Mitochondrial function and oxidative stress in white adipose tissue in a rat model of PCOS: effect of SGLT2 inhibition

Network analysis combined with experimental assessment to explore the therapeutic mechanisms of New Shenqi Pills formula targeting mitochondria on senile diabetes mellitus

Background

The escalation of global population aging has accentuated the prominence of senile diabetes mellitus (SDM) as a consequential public health concern. Oxidative stress and chronic inflammatory cascades prevalent in individuals with senile diabetes significantly amplify disease progression and complication rates. Traditional Chinese Medicine (TCM) emerges as a pivotal player in enhancing blood sugar homeostasis and retarding complication onset in the clinical management of senile diabetes. Nonetheless, an evident research gap persists regarding the integration of TCM's renal tonification pharmacological mechanisms with experimental validation within the realm of senile diabetes therapeutics.

Aims

The objective of this study was to investigate the mechanisms of action of New Shenqi Pills (SQP) in the treatment of SDM and make an experimental assessment.

Methods

Network analysis is used to evaluate target pathways related to SQP and SDM. Mitochondrial-related genes were obtained from the MitoCarta3.0 database and intersected with the common target genes of the disease and drugs, then constructing a protein-protein interaction (PPI) network making use of the GeneMANIA database. Representative compounds in the SQP were quantitatively measured using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to ensure quality control and quantitative analysis of the compounds. A type 2 diabetes mice (C57BL/6) model was used to investigate the pharmacodynamics of SQP. The glucose lowering efficacy of SQP was assessed through various metrics including body weight and fasting blood glucose (FBG). To elucidate the modulatory effects of SQP on pancreatic beta cell function, we measured oral glucose tolerance test (OGTT), insulin histochemical staining and tunel apoptosis detection, then assessed the insulin-mediated phosphoinositide 3-kinase (PI3K)/protein kinase A (Akt)/glycogen synthase kinase-3β (GSK-3β) pathway in diabetic mice via Western blotting. Additionally, we observe the structural changes of the nucleus, cytoplasmic granules and mitochondria of pancreatic islet β cells.

Results

In this investigation, we identified a total of 1876 genes associated with senile diabetes, 278 targets of SQP, and 166 overlapping target genes, primarily enriched in pathways pertinent to oxidative stress response, peptide response, and oxygen level modulation. Moreover, an intersection analysis involving 1,136 human mitochondrial genes and comorbidity targets yielded 15 mitochondria-related therapeutic targets. Quality control assessments and quantitative analyses of SQP revealed the predominant presence of five compounds with elevated concentrations: Catalpol, Cinnamon Aldehyde, Rehmanthin D, Trigonelline, and Paeonol Phenol. Vivo experiments demonstrated notable findings. Relative to the control group, mice in the model group exhibited significant increases in body weight and fasting blood glucose levels, alongside decreased insulin secretion and heightened islet cell apoptosis. Moreover, β-cells nuclear condensation and mitochondrial cristae disappearance were observed, accompanied by reduced expression levels of p-GSK-3β protein in islet cells (p < 0.05 or p < 0.01). Conversely, treatment groups administered SQP and Rg displayed augmented expressions of the aforementioned protein markers (p < 0.05 or p < 0.01), alongside preserved mitochondrial cristae structure in islet β cells.

Conclusion

Our findings suggest that SQP can ameliorate diabetes by reducing islet cell apoptosis and resist oxidative stress. These insulin-mediated PI3K/AKT/GSK-3β pathway plays an important regulatory role in this process.

Effect of SGLT2 Inhibitors on Improving Glucolipid Metabolism and Reproductive Hormone Status in Overweight/Obese Women with PCOS: A Systematic Review and Meta-Analysis

BACKGROUND

Obesity, insulin resistance, and hyperandrogenemia are commonly seen in women with polycystic ovary syndrome (PCOS), and these three conditions form a vicious cycle leading to reproductive and metabolic abnormalities. Metformin improves the symptoms of PCOS by increasing insulin sensitivity but is not therapeutically optimal. Recent studies have reported that sodium-glucose co-transporter protein receptor inhibitors improve insulin resistance and reduce the weight of patients with PCOS. We performed a meta-analysis to assess the influence of sodium-glucose co-transporter protein-2 (SGLT2) inhibitors on anthropometric, glycolipid metabolism and reproductive outcomes after therapy of overweight/obese women with PCOS.

