Beta cell death and dysfunction are central in the development of diabetes mellitus. The aim of our work was to explore causes of beta cell deficit under (patho)physiological conditions that lead to activation of AMP-dependent kinase (AMPK). AMPK is both an energy sensor of the cell and a signal transducer for various hormones, cytokines, and nutrients. Its function is crucial to whole body glucose homeostasis. Its activation in brain regulates food intake while in peripheral tissues it has both insulin-like and insulin-sensitizing effects. In recent years the role of AMPK in physiology and action of anti-diabetic drugs has been studied intensively in liver, muscle and brain but little is known about its role in pancreatic beta cells. The present study first investigates the hypothesis that activation of the metabolic switch AMPK in beta cells can lead to cell dysfunction and apoptotic cell death. Then, we study molecular mechanisms of AMPK-mediated apoptosis. Finally, we explore ways to protect beta cells from AMPK-mediated dysfunction and ensuing death.
Diabetes is a chronic disorder of glucose metabolism and a major cause of premature mortality. The potential use of replacement beta cells as therapy for diabetes requires an ability to culture such cells while maintaining their functional status. Glucose stimulated insulin secretion (GSIS) is lost in long-term cultured MIN6 heterogeneous cells. MIN6 B1, a clonal sub-line derived from MIN6, has been described as highly glucose-responsive. This study aimed to investigate the GSIS function, changes in gene expression and, subsequently, to develop possible experimental approaches to overcome this loss. Understanding the molecular basis for loss of GSIS may contribute to better culture conditions for islets in transplantation programmes; it may also add to our understanding of beta cell insensitivity to high blood glucose in Type 2 diabetes. In parallel, in an attempt to identify more reliable biomarkers for diabetes, we also investigated if extracellular mRNAs are reproducibly detectable in conditioned medium (CM) from a range of insulin-producing cell types and in serum specimens from Type 2 diabetes and controls.
Multiple sclerosis (MS) is a chronic inflammatory autoimmune disease of the central nervous system characterized by perivascular inflammation and demyelination and loss of neurologic function. In this disease and its experimental model (experimental autoimmune encephalomyelitis, EAE), axonal and neuronal loss is thought to play a key role in irreversible loss of function and disability. Regarding the important role of autoreactive T cells (particularly Th1 and Th17 cells) in pathophysiology of MS, it may be suspected that T cell regulator/suppressive factors such as regulatory T cells (Tregs) can control initiation and progression of disease and even treat it. The frequency, function and properties of different subsets of Tregs including natural Tregs (nTregs), IL-10 producing type 1 Tregs (Tr1 cells), TGF-? producing Th3 cells, CD8+ Tregs, and NKT cells in MS and its model EAE, are investigated in several experimental studies. In this long review, we intend to submit the comprehensive information regarding the immunobiology of various subsets of Tregs and their roles and function in immunopathophysiology of MS and its animal model, EAE.
The nutrient and energy sensor AMP-activated protein Kinase regulates cellular and whole-body energy homeostasis through stimulating catabolic ATP-generating and suppressing anabolic ATP-consuming pathways thereby helping cells survive during energy starvation. AMPK plays an important role in autophagy induction in response to starvation, a process that involves phosphorylating TSC2 and mTOR activation. Recent advances indicate the kinase also to exert tumor suppressor activity by stimulating apoptosis, autophagy and cell growth and proliferation. AMPK can be used to protect from metabolic syndrome. This kinase has previously been demonstrated to be either directly or indirectly involved in the regulation of numerous carriers, channels and pumps of high relevance for cellular physiology and pathophysiology. Thus, AMPK provides a necessary link between cellular energy metabolism and cellular transport activity. Better understanding of the AMPK role in the regulation of cell transport under physiological and pathological conditions may represent a potential for developing therapies for many human diseases and disorders, especially cancers.
Diabetes mellitus is a complex of metabolic disease characterized by hyperglycemia , diminished insulin production, impaired insulin action , or a combination of both resulting in the inability of glucose to be transported from the blood stream into the tissues, which in turn results in high blood glucose levels and excretion of glucose in the urine, The cell functions involved in the action of insulin receptor binding enzyme and transporter activities are controlled by membrane properties . Fatty acids composition of membrane phospholipids are affected by the composition of the dietary fat . Changes in the fatty acids composition of erythrocyte membrane , which are easily accessible cells, reflects changes in that of membrane phospholipids of less accessible tissues . The fatty acids composition of cell membrane can influence membrane associated phenomena such as the interaction between insulin and its receptors. Thus it is from interest to study the relationship between cell membrane phospholipids fractions and their role in insulin action, also to study the role of omega-3 fatty acids in reducing oxidative stress in diabetic rats.
