A Case Report of Corynebacterium Tuberculostearicum Infection.

BACKGROUND: The goal was to report a rare case of lymphadenitis caused by Corynebacterium tuberculostearicum, and the laboratory's coping approach in the isolation and identification of this rare pathogen to improve the understanding of the disease. METHODS: Lymph node biopsy was performed in a patient with suspected tuberculous lymphadenitis, and the biopsy tissue was isolated and cultured. RESULTS: The culture was Gram positive Corynebacterium, which was identified as Corynebacterium tuberculostearicum by microbial mass spectrometry and 16S rRNA gene sequencing. Antimicrobial susceptibility test showed that the drug was sensitive to daptomycin, doxycycline, gentamicin, linezolid, vancomycin, and meropenem, but resistant to ciprofloxacin, clindamycin, erythromycin, rifampicin, compound sulfamethoxazole, ceftriaxone, and cefepime. CONCLUSIONS: This is a case of Corynebacterium tuberculostearicum infection. Case reports of Corynebacterium tuberculostearicum infection are relatively rare in China. Through case study, we can provide help for laboratory isolation, identification, clinical diagnosis, and treatment.

Identification and analysis of genes associated with the severity and prognosis of sepsis.

BACKGROUND: With rapid progression, severe illness and high fatality rate, sepsis has become an acute and critical condition that seriously threatens human life and health. OBJECTIVE: To detect miR-210 and miR-494 expression in patients with sepsis and their relationship with severity and prognosis. METHODS: A total of 165 sepsis patients participated, including 105 patients with septic non-shock and 60 patients with septic shock. 53 sepsis patients died in 28 days, and 112 patients survived. The clinical information of all sepsis patients was retrospectively searched and reviewed. Based on the status of 28-day survival, they were categorized into survival group and death group. The expression levels in each group were compared on the first, third and seventh day. The ROC curve was applied to know the expression level of plasma miR-210 and miR-494 to predict the death. RESULTS: The two miRNAs expression of the septic shock group were significantly higher than that in sepsis non-shock group on the first, third and seventh day (all were P< 0.05). The ROC curve found that the AUC combined to predict the death on the third day was the largest, which was 0.925 (95%CI: 0.864-0.983). The sensitivity and specificity were 94.6% and 86.3%, respectively. CONCLUSION: The increased expression levels of plasma miR-210 and miR-494 are closely relevant to the severity and prognosis of sepsis patients. Combining the two items on the third day can predict the death of sepsis patients.

Curcumin-Loaded RH60/F127 Mixed Micelles: Characterization, Biopharmaceutical Characters and Anti-Inflammatory Modulation of Airway Inflammation.

Curcumin's ability to impact chronic inflammatory conditions, such as metabolic syndrome and arthritis, has been widely researched; however, its poor bioavailability limits its clinical application. The present study is focused on the development of curcumin-loaded polymeric nanomicelles as a drug delivery system with anti-inflammatory effects. Curcumin was loaded in PEG-60 hydrogenated castor oil and puronic F127 mixed nanomicelles (Cur-RH60/F127-MMs). Cur-RH60/F127-MMs was prepared using the thin film dispersion method. The morphology and releasing characteristics of nanomicelles were evaluated. The uptake and permeability of Cur-RH60/F127-MMs were investigated using RAW264.7 and Caco-2 cells, and their bioavailability and in vivo/vitro anti-inflammatory activity were also evaluated. The results showed that Cur-RH60/F127-MMs have regular sphericity, possess an average diameter smaller than 20 nm, and high encapsulation efficiency for curcumin (89.43%). Cur-RH60/F127-MMs significantly increased the cumulative release of curcumin in vitro and uptake by cells (p < 0.01). The oral bioavailability of Cur-RH60/F127-MMs was much higher than that of curcumin-active pharmaceutical ingredients (Cur-API) (about 9.24-fold). The treatment of cell lines with Cur-RH60/F127-MMs exerted a significantly stronger anti-inflammatory effect compared to Cur-API. In addition, Cur-RH60/F127-MMs significantly reduced OVA-induced airway hyperresponsiveness and inflammation in an in vivo experimental asthma model. In conclusion, this study reveals the possibility of formulating a new drug delivery system for curcumin, in particular nanosized micellar aqueous dispersion, which could be considered a perspective platform for the application of curcumin in inflammatory diseases of the airways.

