Fecal Metabolomics Reveals Distinct Profiles of Kidney Transplant Recipients and Healthy Controls

Monitoring graft recipients remains dependent on traditional biomarkers and old technologies lacking specificity, sensitivity, or accuracy. Recently, metabolomics is becoming a promising approach that may offer to kidney transplants a more effective and specific monitoring. Furthermore, emerging evidence suggested a fundamental role of gut microbiota as an important determinant of patients’ metabolomes. In the current study, we enrolled forty stable renal allografts recipients compared to twenty healthy individuals. Samples were taken at different time points from patient to patient following transplantation surgery, which varied from 3 months to 22 years post-graft. All patients started the immunosuppression therapy immediately following kidney graft (Day 0). Gas chromatography–mass spectrometry (GC–MS) was employed to perform untargeted analysis of fecal metabolites. Globally, the fecal metabolic signature was significantly different between kidney transplants and the control group. Fecal metabolome was dominated by lipids (sterols and fatty acids) in the stable transplant group compared to the controls (p < 0.05). Overall, 18 metabolites were significantly altered within kidney transplant recipients. Furthermore, the most notable altered metabolic pathways in kidney transplants include ubiquinone and other terpenoid-quinone biosynthesis, tyrosine metabolism, tryptophan biosynthesis, and primary bile acid biosynthesis. Fecal metabolites could effectively distinguish stable transplant recipients from controls, supporting the potential utility of metabolomics in rapid and non-invasive diagnosis to produce relevant biomarkers and to help clinicians in monitoring kidney transplants. Further investigations are needed to clarify the physiological relevance of fecal metabolome and to assess the impact of microbiota modulation

Targeting Tumor Metabolism: A New Challenge to Improve Immunotherapy

Currently, a marked number of clinical trials on cancer treatment have revealed the success of immunomodulatory therapies based on immune checkpoint inhibitors that activate tumor-specific T cells. However, the therapeutic efficacy of cancer immunotherapies is only restricted to a small fraction of patients. A deeper understanding of key mechanisms generating an immunosuppressive tumor microenvironment (TME) remains a major challenge for more effective antitumor immunity. There is a growing evidence that the TME supports inappropriate metabolic reprogramming that dampens T cell function, and therefore impacts the antitumor immune response and tumor progression. Notably, the immunosuppressive TME is characterized by a lack of crucial carbon sources critical for T cell function and increased inhibitory signals. Here, we summarize the basics of intrinsic and extrinsic metabolic remodeling and metabolic checkpoints underlying the competition between cancer and infiltrating immune cells for nutrients and metabolites. Intriguingly, the upregulation of tumor programmed death-L1 and cytotoxic T lymphocyte-associated antigen 4 alters the metabolic programme of T cells and drives their exhaustion. In this context, targeting both tumor and T cell metabolism can beneficially enhance or temper immunity in an inhospitable microenvironment and markedly improve the success of immunotherapies

Integrating Thyroid Hormone Signaling in Hypothalamic Control of Metabolism: Crosstalk Between Nuclear Receptors

The obesity epidemic is well recognized as a significant global health issue. A better understanding of the energy homeostasis mechanisms could help to identify promising anti-obesity therapeutic strategies. It is well established that the hypothalamus plays a pivotal role governing energy balance. The hypothalamus consists of tightly interconnected and specialized neurons that permit the sensing and integration of several peripheral inputs, including metabolic and hormonal signals for an appropriate physiological response. Current evidence shows that thyroid hormones (THs) constitute one of the key endocrine factors governing the regulation and the integration of metabolic homeostasis at the hypothalamic level. THs modulate numerous genes involved in the central control of metabolism, as TRH (Thyrotropin-Releasing Hormone) and MC4R (Melanocortin 4 Receptor). THs act through their interaction with thyroid hormone receptors (TRs). Interestingly, TH signaling, especially regarding metabolic regulations, involves TRs crosstalk with other metabolically linked nuclear receptors (NRs) including PPAR (Peroxisome proliferator-activated receptor) and LXR (Liver X receptor). In this review, we will summarize current knowledge on the important role of THs integration of metabolic pathways in the central regulation of metabolism. Particularly, we will shed light on the crosstalk between TRs and other NRs in controlling energy homeostasis. This could be an important track for the development of attractive therapeutic compounds

MTHFR gene polymorphisms and bladder cancer susceptibility: a meta-analysis including race, smoking status and tumour stage.

