Metabolic dysfunction-associated steatotic liver disease (MASLD) has become the most prevalent chronic liver disease worldwide, affecting approximately 32%-38% of the adult population and posing a growing public health burden. MASLD represents a continuous disease spectrum ranging from simple steatosis to metabolic dysfunction-associated steatohepatitis (MASH), progressive hepatic fibrosis, cirrhosis, and ultimately hepatocellular carcinoma (HCC). The pathological core of MASLD lies in disruption of hepatic lipid metabolic homeostasis, characterized by an imbalance among de novo lipogenesis, fatty acid β-oxidation, and very-low-density lipoprotein (VLDL)-mediated lipid export. This metabolic disequilibrium subsequently drives inflammatory injury and fibrotic progression. Among the multiple regulatory pathways involved, thyroid hormone (TH) signaling has emerged as a central regulator of hepatic metabolic homeostasis. The liver is a major peripheral target organ of TH action, where TH predominantly exerts its metabolic effects through thyroid hormone receptor β (TRβ). Large-scale epidemiological studies and meta-analyses have demonstrated that hypothyroidism is significantly associated with increased MASLD prevalence, more severe histological injury, and advanced hepatic fibrosis, suggesting that dysregulation of TH signaling may participate throughout the entire MASLD disease spectrum. At the molecular level, TH regulates hepatic lipid metabolism by coordinating suppression of lipogenesis, enhancement of mitochondrial fatty acid oxidation, and promotion of VLDL assembly and secretion through integrated genomic actions of the T3-TRβ axis and non-genomic signaling pathways. Across different stages of MASLD, TH signaling exerts stage-dependent protective effects. In the steatosis stage, TH improves metabolic flexibility by modulating insulin sensitivity, glucose metabolism, and lipid droplet clearance, thereby alleviating early lipotoxic stress. During progression to MASH, TH attenuates inflammatory amplification by improving mitochondrial homeostasis, suppressing activation of the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome, and modulating the gut-liver axis microenvironment. In advanced stages, TH signaling influences hepatic stellate cell activation and extracellular matrix deposition, partly through interaction with the transforming growth factor-β (TGF-β)/SMAD pathway, while alterations in intrahepatic TH availability, mediated by dynamic changes in iodothyronine deiodinase 1 (DIO1), contribute to fibrosis progression and hepatocellular dedifferentiation. In hepatocellular carcinoma, coordinated downregulation of TRβ and DIO1 establishes a tumor-associated hypothyroid state that promotes metabolic reprogramming and tumor progression. The clinical relevance of TH signaling in MASLD has been underscored by the recent approval of Resmetirom, a liver-targeted TRβ‑selective agonist, for the treatment of non-cirrhotic MASH with moderate-to-severe fibrosis (F2-F3). This approval represents a landmark transition from mechanistic understanding to metabolism-centered precision therapy in MASLD. Clinical trials have demonstrated that Resmetirom not only improves key histological endpoints, including MASH resolution and fibrosis regression, but also favorably modulates atherogenic lipid profiles, highlighting the therapeutic potential of selectively targeting hepatic TH pathways. This review systematically summarizes the multidimensional regulatory roles of TH across the MASLD disease spectrum and discusses emerging diagnostic and therapeutic implications of TH-based interventions, aiming to inform future mechanistic research and optimize clinical management strategies.

