RAGE signalling contributes to oxidative stress and inflammation in knee osteoarthritis patients with metabolic syndrome.

OBJECTIVES: Metabolic factors play significant role in the natural history of knee osteoarthritis (KO). There is a limited understanding of molecular and cellular events that give rise to the disease in patients. This study explored the possible cellular mechanisms by which metabolic syndrome leads to KO. METHODS: This cross-sectional study enrolled 80 subjects with KO who fulfilled the ACR diagnostic criteria and were undergoing total knee replacement surgery. The patients were divided into two groups: KO patients without metabolic syndrome and KO patients with metabolic syndrome. RESULTS: We hypothesised that metabolic syndrome may accelerate pathogenesis of OA by enhanced RAGE axis in articular cartilage and Infrapatellar fat pad of the knee joint. We have found enhanced protein expression of receptor for advanced glycation end products (RAGE) and its ligands AGEs and HMGB-1 in knee joint tissue of KO patients with metabolic syndrome as compared to KO patients without metabolic syndrome. Further downstream, the gene expression of oxidative stress regulators such as NADPH and inflammation, NFĸB were upregulated in KO patients with MetS as compared to KO patients alone. Higher levels of advanced oxidation products and inflammatory marker IL-17 were exhibited in synovial fluid of KO patients with metabolic syndrome. The enhanced levels of these oxidative stress and inflammatory markers were reflected in the serum of KO patients with metabolic syndrome as well. CONCLUSIONS: We conclude that enhanced function of RAGE axis could be one of the mechanisms by which metabolic syndrome leads to KO.

Comparison of Various Therapeutic Approaches to Manage Infertility in Polycystic Ovarian Syndrome.

OBJECTIVE: To compare the efficacies of common therapeutic regimens and their combinations, used in polycystic ovarian syndrome (PCOS) to improve fertility in reproductive-age women. STUDY DESIGN: A descriptive study. Place and Duration of the Study: Department of Obstetric Gynaecologist, Medicare Cardiac and General Hospital, Karachi, Pakistan, from November 2022 to July 2023. METHODOLOGY: Out of 300 patients with the symptoms of menstrual irregularities and infertility, 152 were diagnosed as PCOS patients based on the ultrasound and hormonal assays and selected for study purpose. They were divided according to their therapeutic regimen into four treatment groups, treated by different therapeutic agents. Group A received metformin 500 mg/day (n = 38); Group B received metformin + myo-inositol 1g (n = 49); Group C received metformin + letrozole 2.5 mg (n = 36), and Group D received metformin + letrozole + myo-inositol (n = 29), orally for three months. All continuous variables, such as body mass index (BMI), FSH, LH, FT4, and FSI were analysed by applying t-test to all therapeutic groups, keeping p ≤0.05 as the level of significance. RESULTS: HCG-positive was found as 86% (n = 33) in Group A, 63% (n = 31) in Group B, 52% (n = 19) in Group C, and 27% (n = 08) in Group D. There were statistically significant (p <0.001) changes in BMI, FSH, LH, FT4, and FSI as well. Metformin alone and metformin plus myo-inositol came out to be more effective than other regimens. CONCLUSION: Metformin alone and myo-inositol plus metformin are effective therapeutic options in PCOS-induced infertility problems. KEY WORDS: Polycystic ovarian syndrome, Infertility, Metformin, Myo-inositol, Letrozole, Menstrual irregularities.

Repeated administration of methylphenidate produces reinforcement and downregulates 5-HT-1A receptor expression in the nucleus accumbens.

AIMS: Methylphenidate (MPD) widely prescribed for the treatment of attention deficit hyperactivity disorder (ADHD), is a psychostimulant and can produce addiction in patients treated with it. In view of growing increase in the use of drug by general population as a cognitive enhancer, the present study is designed to investigate reinforcing and cognition enhancing effects of MPD in rats. Associated changes in serotonin-1A receptor expression are investigated as a potential molecular mechanism involved. METHODS: Learning acquisition and memory retention in Morris water-maze test were used to assess cognitive effects of MPD. Reinforcing effects were evaluated in conditioned place-preference (CPP) paradigm. The expression of 5-hydroxytryptamine (5-HT; serotonin)-1A receptor in the nucleus accumbens and prefrontal cortex of repeated MPD treated animals was determined by qRT-PCR. FINDINGS: Lower doses (0.5 and 2.5 mg/kg) of MPD enhanced learning acquisition and memory retention but higher doses (5 mg/kg) impaired these. The drug administered repeatedly at a dose of 2.5 mg/kg was reinforcing in CPP test, but sensitization like effects of this dose were only transient. These animals tested in water-maze test exhibited improved memory retention but no effect occurred on learning acquisition. The expression of 5-HT-1A receptor was markedly attenuated in the nucleus accumbens; attenuation in the prefrontal cortex was not significant. SIGNIFICANCE: The findings suggest that clinically relevant doses of MPD can produce drug addiction, but effects of the drug on memory retention are retained. A downregulation of 5-HT-1A receptor in the nucleus accumbens seems important in the reinforcing effects of MPD.

New isatin derivative inhibits neurodegeneration by restoring insulin signaling in brain.

