Research Progress of PCNA in Reproductive System Diseases

Transcriptome profiling reveals dysregulation of inflammatory and protein synthesis genes in PCOS

To analyze the differential expression genes of polycystic ovary syndrome (PCOS), clarify their functions and pathways, as well as the protein-protein interaction network, identify HUB genes, and explore the pathological mechanism. PCOS microarray datasets were screened from the GEO database. Common differentially expressed genes (co-DEGs) were obtained using GEO2R and Venn analysis. Enrichment and pathway analyses were conducted using the DAVID online tool, with results presented in bubble charts. Protein-protein interaction analysis was performed using the STRING tool. HUB genes were identified using Cytoscape software and further interpreted with the assistance of the GeneCards database. A total of two sets of co-DEGs (108 and 102), key proteins (15 and 55), and hub genes (10 and 10) were obtained. The co-DEGs: (1) regulated inflammatory responses and extracellular matrix, TNF, and IL-17 signaling pathways; (2) regulated ribosomes and protein translation, ribosome and immune pathways. The key proteins: (1) regulated inflammation, immunity, transcription, matrix metabolism, proliferation/differentiation, energy, and repair; (2) regulated ubiquitination, enzymes, companion proteins, respiratory chain components, and fusion proteins. The Hub genes: (1) encoded transcription factors and cytokines, playing vital roles in development and proliferation; (2) encoded ribosomes and protein synthesis, influencing hormone and protein synthesis, associated with development and infertility. The dysregulated expression of inflammation and protein synthesis genes in PCOS may be the key mechanism underlying its onset and progression.

Excessive proliferating cell nuclear antigen attenuates endometrial adhesive capacity and decidualization in patients with recurrent implantation failure

STUDY QUESTION

Does the expression of proliferating cell nuclear antigen (PCNA) in the endometrium regulate endometrial receptivity in patients with recurrent implantation failure (RIF)?

SUMMARY ANSWER

A high abundance of PCNA attenuates endometrial adhesive capacity and decidualization in patients with RIF.

WHAT IS KNOWN ALREADY

Aberrant expression of PCNA has been discovered in multiple infertility-related disorders. However, the expression pattern and role of PCNA in the establishment of endometrial receptivity and endometrial decidualization in patients with RIF remain unclear.

STUDY DESIGN, SIZE, DURATION

We analysed the expression of PCNA in mid-secretory endometrial tissues from 24 patients with RIF and 24 healthy women. Additionally, PCNA expression levels were measured in proliferative and mid-secretory phase endometrial tissue samples from women with regular menstrual cycles and in decidual tissue samples taken from ten women during normal early pregnancy (n = 10 per phase for each group). The function and regulatory mechanisms of PCNA in endometrial adhesive capacity and endometrial decidualization were investigated using BeWo spheroids, Ishikawa cells, and human endometrial stromal cells (HESCs).

PARTICIPANTS/MATERIALS, SETTING, METHODS

The expression of PCNA in mid-secretory endometrial tissues of patients with RIF and women with normal endometrium and in endometrial tissue at different stages of the menstrual cycle and in decidualized tissues was analysed by RT-qPCR, western blot, and immunohistochemistry staining (IHC). Furthermore, the number of BeWo spheroids directly attached to the Ishikawa cell monolayers, and the potential molecular mechanisms involved, were compared between cells overexpressing PCNA and a control group. Additionally, the effect and regulatory mechanisms of PCNA on the decidualization of HESCs in vitro were investigated.

MAIN RESULTS AND THE ROLE OF CHANCE

Our findings indicated that the abundance of PCNA was dramatically greater in mid-secretory endometrial tissues from patients with RIF than in those from women with healthy endometrium. The expression of PCNA increased in the proliferative phase of the menstrual cycle but decreased gradually in the mid-secretory phase and in decidual tissues. Interestingly, PCNA was expressed in both human endometrial epithelial cells (HEECs) and HESCs. In Ishikawa cells, PCNA overexpression dramatically reduced the endometrial adhesive capacity by inhibiting the expression of adhesion molecules (E-cadherin and integrin β3) and activating the FAK/paxillin signalling pathway. Furthermore, in HESCs, PCNA overexpression attenuated endometrial decidualization by activating the AKT/β-catenin signalling pathway and increasing tight junctions between cells by upregulating ZO-1 and occludin expression. In addition, PCNA-ELAVL1 interactions were confirmed by coimmunoprecipitation in decidualized HESCs.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

The functional analysis of PCNA was limited by the number of human endometrial tissues. A larger sample size is required to further explore the potential roles of PCNA during embryo implantation. Moreover, the present results should be taken with caution, as only a few of the embryos that were transferred in RIF patients population underwent preimplantation genetic testing for embryonic chromosome aneuploidies (PGT-A), despite embryo ploidy testing being significant in the diagnosis of unexplained RIF.

WIDER IMPLICATIONS OF THESE FINDINGS

High PCNA expression attenuates endometrial adhesive capacity and decidualization in patients with RIF. These findings provide new insights into the potential mechanisms underlying the occurrence of implantation failure.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the National Natural Science Foundation of China (82101698), Shandong Provincial Natural Science Foundation (ZR2021MH012), and the Science and Technology Plan of Yantai (2023YD021 and 2022YD031). The authors have no conflicts of interest to disclose.

