The Long Non-Coding RNA NR3C2-8:1 Promotes p53-Mediated Apoptosis through the miR-129-5p/USP10 Axis in Amyotrophic Lateral Sclerosis.

Motor neuron degeneration in amyotrophic lateral sclerosis (ALS) is a form of apoptosis, but the mechanisms underlying this neuronal cell death remain unclear. Numerous studies demonstrate abnormally elevated and active p53 in the central nervous system of ALS patients. Activation of p53-regulated pro-apoptotic signaling pathways may trigger motor neuron death. We previously reported decreased expression of the long non-coding RNA NR3C2-8:1 (Lnc-NR3C) in leukocytes of ALS patients. Here, we show lnc-NR3C promotes p53-mediated cell death in ALS by upregulating USP10 and promoting lnc-NR3C-triggered p53 activation, resulting in cell death. Conversely, lnc-NR3C knockdown inhibited USP10-triggered p53 activation, thereby protecting cells against oxidative stress. As a competitive endogenous RNA, lnc-NR3C competitively binds miR-129-5p, regulating the usp10/p53 axis. Elucidating the link between Lnc-NR3C and the USP10/p53 axis in an ALS cell model reveals a role for long non-coding RNAs in activating apoptosis. This provides new therapeutic opportunities in ALS.

Generation of induced pluripotent stem cell line LNDWCHi001-A from a patient with early-onset Parkinson's disease carrying the homozygous c.1898C > T (p. A633V) mutation in the PLA2G6 gene.

A variant of the phospholipase A2 group VI gene (PLA2G6, PARK14) has been found to cause early-onset Parkinson's disease (EOPD). In this study, we reprogrammed peripheral blood mononuclear cells from a 39-year-old patient with EOPD carrying a homozygous PLA2G6 mutation c.1898C > T (p. A633V) to generate the human induced pluripotent stem cell line LNDWCHi001-A. This cell line was identified based on pluripotent markers and displayed differentiation capacity, providing an essential model for studying the pathogenesis of EOPD and drug screening.

Reduced mitochondrial-encoded NADH dehydrogenase 6 gene expression drives inflammatory CD4+T cells in patients with systemic lupus erythematosus.

Abnormal mitochondrial function has been implicated in the progression of systemic lupus erythematosus (SLE), the prototypical autoimmune disease, yet the underlying cause remains unclear. In this study, mitochondrial-encoded NADH dehydrogenase 6 gene (MT-ND6) was identified as having increased m6A methylation and decreased expression in peripheral blood mononuclear cells of SLE patients by MeRIP-seq analysis. MT-ND6 expression was negatively correlated with SLE disease activity index score and 24-h urine protein level, and lower in patients with positive anti-Sm or anti-dsDNA antibodies. With the reduction of MT-ND6 levels, CD4+ T cells in SLE patients exhibited mitochondrial dysfunction, as evidenced by increased levels of reactive oxygen species (ROS) and mitochondrial ROS and insufficient ATP production. Accordingly, in vitro MT-ND6 silencing induced abnormalities in the above mitochondrial indicators in CD4+ T cells, and promoted the development of both transcription and inflammatory factors in these cells. In contrast, treatment with targeted mitochondrial antioxidants largely counteracted the silencing effect of MT-MD6. Thus, reduced MT-ND6 in SLE patients may lead to mitochondrial dysfunction through ROS overproduction, thereby promoting inflammatory CD4+ T cells.

Integrative analysis defines DDIT3 amplification as a correlative and essential factor for glioma malignancy.