Clinical Report of a Rare Mucinous Staphylococcus Aureus Infection.

BACKGROUND: Staphylococcus aureus is the most common pathogen in suppurative infection, which can cause local suppurative infection, pneumonia, etc. A case of double renal calculi complicated with chronic renal insufficiency and mucinous Staphylococcus aureus infection was analyzed and discussed. METHODS: Bacterial culture, identification, and next-generation sequencing. RESULTS: The mucous colony was identified as Staphylococcus aureus, and the condition improved after symptomatic treatment. CONCLUSIONS: Mucinous Staphylococcus is a rare clinical microorganism, which needs to be verified by experiments to avoid false negative results. Genetic sequencing is used to identify strains if necessary.

Molecular characteristics and antimicrobial resistance profiles of Carbapenem-Resistant Klebsiella pneumoniae isolates at a tertiary hospital in Nanning, China.

PURPOSE: Carbapenem resistant Klebsiella pneumoniae is associated with nosocomial infections and can cause high mortality, which poses great threat to human health. This study was aimed at investigating the molecular epidemiology and antimicrobial resistance profiles of carbapenem resistant Klebsiella pneumoniae isolates and providing clues for management and control of carbapenem resistant Klebsiella pneumoniae infections. METHODS: A total of 2324 Klebsiella pneumoniae strains were isolated from the First Affiliated Hospital of Guangxi Medical University from June 2018 to October 2020, and 103 carbapenem resistant Klebsiella pneumoniae strains from inpatients were collected, and the specimens mainly came from the sputum, urine, secretions, and blood. The antimicrobial susceptibility tests were performed using the VITEK 2 Compact system or the Kirby-Bauer disk-diffusion method. The resistance genes were detected by polymerase chain reaction and sequencing. The homology analysis of carbapenem resistant Klebsiella pneumoniae strains was performed by multilocus sequence typing. RESULTS: Antimicrobial susceptibility results showed that the 103 carbapenem resistant Klebsiella pneumoniae strains were resistant to most common antibiotics. Resistance genes detection showed that the carbapenem resistant Klebsiella pneumoniae isolates mainly carried metallo-beta-lactamase, and the predominant gene was NDM-1. The homology analysis found that the major ST type were ST11, follow by ST15 and ST17. CONCLUSION: The carbapenem resistant Klebsiella pneumoniae isolates in our study shown resistance to most common antibiotics. Of the 103 carbapenem resistant Klebsiella pneumoniae strains, 91 strains (88.35%) carried carbapenemases genes, and NDM was the predominant carbapenemase gene detected. ST11 was the major ST typing of carbapenem resistant Klebsiella pneumoniae in our hospital. Our finding may play a role in control and management of the carbapenem resistant Klebsiella pneumoniae infections and guiding clinical antibiotic therapy. In addition, metallo-beta-lactamase should be served as a key target to be monitored in carbapenem resistant Klebsiella pneumoniae infection.

Clinical Reasoning: A 14-Year-Old Girl With Reversible Peripheral Neuropathy and Encephalopathy.

A 14-year-old girl presented with acute ascending, symmetric numbness, and flaccid paralysis 3 weeks after a suspected gastrointestinal infection. She had experienced anorexia since this gastrointestinal episode. EMG showed a sensorimotor axonal polyneuropathy. Routine CSF analysis and serum-specific antibodies (antiganglioside and node of Ranvier-associated antibodies) were all negative. Laboratory investigations for possible etiologies revealed only mild metabolic perturbations. During her hospitalization, she developed mild cognitive deficits. Brain MRI showed bilateral symmetric basal ganglia lesions with hyperintensity on T2 fluid-attenuated inversion recovery, diffusion-weighted imaging hyperintensity, and corresponding apparent diffusion coefficient hypointensity, but without contrast enhancement. A more thorough and detailed history indicated exercise intolerance, and specific examinations subsequently revealed an underlying etiology. This case presentation discusses specific etiology of an acute-onset diffuse and symmetric neuropathy after an acquired injury in a teenager, emphasizing the need of a broad differential diagnosis in this condition.

Cinnamon cassia oil chitosan nanoparticles: Physicochemical properties and anti-breast cancer activity.

