Metformin treatment alleviates polycystic ovary syndrome by decreasing the expression of MMP‐2 and MMP‐9 via H19/miR‐29b‐3p and AKT/mTOR/autophagy signaling pathways

Whispers of the polycystic ovary syndrome theater: Directing role of long noncoding RNAs

Polycystic Ovary Syndrome (PCOS) is a multifaceted endocrine disorder that implicates a spectrum of clinical manifestations, including hormonal imbalance, metabolic dysfunction, and even compromised ovarian granulosa cell (GC) activity. The underlying molecular mechanisms of PCOS remain elusive, presenting a significant barrier to effective diagnosis and treatment. This review delves into the emerging role of long non-coding RNAs (lncRNAs) in the pathophysiology of PCOS, articulating their intricate interactions with mRNAs, microRNAs, and other epigenetic regulators that collectively influence the hormonal and metabolic milieu of PCOS. We examine the dynamic regulatory networks orchestrated by lncRNAs that impact GC function, steroidogenesis, insulin resistance, and inflammatory pathways. By integrating findings from recent studies, we illuminate the potential of lncRNAs as biomarkers for PCOS and highlight their contribution to the disorder, offering a detailed perspective on the lncRNA-mediated modulation of gene expression and pathogenic pathways. Understanding targeted lncRNA interactions with PCOS proposes novel avenues for therapeutic intervention to ameliorate the reproductive and metabolic disturbances characteristic of the syndrome.

Comparative efficacy of metformin combined with cabergoline versus metformin alone in patients with PCOS and hyperprolactinemia: A systematic review and meta-analysis of randomized controlled trials

Isntroduction. Polycystic ovary syndrome (PCOS) is a multifaceted endocrine-gynecological condition affecting a substantial number of women during their reproductive years. Metformin (MET) has been shown to improve ovarian function in PCOS-related conditions, while cabergoline is recognized for its powerful and sustained ability to reduce prolactin levels. This study investigates the potential impact of combining cabergoline with metformin while comparing it with metformin alone in the treatment of PCOS alongside hyperprolactinemia.

METHOD

To gather data, we searched PubMed, Google Scholar, ScienceDirect, and Cochrane Central. Eligible studies were randomized controlled trials involving patients with PCOS and hyperprolactinemia. Outcome measures included changes in the levels of prolactin, testosterone, DHEAS, BMI and menstrual irregularities. RevMan version 5.4 was used to analyze outcomes.

RESULT

This study incorporated three Randomized Controlled Trials (RCTs) involving 405 participants in total. Patients receiving a combination of metformin and cabergoline experienced significant reductions in prolactin and testosterone levels (p= <0.0001 and p=<0.0001, respectively). Conversely, alterations in DHEAS levels and BMI did not reach statistical significance (p = 0.19 and p = 0.71, respectively). Notably, women solely prescribed metformin exhibited significantly higher rates of menstrual irregularities compared to those receiving both metformin and cabergoline (p=<0.0001).

CONCLUSION

Our analysis underscores the synergistic effect achieved by pairing metformin and cabergoline in patients with PCOS and hyperprolactinemia. However, we encountered only a restricted number of studies meeting our criteria. It is imperative to consistently assess the combined effects of metformin and cabergoline to gain deeper insights into their effectiveness in addressing PCOS and hyperprolactinemia.

Exploring the link between metformin use and adhesive capsulitis of the shoulder: a retrospective cohort study in Taiwan

The risk of adhesive capsulitis of shoulder in diabetic patients taking metformin has not been evaluated. We aimed for evaluating the relative risk of adhesive capsulitis of shoulder in diabetic patients taking metformin at the level of the whole country population. We conducted a retrospective cohort study using a national health insurance database in Taiwan from 2000 to2015. We used International Classification of Diseases, Ninth Revision, to categorise the medical condition for study group and comparison group. We used Cox proportional hazard regression analyses to determined adjusted hazard ratios (aHRs) of adhesive capsulitis of shoulder between study and comparison group after adjusting for sex, age, and comorbidities.Among 30,412 diabetic patients using metformin, 3020 patients were diagnosis with adhesive capsulitis of shoulder during follow up. Of the 121,648 patients without the use of metformin, 11,375 patients developed adhesive capsulitis of shoulder. Adhesive capsulitis of shoulder risk was elevated in patients taking metformin than in non-metformin group (adjusted hazard ratio [HR] 1.179, 95% confidence interval [95% CI] 1.022 to 1.268; p = 0.039). Risk of adhesive capsulitis of shoulder among the diabetic patients taking metformin was higher than those did not taking metformin.

MicroRNAs Associated with Metformin Treatment in the Diabetes Prevention Program

The Diabetes Prevention Program (DPP) randomized controlled trial demonstrated that metformin treatment reduced progression to type 2 diabetes (T2D) by 31% compared to placebo in adults with prediabetes. Circulating micro-ribonucleic acids (miRs) are promising biomarkers of T2D risk, but little is known about their associations with metformin regimens for T2D risk reduction. We compared the change in 24 circulating miRs from baseline to 2 years in a subset from DPP metformin intervention (n = 50) and placebo (n = 50) groups using Wilcoxon signed rank tests. Spearman correlations were used to evaluate associations between miR change and baseline clinical characteristics. Multiple linear regression was used to adjust for covariates. The sample was 73% female, 17% Black, 13% Hispanic, and 50 ± 11 years. Participants were obese, normotensive, prediabetic, and dyslipidemic. Change in 12 miR levels from baseline to 2 years was significantly different in the metformin group compared with placebo after adjusting for multiple comparisons: six (let-7c-5p, miR-151a-3p, miR-17-5p, miR-20b-5p, miR-29b-3p, and miR-93-5p) were significantly upregulated and six (miR-130b-3p, miR-22-3p, miR-222-3p, miR-320a-3p, miR-320c, miR-92a-3p) were significantly downregulated in the metformin group. These miRs help to explain how metformin is linked to T2D risk reduction, which may lead to novel biomarkers, therapeutics, and precision health strategies.

Glucose Promotes EMMPRIN/CD147 and the Secretion of Pro-Angiogenic Factors in a Co-Culture System of Endothelial Cells and Monocytes

Vascular complications in Type 2 diabetes mellitus (T2DM) patients increase morbidity and mortality. In T2DM, angiogenesis is impaired and can be enhanced or reduced in different tissues ("angiogenic paradox"). The present study aimed to delineate differences between macrovascular and microvascular endothelial cells that might explain this paradox. In a monoculture system of human macrovascular (EaHy926) or microvascular (HMEC-1) endothelial cell lines and a monocytic cell line (U937), high glucose concentrations (25 mmole/L) increased the secretion of the pro-angiogenic factors CD147/EMMPRIN, VEGF, and MMP-9 from both endothelial cells, but not from monocytes. Co-cultures of EaHy926/HMEC-1 with U937 enhanced EMMPRIN and MMP-9 secretion, even in low glucose concentrations (5.5 mmole/L), while in high glucose HMEC-1 co-cultures enhanced all three factors. EMMPRIN mediated these effects, as the addition of anti-EMMPRIN antibody decreased VEGF and MMP-9 secretion, and inhibited the angiogenic potential assessed through the wound assay. Thus, the minor differences between the macrovascular and microvascular endothelial cells cannot explain the angiogenic paradox. Metformin, a widely used drug for the treatment of T2DM, inhibited EMMPRIN, VEGF, and MMP-9 secretion in high glucose concentration, and the AMPK inhibitor dorsomorphin enhanced it. Thus, AMPK regulates EMMPRIN, a key factor in diabetic angiogenesis, suggesting that targeting EMMPRIN may help in the treatment of diabetic vascular complications.

