Introduction: Dopaminomas or dopamine-secreting pheochromocytomas are rare neuroendocrine tumors that frequently lack the classic paroxysmal symptoms of catecholamine excess (headache, sweating, palpitation). Diagnosing these tumors is exceptionally challenging when biochemical markers— specifically markedly elevated urinary dopamine—are interpreted in patients receiving exogenous Levodopa (L-DOPA) therapy, as the intake obscures clinical significance. Case: A 76-year-old male with ischemic heart disease, stage 4 chronic kidney disease, and new-onset hypertension was admitted for acute cholecystitis. Imaging studies incidentally revealed bilateral adrenal masses and demonstrated lipid-rich characteristics upon further evaluation with computed tomography (CT) adrenal washout. Biochemical evaluation revealed extreme elevations in 24-hour urinary dopamine (47,534 nmol/24 hours; normal <3,237) and 3-methoxytyramine (18.93 µmol/24 hours; normal <2.60), whereas downstream urinary noradrenaline (5.0 nmol/24 hours; normal 71.5–505.3), adrenaline (4.0 nmol/24 hours; normal 9.2–122.3), normetanephrine (0.22 µmol/24 hours; normal 0.88–2.88), and metanephrine (0.25 µmol/24 hours; normal 0.33–1.53) levels were all significantly below their respective reference ranges. The diagnosis was complicated by the patient’s concurrent use of L-DOPA/Benserazide for flupentixol-induced parkinsonism. L-DOPA is a direct precursor to dopamine; its administration can cause massive, false-positive elevations in urinary dopamine, mimicking a dopaminoma’s biochemical signature. However, the unique combination of profoundly high dopamine alongside suppressed downstream catecholamines and metanephrines suggested a true dopaminesecreting tumor—potentially secondary to dopamine beta-hydroxylase (DBH) deficiency—rather than drug interference. Conclusion This case illustrates the profound difficulty in diagnosing dopaminoma when exogenous L-DOPA therapy creates a near-identical biochemical profile. The diagnostic dilemma is further amplified by vague symptomatology, multiple comorbidities, and non-suggestive imaging. However, the finding of isolated dopamine hypersecretion with suppressed metanephrines serves as a critical clinical clue. This pattern points toward an intratumoral biosynthetic defect rather than drug interference. Clinicians must maintain a high index of suspicion and perform meticulous biochemical fractionation to identify these rare, dopamineisolated secreting tumors.
Dopamine ; Levodopa

Nigella sativa L. seeds have been traditionally utilized in Chinese folk medicine for centuries to treat vitiligo. This study revealed that the ethanolic extract of Nigella sativa L. (HZC) enhances melanogenesis and mitigates oxidative stress-induced cellular senescence and dysfunction in melanocytes. In accordance with established protocols, the ethanol fraction from Nigella sativa L. seeds was extracted, concentrated, and lyophilized to evaluate its herbal effects via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays, tyrosinase activity evaluation, measurement of cellular melanin contents, scratch assays, senescence-associated β-galactosidase (SA-β-gal) staining, enzyme-linked immunosorbent assay (ELISA), and Western blot analysis for expression profiling of experimentally relevant proteins. The results indicated that HZC significantly enhanced tyrosinase activity and melanin content while notably increasing the protein expression levels of Tyr, Mitf, and gp100 in B16F10 cells. Furthermore, HZC effectively mitigated oxidative stress-induced cellular senescence, improved melanocyte condition, and rectified various functional impairments associated with melanocyte dysfunction. These findings suggest that HZC increases melanin synthesis in melanocytes through the activation of the MAPK, PKA, and Wnt signaling pathways. In addition, HZC attenuates oxidative damage induced by H₂O₂ therapy by activating the nuclear factor E2-related factor 2-antioxidant response element (Nrf2-ARE) pathway and enhancing the activity of downstream antioxidant enzymes, thus preventing premature senescence and dysfunction in melanocytes.
Oxidative Stress/drug effects* ; Melanocytes/cytology* ; Cellular Senescence/drug effects* ; Nigella sativa/chemistry* ; Plant Extracts/pharmacology* ; Seeds/chemistry* ; Mice ; Animals ; Melanins/metabolism* ; Monophenol Monooxygenase/metabolism* ; Humans

