Senataxin Mutation Reveals How R-Loops Promote Transcription by Blocking DNA Methylation at Gene Promoters.

R-loops are three-stranded nucleic acid structures found abundantly and yet often viewed as by-products of transcription. Studying cells from patients with a motor neuron disease (amyotrophic lateral sclerosis 4 [ALS4]) caused by a mutation in senataxin, we uncovered how R-loops promote transcription. In ALS4 patients, the senataxin mutation depletes R-loops with a consequent effect on gene expression. With fewer R-loops in ALS4 cells, the expression of BAMBI, a negative regulator of transforming growth factor ß (TGF-ß), is reduced; that then leads to the activation of the TGF-ß pathway. We uncovered that genome-wide R-loops influence promoter methylation of over 1,200 human genes. DNA methyl-transferase 1 favors binding to double-stranded DNA over R-loops. Thus, in forming R-loops, nascent RNA blocks DNA methylation and promotes further transcription. Hence, our results show that nucleic acid structures, in addition to sequences, influence the binding and activity of regulatory proteins.

Total Transperineal Laparoscopic Proctectomy for the Treatment of Crohn's Proctitis.

INTRODUCTION: Completion proctectomy is traditionally performed using a combination of abdominal and perineal approaches. Access to and exposure of the pelvis through the abdominal cavity can be limited in patients with prior surgery or inflammatory conditions. We describe a novel technique for a total transperineal approach for proctectomy for Crohn's proctitis, avoiding technical challenges, risks, and recovery associated with abdominal surgery. TECHNIQUE: We utilized the skills and expertise acquired from our experience with transanal total mesorectal excision to perform a total transperineal laparoscopic proctectomy in a male patient with medically refractory proctitis. He previously underwent an anterior resection, drainage of a chronic presacral abscess, omental pedicle flap transposition to the pelvis, and end colostomy for severe Crohn's colitis. The total transperineal laparoscopic proctectomy approach avoids the need for abdominal access, including the risks associated with abdominal entry, adhesiolysis, pelvic access and visualization, and wound-related issues. Following an initial intersphincteric perineal dissection, the GelPOINT Path minimal access platform is utilized to perform a total transperineal proctectomy. RESULTS: The patient recovered uneventfully and was discharged to home 2 days after surgery. At 1-month postoperative follow-up, the patient is recovering well with complete healing of the perineal wound. CONCLUSION: We demonstrate the feasibility, safety, and technical steps of a minimally invasive completion proctectomy for fistulizing Crohn's proctitis by using a total transperineal approach. This approach allowed us to utilize direct, inline, high-definition visualization to access and safely operate in the distal aspects of a narrow, scarred, and fibrotic pelvis while avoiding the need for any abdominal access. Advanced experience with redo pelvic and minimally invasive transanal surgery is critical. See Video at http://links.lww.com/DCR/B664.

Patient-identified impact of symptoms in spinal and bulbar muscular atrophy.

INTRODUCTION: The effects of spinal bulbar muscular atrophy (SBMA) on quality of life (QoL) are not well understood. This study describes symptoms from the patient's perspective and the impact these symptoms have on QoL. METHODS: We conducted open-ended interviews with 21 adult men with genetically confirmed SBMA. Using a qualitative framework technique, we coded and analyzed interviews to identify symptoms and resulting themes. RESULTS: From these interviews, 729 quotations were extracted. We identified 200 SBMA-specific symptoms and 20 symptomatic themes. Weakness was mentioned by all interviewees. Symptoms within the domain of mental health and the specific themes of emotional issues and psychological impact were also frequently mentioned. DISCUSSION: Numerous symptoms affect QoL for patients with SBMA. We identified previously unrecognized symptoms that are important to address in enhancing clinical care for patients with SBMA and in developing tools to evaluate efficacy in future clinical trials. Muscle Nerve 57: 40-44, 2018.

Impending Backlog of Cleft Palate Patients Due to COVID-19.

Coronavirus disease 2019 (COVID-19) has placed an unprecedented strain on healthcare systems worldwide, but while high-income countries (HICs) have been able to adapt, low- and middle-income countries (LMICs) have been much slower to do so due to a lack of funding, skilled healthcare providers, equipment, and facilities. The redistribution of resources to combat the pandemic in LMICs has resulted in decreased surgical volumes at local surgical centers as well as a dramatic reduction in the number of humanitarian aid missions. Despite recent global investment in improving the surgical capacities of LMICs, even in the pre-COVID-19 era there was a vast unmet surgical need. This deficit in surgical capacity has grown during the pandemic and it will be a significant struggle to overcome the resulting backlog of patients. A topic of particular concern to the authors is the effect that the pandemic will have on the delivery of time-sensitive surgical care to patients with cleft palate deformities as delay in providing care can have enormous physical and psychosocial consequences. This paper draws increased attention to the lasting impact that the COVID-19 pandemic may have on cleft palate patients in LMICs. SSRN Pre-print server link: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3898055.

