OBJECTIVE: To elucidate the epidemiological characteristics and genetic variant profile of Short-chain acyl-CoA dehydrogenase deficiency (SCADD) among newborns from Hainan Province and evaluate its significance within the local neonatal disease screening panel. METHODS: A total of 84 184 newborns born in Hainan Province from February to December 2024 were included. Tandem mass spectrometry (MS/MS) was employed to detect butyrylcarnitine (C4) and propionylcarnitine (C3) levels in dried blood spots. Screening thresholds were set at C4 > 0.43 μ mol/L and C4/C3 ratio > 0.28. Suspected cases underwent confirmatory testing via urinary ethylmalonic acid analysis by gas chromatography-mass spectrometry and whole-exome sequencing for ACADS gene variants. This study was approved by the Medial Ethics Committee of the hospital (Ethics No.: HNWCMC-2024-55). RESULTS: Six SCADD cases (male-to-female ratio = 1:1) were diagnosed, with all carrying compound heterozygous variants at two loci, yielding a prevalence of 7.13 per 100,000 live births. Four known ACADS gene variants were identified, with both c.322G>A and c.625G>A detected at a frequency of 41.7%. Regular follow-up (as of January 2026) revealed that all diagnosed cases have remained asymptomatic with normal growth and development. CONCLUSION The prevalence of SCADD among newborns in Hainan Province is relatively high, with c.322G>A and c.625G>A as the hotspot variants in the region. Given the absence of clinical phenotypes in all screen-detected cases during long-term follow-up, it is recommended to remove this condition from the routine neonatal screening program for this region to reduce unnecessary anxiety and medical cost.
Humans ; Infant, Newborn ; Neonatal Screening/methods* ; Female ; Male ; Lipid Metabolism, Inborn Errors/epidemiology* ; Acyl-CoA Dehydrogenase/genetics* ; China/epidemiology* ; Follow-Up Studies

Currently, the incidence of Parkinson's disease (PD) is on the rise. More and more evidences suggest that mitochondrial dysfunction plays a crucial role in the etiology of PD, and dysfunction of mitochondrial complex I (MCI) is one of the most critical factors leading to mitochondrial dysfunction. On one hand, MCI dysfunction stimulates dopaminergic neurons to produce reactive oxygen species (ROS). On the other hand, MCI dysfunction decreases dopaminergic neuron viability and reduces ATP production. All these outcomes promote the pathological progression of PD. This review summarizes research progress on the role of MCI in the pathogenesis of PD, as well as PD treatment strategies based on MCI.
Parkinson Disease/metabolism* ; Humans ; Electron Transport Complex I/metabolism* ; Mitochondria/physiology* ; Reactive Oxygen Species/metabolism* ; Dopaminergic Neurons/metabolism* ; Animals ; Adenosine Triphosphate/metabolism*

Flavoprotein monooxygenases(FPMOs) and cytochrome P450(CYP450) oxygenases are pivotal monooxygenases in nature, catalyzing crucial redox reactions in diverse biological processes and contributing to the synthesis of highly complex natural products. While CYP450 enzymes have been extensively reported and studied, numerous FPMOs have also been discovered in past research endeavors, yet their classification, catalytic reactions, and catalytic mechanisms remain to be systematically analyzed. This paper comprehensively reviews the latest advancements in FPMOs research, initiating with a classification based on sequence similarities and distinct structural features. It delves into the catalytic characteristics of three subfamilies(FMO, BVMO, and NMO) within Class B FPMOs of plants, which are integral to biosynthetic pathways of natural products. Class B FPMOs encompass two canonical Rossmann fold motifs(FAD-binding GxGxxG and NADPH-binding GxGxxA), along with a central FMO recognition motif FxGxxxHxxxF/Y/W. These enzymes play a key role in regulating various metabolic routes and precisely modulate plant growth and development. Furthermore, the review summarizes the applications of Class B FPMOs of plants, showcasing through concrete examples their potential in synthesizing natural products such as auxins, indigo, and cyanogenic glycosides. These insights will broaden and deepen our understanding of FPMOs, fostering their transition from fundamental research to practical applications. More optimized biosynthetic pathways can be devised by leveraging FPMOs, conducive to the development of novel strategies and tools for agriculture, plant protection, natural product biosynthesis, and synthetic biology.
Biological Products/metabolism* ; Mixed Function Oxygenases/chemistry* ; Flavoproteins/chemistry* ; Plants/metabolism* ; Plant Proteins/chemistry* ; Cytochrome P-450 Enzyme System/genetics*

