Biochemical and histological evidence of thyroid gland dysfunction in estradiol valerate model of the polycystic ovary in Wistar rats.

Thyroid defects and polycystic ovary (PSO) disease are prevalent endocrine problems among humans. While various studies investigated the ovarian function and histological alterations during estradiol valerate model of PCO, yet, there were no available studies examining thyroid gland function and histology. Therefore, the present study aimed to investigate linkage between estradiol valerate-induced PCO and the development of thyroid dysfunction in rats. The study comprises 2 groups of male Wistar rats (n = 12), control group and PCO group. PCO was induced by injecting two doses of estradiol valerate with 6 weeks lag period in between. After twelve weeks, PCO was confirmed by vaginal smear examination which showed marked vaginal cornification. In addition, the light microscopic examination of the ovaries revealed chief histological signs of PCO like numerous cysts and damaged follicles. In addition, PCO-induced rats showed decreased serum LH and increased serum FSH levels. Thyroid hypoactivity was confirmed by increased serum TSH and decreased serum thyroid hormones (T3, and T4). Histologically, the thyroid tissue revealed small-size follicles devoid of the colloid and increased connective tissue between follicles. Semithin sections showed hypertrophied and/or flat follicular cells as well as increased resorption colloidal granules. Ultrathin sections showed low height cells with dark nucleus and heterochromatin. Furthermore, PCO-induced rats thyroid gland tissue revealed increased expression of the apoptotic mediator caspase-3. There was also a decrease in the expression of proliferating cell nuclear antigen. In summary, this study provides several effective biochemical and histological evidences for thyroid gland dysfunction in PCO-induced rats.

High prevalence of deleterious BRCA1 and BRCA2 germline mutations in arab breast and ovarian cancer patients.

PURPOSE: The BRCA1 and BRCA2 (BRCA) genes are heavily involved in mammalian cell DNA repair processes. Germline pathogenic mutations in BRCA increase the lifetime risk of developing breast and/or ovarian cancer in women. In the Arabian Peninsula, most breast and ovarian cancers are diagnosed as early-onset cases, some of which may be due to germline variants in BRCA genes. To identify the BRCA germline mutation frequency and spectrum in the Arab breast and ovarian cancers, we have sequenced the protein-coding exons of these genes. METHODS: All BRCA coding exons were sequenced using genomic DNA isolated from lymphocytes in 173 Arab breast and ovarian cancer patients by a massively parallel sequencing technology and verified by Sanger sequencing. RESULTS: We identified a total of 17 distinct pathogenic mutations, of which four were novel, in 28 patients; nine out of 108 breast (8.3%) and 19 out of 65 ovarian cancer (29.2%) patients. Thirteen of the 17 mutations were detected in BRCA1 and four mutations were found in BRCA2 gene. Four pathogenic BRCA1 mutations (c.1140dupG, c.4136_4137delCT, c.5095C>T, and c.5530delC) accounted for 54% of all the mutations detected in our patient cohort. Additionally, we identified a likely pathogenic BRCA1 missense variant in two of 108 breast (1.9%) and a BRCA2 missense variant in one of 65 ovarian cancer (1.5%) patients. CONCLUSIONS: The overall frequencies of the BRCA germline mutations were 10.2% in breast and 30.7% in ovarian cancer patients. These data shed new light into the prevalence of BRCA mutations in the Arab women population.

Identification of FDA-approved drugs against SARS-CoV-2 RNA-dependent RNA polymerase (RdRp) through computational virtual screening.