International audienceEpidemiological studies have investigated that functional polymorphisms in the methylene-tetrahydrofolate reductase (MTHFR) gene may play an essential role in bladder carcinogenesis, but the numerous published studies have reported inconclusive results. The objective of the current study was to conduct an updated analysis in order to investigate the association between polymorphisms in the MTHFR gene and risk of bladder cancer. We searched the Pubmed database for all articles published up to March 31, 2011 that addressed bladder cancer and polymorphisms and variants or mutations of MTHFR for analysis using statistical software. Results for two polymorphisms (C677T and A1298C) in 27 case-control were studies from 15 articles indicated individuals carrying the 677T allele (TC or TT+TC) to have a reduction to a 29% or 21% compared to the wild genotype (CC) in mixed populations (OR: 0.71, 95%CI: 0.55-0.93 or OR: 0.79, 95%CI: 0.64-0.97, respectively) and it is shown that there is significant positive associations between A1298C polymorphism and bladder cancer in Africans (OR: 1.24, 95%CI: 1.02-1.52 for C vs.A; OR: 1.35, 95%CI: 1.10-1.66 for CA vs. AA; OR: 1.29, 95%CI: 1.08-1.55 for CC+CA vs. AA). However, no significant relationship was found in two polymorphisms in the stratified analysis by smoking status. Interestingly, individuals carrying the 677T allele (TT+TC) demonstrated a higher percentage of invasive than superficial cases (OR: 1.38, 95%CI: 1.13-1.69). The results from the current update analysis suggest that C677T and A1298C polymorphisms in the MTHFR gene are associated with bladder cancer risk and prognosis. Further evaluation based on more studies with larger groups of patients are now required

Genetic Susceptibility to Type 2 Diabetes: A Global Meta-Analysis Studying the Genetic Differences in Tunisian Populations

The present study is the first meta-analysis to evaluate type 2 diabetes (T2D)– associated polymorphisms in cohorts originated from several Tunisian regions. In fact, we evaluated the effect of seven polymorphisms in the following genes—PPARg (Pro12Ala), TNF° (-308A/G), ENPP1(K121Q), TCF7L2(rs7903146°C/T), MTHFR(C677T), ACE(I/D), and CAPN10(3R/2R)—on T2D risk, through a meta-analysis combining data of previous studies performed on Tunisian populations originating from the north, center, or south of the country. R statistics version 2.12.1 software was used to estimate the heterogeneity between studies. Pooled odds ratios were computed by the fixed-effects method of Mantel-Haenszel if no heterogeneity between studies exists. Despite the similarities founded in a number of loci, the Woolf test reported that the contributions of ENPP1 and ACE loci in T2D risk are dependent on the geographic origin of concerned groups, and this heterogeneity could be attributed not only to the variable contribution of the variant in T2D risk but also to diversities of genetic background between tested groups. Interestingly, observed heterogeneity highlighted founding concerning Y chromosome and the mitochondrial DNA about the genetic structure of Tunisian population and proves once again that Tunisians, like the north-Africans, are a mosaic of subpopulations, with significant differences in genetic structure. In homogeneous groups, we replicated the association of single-nucleotide polymorphisms of TCF7L2, MTHFR, CAPN 10, TNF°, and ACE genes with a T2D risk in the Tunisian population with OR ranging from 1.43 to 6.72. However, we reported an absence of the association of PPARg with T2D in the Tunisian population

Pathway Maps of Orphan and Complex Diseases Using an Integrative Computational Approach

