ObjectiveTo observe the clinical efficacy and safety of Yuyin Lidan granules （YYLD） in preventing the recurrence of common bile duct stones （CBDS） in patients with liver and gallbladder dampness-heat syndrome following endoscopic retrograde cholangiopancreatography （ERCP）. MethodsThis randomized， parallel， controlled trial enrolled postoperative CBDS-ERCP patients who met the inclusion and exclusion criteria. Sixty-four patients were randomly assigned to an observation group or a control group， with 32 cases in each. Both groups received conventional Western medical treatment after ERCP， while the observation group additionally received YYLD for 8 weeks. The follow-up period lasted for 1 year. The efficacy indicators included bile bilirubin levels， traditional Chinese medicine （TCM） syndrome scores， clinical efficacy rate， pancreatitis and inflammation markers， postoperative liver function， and CBDS recurrence rate at 1-year follow-up， which were used to jointly evaluate the clinical efficacy and safety of both groups. ResultsA total of 56 patients completed the study and were included in the final analysis， i.e.， 29 in the observation group and 27 in the control group. Baseline characteristics were comparable between the two groups. Compared with pre-treatment and with the control group after treatment， the bile bilirubin level in the observation group significantly decreased （P<0.05）. After treatment， the clinical cure and marked improvement rates were higher in the observation group than in the control group， showing a statistically significant difference in overall clinical efficacy （P<0.05）. Compared with pre-treatment， the primary and secondary symptoms in the observation group， as well as the primary symptom and the secondary symptom of nausea and vomiting in the control group （weeks 4 and 8）， were significantly reduced （P<0.05）. Compared with the control group after treatment， the observation group showed significant reductions in the primary symptom of loose stools/constipation （day 5 and week 4） and in three secondary symptoms， i.e.， bitter taste and sticky dry mouth， abdominal distension and poor appetite （throughout the treatment period）， and general heaviness and fatigue （day 5 and week 4）， with statistical differences （P<0.05）. Compared with pre-treatment， both groups showed decreased lipase and urinary amylase levels （P<0.05）. However， no significant between-group differences were observed in pancreatitis or inflammation-related indices after treatment. Compared with pre-treatment， all liver function indicators in the observation group and alanine aminotransferase （ ALT ）， γ-glutamyl transferase （ γ-GT ）， alkaline phosphatase （ALP）， and conjugated bilirubin in the control group significantly decreased at weeks 4 and 8 （P<0.05）. Compared with the control group after treatment， only serum total bilirubin and unconjugated bilirubin were significantly reduced in the observation group during the treatment period （P<0.05）. ConclusionYYLD combined with conventional Western medical treatment can effectively regulate bilirubin metabolism （in bile and serum）， improve TCM clinical symptoms， and prevent CBDS recurrence after ERCP in patients with liver and gallbladder dampness-heat syndrome. This regimen is safe and effective and is worthy of further clinical research and promotion.