Eight previously undescribed lanostane triterpenoids, including five nortriterpenoids with 26 carbons, ganothenoids A-E (1-5), and three lanostanoids, ganothenoids F-H (6-8), along with 24 known ones (9-32), were isolated from the fruiting bodies of Ganodrma theaecolum. The structures of the novel compounds were elucidated using comprehensive spectroscopic methods, including electronic circular dichroism (ECD) and nuclear magnetic resonance (NMR) calculations. Compounds 1-32 were assessed for their neuroprotective effects against H₂O₂-induced damage in human neuroblastoma SH-SY5Y cells, as well as their inhibitory activities against protein tyrosine phosphatase 1B (PTP1B) and α-glucosidase. Compound 4 demonstrated the most potent neuroprotective activity against H₂O₂-induced oxidative stress by suppressing G₀/G₁ phase cell cycle arrest, reducing reactive oxygen species (ROS) levels, and inhibiting cell apoptosis through modulation of B-cell lymphoma 2 protein (Bcl-2) and Bcl-2 associated X-protein (Bax) protein expression. Compounds 26, 12, and 28 exhibited PTP1B inhibitory activities with IC₅₀ values ranging from 13.92 to 56.94 μmol·L^-1, while compound 12 alone displayed significant inhibitory effects on α-glucosidase with an IC₅₀ value of 43.56 μmol·L^-1. Additionally, enzyme kinetic analyses and molecular docking simulations were conducted for compounds 26 and 12 with PTP1B and α-glucosidase, respectively.
Humans ; Fruiting Bodies, Fungal/chemistry* ; Triterpenes/isolation & purification* ; Neuroprotective Agents/isolation & purification* ; Protein Tyrosine Phosphatase, Non-Receptor Type 1/metabolism* ; Ganoderma/chemistry* ; Apoptosis/drug effects* ; Hypoglycemic Agents/isolation & purification* ; Molecular Structure ; alpha-Glucosidases/metabolism* ; Cell Line, Tumor ; Reactive Oxygen Species/metabolism* ; Oxidative Stress/drug effects* ; Hydrogen Peroxide/toxicity* ; Molecular Docking Simulation

Objective To investigate the effect of FUNDC1 tyrosine phosphorylation site mutations on mitophagy in H9c2 myocardial cells by constructing tyrosine site mutant plasmids (Y11 and Y18) of the FUN14 domain-containing protein 1 (FUNDC1). Methods The mutant plasmids constructed by whole-gene synthesis were transfected into rat myocardial H9c2 cells and divided into five groups: empty plasmid group, FUNDC1 overexpression group, Y11 mutant group, Y18 mutant group, and Y11 combined with Y18 mutant group. The viability of H9c2 cells was assessed using the CCK-8 assay. Additionally, tetramethylrhodamine ethyl ester (TMRE) staining was utilized to detect mitochondrial membrane potential. The protein expression levels of FUNDC1, translocase of the outer mitochondrial membrane 20 (TOM20), and cytochrome c oxidase IV (COX IV) were detected by Western blot analysis. Confocal microscopy was used to evaluate transfection efficiency as well as the co-localization of mitochondria and lysosomes. Results The FUNDC1 overexpression, Y11, Y18, and Y11 combined with Y18 mutant plasmids were successfully constructed. After plasmid transfection, widespread GFP fluorescence expression was observed under confocal microscopy. Compared with the empty plasmid group, FUNDC1 protein expression levels were significantly increased in the FUNDC1 overexpression group, Y11 mutation group, Y18 mutation group, and Y11 combined with Y18 mutation group, while cell viability and mitochondrial membrane potential showed no significant changes. Compared to the empty plasmid group, cells transfected with Y18 and Y11 combined with Y18 mutant plasmids showed increased TOM20 and COX IV expression levels and decreased mitochondrial-lysosomal co-localization. Conclusion Transfection with FUNDC1 Y18 or Y11 combined with Y18 mutant plasmids inhibited mitophagy in H9c2 myocardial cells.
Animals ; Rats ; Mitophagy/genetics* ; Myocytes, Cardiac/cytology* ; Mitochondrial Proteins/metabolism* ; Mutation ; Phosphorylation ; Tyrosine/genetics* ; Cell Line ; Membrane Proteins/metabolism* ; Membrane Potential, Mitochondrial

