RESUMEN
α-cells, which synthesize glucagon, also support β-cell survival and have the capacity to transdifferentiate into β-cells. However, the role of α-cells in pathological conditions and their putative clinical applications remain elusive due in large part to the lack of mature α-cells. Here, we present a new technique to generate functional α-like cells. α-like cells (iAlpha cells) were generated from mouse fibroblasts by transduction of transcription factors, including Hhex, Foxa3, Gata4, Pdx1 and Pax4, which induce α-cell-specific gene expression and glucagon secretion in response to KCl and Arg stimulation. The cell functions in vivo and in vitro were evaluated. Lineage-specific and functional-related gene expression was tested by realtime PCR, insulin tolerance test (ITT), glucose tolerance test (GTT), Ki67 and glucagon immunohistochemistry analysis were done in iAlpha cells transplanted nude mice. iAlpha cells possess α-cell function in vitro and alter blood glucose levels in vivo. Transplantation of iAlpha cells into nude mice resulted in insulin resistance and increased β-cell proliferation. Taken together, we present a novel strategy to generate functional α-like cells for the purposes of disease modeling and regenerative medicine.
Asunto(s)
Animales , Ratones , Glucemia , Fibroblastos , Expresión Génica , Glucagón , Prueba de Tolerancia a la Glucosa , Inmunohistoquímica , Técnicas In Vitro , Insulina , Resistencia a la Insulina , Ratones Desnudos , Reacción en Cadena de la Polimerasa , Medicina Regenerativa , Factores de TranscripciónRESUMEN
Mitogen-activated protein (MAP) kinases comprise a family of protein-serine/threonine kinases, which are highly conserved in protein structures from unicellular eukaryotic organisms to multicellular organisms, including mammals. These kinases, including ERKs, JNKs and p38s, are regulated by a phosphorelay cascade, with a prototype of three protein kinases that sequentially phosphorylate one another. MAPKs transduce extracellular signals into a variety of cellular processes, such as cell proliferation, survival, death, and differentiation. Consistent with their essential cellular functions, MAPKs have been shown to play critical roles in embryonic development, adult tissue homeostasis and various pathologies. In this review, we discuss recent findings that reveal the profound impact of these pathways on chronic inflammation and, particularly, inflammation-associated cancer development.
Asunto(s)
Animales , Humanos , Ratones , Quinasas MAP Reguladas por Señal Extracelular , Metabolismo , Inflamación , Proteínas Quinasas JNK Activadas por Mitógenos , Metabolismo , Sistema de Señalización de MAP Quinasas , Neoplasias , Proteínas Quinasas p38 Activadas por Mitógenos , MetabolismoRESUMEN
<p><b>OBJECTIVE</b>To explore the relation between genetic polymorphisms of NQO1, GSTT1 and risks of chronic benzene poisoning (BP).</p><p><b>METHODS</b>A case-control study was conducted. 152 BP patients and 152 workers occupationally exposed to benzene without poisoning manifestations were investigated. Polymerase chain reaction (PCR), denaturing high-performance liquid chromatography(DHPLC) and sequencing were used to detect the single nucleotide polymorphisms(SNPs) of the promoter and complete coding-region of NQO1 gene. Multiple PCR was used to detect GSTT1 genotype.</p><p><b>RESULTS</b>In smoking population, there was 7.73-fold (95% CI: 1.71-34.97, P = 0.010) of risk in BP subjects carrying NQO1c. 609 T/T genotype, compared with those carrying C/C and C/T. genotype. In drinking population, the individuals carrying the 6th extron of NQO1c. 609 T/T homozygote genotype had a 11.00-fold(95% CI: 1.89-63.83, P = 0.005) risk of BP compared to those with NQO1c. 609 C/T and C/C genotypes.</p><p><b>CONCLUSION</b>The subjects carrying NQO1c. 609 T/T genotype and together with the habit of smoking or drinking may be more susceptible to BP.</p>