The serum concentration of βCGRP is novel marker for type 1 diabetes

Unique Biased Agonism Profile of βCGRP on CGRP Family Receptors

α- and β-calcitonin gene-related peptides (αCGRP and βCGRP, respectively), together with adrenomedullin (AM) and AM2 are endogenous agonists of the CGRP family of receptors; CGRP receptor (CGRPR), AM1 receptor (AM1R), and AM2 receptor (AM2R). The high sequence homology and similar tissue distribution of αCGRP and βCGRP suggests they have overlapping physiological roles in pain pathways, inflammation, and metabolism, but recent data indicate potential differences in the signaling capabilities of these peptides. However, a comprehensive pharmacological characterization of βCGRP activity, compared to αCGRP, AM, and AM2 across the three CGRP family receptors, is lacking. In this study, we assessed proximal G protein coupling/activation, cognate second messenger production, regulatory protein recruitment and receptor trafficking induced by αCGRP, βCGRP, AM, and AM2 at the CGRPR, AM1R, and AM2R. Our findings revealed a distinct profile of transducer and regulatory protein engagement induced by βCGRP compared to αCGRP across these receptors. The identification of differences in pharmacological profiles for αCGRP and βCGRP indicates that they may have more distinct physiological roles than previously appreciated and may assist in distinguishing the roles of these two peptides for exploitation in targeted drug design.

Identification of the hub susceptibility genes and related common transcription factors in the skeletal muscle of Type 2 Diabetes Mellitus

BACKGROUND

Type 2 diabetes mellitus (T2DM) and its related complications contribute to the high morbidity and mortality in worldwide. Skeletal muscle insulin resistance plays a critical role in the onset of T2DM due to the decreasing in the insulin-stimulated glucose uptake. T2DM is associated not only with the inherited factors but also with the noninherited factors. However, the susceptibility genes related with the two factors and the transcription factors (TF) regulating the susceptibility genes in skeletal muscle, which aggravate the development of T2DM were still ill-defined.

METHODS

In the present study, the expression profiles by the array of GSE25462 were retrieved from the GEO database. GEO2R was performed to validate the susceptibility differentially expressed genes (SDEG) in skeletal muscle of T2DM. Gene Ontology (GO) analysis and The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were conducted via The Database for Annotation, Visualization, and Integrated Discovery (DAVID). A Protein-Protein Interaction (PPI) network was performed with the STRING.

RESULTS

With the performance of GEO2R, 229 SDEGs in skeletal muscle of T2DM were identified. The biological processes (BP) of SDEGs was enriched in the cellular response to UV-B most significantly. KEGG pathway analysis revealed that the SDEGs were most significantly enriched in glycosaminoglycan degradation. 5 hub susceptibility genes (GPR84, CALCB, GCG, PTGDR, GNG8) in the skeletal muscle of T2DM were identified. Eventually, the common transcription factors regulating the hub susceptibility genes were identified by means of the online tool PROMO.

CONCLUSIONS

Five hub susceptibility genes (GPR84, CALCB, GCG, PTGDR, GNG8) in the skeletal muscle of T2DM and the common transcription factors were identified. The outputs would provide new clues on the novel potential targets and the therapeutic strategies for treating T2DM and its related diseases.