Glioma, particularly glioblastoma multiforme (GBM), is a highly aggressive and lethal primary brain tumor with poor prognosis. Metabolic reprogramming and endoplasmic reticulum (ER) stress are two crucial factors contributing to glioma pathogenesis. However, the intricate coordination between these processes remains incompletely understood. Here, we conducted an integrative analysis to elucidate the nodal role of DNA Damage Inducible Transcript 3 (DDIT3) to couple metabolisms and stress responses in glioma. We demonstrated a positive association between DDIT3 amplification/enhanced expression with glioma malignancy, indicating its potential as a novel biomarker for prognosis and treatment stratification. Genomic and transcriptomic analyses further revealed the involvement of DDIT3 enhancement in glioma progression. Moreover, immune infiltration analysis showed that distinct DDIT3 expression groups had different immune microenvironment. Finally, in vitro validations confirmed the impact of DDIT3 on proliferation and migration of glioma cells. Our findings provide novel insights into the complex interplay between metabolic reprogramming and ER stress, and defines DDIT3 as a promising therapeutic target in glioma.

Lnc-HIBADH-4 Regulates Autophagy-Lysosome Pathway in Amyotrophic Lateral Sclerosis by Targeting Cathepsin D.

Amyotrophic lateral sclerosis (ALS) is the most prevalent and lethal class of severe motor neuron diseases (MND) with no efficacious treatment. The pathogenic mechanisms underlying ALS remain unclear. Nearly 90% of patients exhibit sporadic onset (sALS). Therefore, elucidating the pathophysiology of ALS is imperative. Long non-coding RNA (lncRNA) is a large class of non-coding RNAs that regulate transcription, translation, and post-translational processes. LncRNAs contribute to the pathogenesis of diverse neurodegenerative disorders and hold promise as targets for interference in the realm of neurodegeneration. However, the mechanisms of which lncRNAs are involved in ALS have not been thoroughly investigated. We identified and validated a downregulated lncRNA, lnc-HIBADH-4, in ALS which correlated with disease severity and overall survival. Lnc-HIBADH-4 acted as a "molecular sponge" regulating lysosomal function through the lnc-HIBADH-4/miR-326/CTSD pathway, thereby impacting autophagy-lysosome dynamics and the levels of cell proliferation and apoptosis. Therefore, this study discovered and revealed the role of lnc-HIBADH-4 in the pathogenesis of ALS. With further research, lnc-HIBADH-4 is expected to provide a new biomarker in the diagnosis and treatment of ALS.

Genetic Modifiers of Age at Onset for Amyotrophic Lateral Sclerosis: A Genome-Wide Association Study.

OBJECTIVE: Age at onset (AAO) is an essential clinical feature associated with disease progression and mortality in amyotrophic lateral sclerosis (ALS). Identification of genetic variants and environmental risk factors influencing AAO of ALS could help better understand the disease's biological mechanism and provide clinical guidance. However, most genetic studies focused on the risk of ALS, while the genetic background of AAO is less explored. This study aimed to identify genetic and environmental determinants for AAO of ALS. METHODS: We performed a genome-wide association analysis using a Cox proportional hazards model on AAO of ALS in 10,068 patients. We further conducted colocalization analysis and in-vitro functional exploration for the target variants, as well as Mendelian randomization analysis to identify risk factors influencing AAO of ALS. RESULTS: The total heritability of AAO of ALS was ~0.16 (standard error [SE] = 0.03). One novel locus rs2046243 (CTIF) was significantly associated with earlier AAO by ~1.29 years (p = 1.68E-08, beta = 0.10, SE = 0.02). Functional exploration suggested this variant was associated with increased expression of CTIF in multiple tissues including the brain. Colocalization analysis detected a colocalization signal at the locus between AAO of ALS and expression of CTIF. Causal inference indicated higher education level was associated with later AAO. INTERPRETATION: These findings improve the current knowledge of the genetic and environmental etiology of AAO of ALS, and provide a novel target CTIF for further research on ALS pathogenesis and potential therapeutic options to delay the disease onset. ANN NEUROL 2023;94:933-941.

Disruption of neuronal RHEB signaling impairs oligodendrocyte differentiation and myelination through mTORC1-DLK1 axis.