Venous thromboembolism risk stratification in trauma using the Caprini risk assessment model.

INTRODUCTION: The Caprini risk assessment model is widely used for venous thromboembolism (VTE) but has limited data in trauma. The study objective was to determine if the Caprini risk assessment model could effectively risk stratify trauma patients. MATERIALS AND METHODS: We performed a retrospective review of trauma patients aged ≥18 years, admitted for greater than 24 h at a level one trauma center from January 1, 2018, to December 31, 2018. Demographic and clinical data were analyzed to generate Caprini scores. Multiple logistic regression assessed odds of inpatient VTE. RESULTS: A total of 1279 patients met study eligibility, with a total of 33 VTE (2.6%). When comparing those with VTE to those without, the mean age was lower (52.5 vs 59.5, p = 0.06, respectively), sex distribution was similar, but mean body mass index was higher (30.2 vs 27.4, p = 0.019, respectively). The mean Caprini score was 9.9, and 75.5% had a score >4, the traditional Caprini high-risk cutoff. The VTE group had a higher mean Injury Severity Score (17.8 vs 12.6, p = 0.011), and mean Caprini score (16.4 vs 9.8, p < 0.001). Multiple logistic regression found Caprini score, not Injury Severity Score, was associated with higher odds of VTE (adjusted odds ratio 1.06, 95% confidence interval 1.02-1.10), after adjusting for Injury Severity Score, any missed doses of VTE chemoprophylaxis, and VTE prophylaxis type. CONCLUSIONS: Higher Caprini scores are associated with elevated odds of inpatient VTE within hospitalized trauma patients. These data support using the Caprini risk assessment model in the trauma population, which may aid in risk stratification.

Nucleocytoplasmic transport defect in a North American patient with ALS8.

Amyotrophic lateral sclerosis 8 (ALS8) is a rare progressive neurodegenerative disease resulting from mutation in the gene for vesicle-associated membrane protein-associated protein B. We evaluated a North American patient using exome sequencing, and identified a P56S mutation. The disease protein had similar subcellular localization and expression levels in the patient and control fibroblasts. Patient fibroblasts showed increased basal endoplasmic reticulum stress and dysfunction of nucleocytoplasmic transport as evidenced by impaired Ran trafficking. This finding extends the identification of ALS8 into North America, and indicates a cellular defect similar to other forms of hereditary motor neuron disease.

Safety, tolerability, and preliminary efficacy of an IGF-1 mimetic in patients with spinal and bulbar muscular atrophy: a randomised, placebo-controlled trial.

BACKGROUND: Spinal and bulbar muscular atrophy is an X-linked neuromuscular disease caused by CAG repeat expansion in the androgen receptor gene. Patients with this disease have low concentrations of insulin-like growth factor-1 (IGF-1), and studies of overexpression and administration of IGF-1 showed benefit in a transgenic model; thus the IGF-1 pathway presents as a potential treatment target. We assessed safety, tolerability, and preliminary efficacy of BVS857, an IGF-1 mimetic, in patients with spinal and bulbar muscular atrophy. METHODS: In this randomised, double-blind, placebo-controlled trial, we recruited patients from neuromuscular centres in Denmark (Copenhagen), Germany (Ulm), Italy (Padova), and three sites within the USA (Bethesda, MD; Irvine, CA; and Columbus, OH). Eligible patients were 18 years or older with a confirmed genetic diagnosis of spinal and bulbar muscular atrophy, were ambulatory, had symptomatic weakness, and had serum IGF-1 concentrations of 170 ng/mL or lower. Patients were randomly assigned (2:1) to study drug or placebo by a number scheme. Patients, investigators, and study personnel were masked to treatment assignment. After a safety and tolerability assessment with eight patients, BVS857 was administered once a week (0·06 mg/kg intravenously) for 12 weeks. Primary outcome measures were safety, tolerability, and the effects of BVS857 on thigh muscle volume (TMV) measured by MRI. The ratio of TMV at day 85 to baseline was analysed with ANCOVA per protocol. Secondary outcomes of muscle strength and function were measured with the Adult Myopathy Assessment Tool, lean body mass through dual energy x-ray absorptiometry, and BVS857 pharmacokinetics. This trial was registered with ClinicalTrials.gov, NCT02024932. FINDINGS: 31 patients were assessed for eligibility, 27 of whom were randomly assigned to either BVS857 treatment (n=18) or placebo (n=9), and 24 were included in the preliminary efficacy analysis (BVS857 group, n=15; placebo group, n=9). BVS857 was generally safe with no serious adverse events. No significant differences were found in adverse events between the BVS857 and placebo groups. Immunogenicity was detected in 13 (72%) of 18 patients in the BVS857 group, including crossreacting antibodies with neutralising capacity to endogenous IGF-1 in five patients. TMV decreased from baseline to day 85 in the placebo group (-3·4% [-110 cm3]) but not in the BVS857 group (0% [2 cm3]). A significant difference in change in TMV was observed in the BVS857 group versus the placebo group (geometric-mean ratio 1·04 [90% CI 1·01-1·07]; p=0·02). There were no differences between groups in measures of muscle strength and function. INTERPRETATION: TMV remained stable in patients with spinal and bulbar muscular atrophy after being given BVS857 for 12 weeks. The intervention was associated with high incidence of immunogenicity and did not improve muscle strength or function. Additional studies might be needed to assess the efficacy of activating the IGF-1 pathway in this disease. FUNDING: Novartis Pharmaceuticals and the US National Institutes of Health.