Orphan diseases (ODs) are progressive genetic disorders, which affect a small number of people. The principal fundamental aspects related to these diseases include insufficient knowledge of mechanisms involved in the physiopathology necessary to access correct diagnosis and to develop appropriate healthcare. Unlike ODs, complex diseases (CDs) have been widely studied due to their high incidence and prevalence allowing to understand the underlying mechanisms controlling their physiopathology. Few studies have focused on the relationship between ODs and CDs to identify potential shared pathways and related molecular mechanisms which would allow improving disease diagnosis, prognosis, and treatment. We have performed a computational approach to studying CDs and ODs relationships through (1) connecting diseases to genes based on genes-diseases associations from public databases, (2) connecting ODs and CDs through binary associations based on common associated genes, and (3) linking ODs and CDs to common enriched pathways. Among the most shared significant pathways between ODs and CDs, we found pathways in cancer, p53 signaling, mismatch repair, mTOR signaling, B cell receptor signaling, and apoptosis pathways. Our findings represent a reliable resource that will contribute to identify the relationships between drugs and disease-pathway networks, enabling to optimise patient diagnosis and disease treatment

Multifaceted Breast Cancer: The Molecular Connection With Obesity

Obesity is characterized by a disruption in energy balance regulation that results in an excess accumulation of body fat. Its increasing prevalence poses a major public health concern because it is a risk factor for a host of additional chronic conditions, including type 2 diabetes, hypertension, and cardiovascular disease. Obesity is increasingly recognized as a growing cause of cancer risk. In particular excessive adipose expansion during obesity causes adipose dysfunction and inflammation that can regulate tumor growth. In obesity, dysregulated systemic metabolism and inflammation induce hyperinsulinemia, hyperglycemia, dyslipidemia, and enhance sex hormone production with increased secretion of proinflammatory adipokine that impact breast cancer development and progression. This review describes how adipose inflammation that characterizes obesity is responsible of microenvironment to promote cancer, and discuss how steroid hormones, that are essential for the maintenance of the normal development, growth and differentiation of the cells, influence the induction and progression of breast cancer. J. Cell. Physiol. 232: 69–77, 2017. © 2016 Wiley Periodicals, Inc

HPV epigenetic mechanisms related to Oropharyngeal and Cervix cancers

Human Papilloma Virus infection is very frequent in humans and is mainly transmitted sexually. The majority of infections are transient and asymptomatic, however, if the infection persists, it can occur with a variety of injuries to skin and mucous membranes, depending on the type of HPV involved. Some types of HPV are classified as high oncogenic risk as associated with the onset of cancer. The tumors most commonly associated with HPV are cervical and oropharyngeal cancer, epigenetic mechanisms related to HPV infection include methylation changes to host and viral DNA and chromatin modification in host species. This review is focused about epigenethic mechanism, such as MiRNAs expression, related to cervix and oral cancer. Specifically it discuss about molecular markers associated to a more aggressive phenotype. In this way we will analyze genes involved in meiotic sinaptonemal complex, transcriptional factors, of orthokeratins, sinaptogirin, they are all expressed in cancer in a way not more dependent on cell differentiation but HPV-dependent

Human subcutaneous adipose tissue Glut 4 mRNA expression in obesity and type 2 diabetes

International audienceCellular resistance to insulin caused by reduced glucose transport and metabolism is a primary defect leading to the development of metabolic disease. While the etiology of insulin resistance is multifactorial, reduced insulin action is associated with impaired activity of the glucose transporter GLUT4 in insulin-sensitive tissues. Yet, the role of adipose tissue GLUT4 deregulation in the pathogenesis of insulin resistance, obesity, and diabetes is still unclear. In this study, we assessed the relative GLUT4 level in human subcutaneous adipose tissue from obese, diabetic, and diabetic obese versus control subjects, using a real-time PCR method. GLUT4 mRNA levels were considerably decreased among type 2 diabetic patients compared with those of the controls (P < 0.01), whereas no such difference was found between obese and normal-weight controls. Multiple linear regressions analysis in both diabetic non-obese and diabetic obese groups showed a negative correlation between GLUT4 mRNA expression and both markers of obesity or insulin resistance (P < 0.01). However, in obese group, GLUT4 was inversely associated only with HOMA-IR (P < 0.01). Our findings showed that adipose GLUT4 gene expression changes were more related to insulin resistance and type 2 diabetes rather than to obesity