L-tyrosine is one of the 20 amino acids that make up proteins and is an essential amino acid for mammals, often used as a nutritional supplement. The conventional methods for synthesizing L-tyrosine have some problems such as the production of many by-products, high requirements for production conditions, and environmental pollution. In this study, we designed and constructed a multi-enzyme cascade for the synthesis of L-tyrosine with alanine, glutamate, ammonium chloride, and phenol as substrates. Initially, the sources of glutamate oxidase, alanine aminotransferase, and tyrosine phenol lyase were screened and analyzed, which was followed by the identification of the rate-limiting enzyme in the reaction process. A colorimetric screening method was established, and the rate-limiting enzyme DbAlaA was engineered to enhance its activity by 40.0%. Subsequently, the reaction conditions, including temperature, pH, cell concentration, and surfactant and coenzyme dosages, were optimized. After optimization, the yield of L-tyrosine reached 9.93 g/L, with a alanine conversion rate of 54.90%. Finally, a feed-batch fermentation strategy was adopted, and the yield of L-tyrosine reached 56.07 g/L after 24 h, with a alanine conversion rate of 65.22%. This study provides a reference for the whole-cell catalytic synthesis of L-tyrosine and its industrialization.
Tyrosine/biosynthesis* ; Escherichia coli/metabolism* ; Tyrosine Phenol-Lyase/genetics* ; Multienzyme Complexes/metabolism* ; Fermentation

Protein tyrosine phosphatases (PTPs, EC 3.1.3.48) are key regulators of cellular processes, with the catalytic activity attributed to the conserved motif (H/V)CX₅R(S/T), where cysteine and arginine residues are critical. Previous studies revealed that alternative splicing of extracellular phosphatase mRNA precursors in Metarhizium anisopliae generated two distinct transcripts, with the longer sequence containing a novel HCPTPMLS motif resembling PTP signatures but lacking the arginine residue. To identify the novel signature motif and characterize its enzymatic properties, we heterologously expressed and purified both proteins in Pichia pastoris and comprehensively characterized their enzymatic properties. The protein containing the HCPTPMLS motif (designated as L-protein) exhibited the highest activity at pH 5.5 and a strong preference for pTyr substrates. Its phosphatase activity was inhibited by Ag⁺, Zn²⁺, Cu²⁺, molybdate, and tungstate, but enhanced by Ca²⁺ and EDTA. AcP101 (lacking HCPTPMLS) showed the maximal activity at pH 6.5 and a strong preference toward pNPP (P < 0.05), with the activity inhibited by NaF and tartrate, but enhanced by Mg²⁺ and Mn²⁺. Functional analysis confirmed that the L-protein retained the PTP activity despite the absence of arginine in its signature motif, while AcP101 functioned as an acid phosphatase. This study provides the first functional validation of an arginine-deficient PTP motif, expanding the definition of PTP signature motifs and offering new insights for phosphatase classification.
Metarhizium/genetics* ; Protein Tyrosine Phosphatases/chemistry* ; Amino Acid Motifs ; Recombinant Proteins/biosynthesis* ; Amino Acid Sequence ; Pichia/metabolism* ; Fungal Proteins/chemistry* ; Substrate Specificity ; Saccharomycetales

OBJECTIVES: To study clinical manifestations and gene mutation features of neonates with centronuclear myopathy. METHODS: A retrospective analysis was conducted on the medical data of 5 neonates with centronuclear myopathy diagnosed in the Neonatal Intensive Care Unit of Children's Hospital, Zhejiang University School of Medicine from January 2020 to August 2024. The data included gender, gestational age, birth weight, Apgar score, clinical manifestations, creatine kinase level, electromyography, genetic testing results and the outcomes of the infants. RESULTS: All 5 male neonates had a history of postpartum asphyxia and resuscitation. They all presented with hypotonia, myasthenia, and respiratory failure; two neonates also had swallowing dysfunction. Of the five neonates, three had normal creatine kinase levels, while two had slightly elevated levels. Electromyography was performed for three neonates, among whom two had myogenic damage. MTM1 gene mutations were identified by genetic testing in all five neonates, including two nonsense mutations and three missense mutations, among which one variant had not been previously reported. Four mutations were inherited from the mother, and the other one was a de novo mutation. The five neonates showed no clinical improvement following treatment, failed weaning from mechanical ventilation, and ultimately died after withdrawal of life-sustaining therapy. CONCLUSIONS Centronuclear myopathy caused by MTM1 gene mutation often has a severe phenotype and a poor prognosis, and it should be considered for neonates with hypotonia and myasthenia after birth. Genetic testing should be performed as soon as possible.
Humans ; Myopathies, Structural, Congenital/genetics* ; Male ; Infant, Newborn ; Retrospective Studies ; Mutation ; Female ; Protein Tyrosine Phosphatases, Non-Receptor/genetics*

