Transforming growth factor beta 1 (TGFβ1) polymorphisms and unexplained infertility: A genetic association study

Genetic Polymorphisms of COL1A1 Promoter Region (rs1800012) and TGFB1 Signal Peptide (rs1800471): Role in Cervical Insufficiency Susceptibility?

A structural or functional cervix problem prevents a woman from carrying a full-term pregnancy, which leads to the disease known as cervical insufficiency. Cervical insufficiency is partially inherited, and in certain situations, variations in genes related to connective tissue metabolism may be involved. The main objective of this investigation was to describe the collagen type I alpha 1 chain (COL1A1) gene rs1800012 polymorphism and the transforming growth factor beta 1 (TGFB1) gene rs1800471 polymorphism in a cohort of patients suffering from cervical insufficiency. Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) assays have been used to analyze the DNAs of 93 patients with cervical insufficiency and 103 healthy controls. The chi-square test was used for statistical analysis. There were significant differences in the genotype frequencies of the COL1A1 gene rs1800012 (G > T) and TGFB1 gene rs1800471 (G > C) polymorphisms between the patient and the control groups (p = 0.049 and p = 0.049, respectively). Also, the C allele of the TGFB1 rs1800471 polymorphism was significantly higher in the patient group than the control group (p = 0.016). Following clinical assessment, the COL1A1 rs1800012 polymorphism was found to be connected to the history of cerclage (p = 0.010). Additionally, the frequency of the TT/GG composite genotype of COL1A1 rs1800012/TGFB1 rs1800471 polymorphisms was significantly lower in the patient group than the control group (p = 0.049). The TT genotype of COL1A1 rs1800012 polymorphism was found to be protective against cervical insufficiency, while the C allele of TGFB1 rs1800471 polymorphism was found to predispose to the disease. It appears that the TT/GG composite genotype of COL1A1 rs1800012/TGFB1 rs1800471 polymorphisms protects against cervical insufficiency.

Role of hypoxia-mediated pyroptosis in the development of extending knee joint contracture in rats

Joint contracture is one of the common diseases clinically, and joint capsule fibrosis is considered to be one of the most important pathological changes of joint contracture. However, the underlying mechanism of joint capsule fibrosis is still controversial. The present study aims to establish an animal model of knee extending joint contracture in rats, and to investigate the role of hypoxia-mediated pyroptosis in the progression of joint contracture using this animal model. 36 male SD rats were selected, 6 of which were not immobilized and were used as control group, while 30 rats were divided into I-1 group (immobilized for 1 week following 7 weeks of free movement), I-2 group (immobilized for 2 weeks following 6 weeks of free movement), I-4 group (immobilized for 4 weeks following 4 weeks of free movement), I-6 group (immobilized for 6 weeks following 2 weeks of free movement) and I-8 group (immobilized for 8 weeks) according to different immobilizing time. The progression of joint contracture was assessed by the measurement of knee joint range of motion, collagen deposition in joint capsule was examined with Masson staining, protein expression levels of HIF-1α, NLRP3, Caspase-1, GSDMD-N, TGF-β1, α-SMA and p-Smad3 in joint capsule were assessed using western blotting, and the morphological changes of fibroblasts were observed by transmission electron microscopy. The degree of total and arthrogenic contracture progressed from the first week and lasted until the first eight weeks after immobilization. The degree of total and arthrogenic contracture progressed rapidly in the first four weeks after immobilization and then progressed slowly. Masson staining indicated that collagen deposition in joint capsule gradually increased in the first 8 weeks following immobilization. Western blotting analysis showed that the protein levels of HIF-1α continued to increase during the first 8 weeks of immobilization, and the protein levels of pyroptosis-related proteins NLRP3, Caspase-1, GSDMD-N continued to increase in the first 4 weeks after immobilization and then decreased. The protein levels of fibrosis-related proteins TGF-β1, p-Smad3 and α-SMA continued to increase in the first 8 weeks after immobilization. Transmission electron microscopy showed that 4 weeks of immobilization induced cell membrane rupture and cell contents overflow, which further indicated the activation of pyroptosis. Knee extending joint contracture animal model can be established by external immobilization orthosis in rats, and the activation of hypoxia-mediated pyroptosis may play a stimulating role in the process of joint capsule fibrosis and joint contracture.

MicroRNAs: key regulators of the trophoblast function in pregnancy disorders

The placenta is essential for a successful pregnancy and healthy intrauterine development in mammals. During human pregnancy, the growth and development of the placenta are inseparable from the rapid proliferation, invasion, and migration of trophoblast cells. Previous reports have shown that the occurrence of many pregnancy disorders may be closely related to the dysfunction of trophoblasts. However, the function regulation of human trophoblast cells in the placenta is poorly understood. Therefore, studying the factors that regulate the function of trophoblast cells is necessary. MicroRNAs (miRNAs) are small, non-coding, single-stranded RNA molecules. Increasing evidence suggests that miRNAs play a crucial role in regulating trophoblast functions. This review outlines the role of miRNAs in regulating the function of trophoblast cells and several common signaling pathways related to miRNA regulation in pregnancy disorders.

miR-2337 induces TGF-β1 production in granulosa cells by acting as an endogenous small activating RNA

Transforming growth factor-β1 (TGF-β1) is essential for ovarian function and female fertility in mammals. Herein, we identified three completely linked variants, including two known variants referred to as c.1583A > G and c.1587A > G and the novel variant c.2074A > C in the porcine TGF-β1 3′-UTR. An important role of these variants in Yorkshire sow fertility was revealed. Variants c.1583A > G and c.1587A > G were located at the miRNA response element (MRE) of miR-2337 and affected miR-2337 regulation of TGF-β1 3′-UTR activity. Interestingly, miR-2337 induces, not reduces the transcription and production of TGF-β1 in granulosa cells (GCs). Mechanistically, miR-2337 enhances TGF-β1 promoter activity via the MRE motif in the core promoter region and alters histone modifications, including H3K4me2, H3K4me3, H3K9me2, and H3K9ac. In addition, miR-2337 controls TGF-β1-mediated activity of the TGF-β signaling pathway and GC apoptosis. Taken together, our findings identify miR-2337 as an endogenous small activating RNA (saRNA) of TGF-β1 in GCs, while miR-2337 is identified as a small activator of the TGF-β signaling pathway which is expected to be a new target for rescuing GC apoptosis and treating low fertility.