Gestational diabetes mellitus (GDM) is defined as glucose intolerance with onset or first detected during pregnancy . There are various risk factors for the development of GDM. One of the most important is obesity (BMI 30) before getting pregnant and obesity during pregnancy. Such pregnant demonstrate elevated circulating concentrations of leptin and raised levels of inflammatory mediators. The role of adipose tissue and circulating adipokines in regulating maternal glucose homeostasis has been recently recognized as an important component in the development of glucose intolerance and insulin resistance. GDM is associated with increased risk of adverse perinatal outcomes for mother and fetus. After delivery some long-term effects occur affecting again mother and infant. Women with a history of GDM have a higher risk of developing of T2DM, metabolic syndrome and cardiovascular diseases. The frequency of GDM also increases in parallel with that of T2DM and obesity. It is not a surprise, because the basic pathogenetic mechanisms in development of GDM and T2DM are one and the same. This book is designed for physicians on general practice, endocrinologists and gynecologists.
Carbapenem resistance due to metallo beta lactamases (MBLs) has grown as a health care problem in recent decades. The present study has investigated the antibiotic susceptibility patterns and screening of MBLs producing P. aeruginosa isolates at two university hospitals in northwest of Iran. Furthermore, serotyping, PFGE and MLST were used for studying the clonal relationship among the isolates. In brief our findings showed that blaVIM and blaIMP types MBLs are common in our area. All MBLs producing isolates were non-susceptible to imipenem, majority of them belonged to MDR phenotype and O10 or O11 serotypes. Also, a multi-drug resistant clone of P. aeruginosa was identified in a burn unit in Orumieh- Iran, which majority of them belonged to O10 serotype, and most of them were sequence type, ST773. In conclusion, since MBLs producing isolates are resistant to most antibacterial agents, early detection of such isolates is crucial to choose appropriate therapeutic regimens and prevent dissemination of this type of resistance. Finally our findings emphasize the importance of continually following the epidemiological relatedness of MDR P. aeruginosa spreading in ICUs and burn units.
According to WHO, India may have 80 million diabetic patients by the year 2030. Oxidative stress may occur as a result of increased free radical generation and/or decreased anti-oxidant defense mechanisms. In the course of evolution, organisms have developed some more or less refined mechanisms protecting them against the harmful activity of free radicals, both in enzymatic and non-enzymatic ways. Diabetes mellitus is one of the stress related disorder, its a state of increased free radical formation occurs. During diabetes homeostasis of carbohydrate, protein and lipid metabolism are improperly regulated by insulin. Streptozotocin (STZ), cytotoxic agent of pancreatic ?-cells induces diabetes by rapid depletion of ?-cells resulting in reduction insulin secretion. In traditional system of Indian medicine, plant formulation and combined extracts of plants are used as drug of choice rather than individual. Glymin, a polyherbal formulation developed by Kerala Ayurveda Ltd, was taken to evaluate the anti-diabetic, free radical scavenging, antioxidant and lipid lowering properties in STZ-induced diabetes.
The prospect of improved regeneration is not only the promise held out by stem cell research, critical studies of unique aspects of early human development are now within reach with the use of embryonic stem cells. Although our understanding of the molecular pathways underlying mesenchymal stem cells differentiation is expanding, translation of this knowledge into tissue engineering strategies remains in its infancy. In the context of orofacial tissue engineering, populations of stem cells that form bone, cementum; dentin and even periodontal ligament have been identified. This has unlocked a new direction of research to restore the form and function of the oral cavity using autologous cells, thereby preventing histocompatibility mismatch and transmission of disease. With the first reports of adult human stem cell populations residing in the periodontal ligament beginning to emerge, the next phase will be to determine the clinical utility of these cells. Accordingly, further studies are now required to determine the efficacy of ex vivo expanded stem cells to repair periodontal defects.
Cancer is an un-control growth of cells. Cancer cells grow in an abnormal fashion, crowd out the normal cells. Liver is the largest organ inside the body; hepatocellular carcinoma is a cancer arising from liver. Laryngeal cancer affects the larynx, which is often called voice box, common in males. Lung cancer is the deadliest cancer in the world, leading cause of death from cancer in men. Multiple gene mutations are involved in cancer pathology. Type I interferons (IFN?, IFN?, IFN?) are the proteins involved in cell signaling and growth. This study was conducted to determine whether mutation in IFN?1 plays a significant role in liver, larynx and lung cancer. Paraffin embedded tissues of liver, larynx and lung were used for DNA isolation. SSCP technique was used to detect mutation. Only two samples of lung carcinoma shows the mobility shift on SSCP gel. It was observed that people in older age have more chances of cancer. In general population, males are more prone to larynx and lung cancer than female. Significant values were observed (p<0. 05), when age, cancer and mutation were analyzed.