The aim of this study was to prepare Cinnamomum cassia essential oil (CEO) impregnated chitosan nanoparticles (CS-CEO) and assess its pharmacological activity against breast cancer. Cinnamon oil-loaded chitosan nanoparticles were investigated for their physicochemical properties, stability, and anti-cancer activities both in vitro and in vivo. The prepared CS-CEO nanoparticles have a particle size, zeta-potential, entrapment efficiency and drug loading of (215.40 ± 3.90) nm, (51.70 ± 1.90) mV, (83.37 ± 0.4)% and (26.42 ± 0.65)%, respectively. CS-CEO showed a regular, uniform, and spherical or quasi-spherical structure under a transmission electron microscope. CS-CEO remained stable upon storage at 4 °C. CS-CEO exhibited enhanced in vitro antitumor activity (52 µg/mL) compared to CEO. The mechanism might be related to the up-regulation of Caspase-3 and AIF protein expression. In in vivo experiments, CS-CEO suppressed the growth of 4T1 breast cancer cells transplanted into mice, inhibited tumor cell proliferation, and induced apoptosis by reducing the expression of the Ki-67 protein. These results indicated that CEO encapsulated in chitosan had a higher physical stability and was also more effective against 4T1 breast tumor model, which can be used as a reference for the application of volatile oil components in traditional Chinese medicine.

A case of mitochondrial myopathy and chronic progressive external ophthalmoplegia. / çº¿ç²’ä½“è‚Œç— åˆå¹¶æ ¢æ€§è¿›è¡Œæ€§çœ¼å¤–è‚Œéº»ç—¹1例（英文）.

Mitochondrial myopathy is a group of multi-system diseases in which mitochondrial DNA (mtDNA) or nuclear DNA (nDNA) defects lead to structural and functional dysfunction of mitochondria. The clinical manifestations of mitochondrial myopathy are complex and varied, and the testing for mtDNA and nDNA is not widely available, so misdiagnosis or missed diagnosis is common. Chronic progressive external ophthalmoplegia (CPEO) is a common type of mitochondrial myopathy, which is characterized by blepharoptosis. Here we report a 38-year-old female with mitochondrial myopathy presented with chronic numbness and weakness of the limbs, accompanied by blepharoptosis that was recently noticed. Laboratory and head magnetic resonance imaging (MRI) examinations showed no obvious abnormalities. Muscle and nerve biopsies showed characteristic ragged red fibers (RRFs) and large aggregates of denatured mitochondria. Testing for mtDNA and nDNA showed a known mutation c.2857C>T (p.R953C) and a novel variant c.2391G>C (p.M797I) in the polymerase gamma (POLG)gene, so the patient was diagnosed as mitochondrial myopathy. Clinicians should pay more attention to long-term unexplained skeletal muscle diseases with recent onset blepharoptosis. Histopathologic examination and genetic testing are of great value in the early diagnosis and therapeutic intervention.

CASQ1-related myopathy: The first report from China and the literature review.

Calsequestrin 1 (CASQ1) is the most crucial Ca2+ binding protein localized in the sarcoplasmic reticulum (SR) of skeletal muscle. With high capacity and low affinity for Ca2+, CASQ1 plays a significant role in maintaining a large amount of Ca2+ necessary for muscle contraction. However, only five mutations in CASQ1 have been identified to date. Here, we report a 42-year-old Chinese female patient who presented with a 12 years history of slowly progressive upper limb weakness, predominantly affecting distal muscles, which was uncommon comparing to other CASQ1-related patients. Next-generation sequencing (NGS) analysis revealed a novel heterozygous mutation (c.766G > A, p.Val256Met) in CASQ1. Functional studies confirmed the likely pathogenicity of this variant. Muscle histopathology revealed rare optically empty vacuoles in myofibers and atypical eosinophilic granules in the cytoplasm, which has not been observed before. We also performed a literature review on all the pathogenic mutations in CASQ1 and summarized their genetic and clinical characteristics. This is the first report on CASQ1-related myopathy from China, further expanding the mutation spectrum of CASQ1 gene and provides new insights into the function of CASQ1.

Calcitriol increases MBNL1 expression and alleviates myotonic dystrophy phenotypes in HSALR mouse models.

