Abstract

Diabetes mellitus with hyperglycaemia is a major risk factor for malignant cardiac dysrhythmias. However, the underlying mechanisms remain unclear, especially during the embryonic developmental phase of the heart. This study investigated the effect of hyperglycaemia on the pulsatile activity of stem cell-derived cardiomyocytes. Mouse embryonic stem cells (mESCs) were differentiated into cardiac-like cells through embryoid body (EB) formation, in either baseline glucose or high glucose conditions. Action potentials (APs) were recorded using a voltage-sensitive fluorescent dye and gap junction activity was evaluated using scrape-loading lucifer yellow dye transfer assay. Molecular components were detected using immunocytochemistry and immunoblot analyses. High glucose decreased the spontaneous beating rate of EBs and shortened the duration of onset of quinidine-induced asystole. Furthermore, it altered AP amplitude, but not AP duration, and had no impact on neither the expression of the hyperpolarisation-activated cyclic nucleotide-gated isoform 4 (HCN4) channel nor on the EB beating rate response to ivabradine nor isoprenaline. High glucose also decreased both the intercellular spread of lucifer yellow within an EB and the expression of the cardiac gap junction protein connexin 43 as well as upregulated the expression of transforming growth factor beta 1 (TGF-β1) and phosphorylated Smad3. High glucose suppressed the autorhythmicity and gap junction conduction of mESC-derived cardiomyocytes, via mechanisms probably involving TGF-β1/ Smad3 signalling. The results allude to glucotoxicity related proarrhythmic effects, with potential clinical implications in foetal diabetic cardiac disease.

Abstract

The exposure of the developing foetal heart to hyperglycaemia in mothers with diabetes mellitus is a major risk factor for foetal cardiac complications that lead to heart failure. We studied the effects of hyperglycaemia on the layout of cardiac myofilament proteins in stem cell-derived cardiomyocytes and their possible underlying mechanisms. Mouse embryonic stem cells (mESCs) were differentiated into cardiac-like cells and cultured in media containing baseline- or high glucose concentrations. Cellular biomarkers were detected using Western blot analysis, immunocytochemistry, 5–ethynyl–2-deoxyuridine (EdU) cell proliferation assay, and terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) assay. High glucose decreased the proportion of cardiac troponin T and α-actinin 2 positive mESCs as well as disrupted the α-actinin 2 striated pattern and the distribution of the cardiac myosin heavy chain α- and β isoforms. However, there was no alteration of the cellular EdU uptake nor the expression of the receptor of advanced glycation end-product (RAGE). High glucose also increased the presence of the oxidative stress marker nitrotyrosine as well as the number of TUNEL-stained nuclei in cardiaclike cells. Treatment with the antioxidant N-acetyl cysteine decreased the number of TUNEL-stained cells in high glucose and improved the α-actinin 2 striated pattern. Hyperglycaemia negatively impacted the expression and cellular organisation of cardiac myofilament proteins in mESC-derived cardiomyocytes through oxidative stress. The results add further insights into the pathophysiological mechanisms of cardiac contractile dysfunction in diabetic cardiac developmental disease.

Abstract

Hyperglycaemia, a key metabolic abnormality in diabetes mellitus, is implicated in pathological cardiogenesis during embryological development. However, the underlying mechanisms and potential therapeutic targets remain unknown. We, therefore, studied the effect of hyperglycaemia on mouse embryonic stem cell (mESC) cardiac differentiation. The mESCs were differentiated via embryoid body (EB) formation and cultured under conditions with baseline (25 mM) or high (50 mM) glucose. Time-lapse microscopy images of pulsatile mESCs and Ca2+ntransients were recorded. Biomarkers of cellular changes were detected using immunocytochemistry, terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) assay, and Western blot analyses. Differentiated, spontaneously beating mESCs stained positive for cardiac troponin T, α-actinin 2,nmyosin heavy chain, and connexin 43. Hyperglycaemia decreased the EB diameter and number of beating EBs as well asnthe cellular amplitude of contraction, the Ca2+ transient, and the contractile response to caffeine (1 mM), but had no effect. on the expression of the sarco-endoplasmic reticulum calcium transport ATPase 2 (SERCA 2). Furthermore, hyperglycaemia decreased the expression of B cell lymphoma 2 (Bcl-2) and increased the expression of cytoplasmic cytochrome c and the number of TUNEL-positive cells, but had no effect on the expression of one of the mitochondrial fusion regulatory proteins, optic atrophy protein 1 (OPA1). Overall, hyperglycaemia suppressed the mESC cardiomyocyte-like differentiation and induced contractile dysfunction. The results are consistent with mechanisms involving abnormal Ca2+ handling and mitochondrial-dependent apoptosis, factors which represent potential therapeutic targets in developmental diabetic cardiac disease.

