Vitiligo is a multifactorial polygenic disorder with a complex pathogenesis, linked with both genetic and non-genetic factors. The precise modus operandi for vitiligo pathogenesis has remained elusive. Theories regarding loss of melanocytes are based on autoimmune, cytotoxic, oxidant-antioxidant and neural mechanisms. Reactive oxygen species (ROS) in excess have been documented in active vitiligo skin. Numerous proteins in addition to tyrosinase are affected. It is possible that oxidative stress is one among the main principal causes of vitiligo. However, there also exists ample evidence for altered immunological processes in vitiligo, particularly in chronic and progressive conditions. Both innate and adaptive arms of the immune system appear to be involved as a primary event or as a secondary promotive consequence. There is speculation on the interplay, if any, between ROS and the immune system in the pathogenesis of vitiligo. The article focuses on the scientific evidences linking oxidative stress and immune system to vitiligo pathogenesis giving credence to a convergent terminal pathway of oxidative stressautoimmunity-mediated melanocyte loss.

Morphogen gradients pattern the endoderm and specify liver and pancreatic progenitors in vivo. However, if specified organ progenitors can be identified and isolated during human pluripotent stem cell (hPSC) differentiation is unknown. Here, we report the identification of two novel surface markers, CD177/NB1 glycoprotein and inducible T cell co-stimulatory ligand CD275/ICOSL, that isolate specified organ progenitors from seemingly homogenous endoderm differentiations in vitro. These markers allow assessing anterior definitive endoderm (ADE) patterning and specification in human revealing different morphogen requirements and induction efficiencies for the generation of specified pancreatic and liver progenitors using known and novel differentiation paradigms. Furthermore, molecular profiling and characterisation of CD177 + and CD275 + ADE subpopulations identified differential expression of signalling components and inverse activation of canonical and non-canonical WNT signalling. This signalling milieu specifies CD275 + ADE progenitors towards the liver fate. In contrast, CD177 + ADE progenitors express and synthesize the secreted WNT, NODAL and BMP antagonist CERBERUS1 and are specified towards the pancreatic fate. Strikingly, isolated CD177 + ADE progenitors differentiate more homogenously into pancreatic progenitors as well as into functionally, more mature and glucose-responsive β-like cells in vitro, when compared to bulk endoderm differentiations. Overall, the identification of novel surface markers allowed us to isolate, monitor and understand human organ progenitor formation for the improved differentiation of β-like cells from hPSC.

Insulin and insulin-like growth factor 1 (Igf1) resistance in pancreatic β-cells causes overt diabetes, thus, therapeutic improvement may protect from β-cell failure 1-3 . Here, we identified a novel inhibitor of insulin (Insr) and Igf1 receptor (Igf1r) signalling in β-cells, which we named insulin inhibitory receptor (Inceptor; Iir). Inceptor contains an extracellular cysteine-rich domain with similarities to the Insr and Igf1r 4 and a mannose-6-phosphate domain found in the Igf2r 5 . Inceptor knock-out (KO) mice die within the first hours after birth with signs of hyperinsulinemia and hypoglycaemia. Molecular and cellular analysis of the Iir -/embryonic and postnatal pancreas showed increased Insr/Igf1r activation, resulting in augmented β-cell proliferation and mass. Similarly, inducible β-cellspecific Iir -/-KO in adult mice and in ex vivo islets led to increased Insr/Igf1r activation and β-cell proliferation, resulting in improved glucose tolerance in vivo. Mechanistically, Inceptor interacts with Insr and Igf1r to facilitate clathrinmediated endocytosis for receptor desensitisation. Blocking this physical interaction using monoclonal antibodies against the extracellular domain of Inceptor retained Inceptor and Insr at the plasma membrane to sustain Insr/Igf1r activation in β-cells. Taken together, Inceptor shields insulin-producing β-cells from constitutive pathway activation and provides a molecular target for Insr/Igf1r sensitisation and potential diabetes therapy.

It is generally accepted that epiblast cells ingress into the primitive streak by epithelial-to-mesenchymal transition (EMT) to give rise to the mesoderm; however, it is less clear how the endoderm acquires an epithelial fate. Here, we used embryonic stem cell and mouse embryo knock‐in reporter systems to combine time-resolved lineage labelling with high-resolution single-cell transcriptomics. This allowed us to resolve the morphogenetic programs that segregate the mesoderm from the endoderm germ layer. Strikingly, while the mesoderm is formed by classical EMT, the endoderm is formed independent of the key EMT transcription factor Snail1 by mechanisms of epithelial cell plasticity. Importantly, forkhead box transcription factor A2 (Foxa2) acts as an epithelial gatekeeper and EMT suppressor to shield the endoderm from undergoing a mesenchymal transition. Altogether, these results not only establish the morphogenetic details of germ layer formation, but also have broader implications for stem cell differentiation and cancer metastasis.