BACKGROUND: Myotonic dystrophy type 1 (DM1), one of the most common forms of adult-onset muscular dystrophy, is caused by abnormally expanded CTG repeats in the 3' untranslated region of the DMPK gene. The CUG repeats transcribed from the expanded CTG repeats sequestrate a splicing factor, MBNL1, causing the clinical symptoms in DM1. Nowadays, only symptomatic treatments are available for DM1, and no rational therapy is available. Recently, upregulation of MBNL1 expression has been found to be one of the promising therapies for DM1. METHODS: All experiments were conducted in the C2C12 myoblasts and HSALR mice, a DM1 mouse model. Real-time PCR and western blot were used to detect the mRNA and protein level, respectively. The rotarod exercise, grip strength and hanging time were used to evaluate the muscle strength of mice. RESULTS: In this study, we demonstrated that calcitriol, an active form of vitamin D3, increased MBNL1 in C2C12 mouse myoblasts as well as in HSALR mice model for DM1. In HSALR mice model, calcitriol improved muscle strength, and corrected aberrant splicing in skeletal muscle. Besides, calcitriol reduced the number of central nuclei, and improved muscle histopathology in HSALR mice. In addition, we identified that calcitriol upregulated MBNL1 expression via activating the promoter of Mbnl1 in C2C12 myogenic cells. CONCLUSION: Our study suggests that calcitriol is a potential pharmacological strategy for DM1 that enhances MBNL1 expression.

Expanding the clinicopathological-genetic spectrum of glycogen storage disease type IXd by a Chinese neuromuscular center.

Background: Glycogen storage disease (GSDs) is characterized by abnormally inherited glycogen metabolism. GSD IXd, which is caused by mutations in the PHKA1 gene, is an X-linked rare disease with mild myopathic symptoms. To date, only 13 patients with GSD IXd have been reported. In this study, we aimed to expand the clinicopathological-genetic spectrum of GSD IXd at a neuromuscular center in China. Methods: Data on patients diagnosed with GSD IXd at our neuromuscular center were collected retrospectively. Clinical features, electrophysiology, muscle pathology, and genetic information were analyzed. Results: Between 2015 and 2021, three patients were diagnosed with GSD IXd based on clinical manifestations, pathological findings, and genetic testing. One patient presented with mitochondrial myopathy. All patients exhibited muscle weakness and elevated levels of creatine kinase. Electromyography-detected myopathic changes were found in two patients, whereas one patient refused to undergo this examination. Pathological examinations in all patients revealed subsarcolemmal accumulation of glycogen under PAS staining. All patients had mutations in the PHKA1 gene and the patient with mitochondrial myopathy also had a mutation in the MT-TL1 gene. Conclusion: Our study expands the clinicogenotype and phenotype of GSD IXd in a Chinese population. Our study also expands the known mutation spectrum for GSD IXd, contributing to a better characterization and understanding of this ultrarare neuromuscular disorder.

Integrating 16S RRNA gene sequencing and metabolomics to evaluate the association between gut microbiota and serum metabolites in patients with myositis.

AIMS: Gut microbiota and metabolites have a profound impact on the maintenance of body health. In this study, we assessed the association between gut microbiota and serum metabolite changes in myositis using 16S rRNA gene sequencing and metabolomics to provide new ideas for screening and treating myositis. METHODS AND RESULTS: Blood and faecal samples were collected from 20 myositis patients and 20 healthy control subjects. Then, 16S rRNA gene sequencing, enzyme-linked immunosorbent assays and untargeted metabolomics study were performed to evaluate the relationship between gut microbiota and serum metabolites in patients with myositis. Compared to healthy control subjects, the blood samples from the patients with myositis had elevated levels of interleukin-4 (IL-4), tumour necrosis factor-α (TNF-α), and malondialdehyde (MDA) and decreased superoxide dismutase (SOD) levels. The increase in Bacteroidota (including Bacteroides and Parabacteroides, but not Prevotella) and the decrease in Firmicutes in the patients were accompanied by functional changes in amino acid and lipid metabolism. The gut microbiota (Bacteroides and Parabacteroides) were negatively correlated with the differential serum metabolites (glutamate and taurine). The differential serum metabolites (glutamate, pyrrolidonecarboxylic acid, and taurine) were also correlated with inflammatory factors (IL-4 and TNF-α) and oxidative stress indexes (MDA and SOD). CONCLUSION: Dysbiosis of gut microbiota in patients with myositis was accompanied by changes in inflammatory factors, oxidative stress indexes, and small molecule metabolites in serum. SIGNIFICANCE AND IMPACT OF STUDY: Blood and faecal biomarkers could be used for screening myositis.

