Role of nutritional factors at the early life stages in the pathogenesis and clinical course of type 1 diabetes

The MHC Class II Antigen-Processing and Presentation Pathway Is Dysregulated in Type 1 Diabetes

Peptide loading of MHC class II (MHCII) molecules is facilitated by HLA-DM (DM), which catalyzes CLIP release, stabilizes empty MHCII, and edits the MHCII-bound peptide repertoire. HLA-DO (DO) binds to DM and modulates its activity, resulting in an altered set of peptides presented at the cell surface. MHCII-peptide presentation in individuals with type 1 diabetes (T1D) is abnormal, leading to a breakdown in tolerance; however, no direct measurement of the MHCII pathway activity in T1D patients has been performed. In this study, we measured MHCII Ag-processing pathway activity in humans by determining MHCII, MHCII-CLIP, DM, and DO levels by flow cytometry for peripheral blood B cells, dendritic cells, and monocytes from 99 T1D patients and 97 controls. Results showed that MHCII levels were similar for all three APC subsets. In contrast, MHCII-CLIP levels, independent of sex, age at blood draw, disease duration, and diagnosis age, were significantly increased for all three APCs, with B cells showing the largest increase (3.4-fold). DM and DO levels, which usually directly correlate with MHCII-CLIP levels, were unexpectedly identical in T1D patients and controls. Gene expression profiling on PBMC RNA showed that DMB mRNA was significantly elevated in T1D patients with residual C-peptide. This resulted in higher levels of DM protein in B cells and dendritic cells. DO levels were also increased, suggesting that the MHCII pathway maybe differentially regulated in individuals with residual C-peptide. Collectively, these studies show a dysregulation of the MHCII Ag-processing pathway in patients with T1D.

Knockdown of c-MYC Controls the Proliferation of Oral Squamous Cell Carcinoma Cells in vitro via Dynamic Regulation of Key Apoptotic Marker Genes

Oral squamous cell carcinoma (OSCC) is the most common malignant epithelial cancer occurring in the oral cavity, where it accounts for nearly 90% of all oral cavity neoplasms. The c-MYC transcription factor plays an important role in the control of programmed cell death, normal-to-malignant cellular transformation, and progression of the cell cycle. However, the role of c-MYC in controlling the proliferation of OSCC cells is not well known. In this study, c-MYC gene was silenced in OSCC cells (ORL-136T), and molecular and cellular responses were screened. To identify the pathway through which cell death occurred, cytotoxicity, colony formation, western blotting, caspase-3, and RT-qPCR analyzes were performed. Results indicated that knockdown of c-MYC has resulted in a significant decrease in the cell viability and c-MYC protein synthesis. Furthermore, caspase-3 was shown to be upregulated leading to apoptosis via the intrinsic pathway. In response to c-MYC knockdown, eight cell proliferation-associated genes showed variable expression profiles: c-MYC (-21.2), p21 (-2.5), CCNA1(1.8), BCL2 (-1.4), p53(-3.7), BAX(1.1), and CYCS (19.3). p27 expression was dramatically decreased in c-MYC-silenced cells in comparison with control, and this might indicate that the relative absence of c-MYC triggered intrinsic apoptosis in OSCC cells via p27 and CYCS.

Cow's milk allergy in infancy and later development of type 1 diabetes-nationwide case-cohort study

BAKGROUND

It is suggested that early intake of cow's milk could be a risk factor for type 1 diabetes (T1DM). Further, the different immunological background, gives a suggestion of an inverse relationship for the occurrence of these diseases. The aim of this study was to explore the association between cow's milk allergy (CMA) and the risk of T1DM in a register-based case-cohort study.

METHODS

Data were obtained from Finnish nationwide health registers. The study included all children born in Finland between January 01, 1986 and December 31, 2008 and diagnosed with T1DM before the age of 16 years (n = 7754). A 10% random sample from each birth year cohort was selected as a reference cohort (n = 137,798). T1DM, CMA, and asthma were defined based on valid special reimbursements for the costs of drugs/special formulas needed in the treatment of the diseases. Child's sex, birth decade, asthma, maternal diabetes and asthma, smoking during pregnancy, and previous deliveries were considered as confounding factors. Time-dependent, weighted Cox regression was applied for statistical analyses.

RESULTS

Children with CMA had an increased risk of developing T1DM in fully adjusted model (HR = 1.17; 95% CI 1.02-1.34), but the association was no longer observed when including the use of special infant formulas in the definition of CMA in the sensitivity analysis (HR = 1.11; 95% CI 0.92-1.32). CMA was associated with an increased risk of T1DM in children without asthma (HR = 1.27; 95%CI 1.10-1.47), but not in children with asthma (HR = 0.80; 95% CI 0.92-1.27).

CONCLUSION

Children with CMA may have an increased risk of T1DM.

Early Nutrition and Risk of Type 1 Diabetes: The Role of Gut Microbiota

Type 1 diabetes (T1D) appears most frequently in childhood, with an alarming increasing incidence in the last decades. Although the genetic predisposition is a major risk factor, it cannot solely explain the complex etiology of T1D which is still not fully understood. In this paper, we reviewed the most recent findings on the role of early nutrition and the involvement of the gut microbiota in the etiopathogenesis of T1D. The main conclusions that are withdrawn from the current literature regarding alleviating the risk of developing T1D through nutrition are the encouragement of long-term breast-feeding for at least the first 6 months of life and the avoidance of early complementary foods and gluten introduction (before 4 months of age) as well as cow milk introduction before 12 months of life. These detrimental feeding habits create a gut microbiota dysbiotic state that can contribute to the onset of T1D in infancy. Finally, we discussed the possibility to introduce probiotics, prebiotics and post-biotics in the prevention of T1D.

