Gm364 coordinates MIB2/DLL3/Notch2 to regulate female fertility through AKT activation

Advances in post-translational modifications and recurrent spontaneous abortion

Recurrent spontaneous abortion (RSA) is defined as two or more pregnancy loss, which affects approximately 1-2% of women's fertility. The etiology of RSA has not yet been fully revealed, which poses a great problem for clinical treatment. Post- translational modifications(PTMs) are chemical modifications that play a crucial role in the functional proteome. A considerable number of published studies have shown the relationship between post-translational modifications of various proteins and RSA. The study of PTMs contributes to elucidating the role of modified proteins in the pathogenesis of RSA, as well as the design of more effective diagnostic/prognostic tools and more targeted treatments. Most reviews in the field of RSA have only focused on RNA epigenomics research. The present review reports the latest research developments of PTMs related to RSA, such as glycosylation, phosphorylation, Methylation, Acetylation, Ubiquitination, etc.

MIB2 Functions in Oocyte Meiosis by Modulating Chromatin Configuration

Chromatin configuration serves as a principal indicator of GV (germinal vesicle)-stage oocyte quality. However, the underlying mechanisms governing the chromatin configuration transition from NSN (non-surrounded nucleolus) to SN (surrounded nucleolus) remain unclear. In this study, by conducting a quantitative proteomic analysis, we identified an increased expression of the MIB2 (MIB E3 ubiquitin protein ligase 2) protein in SN oocytes. Specific depletion of MIB2 in SN oocytes not only leads to severe disruption of the meiotic apparatus and a higher incidence of aneuploidy but also adversely affects meiotic maturation and early embryo development. Notably, overexpression of MIB2 in NSN oocytes facilitates the chromatin configuration transition. Meantime, we observed that forced expression of MIB2 in NSN oocytes significantly mitigates spindle/chromosome disorganization and aneuploidy. In summary, our results suggest that chromatin configuration transition regulated by MIB2 is crucial for oocytes to acquire developmental competence.

Understanding the Mechanisms of Diminished Ovarian Reserve: Insights from Genetic Variants and Regulatory Factors

Delaying childbearing age has become a trend in modern times, but it has also led to a common challenge in clinical reproductive medicine-diminished ovarian reserve (DOR). Since the mechanism behind DOR is unknown and its clinical features are complex, physicians find it difficult to provide targeted treatment. Many factors affect ovarian reserve function, and existing studies have shown that genetic variants, upstream regulatory genes, and changes in protein expression levels are present in populations with reduced ovarian reserve function. However, existing therapeutic regimens often do not target the genetic profile for more individualized treatment. In this paper, we review the types of genetic variants, mutations, altered expression levels of microRNAs, and other related factors and their effects on the regulation of follicular development, as well as altered DNA methylation. We hope this review will have significant implications for the future treatment of individuals with reduced ovarian reserve.

MIB2 promotes the progression of non-small cell lung cancer by regulating cell cycle control pathways

BACKGROUND

Although numerous measures have been used to improve the outcome of lung cancer patients, lung cancer, as the second most common diagnosed cancer, is still the main cause of cancer death. It becomes increasingly urgent for us to deeply deplore the molecular mechanism of lung cancer and to discover the potential therapeutic targets. In our study, we are dedicated to discovering the role of MIB2 in lung cancer development.

METHODS

The public databases were used to compare the expression level of MIB2 in cancer and non-cancer tissue. We analyzed the expression of MIB2 in lung cancer samples by performing Rt-PCR and western blot. We carried out CCK8 and clone assays to study the influence of MIB2 in lung cancer proliferation. The transwell assays and wound healing assays were implemented to study the function of MIB2 in metastasis and invasion. Proteins of cell cycle control pathways are detected to verify the potential mechanism of MIB2 in lung cancer progression.

RESULTS

MIB2 is up regulated in lung cancer tissue compared to adjacent normal lung tissue according to both public databases and our clinical lung cancer samples. Knockdown of MIB2 inhibits proliferation, metastasis, and invasion of lung cancer cell lines. Cyclins and cyclin dependent kinases (CDK) including CDK2, CDK4, and cyclinB1 were down regulated in MIB2 knockdown cells.

CONCLUSION

Our results prove that MIB2 acts as a driver in NSCLC tumorigenesis by regulating cell cycle control pathways.

Intermittent fasting reverses the declining quality of aged oocytes

Decreased oocyte quality and compromised embryo development are particularly prevalent in older females, but the aging-related cellular processes and effective ameliorative approaches have not been fully characterized. Intermittent fasting (IF) can help improve health and extend lifespan; nevertheless, how it regulates reproductive aging and its mechanisms remain unclear. We used naturally aged mice to investigate the role of IF in reproduction and found that just one month of every-other-day fasting was sufficient to improve oocyte quality. IF not only increased antral follicle numbers and ovulation but also enhanced oocyte meiotic competence and embryonic development by improving both nuclear and cytoplasmic maturation in maternally aged oocytes. The beneficial effects of IF manifested as alleviation of spindle structure abnormalities and chromosome segregation errors and maintenance of the correct cytoplasmic organelle reorganization. Moreover, single-cell transcriptome analysis showed that the positive impact of IF on aged oocytes was mediated by restoration of the nicotinamide adenine dinucleotide (NAD+)/Sirt1-mediated antioxidant defense system, which eliminated excessive accumulated ROS to suppress DNA damage and apoptosis. Collectively, these findings suggest that IF is a feasible approach to protect oocytes against advanced maternal age-related oxidation damage and to improve the reproductive outcomes of aged females.

