Project description:Germline mutations in CDKN2A and/or red hair colour variants in MC1R genes are associated with an increased susceptibility to develop cutaneous melanoma. To investigate the impact of germinal p.G101W CDKN2A mutation and MC1R variants on gene expression and transcription profiles associated to skin cancer and melanoma in particular, we set-up primary skin cultures from twins belonging to the melanoma prone-families with and without these genomic features. were analyzed using expression array methodology. Overall, 1535 transcripts were deregulated in CDKN2A mutated cells, finding overexpression of immunity-related genes (HLA-DPB1, CLEC2B, IFI44, IFI44L, IFI27, IFIT1, IFIT2, SP110 and IFNK) and downregulation of genes playing a role in the Notch signaling pathway. 3570 transcripts were deregulated in carriers of MC1R variants. In this case, upregulated genes were involved in oxidative stress and DNA damage pathways as well as in neurodegenerative diseases such as Parkinson’s, Alzheimer and Huntington. In contrast, downregulated genes were associated with pigmentation synthesis/transport and angiogenesis. By using a coculture system, this study identified key molecular functions and/or pathways that are deregulated due to alterations in melanoma susceptibility genes which in turn, could be involved in initiation/progression of the disease. 12 samples total. Several experimental groups: with and without genomic features (CDKN2A, MC1R).
Project description:Germline mutations in CDKN2A and/or red hair colour variants in MC1R genes are associated with an increased susceptibility to develop cutaneous melanoma. To investigate the impact of germinal p.G101W CDKN2A mutation and MC1R variants on gene expression and transcription profiles associated to skin cancer and melanoma in particular, we set-up primary skin cultures from twins belonging to the melanoma prone-families with and without these genomic features. were analyzed using expression array methodology. Overall, 1535 transcripts were deregulated in CDKN2A mutated cells, finding overexpression of immunity-related genes (HLA-DPB1, CLEC2B, IFI44, IFI44L, IFI27, IFIT1, IFIT2, SP110 and IFNK) and downregulation of genes playing a role in the Notch signaling pathway. 3570 transcripts were deregulated in carriers of MC1R variants. In this case, upregulated genes were involved in oxidative stress and DNA damage pathways as well as in neurodegenerative diseases such as Parkinson’s, Alzheimer and Huntington. In contrast, downregulated genes were associated with pigmentation synthesis/transport and angiogenesis. By using a coculture system, this study identified key molecular functions and/or pathways that are deregulated due to alterations in melanoma susceptibility genes which in turn, could be involved in initiation/progression of the disease.
Project description:Amplification of the Melanocortin-1 Receptor in Nephrotic Syndrome Renders a Good Target for Podocyte Cytoskeleton Stabilization During the last years, several reports have been presented of beneficial effects of ACTH in patients with nephrotic syndrome. Among the known ACTH receptors, the melanocortin-1 receptor (MC1R) has been suggested as the mediator of the ACTH renoprotective effect with the mechanism of action resulting in stabilization of the actin cytoskeleton in podocytes. To understand how melanocortin receptors are regulated in nephrotic syndrome and how they are involved in restoration of filtration barrier function, melanocortin receptor expression was evaluated in patients and in a rat model of nephrotic syndrome in combination with cell culture analysis. Phosphoproteomic mass spectrometry was applied and identified MC1R pathways confirmed using biochemical analysis. We found that glomerular MC1R expression was increased in nephrotic syndrome, both in humans and in a rat model. A MC1R agonist protected podocytes from protamine sulfate induced stress fiber loss with the top ranked phoshoproteomic MC1R activated pathway beeing actin cytoskeleton signaling. Actin stabilization through the MC1R consisted of ERK1/2 dependent phosphorylation and inactivation of EGFR signaling with stabilization of synaptopodin and stress fibers in podocytes. These results further explain how patients with nephrotic syndrome show responsiveness to ACTH treatment by depressing EGFR signaling through activation of the MC1R receptor and as a consequence restore filtration barrier function by stabilizing the podocyte actin cytoskeleton.