ObjectiveThis paper aims to assess the effects of Wenfei Guyuan umbilical moxibustion on the quality of life and immune function in patients with chronic obstructive pulmonary disease （COPD） in stable phase. MethodsA multi-center randomized controlled trial design was employed，and the 220 cases of patients with COPD in stable phase from three grade A class-Ⅲ hospitals were included as research objects. The patients were randomly divided into the test group and control group，with each group consisting of 110 cases. Both groups received standardized treatment of western medicine，and the test group received Wenfei Guyuan umbilical moxibustion twice weekly for 13 weeks，followed by a 26-week follow-up period. Quality of life was evaluated by using the COPD assessment test （CAT），the modified COPD patient-reported outcomes （mCOPD-PRO） measure，and the modified effectiveness satisfaction questionnaire for COPD （mESQ-COPD） before treatment，four weeks， eight weeks， and 13 weeks of the treatment period，as well as 13 weeks and 26 weeks of the follow-up period. The number of acute exacerbation cases of patients in both groups was recorded during study period to evaluate the effect of Wenfei Guyuan umbilical moxibustion on acute exacerbations. 30 cases were randomly selected in both observation group and control group. Peripheral blood samples were collected before treatment and at 13 weeks of treatment. Enzyme-linked immunosorbent assay （ELISA） was used to detect the levels of immunoglobulin A （IgA），immunoglobulin G （IgG），immunoglobulin M （IgM），interleukin 10 （IL-10），interleukin 17A （IL-17A），transforming growth factor β1 （TGF-β1），and tumor necrosis factor α （TNF-α）. Flow cytometry was used to detect cluster of differentiation 4 positive （CD4⁺），cluster of differentiation 8 positive （CD8⁺），T helper 17 （Th17），and Treg levels， thereby preliminarily exploring the effect of Wenfei Guyuan umbilical moxibustion on immune function. ResultsA total of 220 patients were included，with five cases dropping out. 215 cases were finally included in the per-protocol set，including 107 in the treatment group and 108 in the control group. Baseline characteristics of the first two groups before treatment were compared between the two groups. In terms of life quality evaluation， the main effect of group differences on the CAT scores was significant （F=15.108，P<0.01）. The main effects of group differences on the physical domain （F=38.807，P<0.01），psychological domain （F=38.996，P<0.01），environmental domain （F=17.436，P<0.01），and total score of mCOPD-PRO （F=41.972，P<0.01） were significant. The main effects of group difference on clinical symptoms domain of mESQ-COPD （F=81.516，P<0.01），work-life ability domain （F=36.549，P<0.001），environmental adaptation ability domain （F=22.677，P<0.01），therapeutic effect domain （F=74.055，P<0.01），and total score of mESQ-COPD （F=73.251，P<0.01） were significant. Regarding acute exacerbations，during the entire study period，as well as the treatment period and follow-up period，the observation group showed fewer patients experiencing acute exacerbations compared to the control group，but the difference between the two groups was not statistically significant. In terms of immune indicators，after 13 weeks of treatment，the levels of IgA，IgG，and IgM in the observation group were significantly better than those in the control group （P<0.05）. The level of IL-10 was significantly higher than that in the control group （P<0.05），and the levels of IL-17A，TGF-β1，and TNF-α were significantly lower than those in the control group （P<0.05）. Compared with those in the control group，the level of CD4⁺/CD8⁺ in the observation group was significantly increased （P<0.05），while the levels of CD4⁺ and Treg were slightly increased，but the difference was not statistically significant. The levels of CD8⁺，Th17，and Th17/Treg were significantly decreased （P<0.05）. ConclusionWenfei Guyuan umbilical moxibustion can improve the quality of life， and immune function in patients with COPD in stable phase. It is worth promoting in clinical practice.

Cancer remains a leading cause of global mortality, necessitating the development of advanced therapeutic strategies with enhanced efficacy and reduced systemic toxicity. Among promising bioactive agents, lactoferrin (LF)—a multifunctional iron-binding glycoprotein abundantly found in mammalian milk and exocrine secretions—has garnered significant interest for its potent and multifaceted anti-cancer properties. This review provides a comprehensive analysis of the current understanding of LF’s role in oncology, encompassing its structural biology, diverse mechanisms of action, and groundbreaking advancements in its application through nano-engineering. LF exerts anti-tumor effects through multiple pathways, including extracellular action, intracellular action, and immune regulation. It demonstrates a remarkable affinity for cancer cell membranes, binding to overexpressed anionic components such as glycosaminoglycans and sialic acids, as well as to specific receptors including the low-density