ObjectiveTo clarify whether METTL14 mediates the core role of acupuncture at Neiguan (PC6) in promoting myelination and improving behavior in young autistic rats through gene intervention technology. MethodsThe ASD model was established by intraperitoneal injection of valproic acid (VPA) in pregnant rats. Male offspring were intracerebroventricularly injected with adenovirus-packaged METTL14 shRNA (sh-METTL14) or its control (sh-NC) on postnatal day 1, with a model group set as well. Subsequently, the juvenile rats were divided into model group, acupuncture group, acupuncture+sh-NC group, and acupuncture+sh-METTL14 group. The acupuncture group received acupuncture at Neiguan (PC6) from postnatal day 7, once daily for 21 consecutive days. Neurobehavioral changes were evaluated by behavioral tests; METTL14 knockdown efficiency and the expression of METTL14, METTL3, and PTEN were detected by quantitative real-time PCR (qRT-PCR) and Western blot (WB); PTEN m⁶A levels were measured by RNA immunoprecipitation-qPCR (RIP-qPCR); myelin ultrastructure, expression of myelin basic protein (MBP) and neurofascin 155 (NF155), and dendritic spine density were observed using transmission electron microscopy (TEM), enzyme-linked immunosorbent assay (ELISA), immunofluorescence, qRT-PCR, and primary neuron culture. ResultsBehaviorally, knockdown of METTL14 significantly counteracted the beneficial effects of acupuncture in improving self-grooming, open field exploration, three-chamber social interaction, and Morris water maze learning and memory (P<0.05, P<0.01). Compared with the acupuncture+sh-NC group, the acupuncture+sh-METTL14 group showed significantly decreased mRNA and protein expression of hippocampal METTL14 (P<0.01), and the upregulating effects of acupuncture on METTL3 and PTEN expression were reversed (P<0.01). Meanwhile, knockdown of METTL14 significantly inhibited the acupuncture-induced increase in PTEN m⁶A levels (P<0.01). Morphologically, knockdown of METTL14 attenuated the improvement of myelin structure by acupuncture, reversed the downregulation of MBP and upregulation of NF155 induced by acupuncture, and blocked the increase in dendritic spine density (P<0.05, P<0.01). ConclusionMETTL14 is a key molecule mediating the therapeutic effect of acupuncture at Neiguan. Acupuncture at Neiguan upregulates METTL14, thereby enhancing m⁶A methylation modification of PTEN mRNA to stabilize its expression, ultimately promoting myelin development and improving behavioral symptoms in ASD juvenile rats. This preliminarily reveals the modern biological connotation of “opening Xuanfu and dredging myelin”.

ObjectiveTo clarify whether METTL14 mediates the core role of acupuncture at Neiguan (PC6) in promoting myelination and improving behavior in young autistic rats through gene intervention technology. MethodsThe ASD model was established by intraperitoneal injection of valproic acid (VPA) in pregnant rats. Male offspring were intracerebroventricularly injected with adenovirus-packaged METTL14 shRNA (sh-METTL14) or its control (sh-NC) on postnatal day 1, with a model group set as well. Subsequently, the juvenile rats were divided into model group, acupuncture group, acupuncture+sh-NC group, and acupuncture+sh-METTL14 group. The acupuncture group received acupuncture at Neiguan (PC6) from postnatal day 7, once daily for 21 consecutive days. Neurobehavioral changes were evaluated by behavioral tests; METTL14 knockdown efficiency and the expression of METTL14, METTL3, and PTEN were detected by quantitative real-time PCR (qRT-PCR) and Western blot (WB); PTEN m⁶A levels were measured by RNA immunoprecipitation-qPCR (RIP-qPCR); myelin ultrastructure, expression of myelin basic protein (MBP) and neurofascin 155 (NF155), and dendritic spine density were observed using transmission electron microscopy (TEM), enzyme-linked immunosorbent assay (ELISA), immunofluorescence, qRT-PCR, and primary neuron culture. ResultsBehaviorally, knockdown of METTL14 significantly counteracted the beneficial effects of acupuncture in improving self-grooming, open field exploration, three-chamber social interaction, and Morris water maze learning and memory (P<0.05, P<0.01). Compared with the acupuncture+sh-NC group, the acupuncture+sh-METTL14 group showed significantly decreased mRNA and protein expression of hippocampal METTL14 (P<0.01), and the upregulating effects of acupuncture on METTL3 and PTEN expression were reversed (P<0.01). Meanwhile, knockdown of METTL14 significantly inhibited the acupuncture-induced increase in PTEN m⁶A levels (P<0.01). Morphologically, knockdown of METTL14 attenuated the improvement of myelin structure by acupuncture, reversed the downregulation of MBP and upregulation of NF155 induced by acupuncture, and blocked the increase in dendritic spine density (P<0.05, P<0.01). ConclusionMETTL14 is a key molecule mediating the therapeutic effect of acupuncture at Neiguan. Acupuncture at Neiguan upregulates METTL14, thereby enhancing m⁶A methylation modification of PTEN mRNA to stabilize its expression, ultimately promoting myelin development and improving behavioral symptoms in ASD juvenile rats. This preliminarily reveals the modern biological connotation of “opening Xuanfu and dredging myelin”.