TRIAL REGISTRATION NUMBER

N/A.

Estetrol Inhibits Endometriosis Development in an In Vivo Murine Model

Endometriosis is characterized by the growth of endometrial-like tissue outside the uterus, and it is associated with alterations in the expression of hormone receptors and inflammation. Estetrol (E4) is a weak estrogen that recently has been approved for contraception. We evaluated the effect of E4 on the growth of endometriotic-like lesions and the expression of TNF-α, estrogen receptors (ERs), and progesterone receptors (PRs) in an in vivo murine model. Endometriosis was induced surgically in female C57BL/6 mice. E4 was delivered via Alzet pump (3 mg/kg/day) from the 15th postoperative day for 4 weeks. E4 significantly reduced the volume (p < 0.001) and weight (p < 0.05) of ectopic lesions. Histologically, E4 did not affect cell proliferation (PCNA immunohistochemistry) but it did increase cell apoptosis (TUNEL assay) (p < 0.05). Furthermore, it modulated oxidative stress (SOD, CAT, and GPX activity, p < 0.05) and increased lipid peroxidation (TBARS/MDA, p < 0.01). Molecular analysis showed mRNA (RT-qPCR) and protein (ELISA) expression of TNF-α decreased (p < 0.05) and mRNA expression of Esr2 reduced (p < 0.05), in contrast with the increased expression of Esr1 (p < 0.01) and Pgr (p < 0.05). The present study demonstrates for the first time that E4 limited the development and progression of endometriosis in vivo.

Icariin protects testicular damage in streptozotocin-induced diabetic rats through regulation of glycolysis pathway

OBJECTIVE

This study aims to investigate potential beneficial actions of icariin (ICA) on testicular spermatogenic function in male rats with streptozotocin (STZ)-induced diabetes and to explore the underlying mechanisms. Background: ICA was found to reduce blood glucose, regulate the endocrine function of the reproductive system, and improve testicular spermatogenic function.

METHODS

Adult rats were intraperitoneally injected with STZ (65 mg/kg) to induce type 1 diabetes mellitus (T1DM). Diabetic rats were randomly classified intoT1DM (n = 6) and T1DM + ICA (n = 6) groups. Rats without STZ and ICA treatment were assigned as control group (n = 6). The morphology of testicular tissues was examined by histological staining. The mRNA and protein expression levels were determined by quantitative real-time PCR, Western blot and immunostaining, respectively.

RESULTS

Rats from T1DM group showed a reduction in epididymis and testis weight, and a decrease in sperm count when compared to control group (p < 0.01), which was attenuated by ICA treatment (p < 0.05) Diabetic rats from T1DM group also exhibited reduced diameter and area of seminiferous tubules, along with decreased spermatogonia and primary spermatocytes number when compared to control group (p < 0.01), which was partially reversed by ICA treatment (p < 0.05) Rats from T1DM group exhibited down-regulation of PCNA mRNA and protein in the testis when compared to control group (p < 0.01); while ICA treatment up-regulated PCNA expression in the testis of diabetic rats compared to T1DM group (p < 0.05). Rats from T1DM group showed up-regulation of Bax and capase-3 and down-regulation of Bcl-2, PKM2, HK2 and lactate dehydrogenase A in the testes when compared to control group (p < 0.05), which was reversed by ICA treatment (p < 0.05).

CONCLUSION

These findings suggest that ICA may exert its protective effects on testicular damage in diabetic rats through modulation of glycolysis pathway and suppression of apoptosis.

An Overview of Traditional Chinese Medicine in the Treatment After Radical Resection of Hepatocellular Carcinoma

According to the Barcelona Clinic Liver Cancer (BCLC) system, radical resection of early stage primary hepatocellular carcinoma (HCC) mainly includes liver transplantation, surgical resection, and radiofrequency ablation (RFA), which yield 5-year survival rates of about 70-79%, 41.3-69.5%, and 40-70%, respectively. The tumor-free 5-year rate for HCC patients undergoing radical resection only reach up to 13.7 months, so the prevention of recurrence after radical resection of HCC is very important for the prognosis of patients. The traditional Chinese medicine (TCM) takes the approach of multitarget and overall-regulation to treat tumors, it can also independently present the "component-target-pathway" related to a particular disease, and its systematic and holistic characteristics can provide a personalized therapy based on symptoms of the patient by treating the patient as a whole. TCM as postoperative adjuvant therapy after radical resection of HCC in Barcelona Clinic liver cancer A or B stages, and the numerous clinical trials confirmed that the efficacy of TCM in the field of HCC has a significant effect, not only improving the prognosis and quality of life but also enhancing patient survival rate. However, with the characteristics of multi-target, multi-component, and multi-pathway, the specific mechanism of Chinese medicine in the treatment of diseases is still unclear. Because of the positive pharmacological activities of TCM in combating anti-tumors, the mechanism studies of TCM have demonstrated beneficial effects on the regulation of immune function, chronic inflammation, the proliferation and metastasis of liver cancer cells, autophagy, and cell signaling pathways related to liver cancer. Therefore, this article reviews the mechanism of traditional Chinese medicine in reducing the recurrence rate of HCC after radical resection.