lipoprotein receptor-related protein-1 (LRP-1). This selective binding facilitates targeted uptake. Upon internalization, LF orchestrates a direct assault by inducing cell-cycle arrest in phases such as G0/G1 or S phase through the modulation of key regulators including cyclins, CDKs, and p53. Furthermore, it promotes programmed cell death via apoptotic pathways, involving caspase activation and downregulation of anti-apoptotic proteins such as survivin. A more recently elucidated mechanism is the induction of ferroptosis, an iron-dependent form of cell death characterized by overwhelming lipid peroxidation. Beyond direct cytotoxicity, LF acts as a potent immunomodulator. It enhances natural killer (NK) cell activity, modulates T-lymphocyte populations, and crucially reprograms tumor-associated macrophages (TAMs) from a pro-tumor M2 state to an anti-tumor M1 state, thereby reversing the immunosuppressive tumor microenvironment (TME). The translation of LF’s potential has been significantly accelerated by nanotechnology. The inherent biocompatibility and natural tumor-targeting capabilities of LF make it an ideal platform for sophisticated drug-delivery systems. This review details various fabrication strategies for LF-based nanoparticles (NPs), including self-assembly, sol-in-oil emulsion, and electrostatic nanocomplexes, among others. Research demonstrates that nano-formulations not only protect LF from degradation but also enhance its bioactivity and anti-cancer potency. More importantly, LF NPs serve as versatile carriers for a wide array of therapeutic agents, including conventional chemotherapeutics, natural compounds, and imaging agents. These engineered systems enable synergistic therapy and facilitate site-specific delivery. Notably, the ability of LF to bind to receptors on the blood-brain barrier (BBB) has been leveraged to develop nano-systems for glioblastoma treatment. Other innovative designs utilize LF to modulate the TME—for instance, by alleviating tumor hypoxia to sensitize cells to radiotherapy and chemotherapy. Despite compelling pre-clinical evidence, the clinical translation of LF and its nano-formulations remains nascent. While early-phase trials have established a favorable safety profile for recombinant human LF, larger Phase III studies have yielded mixed results, underscoring the complexity of its action in humans. Key challenges include enhancing drug targeting, optimizing loading efficiency, ensuring batch-to-batch reproducibility, and achieving deep tumor penetration. Future research must focus on the rational design of next-generation LF-NPs. This entails developing standardized manufacturing protocols, engineering “smart” stimuli-responsive systems for targeted drug release in the TME, and constructing multi-targeting platforms. A concerted interdisciplinary effort is paramount to bridge the gap between bench and bedside. In conclusion, LF, particularly in its nano-engineered forms, represents a highly promising and versatile agent in the oncological arsenal, holding immense potential for precise and effective cancer therapy.

Cancer remains a leading cause of global mortality, necessitating the development of advanced therapeutic strategies with enhanced efficacy and reduced systemic toxicity. Among promising bioactive agents, lactoferrin (LF)—a multifunctional iron-binding glycoprotein abundantly found in mammalian milk and exocrine secretions—has garnered significant interest for its potent and multifaceted anti-cancer properties. This review provides a comprehensive analysis of the current understanding of LF’s role in oncology, encompassing its structural biology, diverse mechanisms of action, and groundbreaking advancements in its application through nano-engineering. LF exerts anti-tumor effects through multiple pathways, including extracellular action, intracellular action, and immune regulation. It demonstrates a remarkable affinity for cancer cell membranes, binding to overexpressed anionic components such as glycosaminoglycans and sialic acids, as well as to specific receptors including the low-density lipoprotein receptor-related protein-1 (LRP-1). This selective binding facilitates targeted uptake. Upon internalization, LF orchestrates a direct assault by inducing cell-cycle arrest in phases such as G0/G1 or S phase through the modulation of key regulators including cyclins, CDKs, and p53. Furthermore, it promotes programmed cell death via apoptotic pathways, involving caspase activation and downregulation of anti-apoptotic proteins such as survivin. A more recently elucidated mechanism is the induction of ferroptosis, an iron-dependent form of cell death characterized by overwhelming lipid peroxidation. Beyond direct cytotoxicity, LF acts as a potent immunomodulator. It enhances natural killer (NK) cell activity, modulates T-lymphocyte populations, and crucially reprograms tumor-associated macrophages (TAMs) from a pro-tumor M2 state to an anti-tumor M1 state, thereby reversing the immunosuppressive tumor microenvironment (TME). The