bluuebunny/crossref_metadata_2025_split huggingface dataset:
A 10 base pair element that is essential for autonomous plasmid replication in procyclic trypanosomes is dispensable in bloodstream‐forms
Authors: Urban John , Sauchelli Mark , Patnaik Pradeep 
Published: June 2021

Trypanosoma brucei is a unicellular digenetic parasitic protozoan that alternates between the bloodstream of its mammalian host (bloodstream–forms) and the mid‐gut and salivary glands of its insect vector (procyclic and metacyclic forms respectively). These stages are bio‐chemically distinct.Chromosomal DNA replication is an unexplored aspect of trypanosome biology. We are using an autonomously replicating plasmid as a model system to identify sequences that regulate this fundamental biological process in the parasite. One such element maps to a developmentally modulated procyclin promoter that drives reporter gene transcription on this episome. Linker substitution of a 10 base‐pair segment within Domain III of this promoter reduces reporter gene expression by ~10 fold, but abolishes the ability of this plasmid to replicate in procyclic trypanosomes. The close association of replication and transcription control elements and the interplay between these two processes as the parasite shifts from one developmental stage to another is of interest to us.We now demonstrate that the requirements for the replication of these episomes differ between the two developmental stages of this parasite as the 10 base pair Domain III element is dispensable in bloodstream‐forms. In addition, our results suggest that the procyclin‐promoter on this plasmid does not support reporter gene expression in bloodstream forms. Since there are no other known T. brucei promoters on this episome, it would appear that transcription (and possibly replication) initiates adventitiously on this plasmid in the blood‐stage of this parasite. Promiscuous initiation of transcription and replication may be an interesting feature of trypanosome biology.Funded by William Paterson University SURP and NIH
The influence of inflammation on the human visceral adipose tissue secretome
Authors: Vonk Roel J. , Szalowska Ewa , Weening Desiree , de Vries Marcel , Hoek Annemieke , Roelofsen Han 
Published: June 2021

Chronic inflammation of obese adipose tissue is involved in the development of insulin resistance and type 2 diabetes, probably via altered secretion of adipokines and free fatty acids. To determine how inflammation changes the adipose tissue secretome, adipose tissue was challenged with LPS, a potent immune activator. Secretome changes were analyzed by a quantitative proteomics approach: Comparison of Isotope Labeled Amino acid Incorporation Rates (CILAIR). CILAIR compares incorporation rates of 13C‐labeled lysine in secreted proteins between conditions (Mol Cell Proteomics 2009, 8:316).MethodsHuman visceral adipose tissue was divided over six dishes. 13C‐Lys containing medium was added and to three dishes also LPS (100 μg/ml). Dishes were incubated for 24 hrs. Media were collected and processed separately, involving SDS‐PAGE fractionation, in‐gel digestion of excised bands and LC‐MS/MS. Database searching with ProteinPilot (Applied Biosystems) provided identifications and C13/C12 ratios.Results37 proteins were significantly changed (p<0.05) in expression of which 19 were up‐regulated by LPS and 19 were down‐regulated. Examples of up‐regulated proteins are: Plasminogen activator inhibitor 2, Growth‐regulated alpha protein and Interleukin‐6. In addition, 12 proteins were only expressed in the inflammatory condition. Examples are: Tumor necrosis factor‐α and C‐C motif chemokine 2 and 20.ConclusionThese results indicate that inflammation profoundly changes the adipose tissue secretome. Secretion of several inflammatory cytokines and chemokines was up‐regulated as well as proteins involved in cell adhesion of attracted immune cells. These findings may have implications for the regulation of whole body insulin sensitivity and energy metabolism.
Differential Gene Expression of Cutaneous Cells Upon Exposure to Staphylococcal Enterotoxin B (SEB) Superantigen
Authors: Srinivasan Seshamalini , Miller Stacy‐Ann , Shupp Jeffrey W , Crosby Margaret C , Hammamieh Rasha , Jett Marti 
Published: June 2021