Objective To gain insights into the biological characteristics of different populations of Culex tritaeniorhynchus within and around the Yellow Sea wetland from the perspective of the occurrence of resistance, we investigated the levels of resistance to deltamethrin and kdr gene mutation in the wetland and its peripheral areas. Methods Specimens were collected from Cx. tritaeniorhynchus populations at two monitoring sites in the Rare Bird National Nature Reserve and Tiaozi Ni Wetland Scenic Area, and also from two populations in Yancheng City and the Liuhe District of Nanjing, and the resistance of these mosquitoes to deltamethrin was determined using the CDC biotest bottle method. For each concentration of deltamethrin assessed, a random subset of exposed specimens was selected for amplification of the kdr gene fragment, followed by Sanger sequencing to identify and analyze resistance-associated mutations. Results The LC50 levels of deltamethrin among mosquitoes from the four populations in Luhe, Yancheng, the Rare Bird National Nature Reserve and the Tiaozi Ni Wetland Scenic Area were 2.048 5, 7.798 2, 3.473 3, and 17.695 5 mg/mL, respectively, with corresponding concentrations of deltamethrin ranging from 0.005 to 5.000,0.050 to 50.000,0.050 to 25.000 and 0.050 to 50.000 mg/mL, respectively. Furthermore, the ranges of the KT50 values were 11.76-107.43, 67.05-216.30,29.77-107.43 and 28.40-329.51 min; the 1-h knockdown rates were 34.58%-99.15%, 9.52%-43.80%, 55.09%-73.01%, and 10.09%-68.07%; and the 24-h mortality rates were 12.15%-67.52%,9.52%-79.56%,13.17%-82.21%, and 11.01%-78.99%, respectively. With respect to kdr gene mutation, we assayed a total of 63,70,59, and 57 mosquitoes for the four populations, for which we detected L1014F mutation frequencies of 14.29%, 35.00%, 20.34%, and 31.58%, respectively, with a majority of these mutations being heterozygous for resistance. In addition, five adult mosquitoes were identified has having synonymous mutations at site 1011[i. e. , AAT(asparagine)mutation to AAC(asparagine)]. Conclusions Our findings revealed the clear resistance of Cx. tritaeniorhynchus to deltamethrin in the Yancheng region of the Yellow Sea wetland, and the resistance phenotype and kdr frequency of Cx. tritaeniorhynchus in the wetland environment were comparable to those of Cx. tritaeniorhynchus in the wetland environment, thereby indicating that the resistance of different populations of Cx. tritaeniorhynchus was homogeneous under the pressure of different insecticide selection within and around the wetland. However, the underlying mechanisms need to be further studied.

Immobilized enzyme-based enzyme electrode biosensors, characterized by high sensitivity and efficiency, strong specificity, and compact size, demonstrate broad application prospects in life science research, disease diagnosis and monitoring, etc. Immobilization of enzyme is a critical step in determining the performance (stability, sensitivity, and reproducibility) of the biosensors. Random immobilization (physical adsorption, covalent cross-linking, etc.) can easily bring about problems, such as decreased enzyme activity and relatively unstable immobilization. Whereas, directional immobilization utilizing amino acid residue mutation, affinity peptide fusion, or nucleotide-specific binding to restrict the orientation of the enzymes provides new possibilities to solve the problems caused by random immobilization. In this paper, the principles, advantages and disadvantages and the application progress of enzyme electrode biosensors of different directional immobilization strategies for enzyme molecular sensing elements by specific amino acids (lysine, histidine, cysteine, unnatural amino acid) with functional groups introduced based on site-specific mutation, affinity peptides (gold binding peptides, carbon binding peptides, carbohydrate binding domains) fused through genetic engineering, and specific binding between nucleotides and target enzymes (proteins) were reviewed, and the application fields, advantages and limitations of various immobilized enzyme interface characterization techniques were discussed, hoping to provide theoretical and technical guidance for the creation of high-performance enzyme sensing elements and the manufacture of enzyme electrode sensors.