MicroRNAs Associated with Metformin Treatment in the Diabetes Prevention Program

The Diabetes Prevention Program (DPP) randomized controlled trial demonstrated that metformin treatment reduced progression to type 2 diabetes (T2D) by 31% compared to placebo in adults with prediabetes. Circulating micro-ribonucleic acids (miRs) are promising biomarkers of T2D risk, but little is known about their associations with metformin regimens for T2D risk reduction. We compared the change in 24 circulating miRs from baseline to 2 years in a subset from DPP metformin intervention (n = 50) and placebo (n = 50) groups using Wilcoxon signed rank tests. Spearman's correlations were used to evaluate associations between miR change and baseline clinical characteristics. Multiple linear regression was used to adjust for covariates. The sample was 73% female, 17% Black, 13% Hispanic, and 50 ± 11 years. Participants were obese, normotensive, prediabetic, and dyslipidemic. Change in 12 miR levels from baseline to 2 years was significantly different in the metformin group compared with placebo after adjusting for multiple comparisons: six (let-7c-5p, miR-151a-3p, miR-17-5p, miR-20b-5p, miR-29b-3p, and miR-93-5p) were significantly upregulated and six (miR-130b-3p, miR-22-3p, miR-222-3p, miR-320a-3p, miR-320c, miR-92a-3p) were significantly downregulated in the metformin group. These miRs help to explain how metformin is linked to T2D risk reduction, which may lead to novel biomarkers, therapeutics, and precision-health strategies.

Long noncoding RNA H19 in ovarian biology and placenta development

As the first long noncoding RNA to be discovered, H19 has gained substantial attention as a key regulator of several biological processes and its roles in female reproductive biology are gradually getting revealed. Herein, we have summarized the current evidence regarding H19 expression pattern and involvement in the developmental and pathological processes associated with the ovary and the placenta. The findings indicate that within the ovaries, H19 is expressed in the antral and cystic atretic follicles as well as in the corpora lutea but absent in the primordial, primary, and secondary follicles. Its normal expression promotes the maturation of antral follicles and prevents their premature selection for the ovulatory journey while its aberrant induction promotes polycystic ovary syndrome development and ovarian cancer metastasis. In the placenta, H19 is highly expressed in the cytotrophoblasts and extravillous trophoblasts but weakly expressed in the syncytiotrophoblast layer and potentially controls trophoblast cell fate decisions during placenta development. Abnormal expression of H19 is observed in the placental villi of pregnancies affected by pre-eclampsia and fetal growth restriction. Therefore, dysregulated H19 is a candidate biomarker and therapeutic target for the mitigation of ovarian and placenta-associated diseases.

Signaling pathways and targeted therapeutic strategies for polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among women of reproductive age. Although promising strides have been made in the field of PCOS over the past decades, the distinct etiologies of this syndrome are not fully elucidated. Prenatal factors, genetic variation, epigenetic mechanisms, unhealthy lifestyles, and environmental toxins all contribute to the development of this intricate and highly heterogeneous metabolic, endocrine, reproductive, and psychological disorder. Moreover, interactions between androgen excess, insulin resistance, disruption to the hypothalamic-pituitary-ovary (HPO) axis, and obesity only make for a more complex picture. In this review, we investigate and summarize the related molecular mechanisms underlying PCOS pathogenesis from the perspective of the level of signaling pathways, including PI3K/Akt, TGF-β/Smads, Wnt/β-catenin, and Hippo/YAP. Additionally, this review provides an overview of prospective therapies, such as exosome therapy, gene therapy, and drugs based on traditional Chinese medicine (TCM) and natural compounds. By targeting these aberrant pathways, these interventions primarily alleviate inflammation, insulin resistance, androgen excess, and ovarian fibrosis, which are typical symptoms of PCOS. Overall, we hope that this paper will pave the way for better understanding and management of PCOS in the future.

THBS1-Mediated Degradation of Collagen via the PI3K/AKT Pathway Facilitates the Metastasis and Poor Prognosis of OSCC

Oral squamous cell carcinoma (OSCC) is a prevalent form of malignant tumor, characterized by a persistently high incidence and mortality rate. The extracellular matrix (ECM) plays a crucial role in the initiation, progression, and diverse biological behaviors of OSCC, facilitated by mechanisms such as providing structural support, promoting cell migration and invasion, regulating cell morphology, and modulating signal transduction. This study investigated the involvement of ECM-related genes, particularly THBS1, in the prognosis and cellular behavior of OSCC. The analysis of ECM-related gene data from OSCC samples identified 165 differentially expressed genes forming two clusters with distinct prognostic outcomes. Seventeen ECM-related genes showed a significant correlation with survival. Experimental methods were employed to demonstrate the impact of THBS1 on proliferation, migration, invasion, and ECM degradation in OSCC cells. A risk-prediction model utilizing four differentially prognostic genes demonstrated significant predictive value in overall survival. THBS1 exhibited enrichment of the PI3K/AKT pathway, indicating its potential role in modulating OSCC. In conclusion, this study observed and verified that ECM-related genes, particularly THBS1, have the potential to influence the prognosis, biological behavior, and immunotherapy of OSCC. These findings hold significant implications for enhancing survival outcomes and providing guidance for precise treatment of OSCC.

Integrated bioinformatics analysis elucidates granulosa cell whole-transcriptome landscape of PCOS in China

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common reproductive, neuroendocrine, and metabolic disorder in women of reproductive age that affects up to 5-10% of women of reproductive age. The aetiology of follicle development arrest and critical issues regarding the abnormal follicular development in PCOS remain unclear. The present study aims to systematically evaluate granulosa cell whole-transcriptome sequencing data to gain more insights into the transcriptomic landscape and molecular mechanism of PCOS in China.

METHODS

In the present study, the microarray datasets GSE138518, GSE168404, GSE193123, GSE138572, GSE95728, and GSE145296 were downloaded from the Gene Expression Omnibus (GEO) database. Subsequently, differential expression analysis was performed on the PCOS and control groups, followed by functional interaction prediction analysis to investigate gene-regulatory circuits in PCOS. Finally, hub genes and their associated ncRNAs were validated by qPCR in human-luteinized granulosa (hGL) cells and were correlated with the clinical characteristics of the patients.

RESULTS

A total of 200 differentially expressed mRNAs, 3 differentially expressed miRNAs, 52 differentially expressed lncRNAs, and 66 differentially expressed circRNAs were found in PCOS samples compared with controls. GO and KEGG enrichment analyses indicated that the DEGs were mostly enriched in phospholipid metabolic processes, steroid biosynthesis and inflammation related pathways. In addition, the upregulated miRNA hsa-miR-205-5p was significantly enriched in the ceRNA network, and two hub genes, MVD and PNPLA3, were regulated by hsa-miR-205-5p, which means that hsa-miR-205-5p may play a fundamental role in the pathogenesis of PCOS. We also found that MVD and PNPLA3 were related to metabolic processes and ovarian steroidogenesis, which may be the cause of the follicle development arrest in PCOS patients.

CONCLUSIONS

In summary, we systematically constructed a ceRNA network depicting the interactions between the ncRNAs and the hub genes in PCOS and control subjects and correlated the hub genes with the clinical characteristics of the patients, which provides valuable insights into the granulosa cell whole-transcriptome landscape of PCOS in China.

The role of long non-coding RNA H19 in infertility

Infertility is defined as the failure to conceive after at least one year of unprotected intercourse. Long non-coding RNAs (lncRNAs) are transcripts that contain more than 200 nucleotides but do not convert into proteins. LncRNAs, particularly lncRNA H19, have been linked to the emergence and progression of various diseases. This review focuses on the role of H19 in infertility caused by polycystic ovary syndrome, endometriosis, uterine fibroids, diminished ovarian reserve, male factor, and assisted reproductive technology-related pathology, highlighting the potential of H19 as a molecular target for the future treatment of infertility.

Transvaginal needle versus laparoscopic ovarian drilling in hormonal profile and pregnancy outcomes of polycystic ovary syndrome: a systematic review and meta-analysis

BACKGROUND

Polycystic ovary syndrome (PCOS) is a prevalent hormonal disorder distinguished by a persistent absence of ovulation. Ovarian drilling is a recognized therapeutic approach for PCOS patients who are unresponsive to medication and can be performed through invasive laparoscopic access or less-invasive transvaginal access. The aim of this systematic review and meta-analysis was to assess the efficacy of transvaginal ultrasound -guided ovarian needle drilling with conventional laparoscopic ovarian drilling (LOD) in patients with PCOS.