Staphylococcus aureus, a gram‐positive bacterium initiates lesions through the production of pyrogenic toxins termed Staphylococcal enterotoxins (SEA‐J), and toxic shock syndrome toxin‐1 (TSST‐1) causing staphylococcal food poisoning and toxic shock syndrome. SEs are prototypical superantigens (sAgs), which trigger massive V‐beta specific T cell proliferation without the need for internalization, processing, or presentation resulting in elevated serum cytokine levels. The presence and the detectability of these sAgs in the sera of burn victims is not clearly understood. We have detected circulating SEA, SEB and TSST‐1 toxins among 20% of the burn victims. In this study, we aim to elucidate the chronology of intoxication along with in vitro studies to better understand the potential effects of this SEB toxin on skin cells. Primary cultures of human keratinocytes, melanocytes, dermal vascular endothelial cells and dermal fibrobalsts were grown and treated with varying doses of SEB for different lengths of time. RNA was extracted by trizol method and oligonucleotide microarray was performed. Feature extraction and statistical analysis show that genes encoding negative acute phase response proteins, oxidative stress response, NFκB signalling, Anti‐apoptosis were highly upregulated and genes responsible for death receptor signalling, endothelin‐1 signalling, growth hormone signalling were significantly downregulated. The objective of this study is to elucidate the pathogenesis of SEB intoxication in skin cells and thereby help with new treatment strategies in wound healing.We extend our heartfelt thanks to Washington Hospital ct Res Fund and Fire Fighters Burn res for their support
Overexpression of recombinant human procathepsin D in E. coli
Authors: Keefer Ryan , McConnell Matthew , Ye Alice , Chmielowski Jennifer , Berryman Laura , Wen Lisa , McConnell Rose 
Published: June 2021

Cathepsin D is an aspartyl lysosomal protease that catalyzes protein cleavage. It is involved in the process of tumor invasion and metastasis. The cathepsin D enzyme has been considered as a potential target for cancer therapy. The objective of this research is to prepare functional recombinant cathepsin D enzyme which will be used in the development of new cathepsin D inhibitors. Human procathepsin D cDNA, purchased from OpenBiosystems, was amplified by PCR and sub‐cloned into XhoI site of pET15b. The procathepsin D‐pET15b construct was then transformed into JM109. The recombinant plasmid was isolated from the JM109 and transformed into BL21(DE3)pLysS cells for expression. Expression of recombinant procathepsin D protein in the transformed BL21(DE3)pLysS cells was induced with IPTG. The level of expression was analyzed by SDS‐PAGE. High level expression (greater than 50% of total cellular proteins) of the His‐tagged procathepsin D fusion protein was achieved when cells were grown in terrific broth. The ability to produce procathepsin D enzyme will permit a drug discovery program for development of newer effective inhibitors of cathepsin D in the near future.Supported by National Cancer Institute at NIH Grant No. 3R15CA086933‐04 and 3R15CA086933‐04A2S1)
Synthetic Method for the Development of Monorhamnolipids
Authors: Coss Clifford Scott , Polt Robin , Pemberton Jeanne , Maier Raina 
Published: June 2021

Presented here is a cost‐effective and efficient synthesis and characterization of a variety of monorhamnolipids for the purpose of identification of biosurfactant properties. A complex mixture of mono‐ and dirhamnolipids can be extracted from the lipopolysaccharide (LPS) of the Gram‐negative bacterium, Pseudomonas aeruginosa, for the identification and understanding of the biosurfactants’ structural features, micellar activity, surface tensions and critical micelle concentrations (CMC). Figure 1 shows examples of a C10, C10‐mono‐ and diramnolipid. However, purification of this complex mixture is quite difficult and tedious and is never truly achieved. Therefore, surface tension and CMC measurements do not represent one pure rhamnolipid micellar system. Pure rhamnolipids can be achieved through synthesis and purification, thereby eliminating a need for extraction and the tedious purification process. Synthesis is achieved using fundamental carbohydrate and lipid chemistry, including an in depth study of rhamnoside glycosylation using a variety of Lewis acids. The final result is a general procedure for the cost‐effective, high‐yield production of monorhamnolipids varying in fatty‐acid chain length. This work is supported by a grant from the National Science Foundation (NSF).Examples of a mono‐ and dirhamnolipid.image
Effect of iron status on lipid and glucose metabolism
Authors: Kim Jonghan , Buckett Peter D. , Liu Sihao , Li Yingxia , Cohen David E. , Lee Chih‐Hao , Wessling‐Resnick Marianne 
Published: June 2021