OBJECTIVE: To investigate the role of DYRK1A in the cytarabine (Ara-C) resistance mechanism of acute myeloid leukemia (AML) cells. METHODS: Overexpression and silencing of DYRK1A gene in THP-1 cells were used to observe whether the sensitivity of THP-1 cells to Ara-C was altered. RT-PCR was used to detect the changes in mRNA expression of related genes during Ara-C transport or metabolism. Western blot and RT-PCR were used to detect SAMHD1 expression after regulating DYRK1A expression in Ara-C treated cells. Co-IP technology was used to detect the interaction between Cyclin L2, DYRK1A, and SAMHD1. RESULTS: Overexpression of DYRK1A decreased Ara-C sensitivity in THP-1 cells while silencing DYRK1A increased it. Overexpression and silencing of DYRK1A did not affect Ara-C transport or metabolic gene expression. Overexpression of DYRK1A could increase the expression of SAMHD1 protein in cells, while silencing DYRK1A reduced SAMHD1 expression. Cyclin L2 interacted with DYRK1A and SAMHD1 in THP-1 cells. CONCLUSION DYRK1A is involved in Ara-C resistance in AML cells, and its mechanism may be related to increased expression of SAMHD1 by interacting with Cyclin L2.
Humans ; Cytarabine/pharmacology* ; Protein-Tyrosine Kinases/metabolism* ; Leukemia, Myeloid, Acute ; Dyrk Kinases ; Drug Resistance, Neoplasm ; Protein Serine-Threonine Kinases/metabolism* ; SAM Domain and HD Domain-Containing Protein 1 ; Cell Line, Tumor

Lung cancer represents one of the most prevalent malignant tumors globally, and its treatment has entered the era of targeted therapy. The epidermal growth factor receptor (EGFR) mutation is a common type of genetic mutation in non-small cell lung cancer (NSCLC), while c-ros oncogene 1 receptor tyrosine kinase (ROS-1) fusion mutation is a rare mutation site. Currently, there are few case reports on the coexistence of EGFR and ROS-1 gene mutations. This study reports a case of NSCLC with coexisting EGFR and ROS-1 gene mutations, aiming to provide relevant treatment strategies for clinical practice.
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Humans ; Carcinoma, Non-Small-Cell Lung/enzymology* ; Lung Neoplasms/enzymology* ; ErbB Receptors/genetics* ; Mutation ; Protein-Tyrosine Kinases/genetics* ; Proto-Oncogene Proteins/genetics* ; Male ; Middle Aged ; Female

OBJECTIVE: To investigate the effects of Bushen Huoxue Granule on the ubiquitin-proteasome system (UPS) in an in vitro model of Parkinson's disease. METHODS: After treated with 1-methyl-4-phenylpyridinium (MPP⁺, 1 mmol/L) for 24 h, the cells were incubated with drug-free serum, Madopar-containing serum or Bushen Huoxue Granule-containing serum (BCS, 5%, 10%, and 20%) for another 24 h. The levels of α-synuclein (α-syn), tyrosine hydroxylase (TH) and UPS-related proteins were detected by Western blot. The expression levels of α-syn in PC12 cells were also analyzed by Western blot after treated with proteasome inhibitor MG132 and WT-α-syn plasmid transfection, respectively, as well as the alterations induced by subsequent BCS intervention. Immunocytochemistry was performed to determine the changes in α-syn phosphorylation at serine 129 (pSer129-α-syn) expression. The 20S proteasome levels were measured by enzyme-linked immunosorbnent assay. RESULTS: BCS (volume fraction ⩽20%) intervention could alleviate the MMP⁺-induced cell viability decrease (P<0.05). In the MPP⁺ treated cells, α-syn was up-regulated, while TH and proteins of UPS such as ubiquitin (Ub), Ub binding with Ub-activating enzyme (UBE1), Parkin and Ub C-terminal hydrolase-1 (UCHL-1) were down-regulated (P<0.05). BCS intervention could attenuate the above changes (P<0.05). The activity of BCS on blocking α-syn accumulation was weakened by MG132 (P<0.05). While α-syn level was significantly increased in cells transfected with plasmid, and reduced by BCS intervention (P<0.05). pSer129-α-syn was increased in MPP⁺-induced PC12 cells, whereas decreased by later BCS intervention (P<0.05). The 20S proteasome activity of MPP⁺-induced PC12 cells was decreased, but increased after BCS intervention (P<0.05). CONCLUSION BCS intervention protected UPS function, increased 20S proteasome activity, promoted pathological α-syn clearance, restored cell viability, and reversed the damage caused by MPP⁺ in the in vitro model of Parkinson's disease.
PC12 Cells ; alpha-Synuclein/metabolism* ; Rats ; Animals ; 1-Methyl-4-phenylpyridinium/toxicity* ; Proteasome Endopeptidase Complex/metabolism* ; Drugs, Chinese Herbal/pharmacology* ; Ubiquitin/metabolism* ; Cell Survival/drug effects* ; Phosphorylation/drug effects* ; Tyrosine 3-Monooxygenase/metabolism*