METHODS

PUBMED, Scopus, and Cochrane databases were systematically searched for eligible randomized controlled trials (RCTs) from articles published from inception to January 2023. We include RCTs of PCOS that compared transvaginal ovarian drilling and LOD and reported on ovulation and pregnancy rates as the main outcome variable. We evaluated study quality using the Cochrane Risk of bias 2 tool. A random-effects meta-analysis was performed and the certainty of the evidence was assessed according to the GRADE approach. We registered the protocol prospectively in PROSPERO (CRD42023397481).

RESULTS

Six RCTs including 899 women with PCOS met the inclusion criteria. LOD was found to significantly reduce anti-Mullerian hormone (AMH) (SMD: -0.22; 95% CI: -0.38, -0.05; I² = 39.85%) and antral follicle count (AFC) (SMD: -1.22; 95% CI: -2.26, -0.19; I² = 97.55%) compared to transvaginal ovarian drilling. Our findings also indicated that LOD significantly increased the ovulation rate by 25% compared to transvaginal ovarian drilling (RR: 1.25; 95% CI: 1.02, 1.54; I2 = 64.58%). However, we found no significant difference between the two groups in terms of follicle stimulating hormone (SMD: 0.04; 95% CI: -0.26, 0.33; I2 = 61.53%), luteinizing hormone (SMD: -0.07; 95% CI: -0.90, 0.77; I2 = 94.92%), and pregnancy rate (RR: 1.37; 95% CI: 0.94, 1.98; I2 = 50.49%).

CONCLUSION

LOD significantly lowers circulating AMH and AFC and significantly increases ovulation rate in PCOS patients compared to transvaginal ovarian drilling. As transvaginal ovarian drillingremains a less-invasive, more cost-effective, and simpler alternative, further studies are warranted to compare these two techniques in large cohorts, with a particular focus on ovarian reserve and pregnancy outcomes.

HDAC1 participates in polycystic ovary syndrome through histone modification to regulate H19/miR-29a-3p/NLRP3-mediated granulosa cell pyroptosis

Histone deacetylase 1 (HDAC1) is known to participate in the molecular etiology of polycystic ovary syndrome (PCOS). However, its role in granulosa cell (GC) pyroptosis remains unclear. This study sought to investigate the mechanism of HDAC1 in PCOS-induced GC pyroptosis through histone modification. Clinical serum samples and the general data of study subjects were collected. PCOS mouse models were established using dehydroepiandrosterone and cell models were established in HGL5 cells using dihydrotestosterone. Expressions of HDAC1, H19, miR-29a-3p, and NLR family pyrin domain containing 3 (NLRP3) and pyroptosis-related proteins and levels of hormones and inflammatory cytokines were determined. Ovarian damage was observed by hematoxylin-eosin staining. Functional rescue experiments were conducted to verify the role of H19/miR-29a-3p/NLRP3 in GC pyroptosis in PCOS. HDAC1 and miR-29a-3p were downregulated whereas H19 and NLRP3 were upregulated in PCOS. HDAC1 upregulation attenuated ovarian damage and hormone disorders in PCOS mice and suppressed pyroptosis in ovarian tissues and HGL5 cells. HDAC1 inhibited H3K9ac on the H19 promoter and H19 competitively bound to miR-29a-3p to improve NLRP3 expression. Overexpressed H19 or NLRP3 or inhibited miR-29a-3p reversed the inhibition of GC pyroptosis by HDAC1 upregulation. Overall, HDAC1 suppressed GC pyroptosis in PCOS through deacetylation to regulate the H19/miR-29a-3p/NLRP3 axis.

Guizhi Fuling Wan inhibits autophagy of granulosa cells in polycystic ovary syndrome mice via H19/miR-29b-3p

OBJECTIVE

To investigate the potential molecular mechanism of traditional Chinese medicine Guizhi Fuling Wan (GZFLW) inhibiting granulosa cells (GCs) autophagy in polycystic ovary syndrome (PCOS).

METHODS

Control GCs and model GCs were cultured and treated with blank serum or GZFLW-containing serum. The levels of H19 and miR-29b-3p in GCs were detected using qRT-PCR, target genes of miR-29b-3p were identified using luciferase assay. The protein expressions of Phosphatase and tensin homolog (PTEN), Matrix Metalloproteinase (MMP)-2, and Bax were measured using western blot. The level of autophagy was detected via MDC staining, the degree of autophagosomes and autophagic polymers was observed using dual fluorescence-tagged mRFP-eGFP-LC3.

RESULTS

GZFLW intervention reduced the expression of autophagy-related proteins PTEN, MMP-2 and Bax, by upregulating the expression of miR-29b-3p and downregulated the expression of H19 (p < .05 or p < .01). The number of autophagosomes and autophagy polymers was significantly decreased by GZFLW treatment. However, the inhibition of miR-29b-3p and overexpression of H19 induced a significant increase in the number of autophagosomes and autophagic polymers, which attenuated the inhibitory effect of GZFLW on autophagy (p < .05 or p < .01). In addition, inhibition of miR-29b-3p or overexpression of H19 can attenuate the effect of GZFLW on the expression of PTEN, MMP-2 and Bax proteins (p < .05 or p < .01).

CONCLUSION

Our study found that GZFLW inhibits autophagy in PCOS GCs via H19/miR-29b-3p pathway.

The effect of metformin on influenza vaccine responses in nondiabetic older adults: a pilot trial

BACKGROUND

Aging is associated with progressive declines in immune responses leading to increased risk of severe infection and diminished vaccination responses. Influenza (flu) is a leading killer of older adults despite availability of seasonal vaccines. Geroscience-guided interventions targeting biological aging could offer transformational approaches to reverse broad declines in immune responses with aging. Here, we evaluated effects of metformin, an FDA approved diabetes drug and candidate anti-aging drug, on flu vaccination responses and markers of immunological resilience in a pilot and feasibility double-blinded placebo-controlled study.

RESULTS

Healthy older adults (non-diabetic/non-prediabetic, age: 74.4 ± 1.7 years) were randomized to metformin (n = 8, 1500 mg extended release/daily) or placebo (n = 7) treatment for 20 weeks and were vaccinated with high-dose flu vaccine after 10 weeks of treatment. Peripheral blood mononuclear cells (PBMCs), serum, and plasma were collected prior to treatment, immediately prior to vaccination, and 1, 5, and 10 weeks post vaccination. Increased serum antibody titers were observed post vaccination with no significant differences between groups. Metformin treatment led to trending increases in circulating T follicular helper cells post-vaccination. Furthermore, 20 weeks of metformin treatment reduced expression of exhaustion marker CD57 in circulating CD4 T cells.

CONCLUSIONS

Pre-vaccination metformin treatment improved some components of flu vaccine responses and reduced some markers of T cell exhaustion without serious adverse events in nondiabetic older adults. Thus, our findings highlight the potential utility of metformin to improve flu vaccine responses and reduce age-related immune exhaustion in older adults, providing improved immunological resilience in nondiabetic older adults.

