Respiratory chain polymorphisms and obesity in the Spanish population, a cross-sectional study

Succinate dehydrogenase complex subunit C: Role in cellular physiology and disease

Succinate dehydrogenase complex subunit C (SDHC) is a subunit of mitochondrial complex II (MCII), which is also known as succinate dehydrogenase (SDH) or succinate: ubiquinone oxidoreductase. Mitochondrial complex II is the smallest respiratory complex in the respiratory chain and contains four subunits. SDHC is a membrane-anchored subunit of SDH, which connects the tricarboxylic acid cycle and the electron transport chain. SDH regulates several physiological processes within cells, plays an important role in generating energy to maintain normal cell growth, and is involved in apoptosis. Currently, SDHC is generally recognized as a tumor-suppressor gene. SDHC mutations can cause oxidative damage in the body. It is closely related to the occurrence and development of cancer, neurodegenerative diseases, and aging-related diseases. Here, we review studies on the structure, biological function, related diseases of SDHC, and the mev-1 Animal Model of SDHC Mutation and its potential use as a therapeutic target of certain human diseases.

Next-Generation Sequencing of a Large Gene Panel for Outcome Prediction of Bariatric Surgery in Patients with Severe Obesity

Obesity is a chronic disease in which abnormal deposition of fat threatens health, leading to diabetes, cardiovascular diseases, cancer, and other chronic illnesses. According to the WHO, 19.8% of the adult population in Italy is obese, and the prevalence is higher among men. It is important to know the predisposition of an individual to become obese and to respond to bariatric surgery, the most up-to-date treatment for severe obesity. To this purpose, we developed an NGS gene panel, comprising 72 diagnostic genes and 244 candidate genes, and we sequenced 247 adult obese Italian patients. Eleven deleterious variants in 9 diagnostic genes and 17 deleterious variants in 11 candidate genes were identified. Interestingly, mutations were found in several genes correlated to the Bardet-Biedl syndrome. Then, 25 patients were clinically followed to evaluate their response to bariatric surgery. After a 12-month follow-up, the patients that carried deleterious variants in diagnostic or candidate genes had a reduced weight loss, as compared to the other patients. The NGS-based panel, including diagnostic and candidate genes used in this study, could play a role in evaluating, diagnosing, and managing obese individuals, and may help in predicting the outcome of bariatric surgery.

Association between genetic variants in oxidative stress-related genes and osteoporotic bone fracture. The Hortega follow-up study

The most widely accepted etiopathogenesis hypothesis of the origin of osteoporosis and its complications is that they are a consequence of bone aging and other environmental factors, together with a genetic predisposition. Evidence suggests that oxidative stress is crucial in bone pathologies associated with aging. The aim of this study was to determine whether genetic variants in oxidative stress-related genes modified the risk of osteoporotic fracture. We analysed 221 patients and 354 controls from the HORTEGA sample after 12-14 years of follow up. We studied the genotypic and allelic distribution of 53 SNPs in 24 genes involved in oxidative stress. The results showed that being a carrier of the variant allele of the SNP rs4077561 within TXNRD1 was the principal genetic risk factor associated with osteoporotic fracture and that variant allele of the rs1805754 M6PR, rs4964779 TXNRD1, rs406113 GPX6, rs2281082 TXN2 and rs974334 GPX6 polymorphisms are important genetic risk factors for fracture. This study provides information on the genetic factors associated with oxidative stress which are involved in the risk of osteoporotic fracture and reinforces the hypothesis that genetic factors are crucial in the etiopathogenesis of osteoporosis and its complications.

Polymorphisms in genes involved in inflammation, the NF-kB pathway and the renin-angiotensin-aldosterone system are associated with the risk of osteoporotic fracture. The Hortega Follow-up Study

Osteoporosis is the most common bone disorder worldwide and is associated with a reduced quality of life with important clinical and economic consequences. The most widely accepted etiopathogenic hypothesis on the origin of osteoporosis and its complications is that they are a consequence of the synergic action of environmental and genetic factors. Bone is constantly being remodelled through anabolic and catabolic pathways in which inflammation, the NF-kB pathway and the renin-angiotensin-aldosterone system (RAAS) are crucial. The aim of our study was to determine whether polymorphisms in genes implicated in inflammation, the NF-kB pathway and RAAS modified the risk of osteoporotic fracture. We analysed 221 patients with osteoporotic fracture and 354 controls without fracture from the HORTEGA sample after 12-14 years of follow up. In addition, we studied the genotypic distribution of 230 single nucleotide polymorphisms (SNPs) in genes involved in inflammation, NF-kB pathway and RAAS. Our results showed that be carrier of the C allele of the rs2228145 IL6R polymorphism was the principal genetic risk factor associated with osteoporotic fracture. The results also showed that variant genotypes of the rs4762 AGT, rs4073 IL8, rs2070699 END1 and rs4291 ACE polymorphisms were important genetic risk factors for fracture. The study provides information about the genetic factors associated with inflammation, the NF-kB pathway and RAAS, which are involved in the risk of osteoporotic fracture and reinforces the hypothesis that genetic factors are crucial in the etiopathogenesis of osteoporosis and its complications.

Polycystic ovary syndrome and mitochondrial dysfunction

Polycystic ovary syndrome (PCOS) is a prevalent hormonal disorder of premenopausal women worldwide and is characterized by reproductive, endocrine, and metabolic abnormalities. The clinical manifestations of PCOS include oligomenorrhea or amenorrhea, hyperandrogenism, ovarian polycystic changes, and infertility. Women with PCOS are at an increased risk of suffering from type 2 diabetes; me\tabolic syndrome; cardiovascular events, such as hypertension, dyslipidemia; gynecological diseases, including infertility, endometrial dysplasia, endometrial cancer, and ovarian malignant tumors; pregnancy complications, such as premature birth, low birthweight, and eclampsia; and emotional and mental disorders in the future. Although numerous studies have focused on PCOS, the underlying pathophysiological mechanisms of this disease remain unclear. Mitochondria play a key role in energy production, and mitochondrial dysfunction at the cellular level can affect systemic metabolic balance. The recent wide acceptance of functional mitochondrial disorders as a correlated factor of numerous diseases has led to the presupposition that abnormal mitochondrial metabolic markers are associated with PCOS. Studies conducted in the past few years have confirmed that increased oxidative stress is associated with the progression and related complications of PCOS and have proven the relationship between other mitochondrial dysfunctions and PCOS. Thus, this review aims to summarize and discuss previous and recent findings concerning the relationship between mitochondrial dysfunction and PCOS.