Epigenetic Control of Pancreatic Regeneration in Diabetes

An Updated Review on the Significance of DNA and Protein Methyltransferases and De-methylases in Human Diseases: From Molecular Mechanism to Novel Therapeutic Approaches

Epigenetic mechanisms are crucial in regulating gene expression. These mechanisms include DNA methylation and histone modifications, like methylation, acetylation, and phosphorylation. DNA methylation is associated with gene expression suppression; however, histone methylation can stimulate or repress gene expression depending on the methylation pattern of lysine or arginine residues on histones. These modifications are key factors in mediating the environmental effect on gene expression regulation. Therefore, their aberrant activity is associated with the development of various diseases. The current study aimed to review the significance of DNA and histone methyltransferases and demethylases in developing various conditions, like cardiovascular diseases, myopathies, diabetes, obesity, osteoporosis, cancer, aging, and central nervous system conditions. A better understanding of the epigenetic roles in developing diseases can pave the way for developing novel therapeutic approaches for affected patients.

Pancreatic regenerative potential of manuka honey evidenced through pancreatic histology and levels of transcription factors in diabetic rat model

Background

Diabetes mellitus is a commonly occurring metabolic disorder accompanied by high morbidity and alarming mortality. Besides various available therapies, induction of pancreatic regeneration has emerged as a promising strategy for alleviating the damaging effect of diabetes. Honey, a potent antioxidative and anti-inflammatory agent, has been reported in the literature archive to exhibit favourable results in the regeneration process of several organ systems.

Design

The current research work was intended to explore the potential role of manuka honey in pancreatic regeneration in alloxan-induced diabetic rats by accessing the pancreatic histology and levels of relevant transcription factors, including MAFA, PDX-1, INS-1, INS-2, NEUROG3, NKX6-1, and NEUROD. An equal number of rats were allocated to all four experimental groups: normal, negative control, positive control, and treatment group. Diabetes was induced in all groups except normal through a single intraperitoneal dose of alloxan monohydrate. No subsequent treatment was given to the negative control group, while the positive control and treatment groups were supplemented with metformin (150 mg/kg/day) and manuka honey (3 g/kg/day), respectively.

Results

Statistical comparison of glucose and insulin levels, oxidative stress indicators, changes in the architecture of pancreatic islets, and expression levels of regeneration-associated transcription factors advocated the potential role of manuka honey in ameliorating the alloxan-induced hyperglycaemia, hyperinsulinemia, oxidative stress, and necrotic changes in islets along with significant upregulation of relevant transcription factors.

Conclusion

This suggests to us the auspicious role of antioxidants in honey in pancreatic regeneration and advocates the favourable role of manuka honey in combating diabetes mellitus.

Regeneration of β-cells of the islet apparatus of the pancreas. Literature review

Diabetes of both type 1 and type 2 is characterized by a progressive loss of β-cell mass, which contributes to the disruption of glucose homeostasis. The optimal antidiabetic therapy would be simple replacement of lost cells, but at present, many researchers have shown that the pancreas (PZ) of adults has a limited regenerative potential. In this regard, significant efforts of researchers are directed to methods of inducing the proliferation of β-cells, stimulating the formation of β-cells from alternative endogenous sources and/or the generation of β-cells from pluripotent stem cells. Factors that regulate β-cell regeneration under physiological or pathological conditions, such as mediators, transcription factors, signaling pathways and potential pharmaceuticals, are also being intensively studied. In this review, we consider recent scientific studies carried out in the field of studying the development and regeneration of insulin-producing cells obtained from exogenous and endogenous sources and their use in the treatment of diabetes. The literature search while writing this review was carried out using the databases of the RSIC, CyberLeninka, Scopus, Web of Science, MedLine, PubMed for the period from 2005 to 2021. using the following keywords: diabetes mellitus, pancreas, regeneration, β-cells, stem cells, diabetes therapy.

The effects of in utero exposure to teratogens on organ size: a prospective paediatric study

In low-income countries, prospective data on combined effects of in utero teratogen exposure are lacking and necessitates new research. The aim of the present study was to explore the effect of in utero teratogen exposure on the size of the kidneys and pancreas 5 years after birth in a low-income paediatric population. Data was collected from 500 mother-child pairs from a low-income setting. Anthropometric measurements included body weight, (BW) body height, mid-upper arm and waist circumference (WC). Clinical measurements included blood pressure (BP), mean arterial pressure and heart rate. Ultrasound measurements included pancreas, and kidney measurements at age 5 years. The main outcome of interest was the effect of maternal smoking and alcohol consumption on ultrasound measurements of organ size at age 5 years. Left and right kidney length measurements were significantly lower in smoking exposed children compared to controls (p = 0.04 and p = 0.03). Pancreas body measurements were significantly lower in smoking exposed children (p = 0.04). Multiple regression analyses were used to examine the associations between the independent variables (IDVs), maternal age, body mass index (BMI), mid-upper arm circumference (MUAC) and BW of the child, on the dependent variables (DVs) kidney lengths and kidney volumes. Also, the association between in utero exposure to alcohol and nicotine and pancreas size. WC was strongest (r = 0.28; p < 0.01) associated with pancreas head [F (4, 454) = 13.44; R2 = 0.11; p < 0.01] and tail (r = 0.30; p < 0.01) measurements at age 5 years, with in utero exposure, sex of the child and BMI as covariates. Kidney length and pancreas body measurements are affected by in utero exposure to nicotine at age 5 years and might contribute to cardiometabolic risk in later life. Also, findings from this study report on ultrasound reference values for kidney and pancreas measurements of children at age 5 years from a low-income setting.

Roles of Epigenetic Modifications in the Differentiation and Function of Pancreatic β-Cells

Diabetes, a metabolic disease with multiple causes characterized by high blood sugar, has become a public health problem. Hyperglycaemia is caused by deficiencies in insulin secretion, impairment of insulin function, or both. The insulin secreted by pancreatic β cells is the only hormone in the body that lowers blood glucose levels and plays vital roles in maintaining glucose homeostasis. Therefore, investigation of the molecular mechanisms of pancreatic β cell differentiation and function is necessary to elucidate the processes involved in the onset of diabetes. Although numerous studies have shown that transcriptional regulation is essential for the differentiation and function of pancreatic β cells, increasing evidence indicates that epigenetic mechanisms participate in controlling the fate and regulation of these cells. Epigenetics involves heritable alterations in gene expression caused by DNA methylation, histone modification and non-coding RNA activity that does not result in DNA nucleotide sequence alterations. Recent research has revealed that a variety of epigenetic modifications play an important role in the development of diabetes. Here, we review the mechanisms by which epigenetic regulation affects β cell differentiation and function.

Advances in Genetics of Regeneration in Metabesity

'Metabesity' is a recent term comprising a wide range of diseases with underlying metabolic disarrangements at its root, and whose aetiology lies in complex relationships among genes and the obesogenic environment to which individuals are currently exposed in most countries. Of note, epigenetic changes are increasingly being reported to play an outstanding role in carrying deleterious information that, together with susceptibility genes, boost the development of metabesity in subsequent generations. In this context, it is noteworthy to mention that the transition from the pre-industrial era to the current high-technology society and global economy, even after suffering two world wars, has been very fast. By contrast, evolution-driven processes, such as biological ones, are slow. In fact, there is a general consensus that at the metabolic level, adipogenic processes and thrifty pathways prevail over those promoting energy expenditure in a way that currently leads to metabolic diseases by excessive energy storage. In such an imbalanced social-biological scenario, genes that were beneficial in the past have shifted to becoming detrimental, i.e., favouring metabesity, which is quickly growing to reach pandemic proportions.