KLHL1 Controls CaV3.2 Expression in DRG Neurons and Mechanical Sensitivity to Pain

Dorsal root ganglion (DRG) neurons process pain signaling through specialized nociceptors located in their peripheral endings. It has long been established low voltage-activated (LVA) CaV3.2 calcium channels control neuronal excitability during sensory perception in these neurons. Silencing CaV3.2 activity with antisense RNA or genetic ablation results in anti-nociceptive, anti-hyperalgesic and anti-allodynic effects. CaV3.2 channels are regulated by many proteins (Weiss and Zamponi, 2017), including KLHL1, a neuronal actin-binding protein that stabilizes channel activity by recycling it back to the plasma membrane through the recycling endosome. We explored whether manipulation of KLHL1 levels and thereby function as a CaV3.2 modifier can modulate DRG excitability and mechanical pain transmission or sensitivity to pain. We first assessed the mechanical sensitivity threshold and DRG properties in the KLHL1 KO mouse model. KO DRG neurons exhibited smaller T-type current density compared to WT without significant changes in voltage dependence, as expected in the absence of its modulator. Western blot analysis confirmed CaV3.2 but not CaV3.1, CaV3.3, CaV2.1, or CaV2.2 protein levels were significantly decreased; and reduced neuron excitability and decreased pain sensitivity were also found in the KLHL1 KO model. Analogously, transient down-regulation of KLHL1 levels in WT mice with viral delivery of anti-KLHL1 shRNA also resulted in decreased pain sensitivity. These two experimental approaches confirm KLHL1 as a physiological modulator of excitability and pain sensitivity, providing a novel target to control peripheral pain.Fil: Martínez Hernández, Elizabeth. Loyola University Chicago; Estados UnidosFil: Zeglin, Alissa. Loyola University Chicago; Estados UnidosFil: Almazan, Erik. Loyola University Chicago; Estados UnidosFil: Perissinotti, Paula Patricia. Loyola University Chicago; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: He, Yungui. University of Minnesota; Estados UnidosFil: Koob, Michael. University of Minnesota; Estados UnidosFil: Martin, Jody L.. Loyola University Chicago; Estados UnidosFil: Piedras-Rentería, Erika S.. Loyola University Chicago; Estados Unido

Epidemiology and Comorbidities of Excoriation Disorder: A Retrospective Case-Control Study

Excoriation disorder is a psychocutaneous disorder characterized by repetitive skin-picking and associated with significant morbidity. Currently, epidemiological data in patients with excoriation disorder are lacking so we sought to characterize common patient demographics and comorbidities. We conducted a retrospective case-control study comparing 250 patients with excoriation disorder with 250 age-, race- and sex-matched controls identified between 2007 and 2019 at a single tertiary care center. We found that the majority of excoriation disorder patients were female (76%), Caucasian (82%) and unmarried (62%), with a mean age of 49 years. Compared to the matched controls, patients with excoriation disorder had increased odds of several psychiatric illnesses, including obsessive compulsive disorder (odds ratio (OR) 28.48, 95% confidence interval (CI): 1.68, 481.75), substance use disorder (OR 24.33, 95% CI: 5.81, 101.77), post-traumatic stress disorder (OR 8.23, 95% CI: 2.24, 129.40), depression (OR 8.19, 95% CI: 4.86, 13.80), bipolar disorder (OR 7.55, 95% CI: 2.22, 25.65), attention-deficit/hyperactivity disorder (OR 5.63, 95% CI: 1.62, 19.57), and anxiety (OR 5.01, 95% CI: 2.92, 8.62). Only a minority (42%) of patients were given psychiatry referrals and of those referred, a majority (64%) did not follow-up with psychiatry. The outcomes were also generally unfavorable as only 21% of patients experienced a resolution or improvement in their symptoms. This highlights the need for a multidisciplinary approach to manage patients with excoriation disorder, involving both dermatologists and psychiatrists

Lymphocytic and collagenous colitis in children and adolescents: Comprehensive clinicopathologic analysis with long-term follow-up