OBJECTIVES: To investigate the effect of downregulation of medium-chain acyl-coenzyme A dehydrogenase (ACADM) on invasion and migration of estrogen receptor-positive breast cancer cells and the underlying mechanism. METHODS: The Kaplan-Meier Plotter database was used to analyze the ACADM expression levels in breast cancer and normal tissues and their association with patient prognosis. Human breast cancer MCF-7 and T47D cell lines with lentivirus-mediated ACADM knockdown were established, and their in situ tumor formation and metastasis after tail vein injection were evaluated in nude mice. The MCF-7 and T47D cells with ACADM knockdown and their unmodified parental cells were examined with oil-red O staining assay, ROS assay, mitochondrial respiratory chain function assay before and after treatments with ROS scavenger, Elamipretide (a cardiolipin oxidation inhibitor) or SC79 (an AKT activator), and the changes in migration and invasion abilities of the treated cells were analyzed with Transwell invasion assay and Boyden chamber assay. Western blotting was used to detect protein expression levels of related signaling pathways in the treated cells. RESULTS: ACADM overexpression was associated with a significantly shorter overall survival of breast cancer patients. In MCF-7 and T47D cells, ACADM knockdown resulted in downregulation of N calnexin, vimentin, p-P13K and p-AKT proteins, increased levels of free fatty acids and reactive oxygen species, lowered activities of mitochondrial respiratory chain complex III and V, and reduced mitochondrial inner phospholipids. ACADM knockdown significantly decreased the invasive capacity of the cells, which were obviously reversed by treatment with ROS scavenger, Elamipretide, and SC79. CONCLUSIONS Down-regulation of ACADM inhibits migration and invasion ability of estrogen receptor-positive breast cancer cells by lowering lipotoxicity and impairing mitochondrial function through the ROS/PI3K/AKT pathway.
Humans ; Breast Neoplasms/metabolism* ; Female ; Mice, Nude ; Down-Regulation ; Neoplasm Invasiveness ; Animals ; Mice ; Receptors, Estrogen/metabolism* ; MCF-7 Cells ; Cell Movement ; Cell Line, Tumor ; Reactive Oxygen Species/metabolism* ; Acyl-CoA Dehydrogenase/genetics* ; Signal Transduction ; Neoplasm Metastasis ; Proto-Oncogene Proteins c-akt/metabolism*

OBJECTIVES: To investigate the genotypes and biochemical phenotypes of neonates with abnormal metabolism of butyrylcarnitine (C4). METHODS: One hundred and twenty neonates with increased C4 levels detected by tandem mass spectrometry in the neonatal screening at Children's Hospital, Zhejiang University School of Medicine from January 2018 to June 2023 were included. The initial screening data and recalled data of C4 and C4/C3 were collected and converted into multiples of C4 reference range. Next generation sequencing was performed and the exons with adjacent 50 bp regions of <i>ACAD8i> and <i>ACADSi> genes were captured by liquid phase capture technique. Variant information was obtained by bioinformatic analysis and the pathogenicity were classified according to the American College of Medical Genetics and Genomics criteria. The Wilcoxon rank sum test was used to analyze the differences in C4 levels among neonates with different variation types. RESULTS: In total, 32 variants in <i>ACAD8i> gene were detected, of which 7 variants were reported for the first time; while 41 variants of <i>ACADSi> gene were detected, of which 17 variants have not been previously reported. There were 39 cases with <i>ACAD8i> biallelic variations and 3 cases with <i>ACAD8i> monoallelic variations; 34 cases with <i>ACADSi> biallelic variations and 36 cases with <i>ACADSi> monoallelic variations. Furthermore, 5 cases were detected with both <i>ACAD8i> and <i>ACADSi> gene variations. Inter group comparison showed that the multiples of C4 reference range in initial screening and re-examination of the <i>ACAD8i> biallelic variations and <i>ACADSi> biallelic variations groups were significantly higher than those of the <i>ACADSi> monoallelic variations group (all <i>Pi><0.01), while the multiples in the <i>ACAD8i> biallelic variations group were significantly higher than those in the <i>ACADSi> biallelic variations group (all <i>Pi><0.01). The multiples of C4 reference range in the initial screening greater than 1.5 times were observed in all neonates carrying <i>ACAD8i> or <i>ACADSi> biallelic variations, while only 25% (9/36) in neonates carrying <i>ACADSi> monoallelic variations. CONCLUSIONS <i>ACAD8i> and/or <i>ACADSi> gene variants are the main genetic causes for elevated C4 in newborns in Zhejiang region with high genotypic heterogeneity. The C4 levels of neonates with biallelic variations are significantly higher than those of neonates with monoallelic variations. The cut-off value for C4 level could be modestly elevated, which could reduce the false positive rate in tandem mass spectrometry neonatal screening.
Child ; Humans ; Infant, Newborn ; Acyl-CoA Dehydrogenase/genetics* ; Genotype ; Phenotype ; Carnitine/metabolism* ; Mutation