The SARS-CoV-2 coronavirus is responsible for the COVID-19 outbreak, which overwhelmed millions of people worldwide; hence, there is an urgency to identify appropriate antiviral drugs. This study focuses on screening compounds that inhibit RNA-dependent RNA-polymerase (RdRp) essential for RNA synthesis required for replication of positive-strand RNA viruses. Computational screening against RdRp using Food and Drug Administration (FDA)-approved drugs identified ten prominent compounds with binding energies of more than - 10.00 kcal/mol, each a potential inhibitor of RdRp. These compounds' binding energy is comparable to known RdRp inhibitors remdesivir (IC50 = 10.09 µM, SI = 4.96) and molnupiravir (EC50 = 0.67 - 2.66 µM) and 0.32-2.03 µM). Remdesivir and molnupiravir have been tested in clinical trial and remain authorized for emergency use in the treatment of COVID-19. In docking simulations, selected compounds are bound to the substrate-binding pocket of RdRp and showed hydrophobic and hydrogen bond interaction. For molecular dynamics simulation, capmatinib, pralsetinib, ponatinib, and tedizolid phosphate were selected from the initial ten candidate compounds. MD simulation indicated that these compounds are stable at 50-ns MD simulation when bound to RdRp protein. The screen hit compounds, remdesivir, molnupiravir, and GS-441524, are bound in the substrate binding pocket with good binding-free energy. As a consequence, capmatinib, pralsetinib, ponatinib, and tedizolid phosphate are potential new inhibitors of RdRp protein with potential of limiting COVID-19 infection by blocking RNA synthesis. Supplementary Information: The online version contains supplementary material available at 10.1007/s11224-022-02072-1.

A research-led flexible cell biology practical for biological sciences undergraduate and postgraduate degree courses.

A challenge in the pandemic era is to implement effective but flexible practical teaching for biological sciences courses. Such teaching needs to deliver conceptual, analytical and practical skills training while having the option to rapidly respond to health and safety issues, local regulations, staff and student concerns. In this paper, we describe a set of cell biology practicals (mini-project) that meets many of these requirements and provides flexibility in providing skills training both through online and in practical laboratory environments. We have used a human adenocarcinoma cell line A431 stably transfected with a fluorescent cell cycle reporter as a biological model to deliver training through discrete work packages encompassing cell culture, fluorescence microscopy, biochemistry and statistics. How such work packages can be modified to, an online format either partially or completely is also described. Furthermore, the activities can be adapted for teaching both undergraduate and postgraduate level courses to ensure effective skills training which is applicable to a wide range of biological degree programs and levels of study.

VEGFR endocytosis: Implications for angiogenesis.

The binding of vascular endothelial growth factor (VEGF) superfamily to VEGF receptor tyrosine kinases (VEGFRs) and co-receptors regulates vasculogenesis, angiogenesis and lymphangiogenesis. A recurring theme is that dysfunction in VEGF signaling promotes pathological angiogenesis, an important feature of cancer and pro-inflammatory disease states. Endocytosis of basal (resting) or activated VEGFRs facilitates signal attenuation and endothelial quiescence. However, increasing evidence suggest that activated VEGFRs can continue to signal from intracellular compartments such as endosomes. In this chapter, we focus on the evolving link between VEGFR endocytosis, signaling and turnover and the implications for angiogenesis. There is much interest in how such understanding of VEGFR dynamics can be harnessed therapeutically for a wide range of human disease states.

Both Matricaria chamomilla and Metformin Extract Improved the Function and Histological Structure of Thyroid Gland in Polycystic Ovary Syndrome Rats through Antioxidant Mechanism.

There is increasing proof that polycystic ovary syndrome (PCOS) is associated with the increased frequency of thyroid disturbances. Chamomile (Matricaria chamomilla L.) herb and metformin showed therapeutic efficacy against polycystic ovary syndrome (PCOS). This study aimed to investigate the possible therapeutic effect of both chamomile flower extract and metformin against thyroid damage associated with PCOS in rats. The PCOS model was developed in rats by injecting estradiol valerate, and it was confirmed to be associated with thyroid hypofunction biochemically and pathologically. Treatment of PCOS rats with both chamomile extract and metformin resulted in an improvement in serum level of thyroid hormones (TSH, p < 0.01; T3 and T4, p < 0.05) and the disappearance of most thyroid gland pathological changes demonstrated by light and electron microscopes. They also reduced the level of serum estrogen (p < 0.01). Both chamomile extract and metformin decreased MDA (p < 0.05) and increased GPx and CAT (p < 0.01). Only chamomile extract increased GSH (p < 0.01). Both treatments reduced the apoptotic death of thyroid cells as noted by the reduction of caspase-3 immunoexpression (p < 0.01). In conclusion, both Matricariachamomilla extract and metformin ameliorated hypothyroidism associated with PCOS through an antioxidant and antiapoptotic mechanism.