Clinicopathological-genetic features of congenital myasthenic syndrome from a Chinese neuromuscular centre.

Congenital myasthenic syndrome (CMS) encompasses a heterogeneous group of inherited disorders affecting nerve transmission across the neuromuscular junction. The aim of this study was to characterize the clinical, physiological, pathohistological and genetic features of nine unrelated Chinese patients with CMS from a single neuromuscular centre. A total of nine patients aged from neonates to 34 years were enrolled who exhibited initial symptoms. Physical examinations revealed that all patients exhibited muscle weakness. Muscle biopsies demonstrated multiple myopathological changes, including increased fibre size variation, myofibrillar network disarray, necrosis, myofiber grouping, regeneration, fibre atrophy and angular fibres. Genetic testing revealed six different mutated genes, including AGRN (2/9), CHRNE (1/9), GFPT1 (1/9), GMPPB (1/9), PLEC (3/9) and SCN4A (1/9). In addition, patients exhibited differential responses to pharmacological treatment. Prompt utilization of genetic testing will identify novel variants and expand our understanding of the phenotype of this rare syndrome. Our findings contribute to the clinical, pathohistological and genetic spectrum of congenital myasthenic syndrome in China.

Findings of limb-girdle muscular dystrophy R7 telethonin-related patients from a Chinese neuromuscular center.

Limb-girdle muscular dystrophy (LGMD) is a group of clinically and genetically heterogeneous neuromuscular disorders. LGMD-R7, which is caused by telethonin gene (TCAP) mutations, is one of the rarest forms of LGMD, and only a small number of LGMD-R7 cases have been described and mostly include patients from Brazil. A total of two LGMD-R7 patients were enrolled at a Chinese neuromuscular center. Demographic and clinical data were collected. Laboratory investigations and electromyography were performed. Routine and immunohistochemistry staining of muscle specimens was performed, and a next-generation sequencing panel array for genes associated with hereditary neuromuscular disorders was used for analysis. The patients exhibited predominant muscle weakness. Electromyography revealed myopathic changes. The muscle biopsy showed myopathic features, such as increased fiber size variation, muscle fiber atrophy and regeneration, slight hyperplasia of the connective tissue, and disarray of the myofibrillar network. Two patients were confirmed to have mutations in the open reading frame of TCAP by next-generation sequencing. One patient had compound heterozygous mutations, and the other patient harbored a novel homozygous mutation. Western blotting analysis of the skeletal muscle lysate confirmed the absence of telethonin in the patients. We described two LGMD-R7 patients presenting a classical LGMD phenotype and a novel homozygous TCAP mutation. Our research expands the spectrum of LGMD-R7 due to TCAP mutations based on patients from a Chinese neuromuscular center.

Expanding the clinicopathological-genetic spectrum of GNE myopathy by a Chinese neuromuscular centre.

GNE myopathy is a heterogeneous group of ultrarare neuromuscular disorders caused by mutations in the GNE gene. An estimated prevalence of 1~21/1,000,000 leads to a deficiency of data and a lack of availability of samples to conduct clinical research on this neuromuscular disorder. Although GNE, which is the mutated gene responsible for the disease, is well known as the key enzyme in the biosynthesis pathway of sialic acid, the clinicopathological-genetic spectrum of GNE mutant patients is still unclear and expanding. This study presents ten unrelated patients with GNE myopathy, discovering five novel missense mutations. Clinical, electrophysiological, imaging, pathological and genetic data are presented in a retrospective manner. Interestingly, several patients in the cohort were found to have peripheral neuropathy and inflammatory cell infiltration in muscle biopsies, which have seldom been reported. This study, conducted by a neuromuscular centre in China, is the first attempt to highlight these abnormal clinicopathological features and associate them with genetic mutations in GNE myopathy.

Clinicopathological features of titinopathy from a Chinese neuromuscular center.

