OBJECTIVE To analyze the prototype components absorbed into blood and brain of Lithocarpus litseifolius leaves， so as to provide a reference for clarifying the pharmacological material basis of its prevention and treatment of central nervous system dis eases. METHODS The ethanol extract of L. litseifolius leaves， as well as the gastric lavage fluid and perfusion solution were prepared. Using rats as subjects， plasma samples of intestinal wall metabolism， intestinal flora metabolism and hepatic metabolism were prepared via in situ intestinal perfusion and closed intestinal loop method； while comprehensive metabolic plasma samples， brain tissue samples， and cerebrospinal fluid samples were collected after intragastric administration. UPLC-HRMS technology was utilized to analyze and identify chemical components and prototype components absorbed into blood and brain of L. litseifolius leaves. RESULTS A total of 66 chemical constituents were identified in L. litseifolius leaves， primarily consisting of flavonoids， organic acids， and others. A total of 16， 13， 11， and 5 prototype components were identified in intestinal wall metabolism， intestinal flora metabolism， hepatic metabolism， and comprehensive metabolic plasma samples， respectively. Additionally， 4 prototype components were detected in brain tissue and 9 in cerebrospinal fluid. Phloridzin， trilobatin， phloretin-2- O -malonyl hexoside， and phloretin were identified as common components across all sample types. CONCLUSIONS Prototype components absorbed into blood and brain of L. litseifolius leaves， such as phloridzin， trilobatin， phloretin， and other components may serve as the pharmacological material basis for their therapeutic effects on central nervous system diseases.

Diabetic retinopathy(DR)remains the leading cause of vision loss in patients with diabetes. Current anti-vascular endothelial growth factor(VEGF)therapies are limited by inadequate response in some patients and the necessity for repeated intravitreal injections, underscoring the urgent need for novel therapeutic targets. Angiopoietin-like protein 4(ANGPTL4), a multifunctional secreted protein, has emerged as a critical regulator in the pathogenesis and progression of DR, positioning it as a promising interventional target. This review systematically elaborates the biological characteristics of ANGPTL4, with a focus on its expression dynamics, molecular mechanisms, and regulatory networks rolesin the development of DR. Furthermore, the prospects of ANGPTL4-targeted therapeutic strategies are discussed, aiming to offer new insights and directions for understanding DR pathogenesis, advancing multi-target drug development, and improving clinical management.

OBJECTIVE To provide reference for medical institutions to establish the record management mode and review rules of off-label use of 5-aminolevulinic acid （ALA） in photodynamic therapy based on the level of evidence. METHODS All ALA-containing outpatient prescriptions in the rational drug use system in our hospital from January 1， 2024 to December 31， 2025 were retrospectively collected. Based on the drug instructions， the current status of off-label use of ALA in photodynamic therapy was identified . The relevant studies in Micromedex， PubMed， CNKI， Wanfang Data and other databases were systematically searched as the relevant evidence-based evidence of ALA off-label use. According to the Off-label Drug Use Filing Standard of the hospital，the evidence-based evaluation method was used to evaluate the evidence-based evidence of ALA off-label use and carry out hierarchical management. RESULTS A total of 1 803 effective prescriptions were included， of which 676 （37.49%） were off-label use， distributed in the dermatology department （564 prescriptions，83.43%） and the plastic surgery department （112 prescriptions，16.57%）. All 676 prescriptions were off-indications medication， involving ten types of skin diseases， primarily including moderate to severe acne （39.94%）， skin warts （25.44%）， Bowen’s disease （11.98%）， and others. According to evidence-based evidence，off-label uses such as moderate to severe acne， actinic keratosis， and Bowen’s disease were managed according to the evidence categoryⅠ orⅡ.The uses of extramammary Paget’s disease and rosacea were managed according to the evidence category Ⅲ.The uses of lichen sclerosus and keloids were managed according to the evidence category Ⅳ.The results of evidence-based evaluation showed that 92.01% of off-label use in our hospital had high-level evidence-based support （ evidence category was gradeⅠ-Ⅱ）. CONCLUSIONS Off-label uses supported by high-level evidence， such as moderate to severe acne， skin warts， and Bowen’s disease， can be managed under filing category Ⅰ or Ⅱ. For the use of lichen sclerosus and keloids， evidence-based evidence is insufficient and should be strictly restricted.The vast majority of ALA off-label use in our hospital has sufficient evidence-based basis.