How neuronal signaling affects brain myelination remains poorly understood. We show dysregulated neuronal RHEB-mTORC1-DLK1 axis impairs brain myelination. Neuronal Rheb cKO impairs oligodendrocyte differentiation/myelination, with activated neuronal expression of the imprinted gene Dlk1. Neuronal Dlk1 cKO ameliorates myelination deficit in neuronal Rheb cKO mice, indicating that activated neuronal Dlk1 expression contributes to impaired myelination caused by Rheb cKO. The effect of Rheb cKO on Dlk1 expression is mediated by mTORC1; neuronal mTor cKO and Raptor cKO and pharmacological inhibition of mTORC1 recapitulate elevated neuronal Dlk1 expression. We demonstrate that both a secreted form of DLK1 and a membrane-bound DLK1 inhibit the differentiation of cultured oligodendrocyte precursor cells into oligodendrocytes expressing myelin proteins. Finally, neuronal expression of Dlk1 in transgenic mice reduces the formation of mature oligodendrocytes and myelination. This study identifies Dlk1 as an inhibitor of oligodendrocyte myelination and a mechanism linking altered neuronal signaling with oligodendrocyte dysfunction.

Efficacy and safety of acupuncture-point stimulation combined with opioids for the treatment of moderate to severe cancer pain: a network meta-analysis of randomized controlled trials.

Background: Pain is one of the most common and troublesome symptoms of cancer. Although potential positive effects of acupuncture-point stimulation (APS) on cancer pain have been observed, knowledge regarding the selection of the optimal APS remains unclear because of a lack of evidence from head-to-head randomized controlled trials (RCTs). Objective: This study aimed to carry out a network meta-analysis to compare the efficacy and safety of different APS combined with opioids in treating moderate to severe cancer pain and rank these methods for practical consideration. Methods: A comprehensive search of eight electronic databases was conducted to obtain RCTs involving different APS combined with opioids for moderate to severe cancer pain. Data were screened and extracted independently using predesigned forms. The quality of RCTs was appraised with the Cochrane Collaboration risk-of-bias tool. The primary outcome was the total pain relief rate. Secondary outcomes were the total incidence of adverse reactions, the incidence of nausea and vomiting, and the incidence of constipation. We applied a frequentist, fixed-effect network meta-analysis model to pool effect sizes across trials using rate ratios (RR) with their 95% confidence intervals (CI). Network meta-analysis was performed using Stata/SE 16.0. Results: We included 48 RCTs, which consisted of 4,026 patients, and investigated nine interventions. A network meta-analysis showed that a combination of APS and opioids was superior in relieving moderate to severe cancer pain and reducing the incidence of adverse reactions such as nausea, vomiting, and constipation compared to opioids alone. The ranking of total pain relief rates was as follows: fire needle (surface under the cumulative ranking curve (SUCRA) = 91.1%), body acupuncture (SUCRA = 85.0%), point embedding (SUCRA = 67.7%), auricular acupuncture (SUCRA = 53.8%), moxibustion (SUCRA = 41.9%), transcutaneous electrical acupoint stimulation (TEAS) (SUCRA = 39.0%), electroacupuncture (SUCRA = 37.4%), and wrist-ankle acupuncture (SUCRA = 34.1%). The ranking of total incidence of adverse reactions was as follows: auricular acupuncture (SUCRA = 23.3%), electroacupuncture (SUCRA = 25.1%), fire needle (SUCRA = 27.2%), point embedding (SUCRA = 42.6%), moxibustion (SUCRA = 48.2%), body acupuncture (SUCRA = 49.8%), wrist-ankle acupuncture (SUCRA = 57.8%), TEAS (SUCRA = 76.3%), and opioids alone (SUCRA = 99.7%). Conclusions: APS seemed to be effective in relieving cancer pain and reducing opioid-related adverse reactions. Fire needle combined with opioids may be a promising intervention to reduce moderate to severe cancer pain as well as reduce opioid-related adverse reactions. However, the evidence was not conclusive. More high-quality trials investigating the stability of evidence levels of different interventions on cancer pain must be conducted. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/#searchadvanced, identifier CRD42022362054.

Cross-Ethnic Variant Screening and Burden Analysis of PTPA in Parkinson's Disease.