The role of Hedgehog and Notch signaling pathway in cancer

Notch and Hedgehog signaling are involved in cancer biology and pathology, including the maintenance of tumor cell proliferation, cancer stem-like cells, and the tumor microenvironment. Given the complexity of Notch signaling in tumors, its role as both a tumor promoter and suppressor, and the crosstalk between pathways, the goal of developing clinically safe, effective, tumor-specific Notch-targeted drugs has remained intractable. Drugs developed against the Hedgehog signaling pathway have affirmed definitive therapeutic effects in basal cell carcinoma; however, in some contexts, the challenges of tumor resistance and recurrence leap to the forefront. The efficacy is very limited for other tumor types. In recent years, we have witnessed an exponential increase in the investigation and recognition of the critical roles of the Notch and Hedgehog signaling pathways in cancers, and the crosstalk between these pathways has vast space and value to explore. A series of clinical trials targeting signaling have been launched continually. In this review, we introduce current advances in the understanding of Notch and Hedgehog signaling and the crosstalk between pathways in specific tumor cell populations and microenvironments. Moreover, we also discuss the potential of targeting Notch and Hedgehog for cancer therapy, intending to promote the leap from bench to bedside.

The Conceivable Functions of Protein Ubiquitination and Deubiquitination in Reproduction

Protein ubiquitination with general existence in virtually all eukaryotic cells serves as a significant post-translational modification of cellular proteins, which leads to the degradation of proteins via the ubiquitin-proteasome system. Deubiquitinating enzymes (DUBs) can reverse the ubiquitination effect by removing the ubiquitin chain from the target protein. Together, these two processes participate in regulating protein stability, function, and localization, thus modulating cell cycle, DNA repair, autophagy, and transcription regulation. Accumulating evidence indicates that the ubiquitination/deubiquitination system regulates reproductive processes, including the cell cycle, oocyte maturation, oocyte-sperm binding, and early embryonic development, primarily by regulating protein stability. This review summarizes the extensive research concerning the role of ubiquitin and DUBs in gametogenesis and early embryonic development, which helps us to understand human pregnancy further.

RNF144B stimulates the proliferation and inhibits the apoptosis of human spermatogonial stem cells via the FCER2/NOTCH2/HES1 pathway and its abnormality is associated with azoospermia

Studies on gene regulation and signaling transduction pathways of human spermatogonial stem cells (SSCs) are of the utmost significance for unveiling molecular mechanisms underlying human spermatogenesis and gene therapy of male infertility. We have demonstrated, for the first time, that RNF144B stimulated cell proliferation and inhibited the apoptosis of human SSCs. The target of RNF144B was identified as FCER2 by RNA sequencing. We revealed that RNF144B interacted with FCER2 by immunoprecipitation. Consistently, overexpression of FCER2 reversed the phenotype of proliferation and apoptosis of human SSCs caused by RNF144B knockdown. Interestingly, FCER2 pulled down N2ICD (NOTCH2 intracellular domain), while N2ICD could bind to FCER2 in human SSCs. The levels of NOTCH2, FCER2, HES1, and HEY1 were reduced by RNF144B siRNA in human SSCs. Significantly, RNF144B was expressed at a lower level in nonobstructive azoospermia (NOA) patients than in the obstructive azoospermia (OA) patients with normal spermatogenesis, and 52 patients with heterozygous mutations of RNF144B were detected in 1,000 NOA patients. These results implicate that RNF144B promotes the proliferation of human SSCs and suppresses their apoptosis via the FCER2/NOTCH2/HES1 pathway and that the abnormality of RNF144B is associated with spermatogenesis failure. This study thus provides novel molecular mechanisms regulating the fate determinations of human SSCs, and it offers new biomarkers for the diagnosis and treatment of male infertility.

Notch signaling pathway: architecture, disease, and therapeutics

The NOTCH gene was identified approximately 110 years ago. Classical studies have revealed that NOTCH signaling is an evolutionarily conserved pathway. NOTCH receptors undergo three cleavages and translocate into the nucleus to regulate the transcription of target genes. NOTCH signaling deeply participates in the development and homeostasis of multiple tissues and organs, the aberration of which results in cancerous and noncancerous diseases. However, recent studies indicate that the outcomes of NOTCH signaling are changeable and highly dependent on context. In terms of cancers, NOTCH signaling can both promote and inhibit tumor development in various types of cancer. The overall performance of NOTCH-targeted therapies in clinical trials has failed to meet expectations. Additionally, NOTCH mutation has been proposed as a predictive biomarker for immune checkpoint blockade therapy in many cancers. Collectively, the NOTCH pathway needs to be integrally assessed with new perspectives to inspire discoveries and applications. In this review, we focus on both classical and the latest findings related to NOTCH signaling to illustrate the history, architecture, regulatory mechanisms, contributions to physiological development, related diseases, and therapeutic applications of the NOTCH pathway. The contributions of NOTCH signaling to the tumor immune microenvironment and cancer immunotherapy are also highlighted. We hope this review will help not only beginners but also experts to systematically and thoroughly understand the NOTCH signaling pathway.