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Current opinion views androgens as the pathogenic driver in the miniaturization of hair follicles of androgenetic alopecia by interfering with the dermal papilla. This cannot be the sole cause and therefore it is important for therapeutic and diagnostic purposes to identify additional pathways. Comparative full transcriptome profile analysis of the hair bulb region of normal and miniaturized hair follicles from vertex and occipital region in males with and without androgenetic alopecia revealed that next to the androgen receptor as well the retinoid receptor and particularly the PPAR pathway is involved in progressive hair miniaturization. We demonstrate the concurrent up-regulation of PPARGC1a in the epithelial compartment and androgen receptor in the dermal papilla of miniaturized hair. Dynamic Ppargc1a expression in the mouse hair cycle suggests a possible role in regulating hair growth and differentiation. This is supported by reduced proliferation of human dermal papilla and predominantly epithelial keratinocytes after incubation with AICAR, the agonist for AMPK signaling which activates PPARGC1a and serves as co-activator of PPARγ. In addition, miRNA profiling shows enrichment of miRNA-targeted genes in retinoid receptors and PPARGC1α/PPARγ signaling, and antigen presentation pathways.

Parkinson disease (PD) is a common neurodegenerative disorder which manifests as bradykinesia, movement rigidity and tremors in affected individuals. Our understanding of the genetic basis of PD has been steadily increasing since the initial report of a-synuclein mutations two decades ago. Mutations implicated in familial PD fully account for monogenic inheritance and point to potential functional mechanisms underlying PD. However, most sporadic PD cannot be accounted for by known familial PD genes, with the late-onset nature of PD making further linkage studies challenging. Genome-wide association and whole exome sequencing studies have implicated a growing list of mutations and genes in PD, which are expected to provide new insights into potential pathways involved in PD pathogenicity. NRF (Natl Research Foundation, S’pore) NMRC (Natl Medical Research Council, S’pore) Accepted version

The hormone, relaxin, inhibits aberrant myofibroblast differentiation and collagen deposition by disrupting the TGF-β1/Smad2 axis, via its cognate receptor, Relaxin Family Peptide Receptor 1 (RXFP1), extracellular signal-regulated kinase (ERK)1/2 phosphorylation (pERK) and a neuronal nitric oxide (NO) synthase (nNOS)-NO-cyclic guanosine monophosphate (cGMP)-dependent pathway. However, the signalling pathways involved in its additional ability to increase matrix metalloproteinase (MMP) expression and activity remain unknown. This study investigated the extent to which the NO pathway was involved in human gene-2 (H2) relaxin's ability to positively regulate MMP-1 and its rodent orthologue, MMP-13, MMP-2 and MMP-9 (the main collagen-degrading MMPs) in TGF-β1-stimulated human dermal fibroblasts and primary renal myofibroblasts isolated from injured rats; by gelatin zymography (media) and Western blotting (cell layer). H2 relaxin (10–100 ng/ml) significantly increased MMP-1 (by ∼50%), MMP-2 (by ∼80%) and MMP-9 (by ∼80%) in TGF-β1-stimulated human dermal fibroblasts; and MMP-13 (by ∼90%), MMP-2 (by ∼130%) and MMP-9 (by ∼115%) in rat renal myofibroblasts (all p