The psychosis risk factor RBM12 encodes a novel repressor of GPCR/cAMP signal transduction.

RBM12 is a high-penetrance risk factor for familial schizophrenia and psychosis, yet its precise cellular functions and the pathways to which it belongs are not known. We utilize two complementary models, HEK293 cells and human iPSC-derived neurons, and delineate RBM12 as a novel repressor of the G protein-coupled receptor/cAMP/PKA (GPCR/cAMP/PKA) signaling axis. We establish that loss of RBM12 leads to hyperactive cAMP production and increased PKA activity as well as altered neuronal transcriptional responses to GPCR stimulation. Notably, the cAMP and transcriptional signaling steps are subject to discrete RBM12-dependent regulation. We further demonstrate that the two RBM12 truncating variants linked to familial psychosis impact this interplay, as the mutants fail to rescue GPCR/cAMP signaling hyperactivity in cells depleted of RBM12. Lastly, we present a mechanism underlying the impaired signaling phenotypes. In agreement with its activity as an RNA-binding protein, loss of RBM12 leads to altered gene expression, including that of multiple effectors of established significance within the receptor pathway. Specifically, the abundance of adenylyl cyclases, phosphodiesterase isoforms, and PKA regulatory and catalytic subunits is impacted by RBM12 depletion. We note that these expression changes are fully consistent with the entire gamut of hyperactive signaling outputs. In summary, the current study identifies a previously unappreciated role for RBM12 in the context of the GPCR-cAMP pathway that could be explored further as a tentative molecular mechanism underlying the functions of this factor in neuronal physiology and pathophysiology.

The psychosis risk factor RBM12 encodes a novel repressor of GPCR/cAMP signal transduction.

RBM12 is a high-penetrance risk factor for familial schizophrenia and psychosis, yet its precise cellular functions and the pathways to which it belongs are not known. We utilize two complementary models, HEK293 cells and human iPSC-derived neurons, and delineate RBM12 as a novel repressor of the G protein-coupled receptor/cyclic AMP/protein kinase A (GPCR/cAMP/PKA) signaling axis. We establish that loss of RBM12 leads to hyperactive cAMP production and increased PKA activity as well as altered neuronal transcriptional responses to GPCR stimulation. Notably, the cAMP and transcriptional signaling steps are subject to discrete RBM12-dependent regulation. We further demonstrate that the two RBM12 truncating variants linked to familial psychosis impact this interplay, as the mutants fail to rescue GPCR/cAMP signaling hyperactivity in cells depleted of RBM12. Lastly, we present a mechanism underlying the impaired signaling phenotypes. In agreement with its activity as an RNA-binding protein, loss of RBM12 leads to altered gene expression, including that of multiple effectors of established significance within the receptor pathway. Specifically, the abundance of adenylyl cyclases, phosphodiesterase isoforms, and PKA regulatory and catalytic subunits is impacted by RBM12 depletion. We note that these expression changes are fully consistent with the entire gamut of hyperactive signaling outputs. In summary, the current study identifies a previously unappreciated role for RBM12 in the context of the GPCR/cAMP pathway that could be explored further as a tentative molecular mechanism underlying the functions of this factor in neuronal physiology and pathophysiology.

Does laparoscopic reoperation yield symptomatic improvements similar to those of primary laparoscopic Heller myotomy in achalasia patients?

BACKGROUND: Laparoscopic Heller myotomy fails in approximately 3.5% to 15% of patients. Evidence of successful laparoscopic reoperation is limited to a few studies. METHODS: This case-control study was conducted in patients who underwent laparoscopic Heller myotomy reoperation (LHM-R) from 2008 to 2016. The operative outcomes, preoperative and last follow-up manometric parameters, and symptom questionnaire results, including the Eckardt, Gastroesophageal Reflux Disease-Health Related Quality of Life (GERD-HRQL) and eating assessment tool (EAT-10) scores, were obtained. The data were compared with those of patients who underwent primary laparoscopic Heller myotomy (LHM-1). RESULTS: Thirty-five patients who underwent LHM-R and 35 patients who underwent LHM-1 were included. The reasons for failure in the LHM-R patient group included incomplete myotomy (71.4%), myotomy fibrosis (25.7%) and structural alterations in fundoplication (2.9%). The follow-up duration was 34 months for the LHM-R group and 24 months for the LHM-1 group (p = 0.557). The procedure was performed by laparoscopy in 100% of the patients in the two groups. No differences were found regarding surgical morbidity (11.4% LHM-R vs. 2.9% LHM-1, p = 0.164). The symptomatic outcomes were equivalent between groups (Eckardt p = 0.063, EAT-10 p = 0.166, GERD-HRQL p = 0.075). An IRP < 15 mmHg was achieved in 100% of the LHM-R and LHM-1 patients. At the last follow-up, 82.1% of the LHM-R patients and 91.4% of the LHM-1 patients were in symptomatic remission (p = 0.271). CONCLUSION: The results achieved with LHM-R are similar to those achieved with LHM-1. Laparoscopic reoperation should be considered an effective and safe treatment after a failed Heller myotomy.