ObjectiveThis study aims to compare the modeling effects of submaxillary gland antigen and salivary gland antigen in the establishment of Sjögren syndrome (SS) mouse models, and to characterize the phenotypic and immunological features of these models in comparison with spontaneous SS-prone non-obese diabetic (NOD)/LtJ mice. MethodsAdult C57BL/6J mice (equal numbers of males and females) were immunized with submaxillary gland antigen or salivary gland antigen, respectively, combined with Freund's adjuvant to induce SS models. Mice immunized with phosphate-buffered saline (PBS) combined with Freund's adjuvant served as the control group. Immunization was induced via multiple subcutaneous injections in the back with antigen combined with Freund's complete adjuvant (FCA) on Days 1 and 7. A booster immunization was administered via multiple subcutaneous injections in the back with antigen combined with Freund's incomplete adjuvant (FIA) on Day 14. Female NOD/LtJ mice were used as the spontaneous SS model group, with ICR mice as the corresponding control strain for comparative analysis. Body weight, water intake, and salivary flow rate of mice were dynamically monitored for 4 weeks. At the end of the experiment, tissue and serum samples were collected, the weights of submaxillary glands, thymus, and spleen were measured, and organ indices (organ-to-body weight ratios) were calculated. Pathological morphological analysis of the submaxillary gland and spleen was performed with hematoxylin and eosin (HE) staining. Serum interleukin-17 (IL-17) level was detected using enzyme-linked immunosorbent assay (ELISA). Real-time quantitative polymerase chain reaction was used to detect the mRNA expression levels of SS type A (SSA) and SS type B (SSB) in submaxillary gland tissues. ResultsFemale mice in the submaxillary gland antigen group exhibited significantly increased water intake (P<0.05) and reduced salivary flow rate (P<0.05) compared with the female control group. No statistically significant differences were observed in the submaxillary gland index, thymus index and spleen index (P>0.05). Focal lymphocytic infiltration was observed in the submaxillary glands, and the splenic marginal zone was enlarged. Serum IL-17 levels were significantly increased (P<0.05). There was no significant difference in submaxillary gland SSA/SSB expression levels (P>0.05). Compared with the female control group, female mice in the salivary gland antigen group showed no statistically significant differences in water intake, salivary flow rate, submaxillary gland index, and spleen index (P>0.05), whereas the thymus index was significantly reduced (P<0.01). Mild inflammatory cell infiltration and glandular atrophy were observed in the submaxillary glands, and the splenic white pulp and marginal zone were slightly enlarged. Serum IL-17 levels and submaxillary gland SSB mRNA expression levels were significantly increased (P<0.01), whereas no significant change was observed in submaxillary gland SSA expression levels (P>0.05). Compared with the male control group, mild submaxillary gland atrophy was observed in male mice in the submaxillary gland antigen group, whereas no obvious changes were found in other modeling-related indicators (P>0.05). Compared with the ICR control group, NOD/LtJ model mice exhibited elevated water intake (P<0.05), significantly reduced salivary flow rate (P<0.01), no significant differences in the submaxillary gland index or spleen index (P>0.05), but a significantly increased thymus index (P<0.05). Marked focal infiltration was observed in the submaxillary glands, the splenic marginal zone was obviously enlarged, and serum IL-17 concentrations as well as submaxillary gland SSA/SSB expression levels were significantly increased (P<0.05). ConclusionSubmaxillary gland antigen and salivary gland antigen can induce SS-related features in female C57BL/6J mice. The SS-related phenotype is more pronounced in the submaxillary gland antigen group than in the salivary gland antigen group, but weaker than that in spontaneously SS-prone female NOD/LtJ mice. Immunization of male C57BL/6J mice with submaxillary or salivary gland antigens fails to induce an obvious SS phenotype.