Belgrade (b/b) rats have impaired divalent metal transporter‐1 (DMT1) activity and display iron‐loading anemia. To investigate the relationship between iron status and lipid/glucose metabolism, we characterized the metabolic phenotype of b/b rats. Fasting serum triglyceride (TG) levels were higher in homozygous b/b rats compared to heterozygous littermate (+/b) control rats at the age of 6–18 weeks. By 18 weeks of age, b/b rats also exhibited mild hyperglycemia. Although serum insulin level was reduced in b/b rats, its secretion was not affected; rather, b/b rats were insulin‐sensitive, suggesting that b/b rats have altered lipid metabolism and consequently, impaired glucose homeostasis. These alterations appear to be related to iron‐loading since anemic +/b rats fed an iron deficient diet showed normal serum TG. Neither hepatic TG levels nor lipogenic gene expression was altered in b/b rats. After injection with Triton WR1339, a lipoprotein lipase inhibitor, TG secretion kinetics were unchanged in b/b rats, suggesting that hypertriglyceridemia results from reduced TG clearance and not from enhanced TG secretion. The apoE/apoB lipoprotein ratio in b/b rats was 50% of that observed for +/b rats, further supporting the idea that b/b rats have slower plasma VLDL removal. Supported by NIH R90 DK071507 and R01 ES014638.Grant Funding Source: NIH
Changes of erythropoietin concentrations in plasma and kidney induced by zinc deficiency in rats
Authors: Konomi Aki , Yokoi Katsuhiko 
Published: June 2021

Some researchers reported that oral zinc (Zn) effectively cured iron refractory anemia. We reported before that Zn deficiency depressed plasma erythropoietin (EPO) concentration in rats. We propose a hypothesis that Zn deficiency depresses EPO production in kidney. To test the hypothesis, thirty 3‐week‐old male SD rats were assigned into 3 groups of 10 for the 4‐week study receiving AIN‐93G‐based EDTA‐treated casein diet: ad libitum fed control group (AIN‐93G), moderate Zn‐deficient group (4.5 mg Zn/kg diet) and pair‐fed group (AIN‐93G). Plasma and kidney (medulla and cortex) EPO concentrations were measured using ELISA kit. Difference between groups was statistically analyzed by Fisher's PLSD. P value less than 0.05 was considered significant. Plasma EPO concentration of Zn‐deficient group was significantly decreased compared with control group, and pair‐fed group was marginally decreased compared with control group (P=0.056). Kidney medulla EPO concentration was decreased in Zn‐deficient group compared with pair‐fed group. Kidney medulla EPO concentration in pair‐fed group was higher than that of control group but the difference was not significant. No significant difference was observed in kidney cortex EPO concentration. These results support the hypothesis that Zn deficiency impairs EPO production in kidney.This work was supported by Japan Society for the Promotion of Science Young Scientists (Start‐up) (21800073).
Soy isoflavones increase bone mineral density without altering markers of whole body vitamin D or calcium metabolism in mice
Authors: Li Yan , Xue Yingben , Fleet James C 
Published: June 2021

The soy isoflavone genistein enhances the biological activity of the vitamin D (VD) metabolite 1,25 dihydroxyvitamin D (1,25D) in cultured cells by inhibiting CYP24‐mediated degradation of the hormone. We examined if similar effects can be recapitulated in vivo to improve calcium and bone metabolism. Weanling male B6D2F1 mice were fed AIN‐93G diets containing 50 or 400 IU VD with, or without, Novasoy® 400 soy isoflavone concentrate (added to provide 250 mg genistein/kg diet) until 13 weeks of age. Bone mineral density (BMD) was measured by DEXA. Serum VD metabolites were measured by RIA. Gene expression in duodenum and kidney was measured by RT‐PCR. Higher dietary VD intake increased serum 25 hydroxyvitamin D (25D) from levels viewed as adequate (61 ± 6 nM) to optimal (164 ± 10 nM) for human health but this had no impact on either BMD or molecular indices of calcium metabolism. In contrast, isoflavones increased both serum 25D and femur BMD by 15% (p < 0.01). However, neither serum 1,25D nor tissue gene expression (e.g. duodenal calbindin D9K, TRPV6; renal calbindin D9K or D28K, TRPV5) was influenced by isoflavones. Our data show that the beneficial effect of soy isoflavones on bone that we observed is independent of their ability to modulate whole body VD or calcium metabolism and suggest a direct effect of isoflavones on bone formation or turnover. We thank ADM for Novasoy® 400. Funding: Purdue‐UAB Botanicals Center Pilot Grant.Grant Funding Source: Purdue‐UAB Botanicals Center Pilot Grant
Low glycinin soymilk ameliorates body fat accumulation and improves serum antioxidant status in overweight men
Authors: Fernandez Dina , Martinez‐Villaluenga Cristina , Bringe Neal A , de Mejia Elvira Gonzalez 
Published: June 2021

