The rockefeller university

Eukaryotic transfer RNAs can become selectively fragmented upon various stresses, generating tRNA-derived small RNA fragments. Such fragmentation has been reported to impact a small fraction of the tRNA pool and thus presumed to not directly impact translation. We report that oxidative stress can rapidly generate tyrosine-tRNA(GUA) fragments in human cells-causing significant depletion of the precursor tRNA. Tyrosine-tRNA(GUA) depletion impaired translation of growth and metabolic genes enriched in cognate tyrosine codons. Depletion of tyrosine tRNA(GUA) or its translationally regulated targets USP3 and SCD repressed proliferation-revealing a dedicated tRNA-regulated growth-suppressive pathway for oxidative stress response. Tyrosine fragments are generated in a DIS3L2 exoribonuclease-dependent manner and inhibit hnRNPA1-mediated transcript destabilization. Moreover, tyrosine fragmentation is conserved in C. elegans. Thus, tRNA fragmentation can coordinately generate trans-acting small RNAs and functionally deplete a tRNA. Our findings reveal the existence of an underlying adaptive codon-based regulatory response inherent to the genetic code.

Objective: Increasing muscle mass and activating beige fat both have great potential for ameliorating obesity and its comorbidities. Myostatin null mice have increased skeletal muscle mass and are protected from obesity and its sequelae. Deletion of myostatin has also been suggested to result in the activation of beige adipocytes, thermogenic fat cells with anti-obesity and anti-diabetes properties. It is not known whether beige fat activation contributes to the protection from obesity in myostatin null mice. Methods: To investigate the role of beige fat activation in the metabolic benefits associated with myostatin deletion, we crossed myostatin null mice to adipocyte-specific PRDM16 knockout mice. We analyzed this new mouse model using molecular profiling, whole mount threedimensional tissue imaging, tissue respiration, and glucose and insulin tolerance tests in models of diet-induced obesity. Results: Here, we report that PRDM16 is required for the activation of beige fat in the absence of myostatin. However, we show in both male and female mice that beige fat activation is dispensable for the protection from obesity, glucose intolerance, insulin resistance, and hepatic steatosis mediated by myostatin deletion. Conclusion: These findings demonstrate that increasing muscle mass can compensate for the inactivation of beige fat and raise the possibility of targeting muscle mass as a therapeutic approach to offset the deleterious effects of adipose tissue dysfunction in obesity and metabolic syndrome. (C) 2020 The Authors. Published by Elsevier GmbH.

Purpose Germline heterozygous mutations of GATA2 underlie a variety of hematological and clinical phenotypes. The genetic, immunological, and clinical features of GATA2-deficient patients with mycobacterial diseases in the familial context remain largely unknown. Methods We enrolled 15 GATA2 index cases referred for mycobacterial disease. We describe their genetic and clinical features including their relatives. Results We identified 12 heterozygous GATA2 mutations, two of which had not been reported. Eight of these mutations were loss-of-function, and four were hypomorphic. None was dominant-negative in vitro, and the GATA2 locus was found to be subject to purifying selection, strongly suggesting a mechanism of haploinsufficiency. Three relatives of index cases had mycobacterial disease and were also heterozygous, resulting in 18 patients in total. Mycobacterial infection was the first clinical manifestation in 11 patients, at a mean age of 22.5 years (range: 12 to 42 years). Most patients also suffered from other infections, monocytopenia, or myelodysplasia. Strikingly, the clinical penetrance was incomplete (32.9% by age 40 years), as 16 heterozygous relatives aged between 6 and 78 years, including 4 older than 60 years, were completely asymptomatic. Conclusion Clinical penetrance for mycobacterial disease was found to be similar to other GATA2 deficiency-related manifestations. These observations suggest that other mechanisms contribute to the phenotypic expression of GATA2 deficiency. A diagnosis of autosomal dominant GATA2 deficiency should be considered in patients with mycobacterial infections and/or other GATA2 deficiency-related phenotypes at any age in life. Moreover, all direct relatives should be genotyped at the GATA2 locus.

New World species of the intracellular protozoan parasites of the Leishmania genus can cause mucocutaneous leishmaniases. The presence of an endosymbiotic Leishmania RNA virus (LRV) in Leishmania guyanensis (L.g.) promotes disease exacerbation and the development of mucocutaneous disease. It was previously reported that LRV blocks the NLRP3 inflammasome, but additional mechanisms remain unclear. Here, we investigated whether LRV interferes with the inflammasome via caspase-11, which induces non-canonical NLRP3 activation and was reported to be activated by Leishmania. By using macrophages and mice, we found that LRV inhibits caspase-11 activation and IL-1 beta release by L.g. in a TLR3- and ATG5-dependent manner. Moreover, LRV exacerbates disease in C57BL/6 mice but not in Casp11(-/-), Nlrp3(-/-), and 129 mice, a mouse strain that is naturally mutant for caspase-11. These results demonstrate that LRV interferes with caspase-11 activation by Leishmania, expanding our understanding about the mechanisms by which LRV promotes disease exacerbation.

