Generation of an Obese Diabetic Mouse Model upon Conditional Atrx Disruption.

Atrx loss was recently ascertained as insufficient to drive pancreatic neuroendocrine tumour (PanNET) formation in mice islets. We have identified a preponderant role of Atrx in the endocrine dysfunction in a Rip-Cre;AtrxKO genetically engineered mouse model (GEMM). To validate the impact of a different Cre-driver line, we used similar methodologies and characterised the Pdx1-Cre;AtrxKO (P.AtrxKO) GEMM to search for PanNET formation and endocrine fitness disruption for a period of up to 24 months. Male and female mice presented different phenotypes. Compared to P.AtrxWT, P.AtrxHOM males were heavier during the entire study period, hyperglycaemic between 3 and 12 mo., and glucose intolerant only from 6 mo.; in contrast, P.AtrxHOM females started exhibiting increased weight gains later (after 6 mo.), but diabetes or glucose intolerance was detected by 3 mo. Overall, all studied mice were overweight or obese from early ages, which challenged the histopathological evaluation of the pancreas and liver, especially after 12 mo. Noteworthily, losing Atrx predisposed mice to an increase in intrapancreatic fatty infiltration (FI), peripancreatic fat deposition, and macrovesicular steatosis. As expected, no animal developed PanNETs. An obese diabetic GEMM of disrupted Atrx is presented as potentially useful for metabolic studies and as a putative candidate for inserting additional tumourigenic genetic events.

Atypical antipsychotics olanzapine and clozapine increase bone loss in female rats with experimental periodontitis.

BACKGROUND AND OBJECTIVES: Periodontitis is a highly prevalent disease in psychiatric patients, including those undergoing symptomatic treatment with second-generation antipsychotics. Some of these drugs, such as clozapine (CLO) and olanzapine (OLA), have prominent metabolic effects such as weight gain, hyperglycemia, and dyslipidemia, which are risk factors for periodontitis. In addition to the metabolic effects, there are reports of changes in salivary flow, gingival bleeding, and caries. In this context, we aimed to evaluate if the metabolic effects of OLA and CLO alter periodontal parameters in an animal model of periodontitis without the environmental and psychosocial biases inherent to human diseases. METHODS: In the first set of experiments, male and female adult Wistar rats received oral administration of CLO, OLA, or vehicle for 45 days. They were evaluated for body mass composition and weight gain, blood glucose parameters (fasting and glucose tolerance and insulin resistance tests), and lipid profile (HDL, total cholesterol, and triglycerides). In a second set of experiments, the same measurements were performed in female rats exposed to the antipsychotics for 45 days and ligature-induced periodontitis on the 30th day of treatment. Macroscopic measurements of exposed roots, microtomography in the furcation region of the first molar, and histological evaluation of the region between the first and second molars were evaluated to assess bone loss. Additionally, gingival measurements of myeloperoxidase activity and pro-inflammatory cytokine TNF-α were made. RESULTS: Only females exposed to OLA had more significant weight gain than controls. They also exhibited differences in glucose metabolism. Ligature-induced periodontitis produced intense bone retraction without changing the density of the remaining structures. The bone loss was even higher in rats with periodontitis treated with OLA or CLO and was accompanied by a local increase in TNF-α caused by CLO. These animals, however, did not exhibit the same metabolic impairments observed for animals without periodontitis. CONCLUSION: The use of clozapine and olanzapine may be a risk factor for periodontal disease, independent of systemic metabolic alterations.

Endocrine-disrupting chemicals and endocrine neoplasia: A forty-year systematic review.

INTRODUCTION: Endocrine disrupting chemicals (EDCs) are exogenous substances recognised as relevant tumourigenic chemicals. Studies show that even EDCs which were long abolished are still contributing to the increasing incidence of neoplasia. AIM: To investigate the association between human exposure to EDCs and the risk of endocrine-related tumours: breast, prostate, thyroid, uterus, testis, and ovary. METHODS: A systematic review using PubMed, Scopus, and Embase was conducted, searching for original observational studies published between 1980 and 2020, approaching EDCs exposure and endocrine tumourigenic risk in humans. We comprised neoplasia of six endocrine organs. We included all the studies on EDCs reporting tumour odds ratio, risk ratio, or hazard ratio. Study levels of confidence and risk of bias were accessed applying accredited guidelines. Human-made accidents and natural EDCs were not considered in the present study. RESULTS: Our search returned 3271 papers. After duplicate removal and screening, only 237 papers were included (corresponding to 268 records). EDCs were grouped from the most frequently (pesticides) to the least frequently studied (salts). The most tumourigenic EDC groups were phthalates (63%), heavy metals (54%), particulate matter (47%), and pesticides (46%). Pesticides group comprised the highest number of retrieved studies (n = 133). Increased neoplasia risk was found in 43-67% of the studies, with a lower value for ovary (43%) and a higher value for thyroid (67%). CONCLUSIONS: The innovative nature of our review comes from including human studies of six endocrine-related neoplasia aiming to understand the contribution of specific EDCs groups to each organ's tumourigenesis. Thyroid was the organ presenting the highest cancer risk after EDC exposure which may explain the increasing thyroid cancer incidence. However, detailed and controlled works reporting the effects of EDCs are scarce, probably justifying conflicting results. Multinational and multicentric human studies with biochemical analysis are needed to achieve stronger and concordant evidence.

