Discovery of a novel and highly selective JAK3 inhibitor as a potent hair growth promoter.

JAK-STAT signalling pathway inhibitors have emerged as promising therapeutic agents for the treatment of hair loss. Among different JAK isoforms, JAK3 has become an ideal target for drug discovery because it only regulates a narrow spectrum of γc cytokines. Here, we report the discovery of MJ04, a novel and highly selective 3-pyrimidinylazaindole based JAK3 inhibitor, as a potential hair growth promoter with an IC50 of 2.03 nM. During in vivo efficacy assays, topical application of MJ04 on DHT-challenged AGA and athymic nude mice resulted in early onset of hair regrowth. Furthermore, MJ04 significantly promoted the growth of human hair follicles under ex-vivo conditions. MJ04 exhibited a reasonably good pharmacokinetic profile and demonstrated a favourable safety profile under in vivo and in vitro conditions. Taken together, we report MJ04 as a highly potent and selective JAK3 inhibitor that exhibits overall properties suitable for topical drug development and advancement to human clinical trials.

Effect of Intracanal Scaffolds on the Success Outcomes of Regenerative Endodontic Therapy - A Systematic Review and Network Meta-analysis.

INTRODUCTION: The scaffolds used in regenerative endodontic therapy (RET) provide structural support for cells so that they can adhere to the scaffolds and also are crucial for cellular proliferation and differentiation. The objective of this network meta-analysis was to compare effects of different intracanal scaffolds on success outcomes of RET. METHODS: PubMed/Medline, EMBASE, Cochrane, CINAHL, Scopus, and Web of Science databases were searched. Studies evaluating and/or comparing clinical and/or radiographic success of RET using different scaffolds with a minimum of 12 months follow-up were included. The Cochrane Collaboration risk of bias (ROB) tool and appropriate tools from Joanna Briggs Institute were used for the assessment of ROB. A network meta-analysis was performed to compare the primary outcome (clinical success) and other success outcomes (root maturation, and pulpal sensibility) using different scaffolds. RESULTS: Twenty-seven studies fulfilled the desired inclusion criteria of which 25 had a low ROB whereas 2 had a moderate ROB. Clinical success of RET using platelet-rich plasma (PRP), blood clot (BC), and platelet-rich fibrin (PRF) scaffolds ranged between 91.66%-100%, 84.61%-100%, and 77%-100% respectively. The different scaffolds did not show any statistically significant difference in clinical success (PRF vs BC [P = 1.000], PRP vs BC [P = 1.000], and PRF vs PRP [P = .999]), apical root closure (PRF vs BC [P = 1.000], PRP vs BC [P = .835], PRF vs PRP [P = .956]), and pulp sensibility (PRF vs BC [P = .980], PRP versus BC [P = .520], and PRF vs PRP [P = .990]). CONCLUSION: The intracanal scaffolds used during RET did not result in significant differences in regard to clinical success, root maturation, and pulpal sensibility.

Exploring the role of the multiple sclerosis susceptibility gene CLEC16A in T cells.

C-type lectin-like domain family 16 member A (CLEC16A) is associated with autoimmune disorders, including multiple sclerosis (MS), but its functional relevance is not completely understood. CLEC16A is expressed in several immune cells, where it affects autophagic processes and receptor expression. Recently, we reported that the risk genotype of an MS-associated single nucleotide polymorphism in CLEC16A intron 19 is associated with higher expression of CLEC16A in CD4+ T cells. Here, we show that CLEC16A expression is induced in CD4+ T cells upon T cell activation. By the use of imaging flow cytometry and confocal microscopy, we demonstrate that CLEC16A is located in Rab4a-positive recycling endosomes in Jurkat TAg T cells. CLEC16A knock-down in Jurkat cells resulted in lower cell surface expression of the T cell receptor, however, this did not have a major impact on T cell activation response in vitro in Jurkat nor in human, primary CD4+ T cells.

CRMP4 Inhibits Bone Formation by Negatively Regulating BMP and RhoA Signaling.

We identified the neuroprotein collapsing response mediator protein-4 (CRMP4) as a noncanonical osteogenic factor that regulates the differentiation of mouse bone marrow skeletal stem cells (bone marrow stromal stem cells [mBMSCs]) into osteoblastic cells. CRMP4 is the only member of the CRMP1-CRMP5 family to be expressed by mBMSCs and in osteoprogenitors of both adult mouse and human bones. In vitro gain-of-function and loss-of-function of CRMP4 in murine stromal cells revealed its inhibitory effect on osteoblast differentiation. In addition, Crmp4-deficient mice (Crmp4-/- ) displayed a 40% increase in bone mass, increased mineral apposition rate, and bone formation rate, compared to wild-type controls. Increased bone mass in Crmp4-/- mice was associated with enhanced BMP2 signaling and BMP2-induced osteoblast differentiation in Crmp4-/- osteoblasts (OBs). Furthermore, Crmp4-/- OBs exhibited enhanced activation of RhoA/focal adhesion kinase (FAK) signaling that led to cytoskeletal changes with increased cell spreading. In addition, Crmp4-/- OBs exhibited increased cell proliferation that was mediated via inhibiting cyclin-dependent kinase inhibitor 1B, p27Kip1 and upregulating cyclin D1 expression which are targets of RhoA signaling pathway. Our findings identify CRMP4 as a novel negative regulator of osteoblast differentiation. © 2016 American Society for Bone and Mineral Research.