Aim:

The aim of this study is to investigate the etiology of infertility in couples seeking medical help from the Infertility Clinics and gynecological departments in hospitals in Western Libya.

Patients and Methods:

Data were collected directly from patients' medical records. However, additional data were collected through interviews.

Results:

The total number of couples recruited was 135. Men (mean±standard deviation of age= 41.7±7.0 years) were significantly older than women (35.2±6.5 years)(P= 0.001). Women were more likely to marry younger than men (mean difference= 6.5 years, 95% confidence interval [CI]= 5.1–7.8 years) and the duration of all participant's marriages before the interviews was 9.0±5.0 years. The causes of fertility were as follows: 33 (24.4%)(95% CI 17.16–31.64) cases were due to a female factor, 92 (68.1%)(95% CI= 60.24–75.96) cases were due to a male factor with 6 (4.4%)(95% CI 0.94–7 

Abstract

Objective: Chronic diabetes mellitus is associated with detrimental cardiovascular complications and electrolyte imbalances such as hypomagnesaemia. We investigated the effect of magnesium (Mg2+) on cardiac function and the possible role of histological and electrical alterations in chronic, streptozotocin-induced diabetic rats.

Methods: Wistar rats were treated once intraperitoneally with streptozotocin or citrate, and then daily with MgSO4 or saline for four weeks. Cardiac contractile and electrocardiographic parameters were measured on Langendorff-perfused hearts. Other hearts were histologically stained or immunoblotted for the mitochondrial ATP synthase (ATP5A).

Results: In diabetic hearts, Mg2+ prevented a diabetes-induced decrease in left ventricular developed pressure and improved contractility indices, as well as attenuated the reduction in heart rate and prolongation of QT interval, but not the QT interval corrected for heart rate (QTc). Histologically, there

were neither differences in cardiomyocyte width nor interstitial collagen. The expression of ATP5A was not different among the treatment groups.

Conclusion: Mg2+ supplementation improved cardiac contractile activity in chronic diabetic hearts via mechanisms unrelated to electrocardiographic or histologically detectable myocardial alterations.

Study question: What are the overall estimate of the different indicators of infertility in the Middle East and North African (MENA) region? Summary answer: The overall clinical primary and total infertility rate in the MENA region are (3.8%, 95% Cl = 1.7-8.4) and (17.2%, 95% Cl = 10.6-26.7) respectively.

Infertility is a worldwide health issue with high impact on the individuals involved and the society as a whole. Estimates of infertility are very important to inform social and economic policies. The aim of this systematic literature review is to estimate the prevalence of primary and secondary infertility in Middle East and North Africa (MENA) region and produce the overall estimate of the different indicators of infertility in MENA region. A systematic search was conducted to identify publications providing data from MENA countries. All titles and abstracts retrieved using this search strategy were managed by Endnote software, duplicates were removed and studies on animals, systematic reviews, and from non-MENA region was removed from the EndNote library. Seven electronic databases and websites were searched for relevant articles and surveys with no language or date restriction on July 2017. Data of prevalence 

Proteomic and molecular studies on the human follicle and follicular fluid: phenotypic differences between human granulosa cell subtypes.

To examine the differences in specific protein expression between mural and cumulus granulosa cells following 24-hour in vitro culture.

DESIGN

Laboratory study.

SETTING

• University Hospital. INTERVENTION(S): Human granulosa cells were collected at the time of egg collection during assisted reproduction. Cumulus cells associated with the oocyte were separated from mural cells from the periphery of the follicle before in vitro culture for 24 hours. Cells were then lysed and subjected to two-dimensional gel electrophoresis. MAIN OUTCOME MEASURE(S): Given that cumulus (cGC) and mural granulosa cells (mGC) differentiate from a single layer, it is likely that phenotypic differences between them may reflect specific molecular processes and structural adaptations. Computer-assisted analysis using dedicated software enabled the presence, absence, or relative volume of each individual protein …

OBJECTIVE: To examine differences in specific protein expression from the surface of the human endometrium with respect to eventual pregnancy in infertile women. DESIGN: Laboratory study. SETTING: University hospital. PATIENT(S): Thirty-one women presenting for investigation into infertility at an assisted reproductive unit. INTERVENTION(S): Endometrial flushings were collected during the proliferative phase of the menstrual cycle and subjected to electrophoretic separation on the basis of isoelectric point and molecular weight. Computerized analysis of the resulting spots was performed, and the proteins were identified using tandem mass spectrometry. MAIN OUTCOME MEASURE(S): The expression of individual isoforms of leucine-rich α2-glycoprotein (LRG) was compared in nonpregnant patients (n = 25), those who became pregnant as a result of treatment (n = 3), and those who had treatment …