METHODS

We searched the relevant literature published up to April 2023. Information on the effect of SGLT2 inhibitors on overweight/obese patients with PCOS was extracted independently by two reviewers. Review Manager 5.3 was used for meta-analysis.

RESULTS

Five randomized controlled trials that met our criteria were retrieved. Our meta-analysis demonstrated that in overweight/obese patients with PCOS, SGLT2 inhibitors treatment was significantly superior to metformin treatment in terms of reducing body weight (P = 0.02, I2 = 36%), decreasing dehydroepiandrosterone sulfate concentrations [SMD = -0.42, 95% CI (-0.76, -0.07), I2 = 22%, P = 0.02], and reducing the incidence of nausea [RR = 0.35, 95% CI (0.21, 0.60), I2 = 71%, P = 0.0001].

CONCLUSIONS

SGLT2 inhibitors are a possible alternative therapy for treating overweight/obese women with PCOS who do not respond favorably to metformin treatment. However, further large randomized controlled trials and cost-effectiveness analyses are warranted to guide the implementation of SGLT2 inhibitors treatment in this population.

Reactive oxygen species signalling in the deterioration of quality of mammalian oocytes cultured in vitro: Protective effect of antioxidants

The in vitro fertilization (IVF) is the first choice of infertile couples worldwide to plan for conception. Besides having a significant advancement in IVF procedure, the success rate is still poor. Although several approaches have been tested to improve IVF protocol, minor changes in culture conditions, physical factors and/or drug treatment generate reactive oxygen species (ROS) in oocytes. Due to large size and huge number of mitochondria, oocyte is more susceptible towards ROS-mediated signalling under in vitro culture conditions. Elevation of ROS levels destabilize maturation promoting factor (MPF) that results in meiotic exit from diplotene as well as metaphase-II (M-II) arrest in vitro. Once meiotic exit occurs, these oocytes get further arrested at metaphase-I (M-I) stage or metaphase-III (M-III)-like stage under in vitro culture conditions. The M-I as well as M-III arrested oocytes are not fit for fertilization and limits IVF outcome. Further, the generation of excess levels of ROS cause oxidative stress (OS) that initiate downstream signalling to initiate various death pathways such as apoptosis, autophagy, necroptosis and deteriorates oocyte quality under in vitro culture conditions. The increase of cellular enzymatic antioxidants and/or supplementation of exogenous antioxidants in culture medium protect ROS-induced deterioration of oocyte quality in vitro. Although a growing body of evidence suggests the ROS and OS-mediated deterioration of oocyte quality in vitro, their downstream signalling and related mechanisms remain poorly understood. Hence, this review article summarizes the existing evidences concerning ROS and OS-mediated downstream signalling during deterioration of oocyte quality in vitro. The use of various antioxidants against ROS and OS-mediated impairment of oocyte quality in vitro has also been explored in order to increase the success rate of IVF during assisted reproductive health management.

Role of epidural fat in the local milieu: what we know and what we don't

PURPOSE

Traditionally, the epidural fat (EF) is known as a physical buffer for the dural sac against the force and a lubricant facilitating the relative motion of the latter on the osseous spine. Along with the development of the studies on EF, controversies still exist on vital questions, such as the underlying mechanism of the spinal epidural lipomatosis. Meanwhile, the scattered and fragmented researches hinder the global insight into the seemingly dispensable tissue.

METHODS

Herein, we reviewed literature on the EF and its derivatives to elucidate the dynamic change and complex function of EF in the local milieu, especially at the pathophysiological conditions. We start with an introduction to EF and the current pathogenic landscape, emphasizing the interlink between the EF and adjacent structures. We generally categorize the major pathological changes of the EF into hypertrophy, atrophy, and inflammation.

RESULTS AND CONCLUSIONS

It is acknowledged that not only the EF (or its cellular components) may be influenced by various endogenic/exogenic and focal/systematic stimuli, but the adjacent structures can also in turn be affected by the EF, which may be a hidden pathogenic clue for specific spinal disease. Meanwhile, the unrevealed sections, which are also the directions the future research, are proposed according to the objective result and rational inference. Further effort should be taken to reveal the underlying mechanism and develop novel therapeutic pathways for the relevant diseases.

