Zinc deficiency deteriorates ovarian follicle development and function by inhibiting mitochondrial function.

Zinc (Zn) is a crucial trace element essential for human growth and development, particularly for reproductive health. Previous research has shown a decrease in serum zinc concentration with age and individuals with conditions such as polycystic ovary syndrome (PCOS) and diabetes mellitus. However, the specific effects of zinc deficiency on the female reproductive system, especially ovarian function, are not fully understood. In our study, we observed a significant reduction in the total number of follicles and mature follicles in the zinc deficiency group. This reduction correlated with decreased level of anti-Mullerian hormone (AMH) and abnormal gene expression affecting hormone secretion regulation. Furthermore, we found that zinc deficiency disrupted mitochondrial dynamics, leading to oxidative stress in the ovaries, which further inhibited autophagy and increased ovarian apoptosis. These changes ultimately resulted in the failure of germinal vesicle breakdown (GVBD) and reduced oocyte quality. Meanwhile, administration of zinc glycine effectively alleviated the oocyte meiotic arrest caused by dietary zinc deficiency. In conclusion, our findings demonstrated that dietary zinc deficiency can affect hormone secretion and follicle maturation by impairing mitochondrial function and autophagy.

O-GlcNAcylation orchestrates porcine oocyte maturation through maintaining mitochondrial dynamics and function.

O-linked ß-N-acetylglucosamine (O-GlcNAc) modification exists widely in cells, playing a crucial role in the regulation of important biological processes such as transcription, translation, metabolism, and the cell cycle. O-GlcNAc modification is an inducible reversible dynamic protein post-translational modification, which regulates complex cellular activities through transient glycosylation and deglycosylation. O-GlcNAc glycosylation is specifically regulated by O-GlcNAc glycosyltransferase (O-GlcNAc transferase, OGT) and O-GlcNAc glycoside hydrolase (O-GlcNAcase). However, the mechanisms underlying the effects of O-GlcNAc modification on the female reproductive system, especially oocyte quality, remain unclear. Here, we found that after OGT was inhibited, porcine oocytes failed to extrude the first polar body and exhibited abnormal actin and microtubule assembly. Meanwhile, the mitochondrial dynamics and function were also disrupted after inhibition of OGT function, resulting in the occurrence of oxidative stress and autophagy. Collectively, these results inform our understanding of the importance of the glycosylation process for oocyte maturation, especially for the maturation quality of porcine oocytes, and the alteration of O-GlcNAc in oocytes to regulate cellular events deserves further investigation.

Zinc deficiency compromises the maturational competence of porcine oocyte by inducing mitophagy and apoptosis.

Zinc, an essential trace mineral, plays a pivotal role in cell proliferation, maintenance of redox homeostasis, apoptosis, and aging. Serum zinc concentrations are reduced in patients with polycystic ovary syndrome (PCOS). However, the underlying mechanism of the effects of zinc deficiency on the female reproductive system, especially oocyte quality, has not been fully elucidated. Thus, we established an in vitro experimental model by adding N,N,N',N'-Tetrakis(2-pyridylmethyl) ethylenediamine (TPEN) into the culture medium, and to determine the potential regulatory function of zinc during porcine oocytes maturation. In the present study, we found that zinc deficiency caused aberrant meiotic progress, accompanied by the disrupted cytoskeleton structure in porcine oocytes. Zinc deficiency impaired mitochondrial function and dynamics, leading to the increase of reactive oxygen species (ROS) and acetylation level of the antioxidative enzyme superoxide dismutase 2 (SOD2), eventually induced the occurrence of oxidative stress and early apoptosis. Moreover, zinc deficiency perturbed cytosolic Ca2+ homeostasis, lipid droplets formation, demonstrating the aberrant mitochondrial function in porcine oocytes. Importantly, we found that zinc deficiency in porcine oocytes induced the occurrence of mitophagy by activating the PTEN-induced kinase 1/Parkin signaling pathway. Collectively, our findings demonstrated that zinc was a critical trace mineral for maintaining oocyte quality by regulating mitochondrial function and autophagy in porcine oocytes.

SLAM family predicting the initiation potential of human acute lymphoblastic leukemia in NOD/SCID mice / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The SLAM family recently has been reported to show an important biological role in lymphocyte development and immunological function, and it is efficient to highly purify hematopoietic stem cells using a simple combination of SLAM family members. To elucidate the presence of this family on acute lymphoblastic leukemia (ALL), as well as its relationship with the leukemia-initiating potential, we analyzed the expression pattern of this family members on human ALL progenitor cells, combined with serial xenotransplantation assay.</p><p><b>METHODS</b>Expression analysis was carried out by flow cytometry. We combined the expression pattern of human CD(150), CD(244) and CD(48) with serial xenotransplantation of B-ALL progenitor cells to indicate their relationship.</p><p><b>RESULTS</b>CD(48) and CD(244) were expressed on most B-ALL progenitor cells, the percentage being (93.08 ± 6.46)% and (63.37 ± 29.31)%, respectively. Interestingly, the proportion of CD(150)(+) cells declined obviously in engrafted cases ((24.94 ± 7.32)%) compared with non-engrafted cases ((77.54 ± 5.93)%, P < 0.01), which indicated that only blast cells with low percentage of CD(150)(+) population were able to reconstitute leukemia into primary, secondary and tertiary NOD/SCID mice.</p><p><b>CONCLUSIONS</b>SLAM family members are present on B-ALL progenitor cells and the leukemia-initiating potential of leukemic blasts is correlated negatively with the proportion of CD(150)(+) cells, the percentage of which can serve as a useful predictor for engraftment success of B-ALL to immune deficient mice.</p>