Venom-inspired somatostatin receptor 4 (SSTR4) agonists as new drug leads for peripheral pain conditions.

Persistent pain affects one in five people worldwide, often with severely debilitating consequences. Current treatment options, which can be effective for mild or acute pain, are ill-suited for moderate-to-severe persistent pain, resulting in an urgent need for new therapeutics. In recent years, the somatostatin receptor 4 (SSTR 4 ), which is expressed in sensory neurons of the peripheral nervous system, has emerged as a promising target for pain relief. However, the presence of several closely related receptors with similar ligand-binding surfaces complicates the design of receptor-specific agonists. In this study, we report the discovery of a potent and selective SSTR 4 peptide, consomatin Fj1, derived from extensive venom gene datasets from marine cone snails. Consomatin Fj1 is a mimetic of the endogenous hormone somatostatin and contains a minimized binding motif that provides stability and drives peptide selectivity. Peripheral administration of synthetic consomatin Fj1 provided analgesia in mouse models of postoperative and neuropathic pain. Using structure-activity studies, we designed and functionally evaluated several Fj1 analogs, resulting in compounds with improved potency and selectivity. Our findings present a novel avenue for addressing persistent pain through the design of venom-inspired SSTR 4 -selective pain therapeutics. One Sentence Summary: Venom peptides from predatory marine mollusks provide new leads for treating peripheral pain conditions through a non-opioid target.

Methylation-dependent silencing at the H19 imprinting control region by MeCP2.

Methylation of CpG dinucleotides is correlated with transcriptional repression of genes, including imprinted genes. In the case of the imprinted H19 gene, a 2 kb imprinting control region (ICR) is subject to differential methylation, as it is methylated only on the silenced paternal allele. This region has previously been shown to act as a silencer element at the endogenous locus. The proteins that bind at the H19 differentially methylated domain (DMD) and mediate transcriptional silencing have yet to be identified, although a family of proteins containing a methyl-CpG-binding domain (MBD), of which MeCP2 is the best characterised, are obvious candidates. MeCP2 can bind to a single methylated CpG dinucleotide through its MBD and also contains a transcriptional repression domain (TRD). The TRD interacts with Sin3a and histone deacetylases (HDACs) in vivo, forming a repressive complex. Here we show that MeCP2 is recruited to the H19 DMD in vivo and can silence a reporter gene regulated by the H19 DMD in a methylation-dependent manner. This repression can be alleviated by deletion of the TRD from MeCP2 or by inhibition of HDAC activity. These data indicate that transcriptional silencing from the H19 ICR involves recruitment of MeCP2 and presumably an associated protein complex with deacetylase activity. This complex may also be recruited to the ICR in vivo, resulting in a compact, repressive chromatin structure capable of silencing the paternal H19 allele.

A randomised efficacy and discontinuation study of etanercept versus adalimumab (RED SEA) for rheumatoid arthritis: a pragmatic, unblinded, non-inferiority study of first TNF inhibitor use: outcomes over 2 years.

OBJECTIVE: To compare adalimumab versus etanercept in patients with active rheumatoid arthritis (RA) to test the hypothesis that adalimumab was not inferior to etanercept in terms of drug continuation by a margin of 15% after 52 weeks of treatment. DESIGN: Pragmatic, randomised, parallel group, multicentre, unblinded and non-inferiority trial. Randomisation stratified by baseline use of methotrexate. PARTICIPANTS: 125 adults with active RA despite treatment with two disease-modifying drugs (DMARDs), including methotrexate randomised (1 : 1) to adalimumab 40 mg alternate weeks or etanercept 50 mg weekly, added to existing medication. MEASUREMENTS: The primary outcome was proportion of patients continuing treatment after 52 weeks. Secondary outcomes included: disease activity score using 28 joints (DAS28), treatment satisfaction (TSQM V.2), health status (Euroqol-5D), drug toxicity and persistence with therapy after 2 years. RESULTS: Persistence with therapy was 65% for adalimumab versus 56.7% for etanercept (one-sided 95% CI for proportion still taking adalimumab minus proportion on etanercept ≥-7.9%); demonstrating non-inferiority at the 15% margin. After 2 years these figures were: adalimumab 58.3% and etanecept 43.3% (CI ≥-1.7%). The proportion of good, moderate and non-responders based on DAS28-C reactive protein, after 52 weeks, were 26.3%, 33.3% and 40.4%, respectively, for adalimumab versus 16.7%, 31.7% and 51.7%, respectively, for etanercept (p=0.158). Baseline median EQ-5D scores improved from 0.52 to 0.69 for adalimumab and from 0.52 to 0.64 for etanercept (p=0.046) after 52 weeks. Global satisfaction, effectiveness, side effects and convenience scores based on the TSQM were similar for both drugs. Fourteen serious adverse events occurred including two deaths from myocardial infarction, one patient with ovarian cancer and one with acute myeloid leukaemia. CONCLUSIONS: Clinicians choosing a first tumour necrosis factor inhibitor for active RA, despite trying two DMARDs including methotrexate, may choose either adalimumab or etanercept in the knowledge that these drugs are similarly effective. CLINICAL TRIAL REGISTRATION NUMBER: EU Clinical Trials Register 2006-006275-21/GB.