Metformin regulates autophagy via LGMN to inhibit choriocarcinoma

Choriocarcinoma has the problem of chemotherapy insensitivity and recurrence. Metformin may be a promising candidate to restrict choriocarcinoma progress because of its indirect and direct beneficial role on inhabitations of cancer cells without severe adverse side effects. In this study, metformin pressed the proliferation and invasion of choriocarcinoma JAR cells in vitro and the growth of the JAR subcutaneous xenografts in vivo. The high throughput sequencing and bioinformatics technology identified the low expression of legumain (LGMN) in lysosomal pathway caused by metformin, which was upregulated in human choriocarcinoma tissues compared with the early pregnancy tissues. As elevating metformin concentration and treatment time, the mRNA and protein expression of LGMN both depressed in two choriocarcinoma cell lines (JAR and JEG-3). LGMN was involved in metformin-mediated inhibition of cell proliferation and invasion. Furthermore, metformin induced autophagy via inhibiting LGMN through AKT/mTOR/LC3II signaling pathway of choriocarcinoma. Autophagy inhibitor could depress metformin-induced autophagy and improve cell proliferation and invasion ability dropped by metformin, while autophagy inducer could partially reverse the change of cell proliferation and invasion modulated by combination of metformin and LGMN overexpression. These results indicated that metformin inhibited cell proliferation and invasion ability by inducing autophagy in a LGMN-dependent manner so as to play a role in the treatment of choriocarcinoma.

Effect of metformin on the long non-coding RNA expression levels in type 2 diabetes: an in vitro and clinical trial study

BACKGROUND

It has been suggested that the anti-hyperglycemic effect of metformin could be associated with its impact on long non-coding RNA (lncRNA) expression levels. Accordingly, in the current study, we evaluated the effect of metformin on the expression of H19, MEG3, MALAT1, and GAS5 in in vitro and in vivo situations.

METHODS

The effect of hyperglycemia and metformin treatment on the lncRNAs expression level was evaluated in HepG2 cells. A total of 179 age- and sex-matched subjects, including 88 newly diagnosed patients with type 2 diabetes (T2D) and 91 healthy volunteers, were included in the case-control phase of the study. Moreover, 40 newly diagnosed patients participated in the study's open-labeled non-controlled clinical trial phase. The expression levels of lncRNA in HepG2 cells and whole blood samples were determined using QRT-PCR.

RESULTS

In vitro results showed that hyperglycemia induced H19 and MALAT1 and decreased GAS5 expression levels. Moreover, metformin decreased H19 and increased GAS5 expression in high glucose-treated cells. Case-control study findings revealed that the circulating levels of H19, MALAT1, and MEG3 were significantly elevated in T2D patients compared to the control subjects. Finally, results showed that the level of circulating H19 levels decreased while GAS5 increased in T2D patients after taking metformin for 2 months.

CONCLUSION

The results of the current study provided evidence that metformin could exert its effect in the treatment of T2D by altering the expression levels of H19 and GAS5.

Metformin Directly Binds to MMP-9 to Improve Plaque Stability

Vulnerable atherosclerotic plaque rupture is the principal mechanism that accounts for myocardial infarction and stroke. High matrix metalloproteinase-9 (MMP-9) expression and activity have been proven to lead to plaque instability. Metformin, a first-line treatment for type 2 diabetes, is beneficial to plaque vulnerability. However, the mechanism underlying its anti-atherogenic effect remains unclear. Molecular docking and surface plasmon resonance experiments showed that metformin directly interacts with MMP-9, and incubated MMP-9 overexpressing HEK293A cells with metformin (1 μmol·L^-1) significantly attenuates MMP-9's activity using zymography and MMP activity assays. Moreover, metformin treatment drives MMP-9 degradation. Next, we constructed a carotid artery atherosclerotic plaque model and administered consecutive 14-day metformin (200 mg·kg^-1·d^-1) treatment by intragastric gavage. Immunofluorescence staining of the right carotid common artery and serum MMP activity assay results showed that metformin treatment decreased local plaque MMP-9 protein level and circulating MMP-9 activity, respectively. Histochemical staining revealed that after metformin treatment, the collagen content in plaque was significantly preserved, and the plaque vulnerability index decreased. These findings suggested that metformin improved atherosclerotic plaque stability by directly binding to MMP-9 and driving its degradation.

Insulin resistance in polycystic ovary syndrome across various tissues: an updated review of pathogenesis, evaluation, and treatment

Polycystic ovary syndrome (PCOS) is a common endocrine disorder characterized by chronic ovulation dysfunction and overabundance of androgens; it affects 6-20% of women of reproductive age. PCOS involves various pathophysiological factors, and affected women usually have significant insulin resistance (IR), which is a major cause of PCOS. IR and compensatory hyperinsulinaemia have differing pathogeneses in various tissues, and IR varies among different PCOS phenotypes. Genetic and epigenetic changes, hyperandrogenaemia, and obesity aggravate IR. Insulin sensitization drugs are a new treatment modality for PCOS. We searched PubMed, Google Scholar, Elsevier, and UpToDate databases in this review, and focused on the pathogenesis of IR in women with PCOS and the pathophysiology of IR in various tissues. In addition, the review provides a comprehensive overview of the current progress in the efficacy of insulin sensitization therapy in the management of PCOS, providing the latest evidence for the clinical treatment of women with PCOS and IR.

Multi-omics analyses reveal the specific changes in gut metagenome and serum metabolome of patients with polycystic ovary syndrome

Objective

The purpose of this study was to investigate the specific alterations in gut microbiome and serum metabolome and their interactions in patients with polycystic ovary syndrome (PCOS).

Methods

The stool samples from 32 PCOS patients and 18 healthy controls underwent the intestinal microbiome analysis using shotgun metagenomics sequencing approach. Serum metabolome was analyzed by ultrahigh performance liquid chromatography quadrupole time-of-flight mass spectrometry. An integrative network by combining metagenomics and metabolomics datasets was constructed to explore the possible interactions between gut microbiota and circulating metabolites in PCOS, which was further assessed by fecal microbiota transplantation (FMT) in a rat trial.

Results

Fecal metagenomics identified 64 microbial strains significantly differing between PCOS and healthy subjects, half of which were enriched in patients. These changed species showed an ability to perturb host metabolic homeostasis (including insulin resistance and fatty acid metabolism) and inflammatory levels (such as PI3K/Akt/mTOR signaling pathways) by expressing sterol regulatory element-binding transcription factor-1, serine/threonine-protein kinase mTOR, and 3-oxoacyl-[acyl-cattier-protein] synthase III, possibly suggesting the potential mechanisms of gut microbiota underlying PCOS. By integrating multi-omics datasets, the panel comprising seven strains (Achromobacter xylosoxidans, Pseudomonas sp. M1, Aquitalea pelogenes, Porphyrobacter sp. HL-46, Vibrio fortis, Leisingera sp. ANG-Vp, and Sinorhizobium meliloti) and three metabolites [ganglioside GM3 (d18:0/16:0), ceramide (d16:2/22:0), and 3Z,6Z,9Z-pentacosatriene] showed the highest predictivity of PCOS (AUC: 1.0) with sensitivity of 0.97 and specificity of 1.0. Moreover, the intestinal microbiome modifications by FMT were demonstrated to regulate PCOS phenotypes including metabolic variables and reproductive hormones.

Conclusion

Our findings revealed key microbial and metabolite features and their interactions underlying PCOS by integrating multi-omics approaches, which may provide novel insights into discovering clinical diagnostic biomarkers and developing efficient therapeutic strategies for PCOS.

The Effect of Stimulation Protocols (GnRH Agonist vs. Antagonist) on the Activity of mTOR and Hippo Pathways of Ovarian Granulosa Cells and Its Potential Correlation with the Outcomes of In Vitro Fertilization: A Hypothesis

Controlled ovarian hyperstimulation (COH) is essential for the success of in vitro fertilization (IVF). Evidence showing the comparison of different COH protocols remains predominantly of low certainty and derives from unspecified infertile and highly heterogeneous populations. Thus, personalized approaches to examine the response of patients to the various COH protocols need to be investigated. Data from in vitro and animal studies have identified the mechanistic target of rapamycin (mTOR) and Hippo signaling pathways play a key role in follicular homeostasis and oocyte quality. To be specific, current data indicate the controlled activation of mTOR and the controlled inhibition of the Hippo pathway within the ovarian granulosa cells (GC). Both are reported to lead to a nurturing follicular microenvironment, increase oocyte quality, and potentially improve reproductive outcomes. As intracellular markers, phosphorylated/unphosphorylated levels of the pathways’ main downstream mediators could be included among the candidate “personalized” predictors of patients’ response to COH protocols and final IVF outcomes. Based on these hypotheses, we make a preliminary attempt to investigate their validity: We propose a prospective cohort study to compare the levels of certain phosphorylated/unphosphorylated components of the investigated pathways (mTOR, ribosomal protein S6 kinase beta-1 (p70S6K-1), yes-associated protein-1 (YAP-1), and transcriptional coactivator with PDZ-binding motif (TAZ)) within the follicular fluid-isolated GC between women undergoing gonadotropin-releasing hormone (GnRH) antagonist/“short” protocols and those receiving GnRH agonist/“long 21” protocols. A case-control design comparing these levels between women achieving pregnancy and those who did not is further planned. Additional analyses addressing the population’s expected heterogeneity are planned after the completion of the pilot phase, during which 100 participants undergoing IVF are intended to be recruited. At this stage, these hypotheses are solely based on in vitro/animal data, and thus, similar studies on humans in this respect are necessary for the investigation of their potential validity.