Low glycinin soybeans were enriched in β‐conglycinins, with similar amino acid, isoflavone, and fatty acid profiles as conventional soybean. β‐conglycinins and other soybean components are potential protective agents against body fat accumulation and inflammation. The objective was to compare low glycinin soymilk (LGS) with conventional soymilk (S) and cow's milk (M) for effects on body fat accumulation, serum lipids, antioxidant capacity and biomarkers of oxidative stress and inflammation. In a randomized, double‐blind, placebo controlled, IRB approved study, overweight men (BMI > 25) were divided into three groups and fed daily for 3 months 500 ml of LGS, S or M. No changes were observed in their calorie intake and physical activity (p > 0.05). LGS consumption caused less total body fat accumulation compared to S and M. Oxidized LDL was dramatically decreased after LGS consumption (−75%) in comparison to M (p = 0.03). The rate of increase of serum antioxidant capacity was faster after consumption of LGS (8%, 16%, and 21%) compared to S (−3%, 12%, and 18%) at 1, 2 and 3 months, respectively, but no increase was observed for M. Interleukin‐6 decreased after 3 months for LGS consumption but not M (p < 0.03). LGS ameliorated body fat accumulation and improved antioxidant status compared to S in overweight men. LGS consumption may be useful to prevent body fat accumulation and reverse oxidative stress.Monsanto Co., ADM and ISAGrant Funding Source: Monsanto, ADM, Illinois Soybean Association
Short‐term celecoxib does not alter endothelial‐dependent dilation in healthy humans
Authors: Wenner Megan M. , Edwards David G. , Farquhar William B. 
Published: June 2021

Cyclooxygenase‐2 (COX‐2) derived prostaglandins play an important role in regulating vascular tone. COX‐2 inhibition has been shown to improve endothelial‐dependent dilation in adults with cardiovascular disease. Variability in dietary salt intake may also influence endothelial‐dependent dilation.PURPOSETo determine if the COX‐2 inhibitor celecoxib (CX2) alters endothelial‐dependent dilation in healthy adults under controlled dietary salt conditions.METHODSTen normotensive men (37±2 years) completed placebo (PL) and CX2 conditions (100 mg BID, Pfizer, Inc.) for 3 days. Each condition was separated by at least 1 month (double blind, crossover). To control for the possible confounding effects of dietary sodium, subjects consumed 100 mmol of sodium/day during the PL and CX2 conditions (controlled feeding study). 24‐hour urinary sodium excretion confirmed dietary compliance. Brachial artery flow mediated dilation (FMD) was measured to assess endothelial‐dependent dilation on the last day of the each condition.RESULTSSystolic and diastolic pressures were similar between PL and CX2 (114±3/65±2 mmHg vs. 115±3/65±2 mmHg; p > 0.20). FMD was not different between PL and CX2 (7.4±1.1 vs. 8.1±1.2 %; p=0.36).CONCLUSIONDuring controlled dietary sodium conditions, short‐term celecoxib does not alter endothelial‐dependent dilation in healthy adults. Supported by HL07485 and AHA 0815504D
PLACENTAL ISCHEMIA TRIGGERS IMMUNE ACTIVATION AS LEUKOCYTE OVERPRODUCTION OF SFlt‐1: A STEP IN THE PATHOGENESIS OF PREECLAMPSIA?
Authors: Wallace Kedra , Rutland Sarah , TamTam Kiran , Weimer Abram , Martin James N , LaMarca Babbette 
Published: June 2021

Plasma, amniotic fluid, and placental soluble fms‐like tyrosine kinase (sFlt‐1) mRNA is increased in patients with preeclampsia. We and others have shown placental ischemia (PI), TNF alpha and agonistic autoantibodies to the angiotensin II type I receptor are important stimuli for sFlt‐1 production during pregnancy. The objective of this study was to determine if leukocytes stimulated in rats with PI are a source of circulating sFlt‐1.Sprague‐Dawley rats were anesthetized on day 14 of pregnancy and underwent either examination under anesthesia (NP) or reduced uterine perfusion pressure (RUPP). Rats were instrumented with a carotid catheter for arterial pressure measurement (MAP) on day 19. Plasma was collected and leukocytes isolated and cultured overnight in RPMI containing, 1.022 ng/ml IL‐2 and 4 ng/ml IL‐12 at 5% CO2 and 37°C. Cell culture media was removed and ELISA utilized to determine sFlt‐1.MAP increased from 102 +/− 1 mmHg in NP rats to 127 +/− 2 mmHg in RUPP rats. Circulating sFlt‐1 was 963 pg/ml in NP rats vs 1493 pg/ml in RUPP rats. In addition, sFlt‐1 from NP PBL culture was 30+/−8 pg/ml while RUPP sFlt‐1 PBL culture increased significantly to 88+/−20 pg/ml (P <0.01)The mechanisms whereby sFlt‐1 over expression occurs during preeclampsia are not well defined. This study demonstrates that immune cells activated response to PI are a source for excess sFlt‐1.
Doxorubicin induced diaphragm muscle weakness is mediated through TNFR1 signaling
Authors: Gilliam Laura A. A. , Reid Michael B. 
Published: June 2021