BACKGROUND: Recently, homozygous variants in PTPA were identified as the disease cause for two pedigrees with early-onset parkinsonism and intellectual disability. Although the initial link between PTPA and parkinsonism has been established, further replication was still necessary. OBJECTIVES: To evaluate the genetic role of PTPA in Parkinson's disease (PD). METHODS: We analyzed rare variants of PTPA in cohorts of Asian and European ancestries (Ncase = 2743, Ncontrol = 8177) with whole-exome sequencing, and further explored the functional effect of the target variant. RESULTS: One patient with early-onset PD from a consanguineous family carried the homozygous variant p.Met329Val, while her parents and elder sister with heterozygous p.Met329Val were healthy. This patient developed minor cognitive decline within 1 year, with a Montreal Cognitive Assessment (MoCA) score dropping from 28 to 25. Functional exploration with overexpression studies suggested that this variant was associated with decreased protein phosphatase 2A (PTPA) protein level by affecting protein stability, but not mRNA expression. CONCLUSIONS: These results have broadened the mutation spectrum of PTPA, and paved the way for further research into the role of PTPA in PD. © 2023 International Parkinson and Movement Disorder Society.

Mutation screening of AOPEP variants in a large dystonia cohort.

STUDY OBJECTIVES: Recently, AOPEP has been identified to be a novel causative gene of autosomal-recessive dystonia. However, no large cohort study has been conducted to confirm the association. We aimed to systematically evaluate the genetic associations of AOPEP with dystonia in a large Chinese dystonia cohort. METHODS: We analyzed rare variants of AOPEP in 878 dystonia patients with whole-exome sequencing. The over-representation of rare variants in patients was examined with Fisher's exact test at allele and gene levels. RESULTS: Among the 878 patients with dystonia, we found two patients with biallelic likely pathogenic variants in the AOPEP gene. One patient carried putative compound heterozygous variants (p.A212D and p.G216R) and presented with childhood-onset segmental dystonia involving the upper limbs and craniocervical muscles accompanied by myoclonus of the dystonia affected areas. One patient carried homozygote of p.M291Nfs*68 and presented with adult-onset isolated cervical dystonia. Another 15 patients were identified to carry heterozygous rare variants in AOPEP, including 2 loss-of-function variants (p.M291Nfs*68 and p.R493X) and 6 missense variants. One loss-of-function variant (p.R493X) was the same as previously reported. Nearly, all of the 15 patients carrying heterozygous variants in AOPEP presented with isolated dystonia with only craniocervical muscles affected, except for one patient who carried the p.R493X variant presented with segmental dystonia affecting the neck and right upper limb combined with parkinsonism. Gene-based burden analysis detected enrichment of rare variants and rare damaging variants of AOPEP in dystonia. CONCLUSIONS: Our study supplemented the evidence on the role of AOPEP in autosomal-recessive dystonia in Chinese population, and expanded the genotypic and phenotypic spectrum of AOPEP.

Dyslipidemia is associated with inflammation and organ involvement in systemic lupus erythematosus.

INTRODUCTION: Disturbed lipid metabolism was observed in systemic lupus erythematosus (SLE) patients. This study aimed to evaluate the relationships between dyslipidemia and visceral organ involvement, disease severity, inflammatory factors, and drug intake in SLE patients. METHOD: Inpatients with SLE (n = 105) and healthy controls (HC) (n = 75) were recruited in this study. Clinical and laboratory data were collected from patient records. The concentrations of tumor necrosis factor receptors superfamily member1A (TNFRSF1A), member1B (TNFRSF1B) and adipokine angiopoietin-like 4 (ANGPTL4) in plasma were measured by ELISA. RESULT: Compared to HC, serum levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL), and apolipoprotein B (ApoB) were significantly increased, while high-density lipoprotein (HDL) and apolipoprotein A1 (ApoA1) were decreased in SLE patients. Patients with higher disease activity and renal damage suffered from more severe dyslipidemia. Renal functional parameters were closely correlated with serum lipid levels. Inflammatory factors were associated with dyslipidemia. The levels of TNFRSF1A and TNFRSF1B were obviously increased and associated with kidney involvement in SLE patients. Patients with high-dose glucocorticoid intake showed more severe dyslipidemia. CONCLUSIONS: Attention should be paid to the dyslipidemia of SLE. Dyslipidemia is associated with inflammation and organ involvement in SLE. These findings might provide a new strategy for the treatment of SLE. Key Points • Serum levels of TG, TC, LDL, and ApoB were significantly increased, while HDL and ApoA1 were decreased in SLE patients. • Patients with higher disease activity and renal damage suffered from more severe dyslipidemia. Renal functional parameters and inflammatory factors were closely correlated with serum lipid levels. • Patients with high-dose glucocorticoid intake showed more severe dyslipidemia. • These findings might provide a new strategy for the treatment of SLE.