Association of Maternal Dietary Components During Pregnancy and/or Lactation with Insulin-Dependent Diabetes Mellitus

CONTEXT

Considering the increasing trend in the incidence of type 1 diabetes mellitus (T1DM), the identification of its environmental determinants, especially those related to the prenatal and lactation period, might ultimately result in primary prevention of the disease. We aimed to review the evidence of the association between mothers' dietary components during pregnancy and/or lactation with T1DM.

EVIDENCE ACQUISITION

An electronic and comprehensive literature search was performed until August 2019 in the international databases, including Web of Science (ISI), PubMed, and Scopus, using the following keywords: type 1 diabetes mellitus, autoimmunity, mother, maternal, diet and lactation in different combinations. Papers related to the objectives of the study were selected.

RESULTS

Based on our review, the maternal consumption of meat, especially processed meat, was associated with increased risk of T1DM, whereas the maternal use of vegetables, potato, low-fat margarine, and berries showed protective effects against the development of T1DM in offspring. There was no significant association between the use of multivitamins and mineral supplements with T1DM, according to the available data. The results of the reviewed studies regarding the association between the maternal use of vitamin D, fatty acids, and coffee during pregnancy with T1DM were not consistent and conclusive.

CONCLUSIONS

Findings of this review indicate that the maternal consumption of some foods is associated with increased or decreased risk of T1DM. However, for some foods or dietary components, including coffee, vitamin D, and fatty acids, the results are not conclusive. We conclude that although maternal diet could influence the development of insulin autoantibodies (IA) and T1DM in offspring, there is no sufficient evidence for most nutrients, and available data are controversial, which should be dealt with in future cohort or interventional studies.

Prevalence of early and late prematurity is similar among pediatric type 1 diabetes patients and the general population

BACKGROUND

The incidence of type 1 diabetes mellitus (T1DM) has increased in recent decades, as has the incidence of preterm births (<37 weeks). We aimed to evaluate and compare the prevalence of prematurity and early prematurity (<34 weeks) and birth season variability among T1DM and non-T1DM children.

METHODS

A nationwide cross-sectional study was conducted, with linkage of data from 13 paediatric diabetes centers and Israeli National Registries, including T1DM patients and general non-T1DM population, born during 2000 to 2013. Gathered data included ethnicity, gender, birth week, weight, and season. The prevalence of prematurity and birth season were compared with the general population birth registry using Pearson Chi-square test.

RESULTS

The study population included 1452 T1DM patients, 52.7% males, and 2 138 668 subjects in the general non-T1DM population, 51.2% males. The prevalence of late and early prematurity was similar between groups (6.1% and 2.2% in the T1DM group vs 5.6% and 2.0% in the general non-T1DM group, P = 0.25 and P = 0.38, respectively). OR for prematurity among T1DM patients was 1.15 (0.95-1.39), P = 0.16. No difference in birth season was demonstrated between preterm and term, in T1DM and general non-T1DM populations. Ethiopian descent was more prevalent among T1DM patients compared with the non-T1DM population, in both term and preterm born.

CONCLUSIONS

This is the largest population-based study, and the first in the Middle East geographical area, indicating that prematurity, including early prematurity, is not associated with T1DM during childhood. The study was registered at https://clinicaltrials.gov/: NCT02929953.

Microbiota and autoimmunity: exploring new avenues

Given the recognized role of the commensal microbiota in regulating host immunity to pathogens, it is not surprising that microbiota are also capable of regulating autoimmune responses. The underlying mechanisms of autoimmune regulation by the microbiota are just beginning to emerge. Here, we discuss possible pressure points toward the development of autoimmune diseases that can be influenced by the microbiota. Besides acting on the adaptive and innate arms of the immune response, the microbiota can affect the targets of autoimmunity directly, even during development in utero, and be involved in regulation of autoimmunity via interactions with hormones.

Dietary fat overload reprograms brown fat mitochondria

Chronic nutrient overload accelerates the onset of several aging-related diseases reducing life expectancy. Although the mechanisms by which overnutrition affects metabolic processes in many tissues are known, its role on BAT physiology is still unclear. Herein, we investigated the mitochondrial responses in BAT of female mice exposed to high fat diet (HFD) at different steps of life. Although adult mice showed an unchanged mitochondrial amount, both respiration and OxPHOS subunits were strongly affected. Differently, offspring pups exposed to HFD during pregnancy and lactation displayed reduced mitochondrial mass but high oxidative efficiency that, however, resulted in increased bioenergetics state of BAT rather than augmented uncoupling respiration. Interestingly, the metabolic responses triggered by HFD were accompanied by changes in mitochondrial dynamics characterized by decreased content of the fragmentation marker Drp1 both in mothers and offspring pups. HFD-induced inactivation of the FoxO1 transcription factor seemed to be the up-stream modulator of Drp1 levels in brown fat cells. Furthermore, HFD offspring pups weaned with normal diet only partially reverted the mitochondrial dysfunctions caused by HFD. Finally these mice failed in activating the thermogenic program upon cold exposure. Collectively our findings suggest that maternal dietary fat overload irreversibly commits BAT unresponsiveness to physiological stimuli such as cool temperature and this dysfunction in the early stage of life might negatively modulate health and lifespan.