Hyperglycemia is a widely prevalent metabolic disorder clinically diagnosed as Diabetes. The clinical profile of diabetes recognized insulin-dependent and insulin-independent forms of this metabolic disorder, implicating pancreatic ?-cells for their diminished capacity to produce insulin, and the glucose phosphorylating enzymes as well as cellular glucose transporters for diminished glucose utilization by the cells. In this context, the present work becomes significant. A result of this investigation speaks for itself and supports an extremely valuable mammalian role for a plant hormone used in this study. Even though the exact mechanism involved in the regulation of circulating glucose level in the experimental rats employed in this study has not been delineated, results of the study identifies an imperative role for the plant hormone in the maintenance of glucose homeostasis in animal cells.
An observational study was conducted on patients suffering from Urinary Tract Infection (UTI) in North East India. The different bacterial agents causing UTI were enumerated and their antimicrobial resistance pattern was studied. Gram negative organisms producing Extended Spectrum Beta Lactamases (ESBL) were determined. The different epidemiological factors having a role in production of ESBL were characterized in this study.
Diabetes mellitus is one of the most common problems caused by a combination of insulin resistance and impaired insulin secretion by pancreatic B cells. Nowadays, there are many drugs to treat diabetes. Oral antidiabetic drugs are associated with side effects such as weight gain, hypoglycaemia, lactate acidosis and none of these drugs have been shown to stop the progressive decline of beta-cell function. Insulin treatment is expensive and troublesome for the patients, and also induces weight gain. Given this background, there is a need for new classes of blood-glucose-lowering drugs that minimise the risk of hypoglycaemia. Incretin hormones derivatives and dipeptidyl peptidase-4 inhibitors are the latest marketed development in this field. Incretin hormones (GLP-1 and GIP) amplify insulin secretion and are rapidly degraded by dipeptidyl peptidase-4, therefore two strategies have been pursued to exploit the beneficial actions of the hormone:(I) development of more stable activators of the GLP-1 receptor (so-called incretin) like liraglutide, taspoglutide and so on (II) inhibitors of DPP-4 like alogloptin, dutagliptin and so on. This book surveys new drugs and therapies in diabetes.
Human Beta Defensins (hBDs) are a class of antimicrobial peptides (AMPs) that play an important role both in innate and adaptive immunity: they kill bacteria, viruses and fungi and exert chemotaxis against lymphocytes and monocytes. Thanks to their properties, hBDs represent a target to develop therapeutic molecules. Previously, Scudiero et al. synthesized the wild type hBD1, hBD3 and designed analogs selecting the sequences crucial for the activity. In the present study, we tested the possibility to find a new defensin analog with enhanced properties. The new peptide has the following features: shorter total sequence; presence of the C-terminus portion of hBD3; presence of inner portion of hBD1. We perform antibacterial and antiviral tests on E. coli, P. aeruginosa, E. faecalis and simplex virus type 1. In addition, we investigated two pharmacological properties of these peptides: the stability in human serum and the cytotoxic effects on human cells. Finally, in order to investigate whether defensins interact with human epithelial cells, we labeled peptides with NBD fluorochrome and performed confocal microscopy experiments.
Hyperglycemia results in excessive production of free radicals which leads to sever oxidative damage of the cell components like lipids, proteins and DNA. These radicals attack the polyunsaturated fatty acids in the cell membrane leading to disturbances in membrane structure and properties such as membrane permeability, integrity and also the binding of insulin to its receptors that is embedded in the cell membrane, Thus it was found that membrane enriched in unsaturated fatty acids tends to bind more insulin than membrane enriched in saturated fatty acids, and the membrane components may be affected by food intake. In this study we aimed to increase omega-3 fatty acids through flaxseed oil supplementation daily as it contains a high proportion of unsaturated fatty acids in order to improve cell membrane components and improve cell membrane functions including the interaction between insulin and its receptors and then increasing insulin sensitivity through improving insulin mechanism.