Esophagogastric junction outflow obstruction: Characterization of a new entity? Clinical, manometric, and neuroimmunological description.

OBJECTIVE: To determine the differences between clinical, manometric, and neuroimmunological profile of esophagogastric junction outflow obstruction (EGJOO) and achalasia patients. METHODS: Seven EGJOO and 27 achalasia patients were enrolled in a blind cross-sectional study. Peripheral blood (PB) of 10 healthy donors and 10 lower esophageal sphincter (LES) muscle biopsies from organ transplant donors were included as controls. The presence of ganglion cells, cells of Cajal, Th22/Th7/Th2/Th1/Tregs/Bregs/pDCregs in tissue, and PB was assessed by immunohistochemistry and flow cytometry. Serum concentration of IL-22/IL-17A/IL-17F/IL-4/IFN-γ/IL-1ß/IL-6/IL-23/IL-33/TNF-α/IL-10 was determined using bioplex plates. ANAs and antineuronal antibodies were evaluated by immunofluorescence and Western blot. KEY RESULTS: EGJOO and achalasia patients had lower ganglion cells and cells of Cajal percentage vs. controls, while fibrosis was present only in achalasia patients. EGJOO and controls had lower cell percentage of Th22/Th17/Th2 vs. achalasia. EGJOO tissue had lower Th1/Treg cell number vs. achalasia, but higher levels vs. control group. Bregs and pDCregs percentage was higher in EGJOO vs. control group. Percentage of PB subpopulations in EGJOO was not significantly different from control group. Serum cytokine levels were higher for IL-1ß/IL-6/TNF-α, while IL-17A levels were lower in EGJOO vs. achalasia and control group. EGJOO group was negative for ANAs, while in achalasia group, 54% were positive. GAD65 and PNMa/Ta2 antibodies were present in achalasia, whereas Yo and recoverin were positive in EGJOO group. CONCLUSIONS AND INFERENCES: Although EGJOO shares some clinical characteristics with achalasia, the neuroimmunological profile is completely different, suggesting that EGJOO might be a different entity.

Dor Vs Toupet Fundoplication After Laparoscopic Heller Myotomy: Long-Term Randomized Controlled Trial Evaluated by High-Resolution Manometry.

BACKGROUND: Laparoscopic Heller myotomy (LHM) with partial fundoplication is an effective treatment for achalasia. However, the type of fundoplication is still a subject of debate. AIM: The aim of the study is to identify which partial fundoplication leads to better control of acid exposure, manometric parameters, and symptoms scores. METHODS: A randomized controlled trial was performed to compare Dor vs Toupet fundoplication after LHM. The preoperative diagnosis was made by high-resolution manometry (HRM), upper endoscopy, and barium esophagogram. Preoperative and postoperative symptoms were evaluated with Eckardt, GERD-HRQL, and EAT-10 questionnaires. RESULTS: Seventy-three patients were randomized, 38 underwent Dor and 35 Toupet. Baseline characteristics were similar between groups. Postoperative HRM showed that the integrated relaxation pressure (IRP) and basal lower esophageal sphincter (LES) pressure were similar at 6 and 24 months. The number of patients with abnormal acid exposure was significantly lower for Dor (6.9%) than that of Toupet (34.0%) at 6 months, but it was not different at 12 or 24 months. No differences were found in postoperative symptom scores at 1, 6, or 24 months. CONCLUSION: There were no differences in symptom scores or HRM between fundoplications in the long term. A higher percentage of abnormal 24-h pH test were found for the Toupet group, with no difference in the long term.