Characterisation of an Atrx Conditional Knockout Mouse Model: Atrx Loss Causes Endocrine Dysfunction Rather Than Pancreatic Neuroendocrine Tumour.

ATRX is a chromatin remodeller that maintains telomere homeostasis. Loss of ATRX is described in approximately 10% of pancreatic neuroendocrine tumours (PanNETs) and associated with poorer prognostic features. Here, we present a genetically engineered mouse model (GEMM) addressing the role of Atrx loss (AtrxKO) in pancreatic ß cells, evaluating a large cohort of ageing mice (for up to 24 months (mo.)). Atrx loss did not cause PanNET formation but rather resulted in worsening of ageing-related pancreatic inflammation and endocrine dysfunction in the first year of life. Histopathological evaluation highlighted an exacerbated prevalence and intensity of pancreatic inflammation, ageing features, and hepatic steatosis in AtrxKO mice. Homozygous floxed mice presented hyperglycaemia, increased weights, and glucose intolerance after 6 months, but alterations in insulinaemia were not detected. Floxed individuals presented an improper growth of their pancreatic endocrine fraction that may explain such an endocrine imbalance. A pilot study of BRACO-19 administration to AtrxKO mice resulted in telomere instability, reinforcing the involvement of Atrx in the maintenance of ß cell telomere homeostasis. Thereby, a non-obese dysglycaemic GEMM of disrupted Atrx is here presented as potentially useful for metabolic studies and putative candidate for inserting additional tumourigenic genetic events.

Manganese systemic distribution is modulated in vivo during tumor progression and affects tumor cell migration and invasion in vitro.

Metastatic disease remains the leading cause of death in cancer and understanding the mechanisms involved in tumor progression continues to be challenging. This work investigates the role of manganese in tumor progression in an in vivo model of tumor growth. Our data revealed that manganese accumulates within primary tumors and secondary organs as manganese-rich niches. Consequences of such phenomenon were investigated, and we verified that short-term changes in manganese alter cell surface molecules syndecan-1 and ß1-integrin, enhance collective cell migration and invasive behavior. Long-term increased levels of manganese do not affect cell growth and viability but enhance cell migration. We also observed that manganese is secreted from tumor cells in extracellular vesicles, rather than in soluble form. Finally, we describe exogenous glycosaminoglycans that counteract manganese effects on tumor cell behavior. In conclusion, our analyses describe manganese as a central element in tumor progression by accumulating in Mn-rich niches in vivo, as well as in vitro, affecting migration and extracellular vesicle secretion in vitro. Manganese accumulation in specific regions of the organism may not be a common ground for all cancers, nevertheless, it represents a new aspect of tumor progression that deserves special attention.

Serum albumin-fatty acid saturation test.

Circulating non-esterified fatty acids (NEFA) are toxic to mammalian cells. They increase in diseases such as diabetes and sepsis. Herein we propose a serum albumin-fatty acid saturation test. •We based our test on three methodologies: isoelectric focusing (IF) of human plasma albumin, staining proteins after isoelectric focusing in gels with Coomassie Brilliant Blue, and serum albumin measurement with bromocresol green.•The test consists in the determination of albumin IF and staining with bromocresol green. If albumin is saturated with NEFA, it focuses on lower pH, meaning it is the threshold to bind to them. Excessive NEFA is free and toxic. Many other tests are available for NEFA quantification as NEFA kit assay. All colorimetric assays are used for quantification of NEFA and other tests need expensive equipment to read out the results, and they do not measure albumin levels.•Our method focused on albumin-NEFA saturation instead of just NEFA quantification. Critically ill patients have an alteration in both albumin and NEFA. Therefore, our test undergoes less daytime variation compared to assays that measure absolute NEFA values, allowing a more reliable use as an indicator of albumin-fatty acid saturation and NEFA toxicity.

Serum albumin saturation test based on non-esterified fatty acids imbalance for clinical employment.

Fatty acids are fundamental as energy and structural source to the human cells. They are not usually found free in human circulation. Alteration in fatty acids metabolism is linked to diseases such as diabetes, preeclampsia, heart disease, and some infectious diseases. Increased levels of non-esterified fatty acids (NEFA) may cause cell dysfunction and lipotoxicity. Since physiologically fatty acids are transported bound to albumin, we propose here a simple and cheap test that consists of albumin isoelectric focusing determination to measure the potential systemic NEFA cytotoxicity. For validation of this method, albumin isoelectric focusing in 51 serum samples from 40 critically ill patients and 11 controls was compared with NEFA/albumin ratios measured by HPLC. We called this approach an albumin saturation test. This test may indicate to physicians the potential NEFA lipotoxicity guiding them throughout better patient management. The albumin saturation test can point out serum albumin-NEFA saturation through a cheap assay that could be performed by any care facility.