Lymph node metastasis (LNM) is a crucial risk factor influencing an unfavorable prognosis in specific cancers. Fundamental research illuminates our understanding of tumor behavior and identifies valuable therapeutic targets. Nevertheless, the exploration of fundamental theories and the validation of clinical therapies hinge on preclinical experiments. Preclinical models, in this context, serve as the conduit connecting fundamental theories to clinical outcomes. In vivo models established in animals offer a valuable platform for comprehensively observing interactions between tumor cells and organisms. Using various experimental animals, including mice, diverse methods, such as carcinogen-induced tumorigenesis, tumor cell line or human tumor transplantation, genetic engineering, and humanization, have been used effectively to construct numerous models for tumor LNM. Carcinogen-induced models simulate the entire process of tumorigenesis and metastasis. Transplantation models, using human tumor cell lines or patient-derived tumors, offer a research platform closely mirroring the histology and clinical behavior of human tumors. Genetically engineered models have been used to delve into the mechanisms of primary tumorigenesis within an intact microenvironment. Humanized models are used to overcome barriers between human and murine immune systems. Beyond mouse models, various other animal models have unique advantages and limitations, all contributing to exploring LNM. This review summarizes existing in vitro and animal preclinical models, identifies current bottlenecks in preclinical research, and offers an outlook on forthcoming preclinical models.
Animals ; Humans ; Mice ; Lymphatic Metastasis/pathology* ; Disease Models, Animal ; Cell Line, Tumor

Objective:To retrospectively analyze the clinical features and surgical efficacy of congenital cholesteatoma （CC） and acquired cholesteatoma （AC） in children. Methods:Clinical data of 169 children with middle ear cholesteatoma were reviewed in the Department of Otorhinolaryngology Head and Neck Surgery, Beijing Children's Hospital, Capital Medical University from January 2010 to July 2020. The clinical characteristics, stages, surgical methods, and postoperative recurrence rates were analyzed and summarized. Results:The age distribution of enrolled children ranged from 2 to 14 years. The mean age of the CC group was （5.60±2.48） years compared with （6.45±2.48） years in the AC group, and the difference was statistically significant （P<0.05）. Preoperative hearing in the CC group was （40.06±13.52） dB HL, which was better than in the AC group at （48.40±13.84） dB HL （P<0.05）. The proportion of stage Ⅰ in the CC group was lower than that in the AC group according to EAONO/JOS staging （P<0.05）. The recurrence rate after primary surgery was 19.23% （10/52） in the CC group compared with 36.29% （45/124） in the AC group （P<0.05）. The mastoid retention rates after all operations were 28.85% （15/52） in the CC group and 5.65% （7/124） in the AC group （P<0.05）. Conclusion:Compared with congenital cholesteatoma, acquired cholesteatoma in children is more aggressive and has more complications, higher postoperative recurrence rate, and less possibility of mastoid retention. Early clinical detection and treatment are required, and canal wall-down tympanoplasty should be considered in surgery.