Project description:Total RNA was extracted from the basal epidermis derived from UVB-irradiated P2.5 normal (Mc1r+/Mc1r+; Kit+/Kit+), Mc1r-mutant (Mc1re/Mc1re) and Kit-mutant (Kit/W-v/Kit/W-v) mice. Biological replicates (cy5) were labelled and co-hybridized with a reference RNA sample (cy3) to a 35K mouse cDNA microarray. A reference experiement design type is where all samples are compared to a common reference. Keywords: reference_design
Project description:Melanocortins mediate their biological functions via five different melanocortin receptors (MC1R - MC5R). MC1R is expressed in the skin and leukocytes and is thus involved in the regulation of skin pigmentation and inflammatory responses. MC1R is also present in the liver and white adipose tissue, but its functional role in these tissues is unclear. This study aimed at determining the regulatory role of MC1R in fatty acid metabolism. Recessive yellow (Mc1re/e) mice, a model of global MC1R deficiency, and hepatocyte-specific MC1R deficient mice (Mc1r LKO) were fed a chow or Western diet for 12 weeks. The mouse models were characterized for body weight and composition, adipose tissue mass, adipocyte size, glucose metabolism and lipid metabolism. Furthermore, qPCR and RNA sequencing analyses were used to investigate gene expression profiles in the liver and adipose tissue. HepG2 cells and primary mouse hepatocytes were to study the effects of pharmacological MC1R activation. Chow- and Western diet-fed Mc1re/e showed increased liver weight, white adipose tissue mass and plasma triglyceride (TG) concentration compared to wild type mice. This phenotype occurred without significant changes in food intake, body weight, physical activity or glucose metabolism. Mc1r LKO mice displayed a similar phenotype characterized by larger fat depots, increased adipocyte hypertrophy and enhanced accumulation of TGs in the liver and plasma. In terms of gene expression, markers of de novo lipogenesis, inflammation and apoptosis were upregulated in the liver of Mc1r LKO mice, while enzymes regulating lipolysis were downregulated in white adipose tissue of these mice. In cultured hepatocytes, selective activation of MC1R reduced ChREBP expression, which is a central transcription factor for lipogenesis. Hepatocyte-specific loss of MC1R disturbs fatty acid metabolism in the liver and leads to an obesity phenotype characterized by enhanced adipocyte hypertrophy and TG accumulation in the liver and circulation.
Project description:Russell’s viper (Daboia russelii) (RV), a category I medically important snake as well as a member of the “Big Four”, is responsible for a heavy toll of snake bite mortality and morbidity in Indian sub-continent. Epidemiological studies suggest highest incidence of RV envenomation in eastern India (EI). In this study the RV venom proteomes from Burdwan and Nadia, the two districts of West Bengal, eastern India was deciphered for the first time using tandem mass spectrometry analysis.
Project description:Total RNA was purified from keratinocytes isolated from FFPE arsenic-induced skin lesion samples collected from individuals exposed to high concentrations of arsenic exceeding 50 ppb in drinking water in Murshidibad district of West Bengal, India.
Project description:O. rhodostigmatus are non-obligative cave dwellers, whose tadpoles keep albinistic phenotype in caves but rapidly darken in light within 24 hours. Their coloration system is an excellent model for exploring the processes and mechanisms of light-induced pigmentation and revealing the genetic adaptation for non-obligative cave dwelling due to complicated life history. Using comparative transcriptomics, we found that melanocyte MCC (including melanogenesis and melanocytes proliferation) was responsible for the rapid skin darkening in was activated in O. rhodostigmatus. Light exposure induced robust activation of growth signals (including growth factor signals, MAPK signal pathways and PIK3-Akt signal pathways) at transcriptional levels, which were likely the upstream activation signals of melanocyte MCC in O. rhodostigmatus tadpoles. These results evidenced that amphibians and mammals likely share similar regulatory signals for light-induced melanocyte MCC. The conservation of pigmentation mechanisms across lower vertebrates and mammals imply that knowledge based on simpler models could also provide implications for causations and therapies of human pigmentation disorders and pigmented tumors. In aspect of genetic adaptation, an in-frame deletion of four amino acids in the membrane/extracellular junctions of the second and third transmembrane domains of O. rhodostigmatus MC1R, the receptor for melanogenesis signal, was identified. This mutation increases the negative charge of the ligand pocket of MC1R and results stereo-tandem of three aspartate residues aligning towards its ligand pocket. The ligand pocket of O. rhodostigmatus MC1R resembles a trap for positively charged ligands (α-MSH and ACTH) and likely increases the ligands-dependent activity of MC1R, providing an explanation for the rapid MCC of O. rhodostigmatus in light. Meanwhile, increased negative charge of ligand pocket likely decreased the constitutive activity of MC1R, in in supporting the albinistic phenotype of cave dwelling tadpoles. Therefore, genetic change of MC1R explains, at least to some extent, how the pigmentation system of O. rhodostigmatus coordinates the capacity of rapid melanogenesis (or other types of pigment production) and pigment regression, a couple of seemingly contradictory coloration requirements. To our knowledge, this is the first study reporting the association between pigmentation phenotype adaptation and MC1R mutations in amphibians or in non-obligative cave dwellers.