Alpha 2-Adrenergic Receptor Agonist Brimonidine Stimulates ERK1/2 and AKT Signaling via Transactivation of EGF Receptors in the Human MIO-M1 Müller Cell Line

Molecular regulation after mucosal injury and regeneration in ulcerative colitis

Ulcerative colitis (UC) is a chronic nonspecific inflammatory disease with a complex etiology. Intestinal mucosal injury is an important pathological change in individuals with UC. Leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5+) intestinal stem cells (ISCs) exhibit self-renewal and high differentiation potential and play important roles in the repair of intestinal mucosal injury. Moreover, LGR5+ ISCs are intricately regulated by both the Wnt/β-catenin and Notch signaling pathways, which jointly maintain the function of LGR5+ ISCs. Combination therapy targeting multiple signaling pathways and transplantation of LGR5+ ISCs may lead to the development of new clinical therapies for UC.

Neuronal Dysfunction Is Linked to the Famine-Associated Risk of Proliferative Retinopathy in Patients With Type 2 Diabetes

Persons with type 2 diabetes born in the regions of famine exposures have disproportionally elevated risk of vision-threatening proliferative diabetic retinopathy (PDR) in adulthood. However, the underlying mechanisms are not known. In the present study, we aimed to investigate the plausible molecular factors underlying progression to PDR. To study the association of genetic variants with PDR under the intrauterine famine exposure, we analyzed single nucleotide polymorphisms (SNPs) that were previously reported to be associated with type 2 diabetes, glucose, and pharmacogenetics. Analyses were performed in the population from northern Ukraine with a history of exposure to the Great Ukrainian Holodomor famine [the Diagnostic Optimization and Treatment of Diabetes and its Complications in the Chernihiv Region (DOLCE study), n = 3,583]. A validation of the top genetic findings was performed in the Hong Kong diabetes registry (HKDR, n = 730) with a history of famine as a consequence of the Japanese invasion during WWII. In DOLCE, the genetic risk for PDR was elevated for the variants in ADRA2A, PCSK9, and CYP2C19*2 loci, but reduced at PROX1 locus. The association of ADRA2A loci with the risk of advanced diabetic retinopathy in famine-exposed group was further replicated in HKDR. The exposure of embryonic retinal cells to starvation for glucose, mimicking the perinatal exposure to famine, resulted in sustained increased expression of Adra2a and Pcsk9, but decreased Prox1. The exposure to starvation exhibited a lasting inhibitory effects on neurite outgrowth, as determined by neurite length. In conclusion, a consistent genetic findings on the famine-linked risk of ADRA2A with PDR indicate that the nerves may likely to be responsible for communicating the effects of perinatal exposure to famine on the elevated risk of advanced stages of diabetic retinopathy in adults. These results suggest the possibility of utilizing neuroprotective drugs for the prevention and treatment of PDR.

Molecular characterization and biological function of CXCR1 in Nocardia seriolae-infected largemouth bass (Micropterus salmoides)

Interleukin-8 (IL-8, CXCL8), a pro-inflammatory chemokine secreted by a variety of cell types, plays a critical role in the development of various immune diseases. Interactions between IL-8 and its receptor CXC receptor 1/2 (CXCR1/2) are known to promote chemotaxis and phagocytosis in many immune responses. In this study, we report the molecular characteristics and pharmacological activity of CXCR1 (MsCXCR1) in largemouth bass (Micropterus salmoides) and evaluated the functional involvement of MsCXCR1 in individuals infected with the pathogen Nocardia seriolae. MsCXCR1 was cloned into the pEGFP-N1 plasmid and the subcellular localization of MsCXCR1 on the cell membrane was verified in MsCXCR1-EGFP-expressing HEK293 cells. Following observation of receptor internalization and intracellular signaling detection, we further determined the functional interaction of secreted interleukin-8 (LcIL-8, the ligand for CXCR1 in large yellow croaker) and MsCXCR1 was further determined, and the ERK phosphorylation signal activation mediated by MsCXCR1 was demonstrated. Quantitative real-time PCR assays were conducted to analyze the transcriptional distribution of MsCXCR1 in various tissues of healthy and diseased largemouth bass. These results illustrate the significant elevation of MsCXCR1 expression in the head kidney, spleen and liver of M. salmoides, suggesting that MsCXCR1 was involved in the immune response in N. seriolae-infected largemouth bass and potentially affects the digestive function of this species.