Humans ; Cholesteatoma, Middle Ear/congenital* ; Child ; Retrospective Studies ; Child, Preschool ; Adolescent ; Male ; Female ; Recurrence ; Cholesteatoma/congenital* ; Tympanoplasty ; Treatment Outcome

ObjectiveTo investigate how Xiaoyao Shukun decoction （XYSKD） regulates the formation and release of neutrophil extracellular traps （NETs） via the phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt）/mammalian target of rapamycin （mTOR） signaling pathway， thereby reducing inflammation， inhibiting the excessive proliferation of fibroblasts in pelvic adhesion tissue， decreasing adhesion and fibrosis， and repairing the tissue damage in sequelae of pelvic inflammatory disease （SPID）. MethodsA total of 84 Wistar rats were randomly allocated into seven groups： blank， model， XYSKD （8 mg·kg^-1）， mTOR agonist （10 mg·kg^-1）， mTOR agonist + XYSKD （10 mg·kg^-1+8 mg·kg^-1）， mTOR inhibitor （2 mg·kg^-1）， and mTOR inhibitor + XYSKD （2 mg·kg^-1+8 mg·kg^-1）. The rat model of SPID was constructed by starvation， fatigue， and ascending Escherichia coli infection. After 14 days of drug intervention， the ultrastructure of fibroblasts in the pelvic adhesion tissue was observed by transmission electron microscopy. The general morphology of the uterus， fallopian tube， and ovary was observed by laparotomy. The levels of interleukin-1β （IL-1β）， interleukin-17 （IL-17）， and tumor necrosis factor-α （TNF-α） in the peritoneal flushing fluid were determined by enzyme-linked immunosorbent assay （ELISA）. The expression of myeloperoxidase （MPO） and citrullinated histone 3 （H3） in the fallopian tube was detected by immunofluorescence. Western blot and Real-time quantitative polymerase chain reaction （Real-time PCR） were employed to determine the relative protein and mRNA levels， respectively， of neutrophil elastase （NE）， intercellular adhesion molecule-1 （CD54）， α-smooth muscle actin （α-SMA）， H3， PI3K， and Akt. ResultsCompared with the blank group， the model group presented a large number of collagen fibers in bundles， numerous cytoplasmic folds of fibroblasts， reduced or absent mitochondrial cristae， and disordered and expanded endoplasmic reticulum. By laparotomy， extensive pelvic congestion， connective tissue hyperplasia， thickening and hardening of the tubal end near the uterus， and tubal and ovarian adhesion or cyst were observed in the model group. In addition， the model group showed raised levels of IL-1β， IL-17， and TNF-α in the peritoneal flushing fluid （P<0.01）， increased average fluorescence intensities of MPO and H3 （P<0.01）， and up-regulated protein and mRNA levels of NE， H3， CD54， PI3K， and Akt （P<0.01）. Compared with the model group， the mTOR agonist group showed increased fibroblasts and cytoplasmic folds， absence of mitochondrial cristae， endoplasmic reticulum dilation， and evident collagen fiber hyperplasia. Pelvic adhesions were observed to cause aggravated damage to the uterine， fallopian tube， and ovarian tissues. The levels of IL-1β， IL-17， and TNF-α in the peritoneal lavage fluid elevated （P<0.01） and the average fluorescence intensities of MPO and H3 enhanced （P<0.01） in the mTOR agonist group. In contrast， the XYSKD group and the mTOR inhibitor group showcased decreased fibroblasts and collagen fibers， alleviated mitochondrial crista loss and endoplasmic reticulum dilation， improved morphology and appearance of the uterine， fallopian tube， and ovarian tissues， lowered levels of IL-1β， IL-17， and TNF-α in the peritoneal lavage fluid （P<0.01）， decreased average fluorescence intensities of MPO and H3 （P<0.01）， and down-regulated protein and mRNA levels of NE， H3， CD54， PI3K， and Akt （P<0.05）. Compared with the mTOR agonist group， the mTOR agonist + XYSKD group showed alleviated pathological changes in the pelvic tissue， declined levels of IL-1β， IL-17， and TNF-α （P<0.01）， decreased average fluorescence intensities of MPO and H3 （P<0.01）， and down-regulated protein levels of NE， H3， CD54， α-SMA， p-PI3K/PI3K， and p-Akt/Akt （P<0.01） and mRNA levels of NE， H3， CD54， α-SMA， PI3K， and Akt （P<0.01）. Compared with the mTOR inhibitor group， the mTOR inhibitor + XYSKD group demonstrated reduced pathological severity of the pelvic tissue， reduced levels of IL-1β， IL-17， and TNF-α （P<0.01）， decreased average fluorescence intensities of MPO and H3 （P<0.01）， and down-regulated protein and mRNA levels of NE and CD54 （P<0.05）. ConclusionXYSKD can inhibit the excessive formation and release of NETs via PI3K/Akt/mTOR to ameliorate the inflammatory environment and reduce fibrosis and adhesion of the pelvic tissue， thereby playing a role in the treatment of SPID. It may exert the effects by lowering the levels of IL-1β， IL-17， and TNF-α and down-regulating the expression of NE， H3， CD54， α-SMA， PI3K， and Akt in the pelvic adhesion tissue.

