UBR5 is a Novel E3 Ubiquitin Ligase involved in Skeletal Muscle Hypertrophy and Recovery from Atrophy

We have recently identified that a HECT domain E3 ubiquitin ligase, named UBR5, was epigenetically altered (via DNA methylation) after human skeletal muscle hypertrophy, where its gene expression was positively correlated with increased lean leg mass in humans [1]. This was counterintuitive given the well-defined role of other E3 ligase family members, MuRF1 and MAFbx in muscle atrophy. Therefore, in the present study we aimed to investigate this relatively uncharacterised E3 ubiquitin ligase using multiple in-vivo and in-vitro models of skeletal muscle atrophy, injury, recovery from atrophy as well as anabolism and hypertrophy. We report for the first time, that during atrophy evoked by tetrodotoxin (TTX) nerve silencing in rats, the UBR5 promoter was significantly hypomethylated with a concomitant increase in gene expression early (3 & 7 days) after the induction of atrophy. However, at these timepoints larger increases in MuRF1/MAFbx were observed, and UBR5 expression had returned to baseline levels during later atrophy (14 days) where muscle mass loss was greatest. We confirmed an alternate gene expression profile for UBR5 versus MuRF1/MAFbx in a secondary model of atrophy induced by 7 days continuous low frequency electrical stimulation, where UBR5 demonstrated no significant increase, whereas MuRF1/MAFbx were elevated. Further, after partial (52%) recovery of muscle mass following 7 days TTX-cessation, UBR5 was hypomethylated and increased at the gene expression level, while alternately, reductions in gene expression of MuRF1 and MAFbx were observed. To substantiate these gene expression findings, we observed a significant increase in UBR5 protein abundance after full recovery (14 days) of muscle mass from hindlimb unloading (HU) in rats. Aged rats also demonstrated a similar temporal increase in UBR5 protein abundance after recovery from HU. Further, we confirmed significant increases in UBR5 protein during recovery from nerve crush injury in mice at 28 and 45 days, that related to a full recovery of muscle mass between 45-60 days. During anabolism and hypertrophy, UBR5 gene expression increased following an acute bout of mechanical loading in three-dimensional bioengineered mouse muscle in-vitro, and after chronic electrical stimulation-induced hypertrophy in rats in-vivo, without increases in MuRF1/MAFbx. Additionally, increased UBR5 protein abundance was identified following synergist ablation/functional overload (FO)-induced hypertrophy of the plantaris muscle in mice in-vivo, and finally over a 7-day time-course of regeneration in primary human muscle cells in-vitro. Finally, genetic association studies (> 700,000 SNPs) in human cohorts identified that the A alleles of rs10505025 and rs4734621 SNPs were strongly associated with larger cross-sectional area of fast-twitch muscle fibres and favoured strength/power versus endurance/untrained phenotypes. Overall, we suggest that UBR5 is a novel E3 ubiquitin ligase that is alternatively regulated compared to MuRF1/MAFbx, and is elevated during early atrophy (but not later atrophy), recovery, anabolism and hypertrophy in animals in-vivo as well as during human muscle cell regeneration in-vitro. In humans, genetic variations of the UBR5 gene are strongly associated with larger fast-twitch muscle fibres and strength/power performance

A Novel Role for DNA-PK in Metabolism by Regulating Glycolysis in Castration Resistant Prostate Cancer

Published first January 24, 2022.Purpose: DNA-dependent protein kinase catalytic subunit (DNA-PKcs, herein referred as DNA-PK) is a multifunctional kinase of high cancer relevance. DNA-PK is deregulated in multiple tumor types, including prostate cancer, and is associated with poor outcomes. DNA-PK was previously nominated as a therapeutic target and DNA-PK inhibitors are currently undergoing clinical investigation. Although DNA-PK is well studied in DNA repair and transcriptional regulation, much remains to be understood about the way by which DNA-PK drives aggressive disease phenotypes. Experimental Design: Here, unbiased proteomic and metabolomic approaches in clinically relevant tumor models uncovered a novel role of DNA-PK in metabolic regulation of cancer progression. DNA-PK regulation of metabolism was interrogated using pharmacologic and genetic perturbation using in vitro cell models, in vivo xenografts, and ex vivo in patient-derived explants (PDE). Results: Key findings reveal: (i) the first-in-field DNA-PK protein interactome; (ii) numerous DNA-PK novel partners involved in glycolysis; (iii) DNA-PK interacts with, phosphorylates (in vitro), and increases the enzymatic activity of glycolytic enzymes ALDOA and PKM2; (iv) DNA-PK drives synthesis of glucosederived pyruvate and lactate; (v) DNA-PK regulates glycolysis in vitro, in vivo, and ex vivo; and (vi) combination of DNA-PK inhibitor with glycolytic inhibitor 2-deoxyglucose leads to additive anti-proliferative effects in aggressive disease. Conclusions: Findings herein unveil novel DNA-PK partners, substrates, and function in prostate cancer. DNA-PK impacts glycolysis through direct interaction with glycolytic enzymes and modulation of enzymatic activity. These events support energy production that may contribute to generation and/or maintenance of DNA-PK–mediated aggressive disease phenotypes.Emanuela Dylgjeri, Vishal Kothari, Ayesha A. Shafi, Galina Semenova, Peter T. Gallagher, Yi F. Guan, Angel Pang, Jonathan F. Goodwin, Swati Irani, Jennifer J. McCann, Amy C. Mandigo, Saswati Chand, Christopher M. McNair, Irina Vasilevskaya, MatthewJ. Schiewer, Costas D. Lallas, Peter A. McCue, Leonard G. Gomella, Erin L. Seifert, Jason S. Carroll, Lisa M. Butler, Jeff Holst, William K. Kelly, and Karen E. Knudse