ObjectiveTo evaluate the antitumor activity of Periplaneta americana extract（PAE） against human-derived lung adenocarcinoma organoids（LUAD-PDOs） and to elucidate its potential mechanism based on transcriptomics. MethodsFresh tumor and adjacent normal tissues from patients with LUAD were collected to construct LUAD-PDOs and normal lung organoid（Nor-PDOs） models using 3D organoid culture technology. The effective intervention concentration of PAE was determined using the cell counting kit-8（CCK-8） assay. Experimental groups included the model group（LUAD-PDOs）， normal group， model administration group（LUAD-PDOs+PAE）， and normal administration group（Nor-PDOs+PAE）. Hematoxylin-eosin（HE） staining was used to observe the pathological structures of PDOs， immunohistochemistry（IHC） was performed to detect the expressions of the proliferation marker Ki-67 and lung adenocarcinoma differentiation markers cytokeratin-7（CK-7） and Napsin A， TUNEL staining was applied to detect cell apoptosis. RNA sequencing（RNA-Seq） was conducted to identify differentially expressed genes（DEGs）， followed by Gene Ontology（GO）， Kyoto Encyclopedia of Genes and Genomes（KEGG）， and Gene Set Enrichment Analysis（GSEA）， alongside protein-protein interaction（PPI） network analysis to screen core mechanisms. Finally， key targets were validated by integrating external database analysis with immunofluorescence（IF）. ResultsNor-PDOs and LUAD-PDOs that highly recapitulated the pathological characteristics of the primary tissues were successfully established. The CCK-8 assay determined that the effective intervention concentration of PAE was 16 g·L^-1. Morphological observation showed that Nor-PDOs exhibited lumen-forming structures， whereas LUAD-PDOs displayed dense， solid structures. CCK-8 and TUNEL assays revealed that， compared with the model group， PAE intervention inhibited the proliferation of LUAD-PDOs and promoted apoptosis in LUAD cells， while showing no significant effect on the viability of Nor-PDOs. Transcriptomic analysis identified 719 DEGs that were significantly reversed after PAE intervention（347 up-regulated and 372 down-regulated）（P<0.05）. GO enrichment analysis indicated that DEGs in the model administration group were significantly enriched in biological processes related to cell cycle regulation compared to the model group. KEGG pathway analysis revealed that PAE affected pathways related to proliferation and metabolism， including pathways in cancer and the p53 signaling pathway. GSEA further confirmed that PAE significantly enhanced the activity of the p53 signaling pathway（P<0.05）. PPI network analysis indicated that breast cancer type 1 susceptibility protein（BRCA1） and checkpoint kinase 1（CHEK1） were the core down-regulated targets in the p53 pathway. IF verified the high expression of BRCA1 and CHEK1 in LUAD-PDOs and their significant downregulation after PAE intervention（P<0.05）. Furthermore， survival analysis based on The Cancer Genome Atlas（TCGA） database indicated that low expression of BRCA1 and CHEK1 was significantly associated with prolonged overall survival in patients with LUAD（P<0.05）. ConclusionPAE effectively inhibits proliferation of LUAD-PDOs and promotes their apoptosis， its anti-tumor mechanism is potentially associated with the activation of the p53 signaling pathway， with BRCA1 and CHEK1 genes likely serving as key downstream targets for the effects of PAE.