OBJECTIVE: To explore the clinical and genetic characteristics of four patients with medium-chain acyl-CoA dehydrogenase deficiency (MCADD). METHODS: Four children who had presented at the Children's Hospital Affiliated to Zhengzhou University between August 2019 and August 2021 were selected as the study subjects. Clinical data of the children were collected. The children were subjected to whole exome sequencing (WES). RESULTS: All of the four children were diagnosed with MCADD. Blood amino acid and ester acyl carnitine spectrum test showed that the concentration of octanoyl carnitine (C8) was significantly increased. The main clinical manifestations included poor mental response (3 cases), intermittent diarrhea with abdominal pain (1 case), vomiting (1 case), increased transaminase (3 cases), and metabolic acidosis (2 cases). Five variants were identified by genetic testing, among which c.341A>G (p.Y114C) was unreported previously. Three were missense variants, one was frameshift variant and one was splicing variant. CONCLUSION The clinical heterogeneity of MCADD is obvious, and the severity of the disease may vary. WES can assist with the diagnosis. Delineation of the clinical symptoms and genetic characteristics of the disease can facilitate early diagnosis and treatment of the disease.
Child ; Humans ; Acyl-CoA Dehydrogenase/genetics* ; Carnitine ; Genetic Testing ; Lipid Metabolism, Inborn Errors/genetics* ; Neonatal Screening

Objective:b> To investigate the clinicopathological features, immunophenotype, ultrastructure, genetic alterations and prognosis of succinate dehydrogenase-deficient renal cell carcinoma (SDH RCC). Methods:b> A total of 11 SDH RCCs, diagnosed from 2010 to 2019, were selected from the Department of Pathology of Nanjing Jingling Hospital, Nanjing University School of Medicine for clinicopathologic, immunohistochemical (IHC), ultrastructural investigation and follow-up. The molecular features of seven cases were analyzed by the panel-targeted DNA next generation sequencing (NGS). Results:b> There were seven males and four females, with ages ranging from 24 to 62 years (mean 41.4 years, median 41 years). Microscopically, SDH RCC was mainly composed of solid and tubular structures with local cystic change. Four cases showed nested or trabecular structure distributed in a loose hypocellular connective tissue or around scar, similar to oncocytoma. The neoplastic cells demonstrated flocculent eosinophilic cytoplasm with typical intracytoplasmic vacuoles. Immunohistochemically, eight cases were negative for SDHB; three cases showed focal and weak expression, whereas normal renal tubular and vascular endothelial cells demonstrated strong cytoplasmic staining. NGS of DNA targeted-panel detected pathogenic mutations of SDHB gene in seven cases (including three cases with equivocal IHC expression of SDHB), without any mutations in other SDH related genes. There were four cases of SDHB missense mutation, one case of frameshift mutation, one case of splicing mutation, and one case of acquired stop codon mutation. Conclusions:b> SDH RCC is a distinct variant of RCCs with genetic tendency or with hereditary cancer syndrome. NGS is recommended to detect the related gene mutations for a definitive diagnosis. The patients should be closely followed up.
Adult ; Carcinoma, Renal Cell/genetics* ; Endothelial Cells ; Female ; Humans ; Kidney Neoplasms/genetics* ; Male ; Middle Aged ; Prognosis ; Succinate Dehydrogenase/genetics* ; Young Adult

Bone regeneration remains a great clinical challenge. Low intensity near-infrared (NIR) light showed strong potential to promote tissue regeneration, offering a promising strategy for bone defect regeneration. However, the effect and underlying mechanism of NIR on bone regeneration remain unclear. We demonstrated that bone regeneration in the rat skull defect model was significantly accelerated with low-intensity NIR stimulation. In vitro studies showed that NIR stimulation could promote the osteoblast differentiation in bone mesenchymal stem cells (BMSCs) and MC3T3-E1 cells, which was associated with increased ubiquitination of the core circadian clock protein Cryptochrome 1 (CRY1) in the nucleus. We found that the reduction of CRY1 induced by NIR light activated the bone morphogenetic protein (BMP) signaling pathways, promoting SMAD1/5/9 phosphorylation and increasing the expression levels of Runx2 and Osterix. NIR light treatment may act through sodium voltage-gated channel Scn4a, which may be a potential responder of NIR light to accelerate bone regeneration. Together, these findings suggest that low-intensity NIR light may promote in situ bone regeneration in a CRY1-dependent manner, providing a novel, efficient and non-invasive strategy to promote bone regeneration for clinical bone defects.
Animals ; Rats ; Bone Morphogenetic Protein 2/metabolism* ; Bone Regeneration ; Cell Differentiation ; Circadian Clocks ; Cryptochromes/metabolism* ; Osteoblasts/metabolism* ; Osteogenesis ; Transcription Factors/metabolism*