Rare variants in IMPDH2 cause autosomal dominant dystonia in Chinese population.

STUDY OBJECTIVES: Recently, IMPDH2 has been linked to dystonia. However, no replication study from other cohorts has been conducted to confirm the association. We aimed to systematically evaluate the genetic associations of IMPDH2 with dystonia in a large dystonia cohort. METHODS: We analyzed rare variants (minor allele frequency < 0.01) of IMPDH2 in 688 Chinese dystonia patients with whole exome sequencing. The over-representation of rare variants in patients was examined with Fisher's exact test at allele and gene levels. RESULTS: Four rare variants were detected in IMPDH2 in four patients with dystonia in our cohort, including three missense variants (p.Ser508Leu, p.Ala396Thr, and p.Phe24Val) and one splice acceptor variant (c.1296-1G>T). Two of them (c.1296-1G>T and p.Ser508Leu) were co-segregated in the family co-segregation analysis and were classified as pathogenic and likely pathogenic variant according to the American College of Medical Genetics and Genomics (ACMG) guidelines, respectively. Gene burden analysis revealed enrichment of rare variants in IMPDH2 in dystonia. CONCLUSIONS: Our work supplemented the evidence on the role of IMPDH2 in autosomal dominant dystonia in Chinese population, and expanded the genetic and phenotypic spectrum of IMPDH2, paving way for future studies.

Genetic Determinants of Survival in Parkinson's Disease in the Asian Population.

BACKGROUND: Patients with Parkinson's disease (PD) have reduced life expectancy compared to the general population. Genetic variation was shown to play a role in the heterogeneity of survival for patients with PD, although the underlying genetic background remains poorly studied. OBJECTIVE: The aim was to explore the genetic determinants influencing the survival of PD. METHODS: We performed a genome-wide association analysis using a Cox proportional hazards model in a longitudinal cohort of 1080 Chinese patients with PD. Furthermore, we built a clinical-genetic model to predict the survival of patients using clinical variables combined with polygenic risk score (PRS) of survival of PD. RESULTS: The cohort was followed up for an average of 7.13 years, with 85 incidents of death. One locus rs12628329 (RPL3) was significantly associated with reduced survival time by ~10.8 months (P = 2.72E-08, ß = 1.79, standard error = 0.32). Functional exploration suggested this variant could upregulate the expression of RPL3 and induce apoptosis and cell death. In addition, adding PRS of survival in the prediction model substantially improved survival predictability (concordance index [Cindex]: 0.936) compared with the clinical model (Cindex: 0.860). CONCLUSIONS: These findings improve the current understanding of the genetic cause of survival of PD and provide a novel target RPL3 for further research on PD pathogenesis and potential therapeutic options. Our results also demonstrate the potential utility of PRS of survival in identifying patients with shorter survival and providing personalized clinical monitoring and treatment. © 2022 International Parkinson and Movement Disorder Society.

Animal models of male subfertility targeted on LanCL1-regulated spermatogenic redox homeostasis.