Objective Hundreds of missense mutations in the coding region of PDX1 exist; however, if these mutations predispose to diabetes mellitus is unknown. Methods In this study, we screened a large cohort of subjects with increased risk for diabetes and identified two subjects with impaired glucose tolerance carrying common, heterozygous, missense mutations in the PDX1 coding region leading to single amino acid exchanges (P33T, C18R) in its transactivation domain. We generated iPSCs from patients with heterozygous PDX1 P33T/+ , PDX1 C18R/+ mutations and engineered isogenic cell lines carrying homozygous PDX1 P33T/P33T , PDX1 C18R/C18R mutations and a heterozygous PDX1 loss-of-function mutation ( PDX1 +/− ). Results Using an in vitro β-cell differentiation protocol, we demonstrated that both, heterozygous PDX1 P33T/+ , PDX1 C18R/+ and homozygous PDX1 P33T/P33T , PDX1 C18R/C18R mutations impair β-cell differentiation and function. Furthermore, PDX1 +/− and PDX1 P33T/P33T mutations reduced differentiation efficiency of pancreatic progenitors (PPs), due to downregulation of PDX1-bound genes, including transcription factors MNX1 and PDX1 as well as insulin resistance gene CES1 . Additionally, both PDX1 P33T/+ and PDX1 P33T/P33T mutations in PPs reduced the expression of PDX1-bound genes including the long-noncoding RNA, MEG3 and the imprinted gene NNAT , both involved in insulin synthesis and secretion. Conclusions Our results reveal mechanistic details of how common coding mutations in PDX1 impair human pancreatic endocrine lineage formation and β-cell function and contribute to the predisposition for diabetes.

The prognosis of patients with pancreatic cancer is extremely poor, and current systemic therapies result in only marginal survival rates for patients. The era of targeted therapies has offered a new avenue to search for more effective therapeutic strategies. Recently, microRNAs (miRNAs) that are small non-coding RNAs (18–24 nucleotides) have been associated with a number of diseases including cancer. Disruption of miRNAs may have important implications in cancer etiology, diagnosis and treatment. So far, focus has been on the mechanisms that are involved in translational silencing of their targets to fine tune gene expression. This review summarizes the approach for rational validation of selected candidates that might be involved in pancreatic tumorigenesis, cancer progression and disease management. Herein, we also focus on the major issues hindering the identification of miRNAs, their linked pathways, and recent advances in understanding their role as diagnostic/prognostic biomarkers and therapeutic tools in dealing with this disease. miRNAs are expected to be robust clinical analytes, valuable for clinical research and biomarker discovery.

BackgroundNeuropeptide Y (NPY) is known to play a role in the regulation of satiety, energy balance, body weight, and insulin release. Interleukin-1beta (IL1B) has been associated with loss of beta-cell mass in type-II diabetes (TIID).ObjectivesThe present study attempts to investigate the association of NPY exon2 +1128 T/C (Leu7Pro; rs16139), NPY promoter -399 T/C (rs16147) and IL1B -511 C/T (rs16944) polymorphisms with TIID and their correlation with plasma lipid levels, BMI, and IL1B transcript levels.MethodsPCR-RFLP was used for genotyping these polymorphisms in a case-control study involving 558 TIID patients and 1085 healthy age-matched controls from Gujarat. Linkage disequilibrium and haplotype analysis of the NPY polymorphic sites were performed to assess their association with TIID. IL1B transcript levels in PBMCs were also assessed in 108 controls and 101 patients using real-time PCR.ResultsOur results show significant association of both structural and promoter polymorphisms of NPY (p<0.0001 and p<0.0001 respectively) in patients with TIID. However, the IL1B C/T polymorphism did not show any association (p = 0.3797) with TIID patients. Haplotype analysis revealed more frequent association of CC and CT haplotypes (p = 3.34 x 10−5, p = 6.04 x 10−9) in diabetics compared to controls and increased the risk of diabetes by 3.02 and 2.088 respectively. Transcript levels of IL1B were significantly higher (p<0.0001) in patients as compared to controls. Genotype-phenotype correlation of IL1B polymorphism did not show any association with its higher transcript levels. In addition, NPY +1128 T/C polymorphism was found to be associated with increased plasma LDL levels (p = 0.01).ConclusionThe present study provides an evidence for a strong correlation between structural and promoter polymorphisms of NPY gene and upregulation of IL1B transcript levels with susceptibility to TIID and altering the lipid metabolism in Gujarat population.

This inventory evaluates toxicological effects and hepatoprotective potential of Clerodendron glandulosum.Coleb (CG) aqueous extract. Acute and subchronic toxicity tests were performed using Swiss albino mice as per the guideline of Organisation for Economic Cooperation and Development (OECD). Also, hepatoprotective potential of CG extract was examined in experimental model of carbon tetrachloride (CCl 4)-induced hepatotoxicity. Acute and subchronic toxicity tests revealed that CG extract is non-toxic and its median lethal dose (LD50) value is >5000 mg/kg bodyweight. Also, rats pretreated with CG extract followed by administration of CCl4 recorded significant decrement in plasma marker enzymes of hepatic damage, total bilirubin content and hepatic lipid peroxidation. While, hepatic reduced glutathione, ascorbic acid content, activity levels of superoxide and catalase and plasma total protein content were significantly increased. Microscopic examination of liver showed that pretreatment with CG extract prevented CCl4-induced hepatic damage in CG + CCl 4 group. CG extract has hepatoprotective potential by modulating activity levels of enzymes and metabolites governing liver function and by helping in maintaining cellular integrity of hepatocytes that is comparable with that of standard drug silymarin. CG extract exhibits potent hepatoprotective activity against CCl4-induced hepatic damage but does not exhibit any toxic manifestations.