G1/S, HDHB is released from the laminB2 and MCM4 origins and much of it is exported from the nucleus. However, a low level of HDHB is retained on bulk chromatin during S phase and this fraction is increased in cells exposed to agents that stall fork progression. To ask whether HDHB may localize at stalled replication forks even in unperturbed cells, we used ChIP to study the FMR1 origin region and the common fragile site FRA16D. HDHB was strongly enriched in S phase at both sites and not in flanking regions. Taken together, the data suggest that HDHB functions in initiation of replication at origins and in preventing or repairing stalled replication forks that arise in specific regions even in unperturbed cells.