Titin, one of the largest proteins in humans, is a major component of muscle sarcomeres. Pathogenic variants in the titin gene (TTN) have been reported to cause a range of skeletal muscle diseases, collectively known as titinopathy. Titinopathy is a heterogeneous group of disabling diseases characterized by muscle weakness. In our study, we aimed to establish the clinicopathological-genetic spectrum of titinopathy from a single neuromuscular center. Three patients were diagnosed as having definite titinopathy, and additional three patients were diagnosed as having possible titinopathy according to the diagnostic criteria. All the patients showed initial symptoms from age one to 40 years. Physical examination revealed that five patients had muscle weakness, and that one patient experienced behavioral changes. Muscle biopsy specimens obtained from all six patients demonstrated multiple myopathological changes, including increased fiber size variation, muscle fiber hypertrophy or atrophy, formation of centralized cell nuclei, necklace cytoplasmic bodies, and formation of rimmed vacuoles and cores. Genetic testing revealed 11 different TTN alterations, including missense (6/11), nonsense (2/11), frameshift (2/11), and splicing (1/11) mutations. Our study provides further evidence that TTN mutations are more likely to be responsible for an increasing proportion of various myopathies, such as hereditary myopathy with early respiratory failure (HMERF), core myopathy, and distal myopathy with rimmed vacuoles, than currently recognized mutations. Our findings expand the clinical, pathohistological and genetic spectrum of titinopathy.

The association between myositis-specific autoantibodies and muscle pathologies in idiopathic inflammatory myopathies.

OBJECTIVE: To investigate specific muscle pathologies of different kinds of myositis-specific autoantibodies (MSAs) in idiopathic inflammatory myopathy (IIM) patients. METHODS: One hundred eleven Chinese patients from Xiangya Hospital, Central South University diagnosed with IIMs according to European Neuromuscular Centre (ENMC) criteria were included. Clinical manifestation, myositis-specific autoantibodies, and histologic findings were evaluated to explore the pattern of necrosis, regeneration, and perifascicular atrophy, inflammatory cells in IIM patients with different MSAs. RESULTS: Anti-SRP group has the lowest muscle strength scores, the highest creatine kinase levels, the most severe degree of necrosis and regeneration (1.90[0.80-3.95], 1.00[0.30-1.71]), and the lowest positive rate of MHC-I staining (35.71%). The anti-MDA5 group demonstrates the mildest pathological changes, with the fewest necrotic and regenerated muscle fibers (0.00[0.00-0.50], 0.00[0.00-0.00]), and the fewest inflammatory cell infiltration, and the highest muscle strength scores. The anti-NXP2 group has the most frequent inflammatory infiltrates, especially CD4+ T cells (31.14[15.00-39.00]). The patients with anti-NXP2 and the anti-TIF1γ antibodies show higher frequency of punched-out fibers (1.50[0.00-3.70], 0.00[0.00-1.00]) and perifascicular atrophy (71.43%, 55.56%). As for anti-synthetase antibodies (ASAs), the anti-Jo-1 group shows the most frequent rate of perifascicular necrosis (60%), while other ASA groups do not show perifascicular necrosis. CONCLUSIONS: Of the MSAs, the anti-SRP antibody leads to the most severe muscle involvement, while the anti-MAD5 antibody the mildest. The anti-NXP2 and anti-TIF1γ groups have the most typical "DM" pathology. Key Points • Anti-SRP group shows severe muscle pathology while anti-MDA5 group shows the mildest. • Anti-NXP2 group has the most frequent inflammatory infiltrates. Pouch-out fibers and perifascicular atrophy are more prevalent in anti-NXP2 and anti-TIF1γ groups. • Anti-Jo-1 group is often accompanied by perifascicular necrosis, while other anti-synthetase antibody groups are not.

PKM2-dependent glycolysis promotes skeletal muscle cell pyroptosis by activating the NLRP3 inflammasome in dermatomyositis/polymyositis.