Objective To investigate the effect of dorsal repulsive axon guidance protein(Draxin)on the migration of trunk neural crest cells during the early development of embryonic mouse spinal cord.Methods Immunohistochemistry and in situ hybridization were used to detect the expression characteristics of Draxin in early embryonic spinal cord(8 mice each group);In situ hybridization was used to detect the change of migration characteristics of trunk neural crest cells in early embryonic spinal cord of different types of mouse(5 mice each group);in vitro culture method was used to check the effect of Draxin on the migration characteristics of embryonic mouse trunk neural crest cells(16 mice each group).Resultsβ-galactosidase gene Z(LacZ)gene was introduced when Draxin gene was knocked out to produce Draxin gene knockout mice.β-galactosidase staining was used to detect LacZ gene expression in Draxin knockout embryonic mice,and the result showed that Draxin expression was observed in the spinal cord of early embryonic mice since 9.5 days(E9.5).Draxin expression was obvious in the embryonic mice spinal cord in E10.5 period.In situ hybridization was used to detect the expression of Draxin gene in the spinal cord of wild type embryonic mice,and the result further verified the obvious expression of Draxin in the early embryonic mice spinal cord in El0.5 period.Sox10 in situ hybridization was used to detect neural crest cell migration in the spinal cord of embryonic mice in E10.5 period.The result showed that segmental migration of neural crest cells in the early embryonic spinal cord of some Draxin knockout mice was delayed compared with the wild type mice.The effect of Draxin on the migration of wild type early embryonic mice trunk neural crest cells in vitro was tested.The result showed that Draxin reduced the migration distance of neural crest cells in vitro.Conclusion In the early developmental stage of embryonic spinal cord(E9.5-E10.5),neural crest cells migrated exuberant.At the same time,Draxin plays an important inhibitory function in the formation of the specific migration pathways of trunk neural crest cells by promoting neural crest cells migrating away from Draxin expressing regions.

AIM To study the chemical constituents from the stems and barks of Maytenus variabilis(Hemsl.)C.Y.Cheng.METHODS The 95％ethanol extract from the stems and barks of M.variabilis was isolated and purified by silica gel,Sephadex LH-20 and semi preparative HPLC,then the structures of obtained compounds were identified by physicochemical properties and spectral data.RESULTS Twenty-three compounds were isolated and identified as β-amyrin(1),3β-acetoxyolean-12-en-11-one(2),ursa-12-ene-11-one-3-ol octocosate(3),friedelin(4),canophyllol(5),pinoresinol(6),medioresinol(7),isolariciresinol(8),dihydrodehydrodiconiferyl alcohol(9),vanillic acid(10),7R,8S-5-methoxydihydrodehydroconiferyl alcohol(11),β-hydroxypropiovanillone(12),triptregeline B(13),triptregeline E(14),(+)-evofolin B(15),2,5-dimethoxybenzoquinone(16),olean-12-ene-3,11-dione(17),β-sitosterol(18),(-)-(7R,7'R,7"S,8S,8'S,8"S)-4',4"-dihydroxy-3,3',3",5-tetramethoxy-7,9',7',9-diepoxy-4,8"-oxy-8,8'-sesquineolignan-7",9"-diol(19),phyllostadimer B(20),rayalinol(21),lyoniresinol(22),dihydrobuddlenol B(23).CONCLUSION Compounds 3,9-11,13-14,16,19-21,23 are isolated from genus Maytenus for the first time,and compounds 2,4-5,7-8,12,15,17,22 are first found from this plant.