Weekly treatment with SAMiRNA targeting the androgen receptor ameliorates androgenetic alopecia.

Androgenetic alopecia (AGA) is the most common type of hair loss in men and women. Dihydrotestosterone (DHT) and androgen receptor (AR) levels are increased in patients with AGA, and DHT-AR signaling correlates strongly with AGA pathogenesis. In this study, treatment with self-assembled micelle inhibitory RNA (SAMiRNA) nanoparticle-type siRNA selectively suppressed AR expression in vitro. Clinical studies with application of SAMiRNA to the scalp and massaging to deliver it to the hair follicle confirmed its efficacy in AGA. For identification of a potent SAMiRNA for AR silencing, 547 SAMiRNA candidates were synthesized and screened. SAMiRNA-AR68 (AR68) was the most potent and could be efficiently delivered to human follicle dermal papilla cells (HFDPCs) and hair follicles, and this treatment decreased the AR mRNA and protein levels. We confirmed that 10 µM AR68 elicits no innate immune response in human PBMCs and no cytotoxicity up to 20 µM with HFDP and HaCaT cells. Clinical studies were performed in a randomized and double-blind manner with two different doses and frequencies. In the low-dose (0.5 mg/ml) clinical study, AR68 was applied three times per week for 24 weeks, and through quantitative analysis using a phototrichogram, we confirmed increases in total hair counts. In the high-dose (5 mg/ml) clinical study, AR68 was given once per week for 24 weeks and showed 83% efficacy in increasing hair counts compared with finasteride. No side effects were observed. Therefore, SAMiRNA targeting AR mRNA is a potential novel topical treatment for AGA.

Glatiramer acetate attenuates the activation of CD4+ T cells by modulating STAT1 and -3 signaling in glia.

Interactions between immune effector cells of the central nervous system appear to directly or indirectly influence the progress/regression of multiple sclerosis (MS). Here, we report that glial STAT1 and -3 are distinctively phosphorylated following the interaction of activated lymphocytes and glia, and this effect is significantly inhibited by glatiramer acetate (GA), a disease-modifying drug for MS. GA also reduces the activations of STAT1 and -3 by MS-associated stimuli such as IFNγ or LPS in primary glia, but not neurons. Experiments in IFNγ- and IFNγ receptor-deficient mice revealed that GA-induced inhibitions of STAT signaling are independent of IFNγ and its receptor. Interestingly, GA induces the expression levels of suppressor of cytokine signaling-1 and -3, representative negative regulators of STAT signaling in glia. We further found that GA attenuates the LPS-triggered enhancement of IL-2, a highly produced cytokine in patients with active MS, in CD4+ T cells co-cultured with glia, but not in CD4+ T cells alone. Collectively, these results provide that activation of glial STATs is an essential event in the interaction between glia and T cells, which is a possible underlying mechanism of GA action in MS. These findings provide an insight for the development of targeted therapies against MS.