Targeting non-coding RNA H19: A potential therapeutic approach in pulmonary diseases

Non-coding RNA is still one of the most popular fields in biology research. In recent years, people paid more attention to the roles of H19 in lung diseases, which expressed abnormally in various pathological process. Therefore, this review focus on the regulatory role of H19 in asthma, pulmonary arterial hypertension (PAH), idiopathic pulmonary fibrosis (IPF), lung injury, pneumonia, lung cancer, etc. And the potential therapeutic agents and molecular treatments of H19 are collected. The aim is to demonstrate its underlying mechanism in pulmonary diseases and to guide the basic research targeting H19 into clinical drug translation.

The role of AMPK-dependent pathways in cellular and molecular mechanisms of metformin: a new perspective for treatment and prevention of diseases

Metformin can suppress gluconeogenesis and reduce blood sugar by activating adenosine monophosphate-activated protein kinase (AMPK) and inducing small heterodimer partner (SHP) expression in the liver cells. The main mechanism of metformin’s action is related to its activation of the AMPK enzyme and regulation of the energy balance. AMPK is a heterothermic serine/threonine kinase made of a catalytic alpha subunit and two subunits of beta and a gamma regulator. This enzyme can measure the intracellular ratio of AMP/ATP. If this ratio is high, the amino acid threonine 172 available in its alpha chain would be activated by the phosphorylated liver kinase B1 (LKB1), leading to AMPK activation. Several studies have indicated that apart from its significant role in the reduction of blood glucose level, metformin activates the AMPK enzyme that in turn has various efficient impacts on the regulation of various processes, including controlling inflammatory conditions, altering the differentiation pathway of immune and non-immune cell pathways, and the amelioration of various cancers, liver diseases, inflammatory bowel disease (IBD), kidney diseases, neurological disorders, etc. Metformin’s activation of AMPK enables it to control inflammatory conditions, improve oxidative status, regulate the differentiation pathways of various cells, change the pathological process in various diseases, and finally have positive therapeutic effects on them. Due to the activation of AMPK and its role in regulating several subcellular signalling pathways, metformin can be effective in altering the cells’ proliferation and differentiation pathways and eventually in the prevention and treatment of certain diseases.

Two MMP2 gene polymorphisms significantly associated with polycystic ovary syndrome: A case-control analysis

PURPOSE

To study the association between MMP2 gene polymorphisms (rs7201 and rs243849) and polycystic ovary syndrome (PCOS) risk.

METHODS

1287 participants, including 592 PCOS and 623 controls, were collected. In analysis, six genotype models (dominant model: MM + MW vs. WW; recessive model: MM vs. MW + WW; over-dominant model: MM + WW vs. MW; co-dominant model: MM vs. MW; co-dominant model: MM vs. WW; allele analysis: M vs. W, where M: minor allele; W: major allele) were applied. Subgroup analyses were performed based on race and obesity.

RESULTS

In the whole sample, only rs7201 was identified to protect from the PCOS (unadjusted: Recessive MM vs MW + WW, OR = 0.551, 95%CI = 0.311-0.974, P = 0.040; co-dominant MM vs WW, OR = 0.541, 95%CI = 0.304-0.964, P = 0.037). Subgroup analysis also identified rs243849 to be significantly associated with PCOS risk in the Han race (unadjusted: co-dominant MM vs WW, OR = 0.383, 95%CI = 0.153-0.961, P = 0.041; Allele M vs W, OR = 0.729, 95%CI = 0.553-0.963, P = 0.026). Moreover, rs243849 could regulate prominently MMP2 gene expression. However, no statistical significances were identified in the obesity groups (body mass Index and waist-hip ratio).

CONCLUSIONS

We identified for the first time that both rs7201 and rs243849 of MMP2 could protect from PCOS. Further studies with larger samples are needed to confirm the conclusion.

The expression and localization of selected matrix metalloproteinases (MMP-2, -7 and -9) and their tissue inhibitors (TIMP-2 and -3) in follicular cysts of sows

Matrix metalloproteinases (MMPs) are a family of enzymes that degrade extracellular matrix (ECM) molecules, playing a vital role in tissue remodeling under physiological and pathological conditions. Their expression and/or activity are regulated by specific tissue inhibitors of MMPs named TIMPs. Recently, an imbalance in the MMP/TIMP system has been found in human and bovine ovarian cysts, but its role in porcine cyst pathogenesis is unknown. This study examined mRNA expression, protein abundance and localization for selected members of the MMP/TIMP system in follicular cysts of sows. Based on histological analysis, we have assessed follicular (FC) and follicular lutein (FLC) cysts with preovulatory follicles (PF) used as a control. Regarding the pattern of MMP expression, increased MMP2, MMP7 and MMP9 mRNA levels were observed in FLC. Furthermore, both pro- and active forms of MMP-2 and MMP-9 proteins were more abundant in FLC. In FC, the abundance of latent and active forms of MMP-9 and the active form of MMP-2 were greater when compared with PF. In relation to TIMPs, TIMP-2 mRNA and protein expression were increased in FLC, whereas TIMP-3 was up-regulated in both FC and FLC only at the protein level. Using immunofluorescence, MMP-2, MMP-7, TIMP-2 and TIMP-3 were detected in granulosa and theca compartments of FC and within the entire luteinized wall of FLC. Notably, MMP-9 occurred weakly in the granulosa layer of FC, but abundantly in the theca compartment of FC and in the luteinized FLC. Taken together, our findings indicate altered expression of the MMP/TIMP system, suggestive of increased ECM degradation, in sow follicular cysts. These components may be involved in the pathogenesis of porcine ovarian cysts through the ECM remodeling.

The Effect of Metformin on Expression of Long Non-coding RNA H19 in Endometrial Cancer

Background: Endometrial cancer is the fourth most widespread cancer among females, with a growing prevalence in recent years. Management by combined therapies along with surgery, radiotherapy, and chemotherapy have improved patients' prognoses. Besides, the development of new therapies helps preserve fertility and prognosis in aggressive tumors. The purpose of this research was to identify the efficacy of metformin on the H19 long non-coding RNA expression in endometrial cancer to provide further insight into the pathogenesis and treatment of the disease. Methods: A total of 23 patients with endometrial cancer, diagnosed by biopsy or diagnostic curettage, were recruited and divided into three groups, before and after metformin treatment and placebo. Real-time PCR was used to evaluate the H19 expression in cancer tissue in all patients. Results: : It has been observed that in endometrial tissue of the "after-metformin" treatment group, the H19 expression level was significantly reduced, compared with the "before-metformin" treatment group, but not in comparison with the placebo. These findings indicate that metformin reduced the H19 expression in endometrial cancer. Conclusion: Anti-diabetic drugs, such as metformin, may be beneficial by reducing the H19 expression in endometrial cancer due to the H19 relation to cancer progression.

Metformin for Cardiovascular Protection, Inflammatory Bowel Disease, Osteoporosis, Periodontitis, Polycystic Ovarian Syndrome, Neurodegeneration, Cancer, Inflammation and Senescence: What Is Next?