Flavoproteins are proteins that contain a nucleic acid derivative of riboflavin: flavin adenine dinucleotide (FAD) or flavin mononucleotide (FMN). Flavoproteins are involved in a wide array of biological processes, such as photosynthesis, DNA repair and natural product biosynthesis. It should be noted that 5%-10% of flavoproteins have a covalently linked flavin prosthetic group. Such covalent linkages benefit the holoenzyme in several ways including improving the stability and catalytic potency. During the past decade, significant progress has been made in covalent flavoproteins, especially with respect to enzyme-dependent biogenesis and discovery of novel linkage types. The present review gives a condensed overview of investigations published from March 2009 to December 2021, with emphasis on the discovery, biogenesis and their catalytic role in natural product biosynthesis.
Flavoproteins/metabolism* ; Flavin-Adenine Dinucleotide/metabolism* ; Flavin Mononucleotide/metabolism* ; Riboflavin ; Biological Products

OBJECTIVE: To analyze the distribution characteristics of hereditary peripheral neuropathy (HPN) pathogenic genes in Chinese Han population, and to explore the potential pathogenesis and treatment prospects of HPN and related diseases. METHODS: Six hundred and fifty-six index patients with HPN were enrolled in Peking University Third Hospital and China-Japan Friendship Hospital from January 2007 to May 2022. The <i>PMP22i> duplication and deletion mutations were screened and validated by multiplex ligation probe amplification technique. The next-generation sequencing gene panel or whole exome sequencing was used, and the suspected genes were validated by Sanger sequencing. RESULTS: Charcot-Marie-Tooth (CMT) accounted for 74.3% (495/666) of the patients with HPN, of whom 69.1% (342/495) were genetically confirmed. The most common genes of CMT were <i>PMP22i> duplication, <i>MFN2i> and <i>GJB1i> mutations, which accounted for 71.3% (244/342) of the patients with genetically confirmed CMT. Hereditary motor neuropathy (HMN) accounted for 16.1% (107/666) of HPN, and 43% (46/107) of HPN was genetically confirmed. The most common genes of HMN were HSPB1, aminoacyl tRNA synthetases and <i>SORDi> mutations, which accounted for 56.5% (26/46) of the patients with genetically confirmed HMN. Most genes associated with HMN could cause different phenotypes. HMN and CMT shared many genes (<i>e.g. HSPB1i>, <i>GARSi>, <i>IGHMBP2i>). Some genes associated with dHMN-plus shared genes associated with amyotrophic lateral sclerosis (<i>KIF5Ai>, <i>FIG4i>, <i>DCTN1i>, <i>SETXi>, <i>VRK1i>), hereditary spastic paraplegia (<i>KIF5Ai>, <i>ZFYVE26i>, <i>BSCL2i>) and spinal muscular atrophy (<i>MORC2i>, <i>IGHMBPi>, <i>DNAJB2i>), suggesting that HMN was a continuum rather than a distinct entity. Hereditary sensor and autosomal neuropathy (HSAN) accounted for a small proportion of 2.6% (17/666) in HPN. The most common pathogenic gene was <i>SPTLC1i> mutation. <i>TTRi> was the main gene causing hereditary amyloid peripheral neuropathy. The most common types of gene mutations were p.A117S and p.V50M. The symptoms were characterized by late-onset and prominent autonomic nerve involvement. CONCLUSION CMT and HMN are the most common diseases of HPN. There is a large overlap between HMN and motor-CMT2 pathogenic genes, and some HMN pathogenic genes overlap with amyotrophic lateral sclerosis, hereditary spastic hemiplegia and spinal muscular atrophy, suggesting that there may be a potential common pathogenic pathway between different diseases.
Amyotrophic Lateral Sclerosis ; Charcot-Marie-Tooth Disease/genetics* ; DNA Helicases/genetics* ; DNA-Binding Proteins/genetics* ; Flavoproteins ; HSP40 Heat-Shock Proteins ; Humans ; Intracellular Signaling Peptides and Proteins/genetics* ; Kinesins ; Ligases/genetics* ; Molecular Chaperones ; Multifunctional Enzymes ; Muscular Atrophy, Spinal/genetics* ; Mutation ; Phosphoric Monoester Hydrolases ; Protein Serine-Threonine Kinases ; RNA Helicases/genetics* ; RNA, Transfer ; Transcription Factors/genetics*