Genetic Deletion of the Nociceptin/Orphanin FQ Receptor in the Rat Confers Resilience to the Development of Drug Addiction

The nociceptin (NOP) receptor is a G-protein-coupled receptor whose natural ligand is the nociceptin/orphanin FQ (N/OFQ) peptide. Evidence from pharmacological studies suggests that the N/OFQ system is implicated in the regulation of several addiction-related phenomena, such as drug intake, withdrawal and relapse. Here, to further explore the role of NOP system in addiction, we used NOP (-/-) rats to study the motivation for cocaine, heroin and alcohol self-administration in the absence of N/OFQ function. Conditioned place preference (CPP) and saccharin (0.2% w/v) self-administration were also investigated. Results showed that NOP (-/-) rats self-administer less cocaine (0.25, 0.125 or 0.5 mg/infusion) both under a Fixed Ratio 1 and a Progressive Ratio schedule of reinforcement compared to wild type (Wt) controls. Consistently, cocaine (10 mg/kg, i.p.) was able to induce CPP in Wt but not in NOP (-/-). When NOP (-/-) rats were tested for heroin (20 μg/infusion) and ethanol (10% v/v) self-administration, they showeda significantly lower drug intake compared to Wt. Conversely, saccharin self-administration was not affected by NOP deletion, excluding the possibility of nonspecific learning deficits or generalized disruption of reward mechanisms in NOP (-/-) rats. These findings were confirmed with pharmacological experiments using two selective NOP antagonists, SB-612111 and LY2817412. Both drugs attenuated alcohol self-administration in Wt rats but not in NOP (-/-) rats. In conclusion, our results demonstrate that genetic deletion of NOP receptors confers resilience to drug abuse and support a role for NOP receptor antagonism as a potential treatment option for drug addiction.Neuropsychopharmacology accepted article preview online, 26 August 2016. doi:10.1038/npp.2016.171

The diversity-generating benefits of a prokaryotic adaptive immune system

Published onlineJOURNAL ARTICLEProkaryotic CRISPR-Cas adaptive immune systems insert spacers derived from viruses and other parasitic DNA elements into CRISPR loci to provide sequence-specific immunity. This frequently results in high within-population spacer diversity, but it is unclear if and why this is important. Here we show that, as a result of this spacer diversity, viruses can no longer evolve to overcome CRISPR-Cas by point mutation, which results in rapid virus extinction. This effect arises from synergy between spacer diversity and the high specificity of infection, which greatly increases overall population resistance. We propose that the resulting short-lived nature of CRISPR-dependent bacteria-virus coevolution has provided strong selection for the evolution of sophisticated virus-encoded anti-CRISPR mechanisms.S.v.H. has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement number 660039. E.R.W. received funding from the People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme (FP7/2007-2013) under Research Executive Agency grant agreement number 327606. E.R.W., A.B. and M.B. also acknowledge the Natural Environment Research Council, the Biotechnology and Biological Sciences Research Council, the Royal Society, the Leverhulme Trust, the Wellcome Trust and the AXA research fund for funding. J.M.B.-D. was supported by the University of California San Francisco Program for Breakthrough in Biomedical Research, the Sandler Foundation, and a National Institutes of Health Director’s Early Independence Award (DP5-OD021344). H.C. was funded by the Erasmus+ programme (European Union), the Explora’Sup programme (Région Rhône-Alpes) and the Centre Régional des Œuvres Universitaires et Scolaires (CROUS; French State)

The physiological period length of the human circadian clock in vivo is directly proportional to period in human fibroblasts.

Diurnal behavior in humans is governed by the period length of a circadian clock in the suprachiasmatic nuclei of the brain hypothalamus. Nevertheless, the cell-intrinsic mechanism of this clock is present in most cells of the body. We have shown previously that for individuals of extreme chronotype ("larks" and "owls"), clock properties measured in human fibroblasts correlated with extreme diurnal behavior

KIBRA Gene Variant Is Associated with Ability in Chess and Science

The kidney and brain expressed protein (KIBRA) plays an important role in synaptic plasticity. Carriers of the T allele of the KIBRA (WWC1) gene rs17070145 C/T polymorphism have been reported to have enhanced spatial ability and to outperform individuals with the CC genotype in working memory tasks. Since ability in chess and science is directly related to spatial ability and working memory, we hypothesized that the KIBRA T allele would be positively associated with chess player status and PhD status in science. We tested this hypothesis in a study involving 2479 individuals (194 chess players, 119 PhD degree holders in STEM fields, and 2166 controls; 1417 males and 1062 females) from three ethnicities (236 Kazakhs, 1583 Russians, 660 Tatars). We found that frequencies of the T allele were significantly higher in Kazakh (66.9 vs. 55.1%; p = 0.024), Russian (44.8 vs. 32.0%; p = 0.0027), and Tatar (51.5 vs. 41.8%; p = 0.035) chess players compared with ethnically matched controls (meta-analysis for CT/TT vs. CC: OR = 2.05, p = 0.0001). In addition, none of the international chess grandmasters (ranked among the 80 best chess players in the world) were carriers of the CC genotype (0 vs. 46.3%; OR = 16.4, p = 0.005). Furthermore, Russian and Tatar PhD holders had a significantly higher frequency of CT/TT genotypes compared with controls (meta-analysis: OR = 1.71, p = 0.009). Overall, this is the first study to provide comprehensive evidence that the rs17070145 C/T polymorphism of the KIBRA gene may be associated with ability in chess and science, with the T allele exerting a beneficial effect