Diabetes is accompanied by several complications. Higher prevalence of cancers, cardiovascular diseases, chronic kidney disease (CKD), obesity, osteoporosis, and neurodegenerative diseases has been reported among patients with diabetes. Metformin is the oldest oral antidiabetic drug and can improve coexisting complications of diabetes. Clinical trials and observational studies uncovered that metformin can remarkably prevent or alleviate cardiovascular diseases, obesity, polycystic ovarian syndrome (PCOS), osteoporosis, cancer, periodontitis, neuronal damage and neurodegenerative diseases, inflammation, inflammatory bowel disease (IBD), tuberculosis, and COVID-19. In addition, metformin has been proposed as an antiaging agent. Numerous mechanisms were shown to be involved in the protective effects of metformin. Metformin activates the LKB1/AMPK pathway to interact with several intracellular signaling pathways and molecular mechanisms. The drug modifies the biologic function of NF-κB, PI3K/AKT/mTOR, SIRT1/PGC-1α, NLRP3, ERK, P38 MAPK, Wnt/β-catenin, Nrf2, JNK, and other major molecules in the intracellular signaling network. It also regulates the expression of noncoding RNAs. Thereby, metformin can regulate metabolism, growth, proliferation, inflammation, tumorigenesis, and senescence. Additionally, metformin modulates immune response, autophagy, mitophagy, endoplasmic reticulum (ER) stress, and apoptosis and exerts epigenetic effects. Furthermore, metformin protects against oxidative stress and genomic instability, preserves telomere length, and prevents stem cell exhaustion. In this review, the protective effects of metformin on each disease will be discussed using the results of recent meta-analyses, clinical trials, and observational studies. Thereafter, it will be meticulously explained how metformin reprograms intracellular signaling pathways and alters molecular and cellular interactions to modify the clinical presentations of several diseases.

The regulatory effects of clomiphene and tamoxifen on mTOR and LC3-II expressions in relation to autophagy in experimental polycystic ovary syndrome (PCOS)

BACKGROUND

Polycystic ovary syndrome (PCOS) is a metabolic disease that causes infertility due to anovulation in women in reproductive age. It is known that clomiphene citrate (CC) and tamoxifen citrate (TMX) induce ovulation in women with PCOS. In this study, we aimed to investigate the effects of CC and TMX on the autophagy pathway in PCOS.

METHODS AND RESULTS

Experimental PCOS model was induced by letrozole (1 mg/kg) in rats by gavage for 21 days. After the last letrozole administration, rats were treated TMX (1 mg/kg) or CC (1 mg/kg) for 5 days. At the end of the experimental procedures, rats in all groups were sacrificed and ovarian tissues were removed. It was observed that mRNA and protein expressions of LC3-II were significantly higher in TMX and CC groups than control and PCOS groups (p < 0.05), while mRNA and protein expressions of mTOR in TMX and CC groups were found significantly lower than control and PCOS groups (p < 0.05).

CONCLUSIONS

In conclusion, present study suggests that TMX and CC induce autophagy in ovaries with PCOS. Autophagy is a promising target for understanding pathophysiology of this disease and for developing more effective and safe new protocols for the treatment of PCOS-related anovulation.

Aberrant H19 Expression Disrupts Ovarian Cyp17 and Testosterone Production and Is Associated with Polycystic Ovary Syndrome in Women

As one of the most common endocrine disorders affecting women, polycystic ovary syndrome (PCOS) is associated with serious conditions including anovulation, endometrial cancer, infertility, hyperandrogenemia, and an increased risk for obesity and metabolic derangements. One contributing etiology to the pathophysiology of hyperandrogenemia associated with PCOS is an intrinsic alteration in ovarian steroidogenesis, leading to enhanced synthesis of androgens including testosterone. Studies have suggested that the increased testosterone synthesis seen in PCOS is driven in part by increased activity of CYP17A1, the rate-limiting enzyme for the formation of androgens in the gonads and adrenal cortex, which represents a critical factor driving enhanced testosterone secretion in PCOS. In this work, we evaluated the hypothesis that dysregulation of the noncoding RNA H19 results in aberrant CYP17 and testosterone production. To achieve this, we measured Cyp17 in ovarian tissues of H19 knockout mice, and quantified serum testosterone levels, in comparison with wild-type controls. We also evaluated circulating and ovarian H19 expression and correlated results with the presence or absence of PCOS in a group of women undergoing evaluation and treatment for infertility. We found that the loss of H19 in a mouse model results in decreased ovarian Cyp17, along with decreased serum testosterone in female mice. Moreover, utilizing serum samples and cumulus cells from women with PCOS, we showed that circulating and ovarian levels of H19 are increased in women with PCOS compared to controls. Findings from our multimodal experimental strategy, involving both a mouse model of dysregulated H19 expression and clinical serum and ovarian cellular samples from women with PCOS, suggest that the loss of H19 may disrupt androgen production via a Cyp17-mediated mechanism. Conversely, excess H19 may play a role in the pathogenesis of PCOS-associated hyperandrogenemia.

Aerobic exercise inhibits inflammatory response in atherosclerosis via Sestrin1 protein

Aerobic exercise plays an important role in prevention and treatment of atherosclerosis. Inflammatory response is the main pathological process during occurrence and development stage of atherosclerosis. SESNs are considered as anti-inflammation protein in atherosclerosis. In current study, a high expression level of SESN1 is identified under the condition of aerobic exercise, further investigation shows levels of IL-1β/IL-6/TNF-α are significantly suppressed compared to those atherosclerosis mice with no aerobic training. Besides, we find that the activation of NF-κB signaling is impeded. Combine with our previous study, SESN1 is considered as the downstream factor of aerobic exercise which tend to inhibit the activation of inflammatory signaling and results in suppressing the expression level of inflammatory factors. Another exciting finding is that MMP9/13 are also suppressed，but the potential mechanism is unclear. Overall, present study sheds light on the significance of aerobic exercise for inflammation and stability of plaque through SESN1 may help developing new clinical treatments of atherosclerosis.

LncRNA-H19 regulates chemoresistance to carboplatin in epithelial ovarian cancer through microRNA-29b-3p and STAT3

Background: Platinum-based chemotherapy is part of current standard treatment for epithelial ovarian cancer (EOC). However, chemoresistance often rapidly developed, leading to chemotherapy failure and unfavored prognosis. Increasing evidence has demonstrated the important role of oncogenic long noncoding RNA H19 in various cancers, including EOC. No current study is available in exploring the role of lncRNA-H19 in carboplatin resistance of EOC and its underlying mechanism.

Methods: Levels of lncRNA-H19, miR-29b-3p, and STAT3 mRNA were measured by qRT-PCR. The 50% inhibitory concentration value was detected with Cell Counting Kit-8 (CCK8). Colony-formation and CCK8 assays were employed to measure cell viability. Cell migration and invasion ability was evaluated with transwells. Western blot assay was utilized to measure P-gp, MRP1, LRP, and STAT3 protein levels. The targeting between lncRNA-H19 and miR-29b-3p, as well as miR-29b-3p and STAT3, was verified by dual-luciferase, RNA immunoprecipitation, and RNA pull-down experiments.

Results: lncRNA-H19 and STAT3 were sharply increased, while miR-29b-3p was decreased in carboplatin-resistant EOC. Carboplatin efficacy was enhanced by lncRNA-H19 silencing in chemo-resistant EOC cells. lncRNA-H19 served as a competing endogenous RNA of miR-29b-3p, causing the derepression of miR-29b-3p downstream target STAT3, leading to chemoresistance in carboplatin-tolerated EOC.

Conclusions: The lncRNA-H19/miR-29b-3p axis improved carboplatin resistance of EOC by targeting STAT3, indicating a possible approach to improving chemotherapy for EOC.