The prevalence of thyroid disease in patients with diabetes is significantly higher than that in the general population. This indicates a possible interplay between thyroid status and insulin sensitivity. Complex interplay between thyroid function and insulin resistance (IR) has been implicated in diabetic dyslipidemia. Homeostatic model assessment (HOMA) of ?-cell function and IR is a method for assessing ?-cell function and IR from basal glucose and insulin or C-peptide concentrations. The use of HOMA to estimate insulin sensitivity and ?-cell function helps to compare ?-cell function and insulin sensitivity In the light of the existing reports we decided to 1) evaluate the correlation between altered thyroid state and development of IR clinically; 2) to assess ? cell function and IR by HOMA-IR. Our study concluded that thyroid disorder, including both hypo- and hyper, have been associated with IR due to various mechanism like altered insulin secretion and lipid levels. Thus even subtle increase or decrease in the thyroid levels can lead to IR leading to risk of glucose related disorder like diabetes dyslipidemia.
Multiple myeloma is a hematological cancer which is characterized by malign proliferation of plasma cells and their precursors. Although myeloma cells express antigens which can be recognized by host T cells they can be rarely eradicated by the immune system because of the immunsupression by tumor microenvironment. The immunsuppressive regulatory T cells (Treg) with CD4+ CD25+ Foxp3+ fenotype are increased in peripheral blood of multiple myeloma patients which have key roles on oto-immune control, T-cell homeostasis, immunmodulation of all the immune response. This book is a combination of Master of Science and PhD dissertations examining the role of Treg cells in multiple myeloma. The interaction of Treg cells with autologous peripheral blood stem cell transplantation and bortezomib treatment is evaluated by ex vivo and in vitro tests. The findings point out the importance of Treg cells in multiple myeloma and the experimental design will help the researchers interested in the same field.
Stage-specific interactions between Sertoli cells and germ cells plays central role in the regulation of spermatogenesis. In the first part of the study, function of Theg (testicular haploid expressed gene) gene was characterized. Theg is specifically expressed in spermatid cells. Its expression is upregulated by some unknown factor(s) from Sertoli cells. To elucidate the function of THEG protein and its role in spermatogenesis, we disrupted the Theg locus in mouse by homologous recombination. The Theg knockout mice from two different genetic backgrounds appeared normal and were fertile, with no gross abnormalities detected in testicular morphology or sperm properties. Our results from knockout mouse model systems clearly illustrate that Theg is not essential for spermatogenesis in the mouse. During the generation Theg knockout mice, an intriguing mutation was discovered, which we named as nax. The nax mice exhibit delayed hair appearance and ataxia in a homozygote state. Histological analyses of nax brain revealed an overall impairment of the cerebellar cortex. We mapped the nax locus between marker D2Mit158 and D2Mit100 within a region of 800 kb in the middle of chromosome 2.
TP53 gene mutations compromising p53 transcriptional function occur in more than 50% of human cancers, including pancreatic adenocarcinoma, and render cancer cells more resistant to conventional therapy. In the last few years, many efforts have been addressed to identify p53-reactivating molecules able to restore the wild-type transcriptionally competent conformation of the mutated proteins. In the present thesis, we show that two of these compounds, CP-31398 and RITA, can induce cell growth inhibition, apoptosis, and autophagy by activating p53/DNA binding and p53 phosphorylation (Ser15), without affecting the total amount of p53. These effects occur in both wild-type and mutant p53 (mutp53) pancreatic adenocarcinoma cell lines, whereas they are much less pronounced in normal human primary fibroblasts. Furthermore, CP-31398 and RITA regulate the axis SESN1- 2/AMPK/mTOR by inducing AMPK phosphorylation in Thr172, which has a crucial role in the autophagic response. Our results support the development of an anti-tumoral strategy based on autophagy inhibition associated to the combined treatment of p53-reactivating molecules with standard chemotherapy,for both wild-type and mutant p53
Despite major advances in standard cancer treatment, many patients relapse or progress after a period of time. Cancer immunotherapy is being extensively investigated to provide a treatment with less side effects impacting on quality of life as compared to classical therapies. Dendritic cells (DC) are professional antigen-capturing and -presenting cells which are capable in balancing the immune system between immune stimulation and tolerance. We explored the use of dendritic cells for the development of immunotherapy in leukemia patients to stimulate and enhance T cell-mediated immune responses. Wilms tumor protein (WT1), overexpressed in many cancer types, was chosen as target antigen. This book describes the way a dendritic cell vaccine is produced: from the early proof of concept experiments to the final generation of a clinical applicable vaccine of WT1-loaded DC in a stage I/II trial with 10 acute myeloid leukemia (AML) patients in remission. The data obtained in this trial and data from other trials using WT1 as target antigen are compared. Altogether this book is valuable for everybody who likes to know more about immunotherapy and dendritic cells in the treatment of AML.