Management of Hypertension in Patients With Polycystic Ovarian Syndrome: A Mini-Review

Polycystic ovarian syndrome (PCOS) is a common problem among young women. It is characterized mainly by hyperandrogenism features, such as hirsutism, menstrual problems, and anovulation. Diagnosis is based on the existence of 2 items out of, oligo-ovulation, hyperandrogenism features, and ultrasounds findings. Cardiovascular complications such as hypertension are a prevalent serious condition in these patients which is mainly predisposed by the high levels of androgens, and insulin resistance. High blood pressure should be controlled well to prevent the progression of other serious conditions. Various antihypertensive drugs could be prescribed. However, in selecting an antihypertensive medication, other therapeutic properties of the drug should also be considered. Up to now, many clinicians do not differ between PCOS patients with hypertension and other hypertensive patients. However, being aware of the potential effects of each hypertension drug could help to choose better options for the patient. Here is a brief review of how each antihypertensive drug could affect PCOS women and if they cause any improvement in the disorder progression.

Therapeutic Effects of Pimpinella anisum Fruit Extract on Polycystic Ovary Syndrome in a Rat Model: Emerging Role of Inflammatory Responses and Oxidative Stress

Background

Polycystic ovary syndrome (PCOS) is the most common gynecological endocrine disorder.

Objectives

This study evaluated the therapeutic effects of Pimpinella anisum L. (P. anisum) fruit on pro-inflammatory cytokines, oxidative stress markers, and ovarian tissue structure in a rat model of PCOS.

Methods

After inducing PCOS, female Wistar rats were randomly divided into control and PCOS groups. They orally received daily doses of normal saline or hydro-alcoholic extract of P. anisum at two doses (200 and 400 mg/kg) for 21 days. At the end of the treatment period, ovarian and liver tissues were collected to measure lipid peroxidation, antioxidant status, TNF-α, IL-6 mRNA expression, and its content. Additionally, histopathological examinations of the ovarian tissue were conducted.

Results

Our findings revealed a dose-dependent change in the biochemical and histopathological parameters. Treatment with P. anisum resulted in a significant decrease in TNF-α and IL-6 mRNA expression levels and their content in the ovarian and liver tissues. It also reduced MDA levels while increasing SOD and GPx activity in both ovarian and liver tissues of PCOS rats. Furthermore, the number of follicular cysts in the PCOS rat model was significantly reduced.

Conclusions

The beneficial effects of P. anisum in PCOS rats are partly attributed to the inhibition of inflammatory and oxidative stress markers in ovarian tissue. These findings suggest that P. anisum could be a potential candidate for the treatment of PCOS disorders.

Novel insights into the role of mitochondria in diabetic cardiomyopathy: molecular mechanisms and potential treatments

Diabetic cardiomyopathy describes decreased myocardial function in diabetic patients in the absence of other heart diseases such as myocardial ischemia and hypertension. Recent studies have defined numerous molecular interactions and signaling events that may account for deleterious changes in mitochondrial dynamics and functions influenced by hyperglycemic stress. A metabolic switch from glucose to fatty acid oxidation to fuel ATP synthesis, mitochondrial oxidative injury resulting from increased mitochondrial ROS production and decreased antioxidant capacity, enhanced mitochondrial fission and defective mitochondrial fusion, impaired mitophagy, and blunted mitochondrial biogenesis are major signatures of mitochondrial pathologies during diabetic cardiomyopathy. This review describes the molecular alterations underlying mitochondrial abnormalities associated with hyperglycemia and discusses their influence on cardiomyocyte viability and function. Based on basic research findings and clinical evidence, diabetic treatment standards and their impact on mitochondrial function, as well as mitochondria-targeted therapies of potential benefit for diabetic cardiomyopathy patients, are also summarized.

Physical exercise alleviates oxidative stress in brown adipose tissue and causes changes in body composition and nutritional behavior in rats with polycystic ovary syndrome

AIM

Polycystic Ovary Syndrome (PCOS) is a very common endocrine disorder in women. We investigate the effect of physical exercise on body composition, nutritional parameters, and oxidative stress in rats with PCOS.

METHODS

Female rats were into three groups: Control, PCOS, and PCOS + Exercise. PCOS was induced by letrozole (1 mg/kg via p.o.) for 21 days consecutively. Physical exercise was swimming, for 21 consecutive days, 1 h/day with 5 % load. In all groups, we assessed the nutritional and murinometric parameters, body composition, thermography, and oxidative stress in brown adipose tissue (BAT) and peri-ovarian adipose tissue (POAT).