translation of LF’s potential has been significantly accelerated by nanotechnology. The inherent biocompatibility and natural tumor-targeting capabilities of LF make it an ideal platform for sophisticated drug-delivery systems. This review details various fabrication strategies for LF-based nanoparticles (NPs), including self-assembly, sol-in-oil emulsion, and electrostatic nanocomplexes, among others. Research demonstrates that nano-formulations not only protect LF from degradation but also enhance its bioactivity and anti-cancer potency. More importantly, LF NPs serve as versatile carriers for a wide array of therapeutic agents, including conventional chemotherapeutics, natural compounds, and imaging agents. These engineered systems enable synergistic therapy and facilitate site-specific delivery. Notably, the ability of LF to bind to receptors on the blood-brain barrier (BBB) has been leveraged to develop nano-systems for glioblastoma treatment. Other innovative designs utilize LF to modulate the TME—for instance, by alleviating tumor hypoxia to sensitize cells to radiotherapy and chemotherapy. Despite compelling pre-clinical evidence, the clinical translation of LF and its nano-formulations remains nascent. While early-phase trials have established a favorable safety profile for recombinant human LF, larger Phase III studies have yielded mixed results, underscoring the complexity of its action in humans. Key challenges include enhancing drug targeting, optimizing loading efficiency, ensuring batch-to-batch reproducibility, and achieving deep tumor penetration. Future research must focus on the rational design of next-generation LF-NPs. This entails developing standardized manufacturing protocols, engineering “smart” stimuli-responsive systems for targeted drug release in the TME, and constructing multi-targeting platforms. A concerted interdisciplinary effort is paramount to bridge the gap between bench and bedside. In conclusion, LF, particularly in its nano-engineered forms, represents a highly promising and versatile agent in the oncological arsenal, holding immense potential for precise and effective cancer therapy.

BACKGROUND:Due to the complex movement of the scapula,which is a six-degree-of-freedom activity in three-dimensional space,it is difficult to measure it accurately using traditional methods.The image and model matching technology based on dual-plane X-ray is a three-dimensional measurement method that has gradually developed and matured in recent years.Two high-speed cameras are used to project and shoot from orthogonal directions.Compared with a single perspective,this method has advantages in observation range and reduction of out-of-plane errors,and is suitable for the study of scapula kinematics.OBJECTIVE:X-ray biplane and image-model registration technology were used to explore the differences in scapular kinematics between normal individuals and patients with rotator cuff tears,providing a basis for the treatment and rehabilitation of rotator cuff tear patients.METHODS:From April 2023 to January 2024,10 patients with normal shoulders and 10 patients with rotator cuff tears who met the inclusion criteria were enrolled from Guanghua Hospital Affiliated to Shanghai University of Traditional Chinese Medicine.The subjects underwent a shoulder CT scan to create a 3D model and a local scapular coordinate system.X-ray biplane images were taken during shoulder abduction with two C-arm machines.The 2D and 3D images were registered to compare scapular kinematic differences between the two groups at 0°,15°,30°,45°,60°,75°,and 90° of abduction,including scapular rotation angle and displacement distance.RESULTS AND CONCLUSION:(1)During shoulder abduction,the scapula of both groups showed upward rotation,but the upward rotation of the rotator cuff tear group was greater than that of the control group,and the difference was significant when the abduction was 30°-90°(P＜0.01).At the same time,the scapula internal rotation of both groups gradually increased,but the rotator cuff tear group was significantly greater than the control group when the abduction was 45°-90°(P＜0.01).In addition,the anteroposterior tilt of the scapula of the two groups was significantly different when the abduction was 15°-90°(P＜0.01).The scapula posterior tilt of the control group gradually increased during abduction,while the scapula of the rotator cuff tear group tilted forward except for a slight posterior tilt at 15°-30° abduction.(2)In terms of displacement,the upward displacement of the rotator cuff tear group was less than that of the control group during abduction,and the difference was significant at 15°-90°(P＜0.05),but there was no significant difference in lateral and anterior-posterior displacement between the two groups(P＞0.05).(3)Rotator cuff tear can cause scapular dyskinesis,characterized by increased upward rotation,internal rotation,and abnormal forward tilt during shoulder abduction.Identifying and addressing scapular dyskinesis is crucial for treating rotator cuff tear.