Background Conjunctivitis is a known comorbidity of atopic dermatitis. Dupilumab clinical trials for moderate-to-severe atopic dermatitis in adults showed a higher conjunctivitis incidence for dupilumab-treated patients than placebo-treated patients, whereas trials for uncontrolled asthma reported lower rates for both dupilumab and placebo. Objective The objective of this study was to evaluate the incidence and severity of conjunctivitis in dupilumab clinical trials in adolescents with moderate-to-severe atopic dermatitis or uncontrolled asthma. Methods We evaluated the incidence of conjunctivitis in adolescents (aged 12 to < 18 years) in three phase III trials. Ocular events were diagnosed and treated based on patient-reported symptoms and an external eye examination by study investigators, in most cases without an ophthalmologic referral. In LIBERTY AD ADOL (16-week, randomized, placebo-controlled, double-blinded trial), adolescents with moderate-to-severe atopic dermatitis were randomized to subcutaneous placebo, dupilumab 300 mg every 4 weeks, or dupilumab every 2 weeks (200 mg, patients < 60 kg at baseline; 300 mg, >= 60 kg at baseline). In LIBERTY AD PED-OLE (open-label extension), pediatric patients from previous dupilumab atopic dermatitis trials received dupilumab 2 mg/kg or 4 mg/kg weekly (up to 300 mg) or 300 mg every 4 weeks. In LIBERTY ASTHMA QUEST (randomized, double-blinded, placebo-controlled trial), patients with uncontrolled moderate-to-severe asthma were randomized to 52 weeks of add-on therapy with dupilumab 200 or 300 mg every 2 weeks or matched-volume placebo. Results In ADOL, more dupilumab-treated (17/165; 10.3%) than placebo-treated patients (4/85; 4.7%) reported one or more conjunctivitis event. All events were mild to moderate in severity; 12 (7.3%) dupilumab-treated and 4 (4.7%) placebo-treated patients received treatment. Most patients with conjunctivitis (dupilumab, 12/17; placebo, 4/4) recovered/resolved during the treatment period. The risk of conjunctivitis showed no relationship with dupilumab serum concentration. In PED-OLE, 12/275 adolescents (4.4%) reported one or more conjunctivitis event. Most conjunctivitis events were mild to moderate. Ten patients received treatment for conjunctivitis. Ten patients recovered/resolved during the study. In QUEST, similar low proportions of dupilumab-treated (2/68, 2.9%) and placebo-treated (1/39, 2.6%) adolescents reported one or more conjunctivitis event. All events were mild to moderate. One dupilumab-treated patient received treatment for conjunctivitis. All cases recovered/resolved during the study. No patients in these trials discontinued study treatment temporarily or permanently because of conjunctivitis. In ADOL, one case of unspecified viral keratitis (specific viral etiology not known) in the dupilumab 300-mg every 4 weeks group and one case of allergic blepharitis in the placebo group were reported; both events resolved during the treatment period, and neither led to treatment discontinuation. Conclusions Dupilumab-treated adolescents in atopic dermatitis trials had a higher incidence of conjunctivitis than placebo-treated patients, whereas overall rates of conjunctivitis among adolescents in the asthma trial were lower than in atopic dermatitis trials and were similar for dupilumab- and placebo-treated patients. Most events were mild to moderate, most recovered/resolved, and none prompted study withdrawal. These results are similar to those reported in adult trials and support a drug-disease interaction. ClinicalTrials.gov Identifiers NCT03054428, NCT02612454, NCT02414854.

Cell fate determination requires faithful execution of gene expression programs, which are increasingly recognized to respond to metabolic inputs. In particular, the family of alpha-ketoglutarate (alpha KG)-dependent dioxygenases, which include several chromatin-modifying enzymes, are emerging as key mediators of metabolic control of cell fate. alpha KG-dependent dioxygenases consume the metabolite alpha KG (also known as 2-oxoglutarate) as an obligate cosubstrate and are inhibited by succinate, fumarate, and 2-hydroxyglutarate. Here, we review the role of these metabolites in the control of dioxygenase activity and cell fate programs. We discuss the biochemical and transcriptional mechanisms enabling these metabolites to control cell fate and review evidence that nutrient availability shapes tissue-specific fate programs via alpha KG-dependent dioxygenases.

The Niemann-Pick disease is an autosomal recessive lysosomal storage disorder caused by the lack or decreased activity of the acid sphingomyelinase enzyme or a deficiency of the Niemann-Pick C intracellular cholesterol transporter protein. As a result of the defect, sphingomyelin and cholesterol accumulate in the lysosomes of the cells. The most common presentation symptom of the disease is abdominal protrusion due to hepatosplenomegaly. The most severe symptoms are the consequences of progressive neurodegeneration. Genetic testing is essential to confirm the diagnosis, which also allows for prenatal genetic testing in the affected families. Early detection of the disease is extremely important as therapeutic options are expanding. Thanks to substrate reduction and enzyme replacement therapies, hepatosplenomegaly can be reduced, and progression of neurological symptoms can be reversed. Through two case reports, the author presents the main types, clinical manifestations, and molecular genetic background of this rare metabolic disorder. The author describes the diagnostic and therapeutic approaches to Niemann-Pick disease.

Hidradenitis suppurativa (HS) is a chronic and often debilitating inflammatory condition characterized by frequent nodules, abscesses, sinus tracts, and scars impacting the intertriginous areas. Many patients with HS often report limited treatment success and symptom coverage with conventional therapies. Recent studies have reported the widespread use of complementary and alternative medicine (CAM) among patients with HS. In this study, our aim was to examine current physician practice patterns, opinions, and comfort with recommending CAM. Our results indicate that provider comfort and opinions on CAM varied based on the provider's experiences, demographics, and the CAM modality itself. Overall, nearly two-thirds (n = 30, 61.2%) of respondents agreed that CAM and conventional medicine were more effective together than either alone. Meanwhile, 44.9% (n = 22) of respondents routinely recommend CAM while 64.6% (n = 31) of respondents reported that they are routinely asked about CAM. The majority (n = 41, 83.7%) of respondents indicated a lack of scientific evidence in the medical literature as a barrier to recommending CAM along with efficacy concerns (n = 34, 69.4%) and ability to recommend reputable CAM products (n = 32, 65.3%) and practitioners (n = 32, 65.3%). Future investigations are warranted to establish a better understanding of the efficacy and benefit of CAM methods in conjunction with conventional methods.