Oxidative stress in spermatozoa is a major contributor to male subfertility, which makes it an informed choice to generate animal models of male subfertility with targeted modifications of the antioxidant systems. However, the critical male germ cell-specific antioxidant mechanisms have not been well defined yet. Here we identify LanCL1 as a major male germ cell-specific antioxidant gene, reduced expression of which is related to human male infertility. Mice deficient in LanCL1 display spermatozoal oxidative damage and impaired male fertility. Histopathological studies reveal that LanCL1-mediated antioxidant response is required for mouse testicular homeostasis, from the initiation of spermatogenesis to the maintenance of viability and functionality of male germ cells. Conversely, a mouse model expressing LanCL1 transgene is protected against high-fat-diet/obesity-induced oxidative damage and subfertility. We further show that germ cell-expressed LanCL1, in response to spermatogenic reactive oxygen species, is regulated by transcription factor specific protein 1 (SP1) during spermatogenesis. This study demonstrates a critical role for the SP1-LanCL1 axis in regulating testicular homeostasis and male fertility mediated by redox balance, and provides evidence that LanCL1 genetically modified mice have attractive applications as animal models of male subfertility.

Rheb-regulated mitochondrial pyruvate metabolism of Schwann cells linked to axon stability.

The metabolic coupling of Schwann cells (SCs) and peripheral axons is poorly understood. Few molecules in SCs are known to regulate axon stability. Using SC-specific Rheb knockout mice, we demonstrate that Rheb-regulated mitochondrial pyruvate metabolism is critical for SC-mediated non-cell-autonomous regulation of peripheral axon stability. Rheb knockout suppresses pyruvate dehydrogenase (PDH) activity (independently of mTORC1) and shifts pyruvate metabolism toward lactate production in SCs. The increased lactate causes age-dependent peripheral axon degeneration, affecting peripheral nerve function. Lactate, as an energy substrate and a potential signaling molecule, enhanced neuronal mitochondrial metabolism and energy production of peripheral nerves. Albeit beneficial to injured peripheral axons in the short term, we show that persistently increased lactate metabolism of neurons enhances ROS production, eventually damaging mitochondria, neuroenergetics, and axon stability. This study highlights the complex roles of lactate metabolism to peripheral axons and the importance of lactate homeostasis in preserving peripheral nerves.

Rheb mediates neuronal-activity-induced mitochondrial energetics through mTORC1-independent PDH activation.

Neuronal activity increases energy consumption and requires balanced production to maintain neuronal function. How activity is coupled to energy production remains incompletely understood. Here, we report that Rheb regulates mitochondrial tricarboxylic acid cycle flux of acetyl-CoA by activating pyruvate dehydrogenase (PDH) to increase ATP production. Rheb is induced by synaptic activity and lactate and dynamically trafficked to the mitochondrial matrix through its interaction with Tom20. Mitochondria-localized Rheb protein is required for activity-induced PDH activation and ATP production. Cell-type-specific gain- and loss-of-function genetic models for Rheb reveal reciprocal changes in PDH phosphorylation/activity, acetyl-CoA, and ATP that are not evident with genetic or pharmacological manipulations of mTORC1. Mechanistically, Rheb physically associates with PDH phosphatase (PDP), enhancing its activity and association with the catalytic E1α-subunit of PDH to reduce PDH phosphorylation and increase its activity. Findings identify Rheb as a nodal point that balances neuronal activity and neuroenergetics via Rheb-PDH axis.

LanCL1 promotes motor neuron survival and extends the lifespan of amyotrophic lateral sclerosis mice.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive loss of motor neurons. Improving neuronal survival in ALS remains a significant challenge. Previously, we identified Lanthionine synthetase C-like protein 1 (LanCL1) as a neuronal antioxidant defense gene, the genetic deletion of which causes apoptotic neurodegeneration in the brain. Here, we report in vivo data using the transgenic SOD1G93A mouse model of ALS indicating that CNS-specific expression of LanCL1 transgene extends lifespan, delays disease onset, decelerates symptomatic progression, and improves motor performance of SOD1G93A mice. Conversely, CNS-specific deletion of LanCL1 leads to neurodegenerative phenotypes, including motor neuron loss, neuroinflammation, and oxidative damage. Analysis reveals that LanCL1 is a positive regulator of AKT activity, and LanCL1 overexpression restores the impaired AKT activity in ALS model mice. These findings indicate that LanCL1 regulates neuronal survival through an alternative mechanism, and suggest a new therapeutic target in ALS.