KEY FINDINGS

In PCOS we observed an increase (P < 0.05) in body weight vs. the Control group. But, the PCOS + Exercise group prevent this weight gain (P < 0.05). The temperature in BAT, decrease (P < 0.05) in the PCOS group vs. Control group. PCOS + Exercise prevented this reduction (P < 0.05) in BAT temperature vs. PCOS groups. We observed decreases (P < 0.05) in Lee Index and BMI in POS + Exercise vs. PCOS group. In PCOS rats, we observed an increase (P < 0.05) in murinometric (SRWG, EI, and FE) and body composition parameters (TWB, ECF, ICF, and FFM) vs. the Control group. The PCOS + Exercise prevents (P < 0.05) these changes in all groups, compared with PCOS. Regarding the BAT, we observe an increase (P < 0.05) in MPO and MDA levels in the PCOS vs. Control group. PCOS + Exercise prevents (P < 0.05) these increases vs. the PCOS group.

SIGNIFICANCE

PCOS modifies body composition, and nutritional parameters, and induces changes in oxidative stress in BAT. Physical exercise prevented these alterations.

The Potential of SGLT-2 Inhibitors in the Treatment of Polycystic Ovary Syndrome: The Current Status and Future Perspectives

Polycystic ovary syndrome (PCOS) is the most frequent endocrinopathy during women’s reproductive age. PCOS is a heterogeneous disorder featuring specific cardiometabolic properties. The association between the presence of metabolic disorders and PCOS supports the claim that the regulation of glycemic status is very important in these patients. There is a wide range of therapeutic options (including those treating diabetes mellitus type 2) with potential advantages available for the management of PCOS. Sodium–glucose cotransporter type 2 inhibitors (SGLT-2is) improve glucose metabolism, reduce fat tissue, lower blood pressure, reduce oxidative stress and inflammation, and protect the cardiovascular system. Currently, the use of SGLT-2is is not widespread in PCOS therapy, although these drugs represent a promising new therapeutic approach. Therefore, it is necessary to initiate further study in order to determine more effective therapies for PCOS and investigate the effect of SGLT-2is, both as a monotherapy and in combination with other drugs. It is necessary to understand the mechanisms underlying SGLT-2is in PCOS and their effects on long-term complications, especially since the gold standard treatment for PCOS, such as metformin and oral contraceptives, do not have long-term cardioprotective effects. The effects of SGLT-2is seem to involve cardiac protection, while diminishing endocrine and reproductive abnormalities in PCOS. In the current narrative review, we examine the most recent clinical evidence and discuss the potential applications of SGLT-2is for PCOS therapy.

The Impact of SGLT2 Inhibitor Dapagliflozin on Adropin Serum Levels in Men and Women with Type 2 Diabetes Mellitus and Chronic Heart Failure

BACKGROUND

adropin plays a protective role in cardiac remodeling through supporting energy metabolism and water homeostasis and suppressing inflammation. Low circulating levels of adropin were positively associated with the risk of cardiovascular diseases and type 2 diabetes mellitus (T2DM). We hypothesized that sodium-glucose linked transporter 2 (SGLT2) inhibitor dapagliflosin might represent cardiac protective effects in T2DM patients with known chronic HF through the modulation of adropin levels.

METHODS

we prospectively enrolled 417 patients with T2DM and HF from an entire cohort of 612 T2DM patients. All eligible patients were treated with the recommended guided HF therapy according to their HF phenotypes, including SGLT2 inhibitor dapagliflozin 10 mg, daily, orally. Anthropometry, clinical data, echocardiography/Doppler examinations, and measurements of biomarkers were performed at the baseline and over a 6-month interval of SGLT2 inhibitor administration.

RESULTS

in the entire group, dapagliflozin led to an increase in adropin levels by up to 26.6% over 6 months. In the female subgroup, the relative growth (Δ%) of adropin concentrations was sufficiently higher (Δ% = 35.6%) than that in the male subgroup (Δ% = 22.7%). A multivariate linear regression analysis of the entire group showed that the relative changes (Δ) in the left ventricular (LV) ejection fraction (LVEF), left atrial volume index (LAVI), and E/e' were significantly associated with increased adropin levels. In the female subgroup, but not in the male subgroup, ΔLVEF (p = 0.046), ΔLAVI (p = 0.001), and ΔE/e' (p = 0.001) were independent predictive values for adropin changes.