Objective To analyze survival outcomes and influencing factors among patients with colorectal cancer in Yunnan Province. Methods Clinical data were retrospectively collected from 4 892 patients with colorectal cancer. Survival data were obtained through follow-up. Overall survival (OS) was calculated by using the Kaplan-Meier method. Univariate analysis was performed by applying the log-rank test. Meanwhile, multivariate analysis employed the Cox proportional hazards regression model. Results The 1-, 3-, 5-, and 10-year OS rates for the entire cohort were 91.90%, 74.40%, 64.40%, and 28.70%, respectively. Univariate analysis revealed that age, ethnicity, region, differentiation grade, TNM stage, clinical stage, metastatic status, histological type, and treatment modality (chemotherapy, radiotherapy, and surgery) were associated with patient prognosis (all P<0.05). Multivariate analysis identified age (HR=1.250), region (HR=1.262), differentiation grade (HR=0.761), clinical stage (HR=3.128), and treatment modality (chemotherapy, HR=0.644; radiotherapy, HR=1.605; surgery, HR=0.384) as independent factors affecting survival prognosis in patients with colorectal cancer (all P<0.001). Conclusion Age, region, clinical stage, and treatment modality are independent factors influencing survival among patients with colorectal cancer in Yunnan Province. In clinical practice, these factors should be integrated to develop individualized prevention and treatment strategies, thereby improving patient outcomes.

ObjectiveMultiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS); however, its underlying neurological pathogenic mechanisms remain incompletely understood. Endogenous formaldehyde (FA), a metabolic byproduct of methylation-demethylation cycles, has recently been implicated in neurotoxicity, oxidative damage, and cognitive impairment. This study aimed to investigate whether excessive FA contributes to myelin sheath demyelination in mice and to evaluate the protective effects and mechanisms of two FA-elimination strategies: sodium bisulfite (NaHSO₃), a classical FA scavenger, and polyethylene glycol-modified astaxanthin nanoparticles (PEG-ATX@NPs), a brain-targeted nano-antioxidant formulation. MethodsA chronic demyelination model was established by feeding female C57BL/6J mice a diet containing 0.2% cuprizone (CPZ) for four weeks, followed by a two-week intervention period. Eighty mice were randomly assigned to four groups: NS (normal saline), CPZ+NS, CPZ+NaHSO₃, and CPZ+PEG-ATX@NPs. Behavioral tests, including open-field, Y-maze, and pole-climbing assays, were conducted to assess locomotor activity, motor coordination, and working memory. FA levels in serum, corpus callosum, and spinal cord were measured using an Na-FA fluorescent probe and quantified via in vivo and ex vivo fluorescence imaging. Neuroinflammatory responses were evaluated by measuring TNF-α, IL-1β, and IL-6 levels using ELISA, while oxidative stress was assessed by reactive oxygen species (ROS) fluorescence intensity. Demyelination was examined via Luxol fast blue staining, and microglial activation was analyzed by Iba1 immunofluorescence. Correlation analyses were performed to explore relationships among FA levels, inflammatory cytokines, ROS intensity, and behavioral parameters. ResultsCompared with the NS group, mice in the CPZ+NS group exhibited significant weight loss, impaired motor coordination and memory, and markedly reduced myelin regeneration (P<0.05). FA levels and pro-inflammatory cytokines were significantly elevated in serum, corpus callosum, and spinal cord (P<0.05). FA-associated fluorescence in brain and spinal tissues, as well as ROS intensity across all tissues examined, also increased substantially (P<0.05). CPZ treatment induced pronounced microglial activation and severe demyelination in the corpus callosum (P<0.01). Both NaHSO₃ and PEG-ATX@NPs effectively reduced FA accumulation in the brain and spinal cord, attenuated demyelination, suppressed microglial activation, decreased inflammatory cytokine levels, and improved motor and cognitive performance. These results confirm that CPZ induced severe demyelination accompanied by oxidative stress, neuroinflammation, and abnormal FA accumulation. Following intervention with either NaHSO₃ or PEG-ATX@NPs, endogenous FA levels in the CNS were substantially reduced. Both treatments alleviated demyelination and significantly decreased the number of activated microglia. Levels of TNF-α, IL-1β, and IL-6 in serum, corpus callosum, and spinal cord were downregulated. Behavioral performance improved significantly, as evidenced by enhanced locomotor activity, better coordination, and improved memory function. These findings indicate that both FA-scavenging agents mitigate CPZ-induced biochemical and behavioral abnormalities. ConclusionThis study demonstrates that excessive endogenous FA is closely associated with cognitive impairment, inflammatory dysregulation, and demyelination in a CPZ-induced chronic demyelination mouse model. Clearing abnormally elevated FA effectively reduces neuroinflammation, suppresses microglial overactivation, decreases oxidative stress, and alleviates demyelination, ultimately improving motor and cognitive outcomes in mice. These results suggest that targeting endogenous FA represents a promising therapeutic strategy for MS and other demyelinating disorders. Further investigations are warranted to explore the long-term safety, dosage optimization, and molecular pathways involved in FA-mediated neurotoxicity.

ObjectiveMultiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS); however, its underlying neurological pathogenic mechanisms remain incompletely understood. Endogenous formaldehyde (FA), a metabolic byproduct of methylation-demethylation cycles, has recently been implicated in neurotoxicity, oxidative damage, and cognitive impairment. This study aimed to investigate whether excessive FA contributes to myelin sheath demyelination in mice and to evaluate the protective effects and mechanisms of two FA-elimination strategies: sodium bisulfite (NaHSO₃), a classical FA scavenger, and polyethylene glycol-modified astaxanthin nanoparticles (PEG-ATX@NPs), a brain-targeted nano-antioxidant formulation. MethodsA chronic demyelination model was established by feeding female C57BL/6J mice a diet containing 0.2% cuprizone (CPZ) for four weeks, followed by a two-week intervention period. Eighty mice were randomly assigned to four groups: NS (normal saline), CPZ+NS, CPZ+NaHSO₃, and CPZ+PEG-ATX@NPs. Behavioral tests, including open-field, Y-maze, and pole-climbing assays, were conducted to assess locomotor activity, motor coordination, and working memory. FA levels in serum, corpus callosum, and spinal cord were measured using an Na-FA fluorescent probe and quantified via in vivo and ex vivo fluorescence imaging. Neuroinflammatory responses were evaluated by measuring TNF-α, IL-1β, and IL-6 levels using ELISA, while oxidative stress was assessed by reactive oxygen species (ROS) fluorescence intensity. Demyelination was examined via Luxol fast blue staining, and microglial activation was analyzed by Iba1 immunofluorescence. Correlation analyses were performed to explore relationships among FA levels, inflammatory cytokines, ROS intensity, and behavioral parameters. ResultsCompared with the NS group, mice in the CPZ+NS group exhibited significant weight loss, impaired motor coordination and memory, and markedly reduced myelin regeneration (P<0.05). FA levels and pro-inflammatory cytokines were significantly elevated in serum, corpus callosum, and spinal cord (P<0.05). FA-associated fluorescence in brain and spinal tissues, as well as ROS intensity across all tissues examined, also increased substantially (P<0.05). CPZ treatment induced pronounced microglial activation and severe demyelination in the corpus callosum (P<0.01). Both NaHSO₃ and PEG-ATX@NPs effectively reduced FA accumulation in the brain and spinal cord, attenuated demyelination, suppressed microglial activation, decreased inflammatory cytokine levels, and improved motor and cognitive performance. These results confirm that CPZ induced severe demyelination accompanied by oxidative stress, neuroinflammation, and abnormal FA accumulation. Following intervention with either NaHSO₃ or PEG-ATX@NPs, endogenous FA levels in the CNS were substantially reduced. Both treatments alleviated demyelination and significantly decreased the number of activated microglia. Levels of TNF-α, IL-1β, and IL-6 in serum, corpus callosum, and spinal cord were downregulated. Behavioral performance improved significantly, as evidenced by enhanced locomotor activity, better coordination, and improved memory function. These findings indicate that both FA-scavenging agents mitigate CPZ-induced biochemical and behavioral abnormalities. ConclusionThis study demonstrates that excessive endogenous FA is closely associated with cognitive impairment, inflammatory dysregulation, and demyelination in a CPZ-induced chronic demyelination mouse model. Clearing abnormally elevated FA effectively reduces neuroinflammation, suppresses microglial overactivation, decreases oxidative stress, and alleviates demyelination, ultimately improving motor and cognitive outcomes in mice. These results suggest that targeting endogenous FA represents a promising therapeutic strategy for MS and other demyelinating disorders. Further investigations are warranted to explore the long-term safety, dosage optimization, and molecular pathways involved in FA-mediated neurotoxicity.