Nonalcoholic fatty liver disease in spinal and bulbar muscular atrophy.

OBJECTIVE: To determine the prevalence and features of fatty liver disease in spinal and bulbar muscular atrophy (SBMA). METHODS: Two groups of participants with SBMA were evaluated. In the first group, 22 participants with SBMA underwent laboratory analysis and liver imaging. In the second group, 14 participants with SBMA were compared to 13 female carriers and 23 controls. Liver biopsies were done in 4 participants with SBMA. RESULTS: Evidence of fatty liver disease was detected by magnetic resonance spectroscopy in all participants with SBMA in the first group, with an average dome intrahepatic triacylglycerol of 27% (range 6%-66%, ref ≤5.5%). Liver dome magnetic resonance spectroscopy measurements were significantly increased in participants with SBMA in the second group relative to age- and sex-matched controls, with average disease and male control measurements of 17% and 3%, respectively. Liver biopsies were consistent with simple steatosis in 2 participants and nonalcoholic steatohepatitis in 2 others. CONCLUSIONS: We observed evidence of nonalcoholic liver disease in nearly all of the participants with SBMA evaluated. These observations expand the phenotypic spectrum of the disease and provide a potential biomarker that can be monitored in future studies.

IRE1α is an endogenous substrate of endoplasmic-reticulum-associated degradation.

Endoplasmic reticulum (ER)-associated degradation (ERAD) represents a principle quality control mechanism to clear misfolded proteins in the ER; however, its physiological significance and the nature of endogenous ERAD substrates remain largely unexplored. Here we discover that IRE1α, the sensor of the unfolded protein response (UPR), is a bona fide substrate of the Sel1L-Hrd1 ERAD complex. ERAD-mediated IRE1α degradation occurs under basal conditions in a BiP-dependent manner, requires both the intramembrane hydrophilic residues of IRE1α and the lectin protein OS9, and is attenuated by ER stress. ERAD deficiency causes IRE1α protein stabilization, accumulation and mild activation both in vitro and in vivo. Although enterocyte-specific Sel1L-knockout mice (Sel1L(ΔIEC)) are viable and seem normal, they are highly susceptible to experimental colitis and inflammation-associated dysbiosis, in an IRE1α-dependent but CHOP-independent manner. Hence, Sel1L-Hrd1 ERAD serves a distinct, essential function in restraint of IRE1α signalling in vivo by managing its protein turnover.

The ER-associated degradation adaptor protein Sel1L regulates LPL secretion and lipid metabolism.

Sel1L is an essential adaptor protein for the E3 ligase Hrd1 in the endoplasmic reticulum (ER)-associated degradation (ERAD), a universal quality-control system in the cell; but its physiological role remains unclear. Here we show that mice with adipocyte-specific Sel1L deficiency are resistant to diet-induced obesity and exhibit postprandial hypertriglyceridemia. Further analyses reveal that Sel1L is indispensable for the secretion of lipoprotein lipase (LPL), independent of its role in Hrd1-mediated ERAD and ER homeostasis. Sel1L physically interacts with and stabilizes the LPL maturation complex consisting of LPL and lipase maturation factor 1 (LMF1). In the absence of Sel1L, LPL is retained in the ER and forms protein aggregates, which are degraded primarily by autophagy. The Sel1L-mediated control of LPL secretion is also seen in other LPL-expressing cell types including cardiac myocytes and macrophages. Thus, our study reports a role of Sel1L in LPL secretion and systemic lipid metabolism.