Diabetes is associated with neurodegeneration. Glycation ensues in diabetes and glycated proteins cause insulin resistance in brain resulting in amyloid plaques and NFTs. Also glycation enhances gliosis by promoting neuroinflammation. Currently there is no therapy available to target neurodegenration in brain therefore, development of new therapy that offers neuroprotection is critical. The objective of this study was to evaluate mechanistic effect of isatin derivative URM-II-81, an anti-glycation agent for improvement of insulin action in brain and inhibition of neurodegenration. Methylglyoxal induced stress was inhibited by treatment with URM-II-81. Also, Ser473 and Ser9 phosphorylation of Akt and GSK-3ß respectively were restored by URM-II-81. Effect of URM-II-81 on axonal integrity was studied by differentiating Neuro2A using retinoic acid. URM-II-81 restored axonal length in MGO treated cells. Its effects were also studied in high fat and low dose streptozotocin induced diabetic mice where it reduced RBG levels and inhibited glycative stress by reducing HbA1c. URM-II-81 treatment also showed inhibition of gliosis in hippocampus. Histological analysis showed reduced NFTs in CA3 hippocampal region and restoration of insulin signaling in hippocampii of diabetic mice. Our findings suggest that URM-II-81 can be developed as a new therapeutic agent for treatment of neurodegenration.

Developmental androgen excess programs sympathetic tone and adipose tissue dysfunction and predisposes to a cardiometabolic syndrome in female mice.

Among women, the polycystic ovarian syndrome (PCOS) is considered a form of metabolic syndrome with reproductive abnormalities. Women with PCOS show increased sympathetic tone, visceral adiposity with enlarged adipocytes, hypoadiponectinemia, insulin resistance, glucose intolerance, increased inactive osteocalcin, and hypertension. Excess fetal exposure to androgens has been hypothesized to play a role in the pathogenesis of PCOS. Previously, we showed that neonatal exposure to the androgen testosterone (NT) programs leptin resistance in adult female mice. Here, we studied the impact of NT on lean and adipose tissues, sympathetic tone in cardiometabolic tissues, and the development of metabolic dysfunction in mice. Neonatally androgenized adult female mice (NTF) displayed masculinization of lean tissues with increased cardiac and skeletal muscle as well as kidney masses. NTF mice showed increased and dysfunctional white adipose tissue with increased sympathetic tone in both visceral and subcutaneous fat as well as increased number of enlarged and insulin-resistant adipocytes that displayed altered expression of developmental genes and hypoadiponectinemia. NTF exhibited dysfunctional brown adipose tissue with increased mass and decreased energy expenditure. They also displayed decreased undercarboxylated and active osteocalcin and were predisposed to obesity during chronic androgen excess. NTF showed increased renal sympathetic tone associated with increased blood pressure, and they developed glucose intolerance and insulin resistance. Thus, developmental exposure to testosterone in female mice programs features of cardiometabolic dysfunction, as can be observed in women with PCOS, including increased sympathetic tone, visceral adiposity, insulin resistance, prediabetes, and hypertension.

Paracrine and intracrine contributions of androgens and estrogens to adipose tissue biology: physiopathological aspects.

In mammals, the male and female hormones androgen and estrogen act as endocrine regulators of energy metabolism. However, adipose tissue is also a site of androgen and estrogen synthesis; androgens convert to estrogens in these tissues, and adipose tissue is also a reservoir of steroids that act locally in a paracrine and intracrine manner. Thus, in adipose tissue, the local output of sex hormones is more complex than would be suggested by routine measurement of serum hormone concentrations. This review integrates studies on the effects of androgens and estrogens in the developmental programming of adipose tissue function in early life and addresses the contributions of local androgen and estrogen metabolism on adipose tissue function in adults.

Early-life exposure to testosterone programs the hypothalamic melanocortin system.

In mammals, males consume more food, which is considered a masculinized behavior, but the underlying mechanism of this sex-specific feeding behavior is unknown. In mice, neonatal testosterone (NT) is critical to masculinize the developing brain, leading to sex differences in reproductive physiology. The proopiomelanocortin (POMC) neurons of the hypothalamic arcuate nucleus (ARC) are critical to suppress energy intake and POMC innervation of hypothalamic feeding circuits develops to a large extent neonatally. We hypothesized that NT programs the masculinization of energy intake by programming POMC neurons. We tested this hypothesis by comparing control females and control males (CMs) with female mice neonatally androgenized with testosterone (NTFs). We show that increased food intake in CMs is associated with reduced POMC expression and decreased intensity of neuronal projections from POMC neurons within the ARC compared with control females. We found that NTFs display a masculinized energy intake and ARC POMC expression and innervation as observed in CMs, which can be mimicked by neonatal exposure to the androgen receptor agonist dihydrotestosterone (DHT). NTFs also exhibit hyperleptinemia and a decreased ability of leptin to up-regulate POMC, suppress food intake, and prevent adipose tissue accumulation, independent of signal transducer and activator of transcription 3. However, this leptin resistance is specific to NTFs, is not a consequence of masculinization, and is reproduced by neonatal exposure to estrogen but not DHT. Thus, NT programs a sexual differentiation of POMC neurons in female mice via DHT but also predisposes to leptin resistance and obesity in an estrogen-dependent manner.