p21 (encoded by the CDKN1A gene) is a critical cell cycle regulatory protein endowed with versatile biological functions. In various sex hormone-related cancers, p21 exhibits a paradoxical dual role, capable of both inhibiting tumorigenesis and promoting cancer progression, exerting dual, often opposing, effects on cellular fate that are dictated by the specific context. The clinical targeting of p21 remains elusive, largely due to its functionally pleiotropic and context-dependent nature within intricate regulatory networks. During the initial, hormone-dependent phase of cancers like breast and prostate cancer, p21 expression and activity are largely governed by the transcriptional programs of estrogen or androgen receptor signaling. This hormonal regulation contributes to the control of tumor cell proliferation and underpins the initial efficacy of endocrine therapies. In contrast, as these diseases advance to late stages or evolve into non-hormone-dependent subtypes—exemplified by castration-resistant prostate cancer (CRPC) and specific forms of triple-negative breast cancer (TNBC)—these conventional hormonal control mechanisms often become dysfunctional or are entirely bypassed. This fundamental transition creates a critical therapeutic void, highlighting the urgent need to identify and exploit alternative molecular pathways to effectively target p21’s function. Promising strategies may include the precise modulation of its upstream transcriptional regulators, downstream effector proteins, or the intersecting parallel signaling networks that critically influence its activity. This review provides a systematic synthesis of the intricate and interconnected mechanisms that underpin the dual effects of p21 in sex hormone-related tumors. These mechanisms are categorized into three core, interrelated functional domains. (1) cell cycle regulation: p21 executes its canonical tumor-suppressive role by binding to and inhibiting cyclin-dependent kinases (CDKs) and by directly interacting with proliferating cell nuclear antigen (PCNA), thereby inducing cell cycle arrest, predominantly at the G1/S checkpoint; (2) apoptosis modulation: p21 exerts a highly context-dependent influence on programmed cell death, functioning either as a pro-apoptotic agent under severe genotoxic stress or as a pro-survival factor by inhibiting apoptosis through interactions with proteins like Bcl-2; (3) hormonal and signaling crosstalk: p21 is an integral node within broader cellular networks, engaging in direct physical interactions with hormone receptors(e.g., AR, ER) and participating in complex feedback loops with key oncogenic pathways, including PI3K/AKT, MAPK/ERK, and p53. Critically, the role of p21 is not static but highly dynamic. It can undergo a functional switch from tumor-suppressive to tumor-promoting in response to therapeutic pressures, metabolic alterations, or evolving tumor microenvironment cues. These adaptive shifts are frequently implicated in the development of therapy resistance and disease recurrence, particularly in advanced, hormone-resistant cancers. By synthesizing these insights, this review aims to establish a coherent theoretical framework to guide the future development of novel therapeutic strategies that target the p21 pathway. It underscores the necessity of moving beyond a simplistic, binary view of p21 and emphasizes the forthcoming challenges, such as the discovery of reliable biomarkers to predict its functional state and the rational design of context-specific pharmacological modulators to selectively harness its therapeutic potential.

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.