Allelic imbalance of multiple sclerosis susceptibility genes IKZF3 and IQGAP1 in human peripheral blood.

BACKGROUND: Multiple sclerosis is a chronic inflammatory, demyelinating disease of the central nervous system. Recent genome-wide studies have revealed more than 110 single nucleotide polymorphisms as associated with susceptibility to multiple sclerosis, but their functional contribution to disease development is mostly unknown. RESULTS: Consistent allelic imbalance was observed for rs907091 in IKZF3 and rs11609 in IQGAP1, which are in strong linkage disequilibrium with the multiple sclerosis associated single nucleotide polymorphisms rs12946510 and rs8042861, respectively. Using multiple sclerosis patients and healthy controls heterozygous for rs907091 and rs11609, we showed that the multiple sclerosis risk alleles at IKZF3 and IQGAP1 are expressed at higher levels as compared to the protective allele. Furthermore, individuals homozygous for the multiple sclerosis risk allele at IQGAP1 had a significantly higher total expression of IQGAP1 compared to individuals homozygous for the protective allele. CONCLUSIONS: Our data indicate a possible regulatory role for the multiple sclerosis-associated IKZF3 and IQGAP1 variants. We suggest that such cis-acting mechanisms may contribute to the multiple sclerosis association of single nucleotide polymorphisms at IKZF3 and IQGAP1.

Multiple Sclerosis Risk Allele in CLEC16A Acts as an Expression Quantitative Trait Locus for CLEC16A and SOCS1 in CD4+ T Cells.

For multiple sclerosis, genome wide association studies and follow up studies have identified susceptibility single nucleotide polymorphisms located in or near CLEC16A at chromosome 16p13.13, encompassing among others CIITA, DEXI and SOCS1 in addition to CLEC16A. These genetic variants are located in intronic or intergenic regions and display strong linkage disequilibrium with each other, complicating the understanding of their functional contribution and the identification of the direct causal variant(s). Previous studies have shown that multiple sclerosis-associated risk variants in CLEC16A act as expression quantitative trait loci for CLEC16A itself in human pancreatic ß-cells, for DEXI and SOCS1 in thymic tissue samples, and for DEXI in monocytes and lymphoblastoid cell lines. Since T cells are major players in multiple sclerosis pathogenesis, we have performed expression analyses of the CIITA-DEXI-CLEC16A-SOCS1 gene cluster in CD4+ and CD8+ T cells isolated from multiple sclerosis patients and healthy controls. We observed a higher expression of SOCS1 and CLEC16A in CD4+ T cells in samples homozygous for the risk allele of CLEC16A rs12927355. Pair-wise linear regression analysis revealed high correlation in gene expression in peripheral T cells of CIITA, DEXI, CLEC16A and SOCS1. Our data imply a possible regulatory role for the multiple sclerosis-associated rs12927355 in CLEC16A.

Dact1-3 mRNAs exhibit distinct expression domains during tooth development.

Wnt signaling is essential for tooth formation and Dact proteins modulate Wnt signaling by binding to the intracellular protein Dishevelled (Dvl). Comparison of the three known mouse Dact genes, Dact1-3, from the morphological initiation of mandibular first molar development through the onset of root formation using section in situ hybridization showed distinct, complementary and overlapping expression patterns for these genes. Whereas Dact2 expression was restricted to the dental epithelium, including the enamel knot signaling centers and pre-ameloblasts, Dact1 and Dact3 showed developmentally regulated expression in the dental mesenchyme. Both Dact1 and Dact3 mRNAs were first detected in the presumptive dental mesenchyme. After being downregulated from the condensing dental mesenchyme of the bud stage tooth germ, Dact1 was upregulated in the dental follicle mesenchyme at the cap stage and subsequently also in the dental papilla at the bell stage, where the expression persisted to the postnatal stages. In contrast, Dact3 transcripts persisted throughout the dental mesenchyme, including the preodontoblasts, during embryogenesis before transcripts were largely downregulated from the tooth germ postnatally. Collectively, these results suggest that Dact1 and -3 may contribute to early tooth formation by modulation of Wnt signaling pathways in the mesenchyme, including preodontoblasts, whereas Dact2 may play important signal-modulating roles in the adjacent epithelial cells including the enamel knot signaling centers and pre-ameloblasts. Future loss-of-function studies will help elucidate whether any of these functions are redundant, particularly for Dact1 and Dact3.