Cancer patients who receive doxorubicin, a common chemotherapy drug, exhibit decreased maximal inspiratory pressures. This decrement suggests diaphragm weakness, which may cause dyspnea and exercise intolerance. Previous data from our laboratory shows that doxorubicin‐induced limb muscle weakness involves TNF/TNFR1 signaling, leading us to hypothesize that doxorubicin causes diaphragm muscle dysfunction through TNF/TNFR1 signaling. We injected C57BL/6 male mice intravenously with doxorubicin (20 mg/kg), a dose equivalent to chemotherapy given to lung cancer patients. Diaphragm bundles were excised three days post injection. Compared to controls, doxorubicin lowered maximal force in the diaphragm by 23 ± 4 % (mean ± SE; n= 11, p<0.05). TNFR1 receptor‐deficient mice injected with doxorubicin (20 mg/kg) were protected against the depression in specific force (TNFR1−/−; dox: 21 ± 2 N/cm2, control: 22 ± 1; n= 8/group). We tested whether a clinically available anti‐TNF drug, etanercept, could prevent diaphragm weakness. Mice were injected with etanercept (5 mg/kg), a soluble TNF receptor, in combination with doxorubicin (20 mg/kg). Etanercept prevented the depression in force caused by doxorubicin (etanercept + dox: 22 ± 2 N/cm2, dox: 16 ± 1; n= 5/group). Our data shows that doxorubicin causes diaphragm muscle weakness, an effect mediated through TNF/TNFR1 signaling.Supported by: T32 HL086341‐02 and AHA predoctoral fellowship (LAAG)
uPA and macrophages in muscle regeneration
Authors: Novak Margaret L , Nguyen Mai‐Huong , Cheng Ming , Sisson Thomas H , Koh Timothy J 
Published: June 2021

The plasminogen system and macrophages play important roles in tissue repair following injury. Mice deficient in the urokinase‐type plasminogen activator (uPA) exhibit impaired accumulation of macrophages following muscle injury and severely impaired muscle fiber regeneration. We hypothesized that macrophage expression of uPA promotes macrophage migration into damaged muscle and subsequent muscle regeneration. To test this hypothesis, we cross‐bred macrophage‐specific uPA overexpressing mice with uPA null mice to generate mice that express uPA only in macrophages. Such macrophage‐only uPA expression was sufficient to restore uPA activity, macrophage accumulation and muscle fiber regeneration in otherwise uPA null mice. In addition, macrophage‐specific overexpression of uPA appears to enhance muscle fiber regeneration in wild‐type mice. In vitro studies demonstrated that uPA promotes macrophage migration through both proteolytic and non‐proteolytic mechanisms, which may include the proteolytic activation of HGF. We also found that uPA promotes myoblast proliferation in vitro through its proteolytic activity and this process was inhibited by an HGF blocking antibody. In summary, macrophage expression of uPA plays a critical role in muscle regeneration.Supported by the Department of Defense Peer Reviewed Medical Research Program.
Effect of menstrual cycle on exercise performance and cardiovascular responses in female long‐distance runners
Authors: Nagai Mizuki , Chiba Haruka , Haga Mayu , Sasaki Konosuke , Maruyama Ryoko 
Published: June 2021

PurposeThe aim of the study was to investigate the effects of the menstrual cycle on exercise performance and cardiovascular responses in female long‐distance runners.MethodsFifteen well‐trained female long‐distance runners aged 19.4±1.1 years were monitored for basal body temperature (BBT), systolic and diastolic blood pressure (SBP, DBP) and heart rate (HR) every morning for 2 months. They also recorded their menstrual periods, and ratings of perceived exertion (RPE) as exercise performance during the menstrual phase, the follicular phase, and the luteal phase.ResultSeven runners had normal menstrual cycle (NMC). Eight runners had abnormal menstrual cycle (AMC), including polymenorrhea (n = 2), oligomenorrhea (n = 3) and amenorrhea (n = 3). SBP, DBP, and RPE were significantly higher in the menstrual phase than in the follicular phase in runners with NMC, whereas SBP and DBP did not change significantly during the menstrual cycle in those with AMC. SBP and DBP tended to be higher in the luteal phase than in the follicular phase in runners with NMC. HR did not change significantly during the menstrual cycle in either group.ConclusionA large number of female long‐distance runners appear to have menstrual disturbances, and increased SBP and DBP in the menstrual phase may negatively influence exercise performance.