The Potential Effect of Rhizoma coptidis on Polycystic Ovary Syndrome Based on Network Pharmacology and Molecular Docking

Background

Rhizoma coptidis (RC) showed a significant effect on PCOS, but its mechanism in PCOS remains unclear.

Methods

The components of RC were searched by TCMSP. The Smiles number of the active ingredients was queried through PubChem, and the predicted targets were obtained from the SwissTargetPrediction database. The DrugBank, GeneCards, and DisGeNET databases were retrieved to acquire the related targets of PCOS. Then, the network of compound-target was constructed. The core targets were analyzed using protein-protein interaction (PPI) analysis, and the binding activities were verified by molecular docking. The enriched pathways of key targets were examined by GO and KEGG.

Results

13 components and 250 targets of RC on PCOS were screened. The core network was filtered based on topological parameters, and the key components were palmatine, berberine, berberrubine, quercetin, and epiberberine. The key targets included DRD2, SLC6A4, CDK2, DPP4, ESR1, AKT2, PGR, and AKT1. Molecular docking displayed that the active ingredients of RC had good binding activities with potential targets of PCOS. After enrichment analysis, 30 functional pathways were obtained, including neuroactive ligand-receptor interaction, dopaminergic synapse, and cAMP signaling pathway.

Conclusion

In summary, this study clarified the potential effect of RC on PCOS, which is helpful to provide references for clinical practice. It is also conducive to the secondary development of RC and its monomer components.

Downregulation of miR‑29b‑3p promotes α‑tubulin deacetylation by targeting the interaction of matrix metalloproteinase‑9 with integrin β1 in nasal polyps

Matrix metalloproteinase (MMP)‑9 is a key enzyme responsible for extracellular matrix degradation and contributes to the progressive histological changes observed in lower respiratory tract infections. Integrin β1 and α‑tubulin are potential MMP‑9‑interacting proteins, and microRNA (miR)‑29b‑3p can regulate MMP‑9 expression. MMP‑9 is highly expressed in chronic rhinosinusitis with nasal polyps (CRSwNPs), regardless of its effects on miR‑29b‑3p, integrin β1 and α‑tubulin expression. In the present study, samples from 100 patients with CRSwNPs were examined via reverse transcription‑quantitative PCR to assess the mRNA expression of miR‑29b‑3p, and western blotting was performed to assess the protein expression of MMP‑2, MMP‑9, acetyl‑α‑tubulin, integrin β1 and tissue inhibitor of metalloproteinase 1 (TIMP‑1). A dual‑luciferase reporter assay was used to verify the direct binding of miR‑29b‑3p and MMP‑2/MMP‑9. Co‑immunoprecipitation (Co‑IP) and GST pull‑down assays showed that integrin β1 and α‑tubulin were MMP‑9‑interacting proteins. Cell viability, apoptosis and inflammatory cytokine levels were determined via a Cell Counting Kit‑8 assay, flow cytometry and ELISA, respectively. miR‑29b‑3p expression was found to be positively correlated with MMP‑2 and MMP‑9 expression. Whereas, TIMP‑1 expression was negatively correlated with MMP‑2 and MMP‑9 expression. The dual‑luciferase assay revealed that miR‑29b‑3p targeted the 3' untranslated region of MMP‑2/MMP‑9. The Co‑IP and GST pull‑down assays showed that MMP‑9 could directly bind to integrin β1 and indirectly bind to α‑tubulin. Finally, the overexpression of miR‑29b‑3p decreased the expression of MMP‑9 and increased the levels of acetyl‑α‑tubulin. By contrast, the knockdown of miR‑29b‑3p increased the expression of MMP‑9 and decreased the levels of acetyl‑α‑tubulin. Additionally, MMP‑9 expression was found to be negatively correlated with acetyl‑α‑tubulin expression. Of note, the expression of integrin β1 did not change following the overexpression and knockdown of MMP‑9. Finally, the overexpression of miR‑29b‑3p not only decreased MMP‑9 expression, but also alleviated lipopolysaccharide‑induced inflammation in NP69 cells. The results showed that the downregulation of miR‑29b‑3p promoted α‑tubulin deacetylation by increasing the number of MMP‑9‑integrin β1 complexes in CRSwNPs, thus targeting miR‑29b‑3p/MMP‑9 may be a potential novel strategy for the clinical treatment of CRSwNPs.

Metformin and insulin-resistant related diseases: Emphasis on the role of microRNAs

Metformin is one of the most prescribed drugs in type II diabetes (T2DM) which has recently found new applications in the prevention and treatment of various illnesses, from metabolic disorders to cardiovascular and age-related diseases. Metformin improves insulin resistance (IR) by modulating metabolic mechanisms and mitochondrial biogenesis. Alternation of microRNAs (miRs) in the treatment of IR-related illnesses has been observed by metformin therapy. MiRs are small non-coding RNAs that play important roles in RNA silencing, targeting the 3'untranslated region (3'UTR) of most mRNAs and inhibiting the translation of related proteins. As a result, their dysregulation is associated with many diseases. Metformin may alter miRs levels in the treatment of various diseases by AMPK-dependent or AMPK-independent mechanisms. Here, we summarized the therapeutic role of metformin by modifying the aberrant expression of miRs as potential biomarkers or therapeutic targets in diseases in which IR plays a key role.

Metformin inhibits testosterone-induced endoplasmic reticulum stress in ovarian granulosa cells via inactivation of p38 MAPK

STUDY QUESTION

Does metformin inhibit excessive androgen-induced endoplasmic reticulum (ER) stress in mouse granulosa cells (GCs) in vivo and in vitro?

SUMMARY ANSWER

Metformin inhibits testosterone-induced ER stress and unfolded protein response (UPR) activation by suppressing p38 MAPK phosphorylation in ovarian GCs.

WHAT IS KNOWN ALREADY

Polycystic ovary syndrome (PCOS) is associated with hyperandrogenism. Excessive testosterone induces ER stress and UPR activation in human cumulus cells, leading to cell apoptosis. Metformin has potential inhibitory effects on ER stress and UPR activation, as demonstrated in human pancreatic beta cells and obese mice.

STUDY DESIGN, SIZE, DURATION

Cumulus cells and follicular fluid were collected from 25 women with PCOS and 25 controls at our IVF centre. A dihydrotestosterone (DHT)-induced PCOS mouse model was constructed and treated with or without metformin. Primary mouse GCs and cumulus-oocyte complexes (COCs) were cultured with testosterone, metformin, a p38 MAPK inhibitor, or p38 MAPK small interfering RNA.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The levels of UPR sensor proteins and UPR-related genes were measured in cumulus cells from PCOS and control patients by real-time quantitative PCR (qPCR) and western blot. The ovaries, oocytes, GCs and COCs were collected from PCOS mice treated with metformin and controls. The expressions of ER stress markers and p38 MAPK phosphorylation were assessed by qPCR, western blot and immunofluorescence. A subsequent in vitro analysis with primary cultured GCs and COCs was used to confirm the influence of metformin on ER stress activation by qPCR and western blot. Finally, the effects of ER stress activation on GCs and COCs in relation to LH responsiveness were examined by qPCR and COC expansion.

MAIN RESULTS AND THE ROLE OF CHANCE

The expression of the ER stress markers GRP78, CHOP and XBP1s in the cumulus cells was higher in PCOS patients than in control patients, as were the levels of the UPR sensor proteins p-IRE1α, p-EIF2α and GRP78. Compared to those of control mice, the ovaries, GCs and COCs of DHT-treated PCOS mice showed increased levels of ER stress marker genes and proteins. Hyperandrogenism in PCOS mouse ovaries also induced p38 MAPK phosphorylation in COCs and GCs. Metformin inhibited ER stress activation was associated with decreased p-p38 MAPK levels. In vitro experiments, testosterone-induced ER stress was mitigated by metformin or p38 MAPK inhibition in primary cultured GCs and COCs. COCs expanded rapidly in the presence of testosterone during LH administration, and ovulation-related genes, namely, Areg, Ereg, Ptgs2, Sult1e1, Ptx3 and Tnfaip6, were strongly expressed in the COCs and GCs. These effects were reversed by treatment with metformin, an ER stress inhibitor or by knockdown of p38 MAPK.