Microscopic colitis (MC) is characterized by chronic watery diarrhea, endoscopically normal findings, and abnormal histology. While mostly encountered in adults, pediatric cases are rare and may show varying presentations. Our pathology data system was searched from 1984 to 2019 for patients ≤18 years of age with a lymphocytic colitis (LC) or collagenous colitis (CC) pattern of injury. Twenty-seven cases (23 LC and 4 CC) were retrieved. LC was more prevalent than CC (85% vs 15%, respectively) and affected slightly younger individuals (mean, 9.8 years versus 12.25 years). Immune dysregulation was documented in 11 (41%) patients. Most patients presented with watery diarrhea (n = 26, 96%) and either abdominal pain (n = 18, 67%), nausea/vomiting (n = 5, 19%), flatulence (n = 6, 22%), and/or weight loss (n = 1, 4%). A subset of patients (n = 10, 37%) demonstrated endoscopic abnormalities. Histologically, some patients with LC and CC displayed focal cryptitis or crypt abscess formation (n = 7, 26%) and focally increased crypt apoptosis (n = 9, 33%) in the absence of chronic injury. Clinical follow-up data were available for 23 (85%) patients with variable clinical responses recorded. Only 8 patients experienced complete symptom resolution. Twelve patients (11 LC and 1 CC) had subsequent biopsy material; of which, one developed histologic features of inflammatory bowel disease and another was found to have a CTLA-4 deficiency. Our study shows that pediatric patients with MC may have atypical clinical, histologic, and endoscopic findings and variable clinical responses. Underlying inflammatory and/or genetic conditions may be eventually unmasked, and genetic testing may be helpful in a small subset of patients

Gene silencing of the tick protective antigens, Bm86, Bm91 and subolesin, in the one-host tick Boophilus microplus by RNA interference

The use of RNA interference (RNAi) to assess gene function has been demonstrated in several three-host tick species but adaptation of RNAi to the one-host tick, Boophilus microplus, has not been reported. We evaluated the application of RNAi in B. microplus and the effect of gene silencing on three tick-protective antigens: Bm86, Bm91 and subolesin. Gene-specific double-stranded (dsRNA) was injected into two tick stages, freshly molted unfed and engorged females, and specific gene silencing was confirmed by real time PCR. Gene silencing occurred in injected unfed females after they were allowed to feed. Injection of dsRNA into engorged females caused gene silencing in the subsequently oviposited eggs and larvae that hatched from these eggs, but not in adults that developed from these larvae. dsRNA injected into engorged females could be detected by quantitative real-time RT-PCR in eggs 14 days from the beginning of oviposition, demonstrating that unprocessed dsRNA was incorporated in the eggs. Eggs produced by engorged females injected with subolesin dsRNA were abnormal, suggesting that subolesin may play a role in embryonic development. The injection of dsRNA into engorged females to obtain gene-specific silencing in eggs and larvae is a novel method which can be used to study gene function in tick embryogenesis

High Coronary Artery Calcium Score Is Associated With Increased Major Adverse Cardiac Events After Liver Transplantation

Background. Liver transplantation (LT) candidates frequently have multiple cardiovascular risk factors, and cardiovascular disease is a major cause of morbidity and mortality after LT. Coronary artery calcium (CAC) scores are a noninvasive assessment of coronary artery disease using computed tomography. This study examines CAC scores and cardiac risk factors and their association with outcomes after LT. Methods. Patients who underwent LT between January 2010 and June 2019 with a pretransplant CAC score were included in this study. Patients were divided by CAC score into 4 groups (CAC score 0, CAC score 1–100, CAC score 101–400, CAC score >400). Major adverse cardiovascular events (MACEs) were defined as myocardial infarction, stroke, revascularization, heart failure, atrial fibrillation, and cardiovascular death. Associations between CAC score and MACE or all-cause mortality within the 5-y post-LT follow-up period were analyzed using Cox regression. Statistical significance was defined as P < 0.05. Results. During the study period, 773 adult patients underwent their first LT, and 227 patients met our study criteria. The median follow-up time was 3.4 (interquartile range 1.9, 5.3) y. After 5 y, death occurred in 47 patients (20.7%) and MACE in 47 patients (20.7%). In multivariable analysis, there was no difference in death between CAC score groups. There was significantly higher risk of MACE in the CAC score >400 group, with a hazard ratio 2.58 (95% confidence interval 1.05, 6.29). Conclusions. CAC score was not associated with all-cause mortality. Patients with CAC score >400 had an increase in MACEs within the 5-y follow-up period compared with patients with a CAC score = 0. Further research with larger cohorts is needed to examine cardiac risk stratification in this vulnerable patient population