Constructing and Validating a Nomogram Model for Short-Term Prognosis of Patients with AChR-Ab+ GMG.

OBJECTIVE: This study aimed to establish and validate a nomogram prognostic model for predicting short-term efficacy of acetylcholine receptor antibody-positive (AChR-Ab+) generalized myasthenia gravis (GMG). METHODS: A retrospective observational study was conducted at the First Hospital of Shanxi Medical University, enrolling patients diagnosed with AChR-Ab+ GMG from May 2020 to September 2022. The primary outcome was the change in the Myasthenia Gravis Foundation of America (MGFA) post-intervention status after 6 months of standard treatment. Predictive factors were identified through univariate and multivariate logistic regression analyses, with significant factors incorporated into the nomogram. The bootstrap test was used for internal validation of the nomogram model. Model performance was assessed using calibration curves, receiver-operating characteristic curve analysis, and decision curve analysis (DCA). RESULTS: A total of 90 patients were enrolled, of whom 30 achieved unchanged or worse status after 6 months of standard therapy. Univariate logistic regression analysis showed that quantitative myasthenia gravis score, gender, body mass index, course of disease, hemoglobin levels, and white blood cell counts were six potential predictors. These factors were used for multivariate logistic regression analysis, and a nomogram was constructed. The calibration curve showed that the predicted value was in good agreement with the actual value (p = 0.707), and the area under the curve value (0.792, 95% CI 0.686-0.899) indicated good discrimination ability. DCA suggests that this model has potential clinical application value. CONCLUSION: The constructed nomogram, based on key patient indicators, shows promise as a clinically useful tool for predicting the short-term efficacy of treatment of AChR-Ab+ GMG. Validation in larger, multicenter cohorts is needed to further substantiate its applicability.

A novel autosomal dominant ERLIN2 variant activates endoplasmic reticulum stress in a Chinese HSP family.

OBJECTIVE: Hereditary spastic paraplegia (HSP) has been reported rarely because of a monoallelic variant in ERLIN2. The present study aimed at describing a novel autosomal dominant ERLIN2 pedigree in a Chinese family and exploring the possible mechanism of HSP caused by ERLIN2 variants. METHODS: The proband and his family underwent a comprehensive medical history inquiry and neurological examinations. Whole-exome sequencing was performed on the proband, and Sanger sequencing was performed on some family members. HeLa cell lines and mouse primary cortical neurons were used for immunofluorescence (IF) and reverse transcription-PCR (RT-PCR). RESULTS: Seven patients were clinically diagnosed with pure spastic paraplegia in four consecutive generations with the autosomal dominant inheritance model. All patients presented juvenile-adolescent onset and gradually worsening pure HSP phenotype. Whole-exome sequencing of the proband and Sanger sequencing of all available family members identified a novel heterozygous c.212 T>C (p.V71A) variant in exon 8 of the ERLIN2 gene. The c.212 T>C demonstrated a high pathogenic effect score through functional prediction. RT-PCR and IF analysis of overexpressed V71A revealed an altered ER morphology and increased XBP-1S mRNA levels, suggesting the activation of ER stress. Overexpression of V71A in primary cultured cortical neurons promoted axon growth. INTERPRETATION: The novel c.212 T>C heterozygous variant in human ERLIN2 caused pure HSP. Moreover, c.212 T>C heterozygous variant in ERLIN2 increased ER stress and affected axonal development.

Data-independent acquisition-based quantitative proteomic analysis of m.3243A>G MELAS reveals novel potential pathogenesis and therapeutic targets.

The pathogenesis of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke like episodes (MELAS) syndrome has not been fully elucidated. The m.3243A > G mutation which is responsible for 80% MELAS patients affects proteins with undetermined functions. Therefore, we performed quantitative proteomic analysis on skeletal muscle specimens from MELAS patients. We recruited 10 patients with definitive MELAS and 10 age- and gender- matched controls. Proteomic analysis based on nanospray liquid chromatography-mass spectrometry (LC-MS) was performed using data-independent acquisition (DIA) method and differentially expressed proteins were revealed by bioinformatics analysis. We identified 128 differential proteins between MELAS and controls, including 68 down-regulated proteins and 60 up-regulated proteins. The differential proteins involved in oxidative stress were identified, including heat shock protein beta-1 (HSPB1), alpha-crystallin B chain (CRYAB), heme oxygenase 1 (HMOX1), glucose-6-phosphate dehydrogenase (G6PD) and selenoprotein P. Gene ontology and kyoto encyclopedia of genes and genomes pathway analysis showed significant enrichment in phagosome, ribosome and peroxisome proliferator-activated receptors (PPAR) signaling pathway. The imbalance between oxidative stress and antioxidant defense, the activation of autophagosomes, and the abnormal metabolism of mitochondrial ribosome proteins (MRPs) might play an important role in m.3243A > G MELAS. The combination of proteomic and bioinformatics analysis could contribute potential molecular networks to the pathogenesis of MELAS in a comprehensive manner.

Development of Organogels for Live Yarrowia lipolytica Encapsulation.

Encapsulation of cells/microorganisms attracts great attention in many applications, but current studies mainly focus on hydrophilic encapsulation materials. Herein, we develop a new class of hydrophobic and lipophilic organogels for highly efficient encapsulation of Yarrowia lipolytica, an oleaginous yeast, by a mild and nonsolvent photopolymerization method. The organogels allow free diffusion of hydrophobic molecules that oleaginous yeasts require to survive and function. Moreover, they are mechanically robust and possess favorable biocompatibility, thus providing a free-standing platform and an ideal survival environment for oleaginous Y. lipolytica encapsulation. By tuning monomer structures and cross-linking densities, the optimized organogel, Gel12-1.5%, achieves the highest viability of ∼96%. Furthermore, organogels can inhibit the cryoinjuries to oleaginous yeasts in cryopreservation, exhibiting the potential for long-term storage. It is also found that with varying alkyl lengths, the organogels show different temperature-dependent phase transition properties, which enable the rapid selection of targeted yeasts for steganography. Findings in this work provide guidance for designing biocompatible, hydrophobic, and lipophilic encapsulation materials.

Neuromuscular junction disorders: Experimental models and pathophysiological mechanisms.

Located between skeletal muscle fibers and motoneurons, the neuromuscular junction is a chemical synapse essential for the transmission of information from nervous system to skeletal muscle. There are many diseases related to neuromuscular junction dysfunction, including myasthenia gravis, Lambert­Eaton myasthenic syndrome, congenital myasthenic syndromes, amyotrophic lateral sclerosis, and spinal muscular atrophy. The pathophysiological mechanisms of these diseases have been investigated using many animal models. Among them, mouse models are the most commonly used and have provided the majority of current data. Moreover, advances in human induced pluripotent stem cell technology has resulted in new opportunities to study neuromuscular junction disorders from both patients and healthy individuals. Currently, patient­specific induced pluripotent stem cells derived from motor neurons have begun to be studied. These studies will help us achieve a more comprehensive understanding of diseases related to neuromuscular junction disorders. We will describe the research models of neuromuscular junction disorders and provide an overview of recent key findings.