OBJECTIVES: Muscle cell necrosis is the most common pathological manifestation of idiopathic inflammatory myopathies. Evidence suggests that glycolysis might participate in it. However, the mechanism is unclear. This study aimed to determine the role of glycolysis in the muscle damage that occurs in DM/PM. METHODS: Mass spectrometry was performed on muscle lesions from DM/PM and control subjects. The expression levels of pyruvate kinase isozyme M2 (PKM2), the nucleotide-binding and oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome and pyroptosis-related genes in muscle tissues or plasma were determined by real-time PCR, western blot analysis, IF and ELISA. In addition, IFNγ was used to stimulate myotubes, and the relationships among PMK2 expression, NLRP3 inflammasome activation and pyroptosis were investigated. RESULTS: Mass spectrometry and bioinformatics analysis suggested that multiple glycolysis processes, the NLRP3 inflammasome and programmed cell death pathway-related proteins were dysregulated in the muscle tissues of DM/PM. PKM2 and the NLRP3 inflammasome were upregulated and positively correlated in the muscle fibres of DM/PM. Moreover, the pyroptosis-related proteins were increased in muscle tissues of DM/PM and were further increased in PM. The levels of PKM2 in muscle tissues and IL-1ß in plasma were high in patients with anti-signal recognition particle autoantibody expression. The pharmacological inhibition of PKM2 in IFNγ-stimulated myotubes attenuated NLRP3 inflammasome activation and subsequently inhibited pyroptosis. CONCLUSION: Our study revealed upregulated glycolysis in the lesioned muscle tissues of DM/PM, which activated the NLRP3 inflammasome and leaded to pyroptosis in muscle cells. The levels of PKM2 and IL-1ß were high in patients with anti-signal recognition particle autoantibody expression. These proteins might be used as new biomarkers for muscle damage.

Expanding the Clinico-Genetic Spectrum of Myofibrillar Myopathy: Experience From a Chinese Neuromuscular Center.

Background: Myofibrillar myopathy is a group of hereditary neuromuscular disorders characterized by dissolution of myofibrils and abnormal intracellular accumulation of Z disc-related proteins. We aimed to characterize the clinical, physiological, pathohistological, and genetic features of Chinese myofibrillar myopathy patients from a single neuromuscular center. Methods: A total of 18 patients were enrolled. Demographic and clinical data were collected. Laboratory investigations, electromyography, and cardiac evaluation was performed. Routine and immunohistochemistry stainings against desmin, αB-crystallin, and BAG3 of muscle specimen were carried out. Finally, next-generation sequencing panel array for genes associated with hereditary neuromuscular disorders were performed. Results: Twelve pathogenic variants in DES, BAG3, FLNC, FHL1, and TTN were identified, of which seven were novel mutations. The novel DES c.1256C>T substitution is a high frequency mutation. The combined recessively/dominantly transmitted c.19993G>T and c.107545delG mutations in TTN gene cause a limb girdle muscular dystrophy phenotype with the classical myofibrillar myopathy histological changes. Conclusions: We report for the first time that hereditary myopathy with early respiratory failure patient can have peripheral nerve and severe spine involvement. The mutation in Ig-like domain 16 of FLNC is associated with the limb girdle type of filaminopathy, and the mutation in Ig-like domain 18 with distal myopathy type. These findings expand the phenotypic and genotypic correlation spectrum of myofibrillar myopathy.

Investigation of adult-onset multiple acyl-CoA dehydrogenase deficiency associated with peripheral neuropathy.

Multiple Acyl-CoA dehydrogenase deficiency (MADD), one of the most common lipid storage myopathies (LSMs), is a heterogeneous inherited muscular disorder that is pathologically characterized by numerous lipid droplets in muscle fibers due to lipid metabolism disturbance. MADD exhibits a wide range of clinical features, including skeletal muscle weakness and multisystem dysfunctions. However, MADD, as well as other types of LSM, associated with peripheral neuropathy has rarely been reported during the past four decades. Here, we present four Chinese patients affected by MADD with peripheral neuropathy in our neuromuscular center. Clinically, these four patients showed skeletal muscle weakness and prominent paresthesia. Muscle biopsy detected characteristic myopathological patterns of LSM, such as obvious lipid droplets in muscle fibers. Sural nerve biopsy revealed a severe reduction in number of myelinated nerve fibers, which is a typical neuropathological pattern of peripheral neuropathy. Causative ETFDH mutations were found in all four cases. The skeletal muscle weakness was rapidly improved after some treatments while paresthesia showed unsatisfactory improvement. The features of previously reported patients of this specific type are also summarized in this paper. We propose that MADD with peripheral neuropathy may be a new phenotypic subtype because the pathology and reaction to riboflavin treatment are different from those of traditional MADD, although further research on the precise pathogenesis and mechanisms is needed.