Zhengchao Wang

By Zonghao Tang and Zhengchao Wang

Mammalian spermatogenesis is a high regulated biological process occurring in the seminiferous tubules in the testis. The processing of this program requires delicate balance between cell proliferation, differentiation, apoptosis, and expedite cell interaction. Autophagy, an evolutionarily conserved cell reprograming machinery, had been shown to function as an important regulatory mechanism in spermatogenesis and steroid production in testis. Herein, we mainly focused on our understanding of autophagy in mammalian testis. By showing autophagy in physiological and pathophysiological conditions, we try to elicit the regulatory role of autophagy in spermatogenic cells and somatic cells of testis. Moreover, this review is intended to point out factors and mechanisms, which contribute to the initiation of autophagy in testicular cells.

Part of the book: Testes and Ovaries

By Fan Wang and Zhengchao Wang

Polycystic ovary syndrome (PCOS) is one of the most common reproductive endocrine diseases occurs among women of childbearing age, which is affected by many factors, but its precise pathophysiology has not yet been determined. The heterogeneous of PCOS is reflected in its complex endocrine dysfunction of the hypothalamic-pituitary-gonadal axis (HPG axis) and its multiple clinical features, such as obesity, insulin resistance, hyperandrogenism and anovulation. Meanwhile, women with PCOS also have an increased risk of major cardiovascular events, most notably type 2 diabetes, cardiovascular disease and atherosclerosis. So far, many therapies are available for improving reproductive and metabolic abnormalities in PCOS patients, in which lifestyle modification and insulin-sensitizing agents are more effective management strategies.

Part of the book: Testes and Ovaries

By Qingqiang Lin, Hong Zhang, Jiuhua Zhao and Zhengchao Wang

Our previous studies have demonstrated that insulin signaling pathway has an important role in the pathophysiology of polycystic ovary syndrome (PCOS), including phosphatidylinositol 3-kinase and protein kinase B signaling, which is critically implicated in insulin resistance, androgen secretion, obesity, and follicular development. PCOS manifests as defective ovarian steroid biosynthesis and hyperandrogenemia, and 50–70% of women with PCOS exhibit insulin resistance and are hyperinsulinemic, indicating that insulin resistance and hyperinsulinism may have an important role in the pathophysiology of PCOS. Therefore, the present article will review the contribution of insulin signaling pathway to the abnormal regulation of follicular growth and ovulation, which can cause corresponding reproductive endocrine diseases and affect women’s reproductive health. Exploring the mechanism of insulin signaling pathway in PCOS will help not only to understand the physiology and pathology of follicular development but also to provide theoretical basis for the treatment of PCOS.

Part of the book: Polycystic Ovarian Syndrome

By Zhenghong Zhang, Yan Zhang, Fengping Lin and Zhengchao Wang

In mammals, the follicular development and following ovulation are regulated by reproductive hormones, while polycystic ovary syndrome (PCOS) is an endocrine disorder syndrome with reproductive dysfunction and abnormal glucose metabolism in most PCOS women. Its characteristics are hyperandrogenism, ovarian dysfunction, and the exclusion of other androgen excess or related diseases. Its clinical characteristics are large antral follicle pool from which to recruit and persistent anovulation. The incidence of PCOS in women of childbearing age ranged from 4 to 12%. About one-third of infertility cases had no ovulation, and 90% of them had PCOS. Therefore, further studying the regulatory mechanism of follicular hyperrecruitment and anovulation can provide theoretical basis for exploring the pathogenesis of PCOS and guiding clinical treatment, especially for protecting female fertility and preventing the occurrence of metabolic disorder syndrome. The present article will review the progress in endocrine characteristics and regulatory mechanism of follicular development and ovulation failure in the mammalian ovary.

Part of the book: Polycystic Ovarian Syndrome

By Congjian Shi, Hongqin Yang, Zhengchao Wang and Zhenghong Zhang

Extracellular vesicles (EVs) are a heterogeneous group of endogenous nanoscale vesicles that are secreted by various cell types. Based on their biogenesis and size distribution, EVs can be broadly classified as exosomes and microvesicles. Exosomes are enveloped by lipid bilayers with a size of 30–150 nm in diameter, which contain diverse biomolecules, including lipids, proteins and nucleic acids. Exosomes transport their bioactive cargoes from original cells to recipient cells, thus play crucial roles in mediating intercellular communication. Breast cancer is the most common malignancy among women and remains a major health problem worldwide, diagnostic strategies and therapies aimed at breast cancer are still limited. Growing evidence shows that exosomes are involved in the pathogenesis of breast cancer, including tumorigenesis, invasion and metastasis. Here, we provide a straightforward overview of exosomes and highlight the role of exosomes in the pathogenesis of breast cancer, moreover, we discuss the potential application of exosomes as biomarkers and therapeutic tools in breast cancer diagnostics and therapeutics.

Part of the book: Global Women's Health