Nesfatin-1 in a reptile: its role and hormonal regulation in wall lizard testis

Nesfatin-1 is a pleiotropic hormone implicated in various physiological functions including reproduction. Studies though limited, have established an important role of the peptide in regulation of testicular functions in mammals and fishes. However, role of nesfatin-1 in regulation of spermatogenesis and testicular steroidogenesis remains completely unexplored in reptiles. Therefore, present study aimed to develop an insight into reproductive phase-dependent testicular expression, function and regulation of nucb2/nesfatin-1 in a reptile, Hemidactylus flaviviridis. Expression of nucb2/nesfatin-1 in testis of wall lizard varied significantly depending upon reproductive phase, being highest in the active phase while lowest during regressed phase. Further, in vitro treatment of wall lizard testis with nesfatin-1 showed a concentration- and time-dependent stimulatory effect of the peptide on expression of cell proliferation and differentiation markers like scf, c-kit and pcna suggesting a spermatogenic role of nesfatin-1 in wall lizard. Also, nesfatin-1 stimulated the anti-apoptotic marker, bcl-2 while inhibited the apoptotic marker, caspase-3, suggesting its role as an inhibitor of apoptosis of testicular cells. Further, treatment with nesfatin-1 resulted in significantly higher expression of star along with a concomitant increase in testosterone production by the lizard testis. The present study also demonstrates hormonal regulation of testicular nucb2/nesfatin-1 wherein follicle-stimulating hormone (FSH) inhibited while sex steroids like dihydrotestosterone (DHT) and 17β-estradiol-3-benzoate (E2) stimulated the mRNA expression of nesfatin-1. Observations from the current study for the first time provide comprehensive evidence of spermatogenic and steroidogenic role of nesfatin-1 as well as its hormonal regulation in the testis of a reptile, H. flaviviridis.

Ketogenic diet restores hormonal, apoptotic/proliferative balance and enhances the effect of metformin on a letrozole-induced polycystic ovary model in rats

OBJECTIVE

Polycystic ovaries (PCO) is a hormonal disorder that is a leading cause of infertility. The formation of multiple persistent cysts and hormonal imbalance are hallmarks of PCO. Recent clinical studies reported a beneficial effect of the ketogenic diet (KD; high-fat, low-carbohydrate) on PCO. The aim of this study was to investigate the effect of the KD alone and in combination with metformin on letrozole-induced PCO in female rats.

METHODS

Female rats were grouped into control and PCO (letrozole; 1 mg/kg for 21 days). The PCO group was subdivided into PCO (non-treated), PCO-metformin (300 mg/kg), PCO rats fed with KD only, and PCO rats treated with metformin and fed with KD. All groups continued to receive letrozole during the 21-day treatment period. At the end of the experiment, serum and ovaries were collected for further analysis.

RESULTS

The untreated-PCO rats showed increased testosterone, LH/FSH ratio, and ovary weights. Disturbed apoptosis and proliferation balance were evident as a low caspase-3 activation and proliferating cell nuclear antigen expression and increased TGF-β expression. The KD improved the letrozole-induced effects, which was comparable to the effect of metformin. Combining the KD with metformin treatment additively enhanced the metformin effect.

CONCLUSION

Our results indicate that the KD has a protective role against PCO in rats, especially when combined with metformin. This study reveals a potential therapeutic role of the KD in PCO, which could prompt valuable future clinical applications.

The Novel Diagnostic Techniques and Biomarkers of Canine Mammary Tumors

Canine mammary tumors (CMTs) are considered a serious clinical problem in older bitches. Due to the high malignancy rate and poor prognosis, an early diagnosis is essential. This article is a summary of novel diagnostic techniques as well as the main biomarkers of CMTs. So far, CMTs are detected only when changes in mammary glands are clinically visible and surgical removal of the mass is the only recommended treatment. Proper diagnostics of CMT is especially important as they represent a very diverse group of tumors and therefore different treatment approaches may be required. Recently, new diagnostic options appeared, like a new cytological grading system of CMTs or B-mode ultrasound, the Doppler technique, contrast-enhanced ultrasound, and real-time elastography, which may be useful in pre-surgical evaluation. However, in order to detect malignancies before macroscopic changes are visible, evaluation of serum and tissue biomarkers should be considered. Among them, we distinguish markers of the cell cycle, proliferation, apoptosis, metastatic potential and prognosis, hormone receptors, inflammatory and more recent: metabolomic, gene expression, miRNA, and transcriptome sequencing markers. The use of a couple of the above-mentioned markers together seems to be the most useful for the early diagnosis of neoplastic diseases as well as to evaluate response to treatment, presence of tumor progression, or further prognosis. Molecular aspects of tumors seem to be crucial for proper understanding of tumorigenesis and the application of individual treatment options.