LIMITATIONS, REASONS FOR CAUTION

The number of PCOS patients in this study was small.

WIDER IMPLICATIONS OF THE FINDINGS

This study provides further evidence for metformin as a PCOS treatment.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the National Key Research and Developmental Program of China (2018YFC1004800), the Key Research and Development Program of Zhejiang Province (2017C03022), the Zhejiang Province Medical Science and Technology Plan Project (2017KY085, 2018KY457), the National Natural Science Foundation of China (31701260, 81401264, 81701514), and the Special Funds for Clinical Medical Research of the Chinese Medical Association (16020320648). The authors report no conflict of interest in this work and have nothing to disclose.

TRIAL REGISTRATION NUMBER

N/A.

Improvement Effect of Metformin on Female and Male Reproduction in Endocrine Pathologies and Its Mechanisms

Metformin (MF), a first-line drug to treat type 2 diabetes mellitus (T2DM), alone and in combination with other drugs, restores the ovarian function in women with polycystic ovary syndrome (PCOS) and improves fetal development, pregnancy outcomes and offspring health in gestational diabetes mellitus (GDM) and T2DM. MF treatment is demonstrated to improve the efficiency of in vitro fertilization and is considered a supplementary drug in assisted reproductive technologies. MF administration shows positive effect on steroidogenesis and spermatogenesis in men with metabolic disorders, thus MF treatment indicates prospective use for improvement of male reproductive functions and fertility. MF lacks teratogenic effects and has positive health effect in newborns. The review is focused on use of MF therapy for restoration of female and male reproductive functions and improvement of pregnancy outcomes in metabolic and endocrine disorders. The mechanisms of MF action are discussed, including normalization of metabolic and hormonal status in PCOS, GDM, T2DM and metabolic syndrome and restoration of functional activity and hormonal regulation of the gonadal axis.

The umbilical cord mesenchymal stem cell-derived exosomal lncRNA H19 improves osteochondral activity through miR-29b-3p/FoxO3 axis

BACKGROUND

Our previous study revealed that the exosomal lncRNA H19 derived from umbilical cord mesenchymal stem cells (UMSCs) plays a pivotal role in osteochondral regeneration. In this study, we investigated whether the exosomal lncRNA H19 could act as a competing endogenous RNA (ceRNA) to potentiate osteochondral activity in chondrocytes.

METHODS

Dual-luciferase reporter assay, RNA pull-down, RNA immunoprecipitation (RIP), and fluorescence in situ hybridization (FISH) were carried to verify the interaction between miR-29b-3p and both lncRNA H19 and the target mRNA FoxO3. Chondrocytes were treated with UMSC-derived exosomes, which highly expressing lncRNA H19 expression, followed by apoptosis, migration, senescence, and matrix secretion assessments. An in vivo SD rat cartilage defect model was carried out to explore the role and mechanism of lncRNA H19/miR-29b-3p.

RESULTS

UMSCs were successfully identified, and exosomes were successfully extracted. Exosomes exhibited the ability to transfer lncRNA H19 to chondrocytes. Mechanistically, exosomal lncRNA H19 potentiated osteochondral activity by acting as a competing endogenous sponge of miR-29b-3p, and miR-29b-3p directly targeted FoxO3. Intra-articular injection of exosomes overexpressing lncRNA H19 could promote sustained cartilage repair; however, this effect could be undermined by miR-29b-3p agomir.

CONCLUSIONS

Our study revealed a significant role in the development of strategies against cartilage defects for UMSC-derived exosomes that overexpress lncRNA H19. Exosomal H19 was found to promote chondrocyte migration, matrix secretion, apoptosis suppression, as well as senescence suppression, both in vitro and in vivo. The specific mechanism lies in the fact that exosomal H19 acts as a ceRNA against miR-29b-3p to upregulate FoxO3 in chondrocytes.

Effects of inflammatory and anti-inflammatory environments on the macrophage mitochondrial function

Mitochondrial response to inflammation is crucial in the metabolic adaptation to infection. This study aimed to explore the mitochondrial response under inflammatory and anti-inflammatory environments, with a focus on the tricarboxylic acid (TCA) cycle. Expression levels of key TCA cycle enzymes and the autophagy-related protein light chain 3b (LC3b) were determined in raw 264.7 cells treated with lipopolysaccharide (LPS) and metformin (Met). Additionally, reactive oxygen species (ROS) levels and mitochondrial membrane potential were assessed using flow cytometry. Moreover, 8-week-old C57BL/6J mice were intraperitoneally injected with LPS and Met to assess the mitochondrial response in vivo. Upon LPS stimulation, the expression of key TCA enzymes, including citrate synthase, α-ketoglutarate dehydrogenase, and isocitrate dehydrogenase 2, and the mitochondrial membrane potential decreased, whereas the levels of LC3b and ROS increased. However, treatment with Met inhibited the reduction of LPS-induced enzyme levels as well as the elevation of LC3b and ROS levels. In conclusion, the mitochondrial TCA cycle is affected by the inflammatory environment, and the LPS-induced effects can be reversed by Met treatment.

Development of a pH-responsive polymersome inducing endoplasmic reticulum stress and autophagy blockade

Autophagy is involved in the occurrence and development of tumors. Here, a pH-responsive polymersome codelivering hydroxychloroquine (HCQ) and tunicamycin (Tuni) drugs is developed to simultaneously induce endoplasmic reticulum (ER) stress and autophagic flux blockade for achieving an antitumor effect and inhibiting tumor metastasis. The pH response of poly(β-amino ester) and HCQ synergistically deacidifies the lysosomes, thereby blocking the fusion of autophagosomes and lysosomes and lastly blocking autophagic flux. The function mechanism of regulating autophagy was systematically investigated on orthotopic luciferase gene-transfected, 4T1 tumor-bearing BALB/c mice through Western blot and immunohistochemistry analyses. The Tuni triggers ER stress to regulate the PERK/Akt signaling pathway to increase the autophagic level. The "autophagic stress" generated by triggering ER stress-induced autophagy and blocking autophagic flux is effective against tumors. The reduced expression of matrix metalloproteinase-2 due to ER stress and reduced focal adhesions turnover due to the blockade of autophagic flux synergistically inhibit tumor metastasis.

The microRNA-155 mediates hepatitis B virus replication by reinforcing SOCS1 signalling-induced autophagy

As small conserved RNAs without a coding function, microRNAs are expressed in multicellular organisms and contribute to the modulation of multiple cellular reactions, such as viral replication, as well as autophagy. microRNAs can regulate host gene expression and inhibit or reinforce hepatitis B virus (HBV) replication. Hepatic cells express miR-155 noticeably. Consequently, our study explored miR-155 modulation of HBV replication and investigated the potential mechanism involved. miR-155 was inhibited on HBV infection. miR-155 transfection remarkably reinforced HBV replication, antigen expression, and progeny secretion in HepG2215 cells. Moreover, miR-155 impaired the inhibition of the cytokine signalling 1 (SOCS1)/Akt/mTOR axis and reinforced HepG2215 autophagy. Additionally, the autophagy inhibitor (3-MA) eliminated HBsAg secretion triggered by miR-155. Taken together, miR-155 reinforced HBV replication by reinforcing SOCS1-triggered autophagy. SIGNIFICANCE OF THE STUDY: The research studied the potential mechanism involved in HBV replication and miR-155 that miR-155 reinforces HBV replication by reinforcing the SOCS1/Akt/mTOR axis-stimulated autophagy, and therefore, it can provide medical practitioners with the inspiration that chronic HBV might be cured or improved by regulating the activation of miR-155 in cells. In the study, the experiments show that autophagy inhibitors (3-MA) counteracted miR-155 contribution to HBV replication, and it might be a practicable way to improve HBV through some therapies that can repress the autophagy in related cells.