Terahertz Spectroscopic Diagnosis of Myelin Deficit Brain in Mice and Rhesus Monkey with Chemometric Techniques.

While myelin deficit of the central nervous system leads to several severe diseases, the definitive diagnostic means are lacking. We proposed and performed terahertz time-domain spectroscopy (THz-TDS) combined with chemometric techniques to discriminate and evaluate the severity of myelin deficit in mouse and rhesus monkey brains. The THz refractive index and absorption coefficient of paraffin-embedded brain tissues from both normal and mutant dysmyelinating mice are shown. Principal component analysis of time-domain THz signal (PCA-tdTHz) and absorption-refractive index relation of THz spectrum identified myelin deficit without exogenous labeling or any pretreatment. Further, with the established PCA-tdTHz, we evaluated the severity of myelin deficit lesions in rhesus monkey brain induced by experimental autoimmune encephalomyelitis, which is the most-studied animal model of multiple sclerosis. The results well matched the pathological analysis, indicating that PCA-tdTHz is a quick, powerful, evolving tool for identification and evaluation myelin deficit in preclinical animals and potentially in para-clinical human biopsy.

Orai1-Mediated Antimicrobial Secretion from Pancreatic Acini Shapes the Gut Microbiome and Regulates Gut Innate Immunity.

The gut microbiome participates in numerous physiologic functions and communicates intimately with the host immune system. Antimicrobial peptides are critical components of intestinal innate immunity. We report a prominent role for antimicrobials secreted by pancreatic acini in shaping the gut microbiome that is essential for intestinal innate immunity, barrier function, and survival. Deletion of the Ca2+ channel Orai1 in pancreatic acini of adult mice resulted in 60%-70% mortality within 3 weeks. Despite robust activation of the intestinal innate immune response, mice lacking acinar Orai1 exhibited intestinal bacterial outgrowth and dysbiosis, ultimately causing systemic translocation, inflammation, and death. While digestive enzyme supplementation was ineffective, treatments constraining bacterial outgrowth (purified liquid diet, broad-spectrum antibiotics) rescued survival, feeding, and weight gain. Pancreatic levels of cathelicidin-related antimicrobial peptide (CRAMP) were reduced, and supplement of synthetic CRAMP prevented intestinal disease. These findings reveal a critical role for antimicrobial pancreatic secretion in gut innate immunity.

Targeting human Mas-related G protein-coupled receptor X1 to inhibit persistent pain.

Human Mas-related G protein-coupled receptor X1 (MRGPRX1) is a promising target for pain inhibition, mainly because of its restricted expression in nociceptors within the peripheral nervous system. However, constrained by species differences across Mrgprs, drug candidates that activate MRGPRX1 do not activate rodent receptors, leaving no responsive animal model to test the effect on pain in vivo. Here, we generated a transgenic mouse line in which we replaced mouse Mrgprs with human MrgprX1 This humanized mouse allowed us to characterize an agonist [bovine adrenal medulla 8-22 (BAM8-22)] and a positive allosteric modulator (PAM), ML382, of MRGPRX1. Cellular studies suggested that ML382 enhances the ability of BAM8-22 to inhibit high-voltage-activated Ca2+ channels and attenuate spinal nociceptive transmission. Importantly, both BAM8-22 and ML382 effectively attenuated evoked, persistent, and spontaneous pain without causing obvious side effects. Notably, ML382 by itself attenuated both evoked pain hypersensitivity and spontaneous pain in MrgprX1 mice after nerve injury without acquiring coadministration of an exogenous agonist. Our findings suggest that humanized MrgprX1 mice provide a promising preclinical model and that activating MRGPRX1 is an effective way to treat persistent pain.