CONCLUSION

the levels of adropin seem to be a predictor for the favorable modification of hemodynamic performances during SGLT2 inhibition, independent ofN-terminal brain natriuretic pro-peptide levels.

Polycystic ovary syndrome and adipose tissue

Polycystic ovary syndrome (PCOS) is the most common endocrine metabolic disorder in women of reproductive age. Typically, it is associated with ovulatory dysfunction: dysovulation or anovulation, and symptoms of hyperandrogenism. It incurs risk of metabolic disorders such as diabetes, dyslipidemia and fatty liver. As a key endocrine organ in metabolic homeostasis, adipose tissue is often implicated in these complications. Studies of white adipose tissue (WAT) in PCOS have focused on the mechanism of insulin resistance in this tissue. Clinically, abnormalities in WAT distribution are seen, with decreased waist-to-hip ratio and increased ratio of adipose to lean mass. Such abnormalities are greater when total circulating androgens are elevated. At tissue level, white adipocyte hyperplasia occurs, along with infiltration of macrophages. Secretion of adipokines, cytokines and chemo-attractant proteins is increased in a pro-inflammatory manner, leading to reduced insulin sensitivity via alteration of glucose transporters, and hence decreased glucose uptake. The kinetics of non-esterified fatty acids (or free fatty acids) is also altered, leading to lipotoxicity. In recent years, brown adipose tissue (BAT) has been studied in women with PCOS. Although abundance is low in the body, BAT appears to play a significant role in energy expenditure and metabolic parameters. Both supra-clavicular skin temperature, which reflects BAT activity, and BAT mass are reduced in women with PCOS. Moreover, BAT mass and body mass index (BMI) are inversely correlated in patients. In the adipocyte, increased total circulating androgen levels reduce expression of uncoupling protein 1 (UCP1), a key protein in the brown adipocyte, leading to reduced biogenesis and mitochondrial respiration and hence a reduction in post-prandial thermogenesis. BAT is currently being investigated as a possible new therapeutic application.

Obesity-associated cardiometabolic complications in polycystic ovary syndrome: The potential role of sodium-glucose cotransporter-2 inhibitors

Polycystic Ovary Syndrome (PCOS) is the most common endocrine disorder in reproductive-age women. PCOS is characterized by androgen excess, oligo/anovulation, and polycystic appearance of the ovaries. Women with PCOS have an increased prevalence of multiple cardiovascular risk factors such as insulin resistance, hypertension, renal injury, and obesity. Unfortunately, there is a lack of effective, evidence-based pharmacotherapeutics to target these cardiometabolic complications. Sodium-glucose cotransporter-2 (SGLT2) inhibitors provide cardiovascular protection in patients with and without type 2 diabetes mellitus. Although the exact mechanisms of how SGLT2 inhibitors confer cardiovascular protection remains unclear, numerous mechanistic hypotheses for this protection include modulation of the renin-angiotensin system and/or the sympathetic nervous system and improvement in mitochondrial function. Data from recent clinical trials and basic research show a potential role for SGLT2 inhibitors in treating obesity-associated cardiometabolic complications in PCOS. This narrative review discusses the mechanisms of the beneficial effect of SGLT2 inhibitors in cardiometabolic diseases in PCOS.

Update on Animal Models of Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a complex disease affecting up to 15% of women of reproductive age. Women with PCOS suffer from reproductive dysfunctions with excessive androgen secretion and irregular ovulation, leading to reduced fertility and pregnancy complications. The syndrome is associated with a wide range of comorbidities including type 2 diabetes, obesity, and psychiatric disorders. Despite the high prevalence of PCOS, its etiology remains unclear. To understand the pathophysiology of PCOS, how it is inherited, and how to predict PCOS, and prevent and treat women with the syndrome, animal models provide an important approach to answering these fundamental questions. This minireview summarizes recent investigative efforts on PCOS-like rodent models aiming to define underlying mechanisms of the disease and provide guidance in model selection. The focus is on new genetic rodent models, on a naturally occurring rodent model, and provides an update on prenatal and peripubertal exposure models.