BACKGROUND:Due to the complex movement of the scapula,which is a six-degree-of-freedom activity in three-dimensional space,it is difficult to measure it accurately using traditional methods.The image and model matching technology based on dual-plane X-ray is a three-dimensional measurement method that has gradually developed and matured in recent years.Two high-speed cameras are used to project and shoot from orthogonal directions.Compared with a single perspective,this method has advantages in observation range and reduction of out-of-plane errors,and is suitable for the study of scapula kinematics.OBJECTIVE:X-ray biplane and image-model registration technology were used to explore the differences in scapular kinematics between normal individuals and patients with rotator cuff tears,providing a basis for the treatment and rehabilitation of rotator cuff tear patients.METHODS:From April 2023 to January 2024,10 patients with normal shoulders and 10 patients with rotator cuff tears who met the inclusion criteria were enrolled from Guanghua Hospital Affiliated to Shanghai University of Traditional Chinese Medicine.The subjects underwent a shoulder CT scan to create a 3D model and a local scapular coordinate system.X-ray biplane images were taken during shoulder abduction with two C-arm machines.The 2D and 3D images were registered to compare scapular kinematic differences between the two groups at 0°,15°,30°,45°,60°,75°,and 90° of abduction,including scapular rotation angle and displacement distance.RESULTS AND CONCLUSION:(1)During shoulder abduction,the scapula of both groups showed upward rotation,but the upward rotation of the rotator cuff tear group was greater than that of the control group,and the difference was significant when the abduction was 30°-90°(P＜0.01).At the same time,the scapula internal rotation of both groups gradually increased,but the rotator cuff tear group was significantly greater than the control group when the abduction was 45°-90°(P＜0.01).In addition,the anteroposterior tilt of the scapula of the two groups was significantly different when the abduction was 15°-90°(P＜0.01).The scapula posterior tilt of the control group gradually increased during abduction,while the scapula of the rotator cuff tear group tilted forward except for a slight posterior tilt at 15°-30° abduction.(2)In terms of displacement,the upward displacement of the rotator cuff tear group was less than that of the control group during abduction,and the difference was significant at 15°-90°(P＜0.05),but there was no significant difference in lateral and anterior-posterior displacement between the two groups(P＞0.05).(3)Rotator cuff tear can cause scapular dyskinesis,characterized by increased upward rotation,internal rotation,and abnormal forward tilt during shoulder abduction.Identifying and addressing scapular dyskinesis is crucial for treating rotator cuff tear.

low transit constipation （STC） is a common functional intestinal disorder caused by impaired colonic transit function， characterized by reduced bowel movement frequency， hard stools， and difficulty in defecation. The mitogen-activated protein kinase （MAPK） signaling pathway， which mainly includes extracellular signal-regulated kinase （ERK）， c-Jun N-terminal kinase （JNK）， and p38 subtypes， plays a critical regulatory role in the occurrence and development of STC. This paper systematically reviews the multiple pathogenic mechanisms of the MAPK signaling pathway in STC and the research progress of traditional Chinese medicine （TCM） intervention.At the mechanistic level， the MAPK signaling pathway promotes the progression of STC through the following links：（1） Activation of p38 upregulates the expression of aquaporin 3 （AQP3）/AQP4 in the colon， leading to excessive reabsorption of water in the intestinal lumen； （2） It forms a positive feedback loop with nuclear factor-κB （NF-κB） to maintain low-grade intestinal inflammation， releases inflammatory factors such as tumor necrosis factor-α （TNF-α） and interleukin-1β （IL-1β）， and inhibits smooth muscle contraction； （3） Overactivation of p38 downregulates the expression of occludin and mucin 2 while upregulates the expression of claudin-2， thereby disrupting the mucosal barrier； （4） The JNK/p38 signaling pathway activates the caspase cascade to induce apoptosis of intestinal epithelial cells， neurons， and interstitial cells of Cajal； （5） Abnormal ERK signaling and excessive activation of p38/JNK inhibit intestinal smooth muscle contraction and reduce 5-hydroxytryptamine secretion， ultimately resulting in impaired colonic transit function.At the intervention level， TCM compound formulas and single herbs have been proven to improve STC by regulating the MAPK signaling pathway. Their effects are syndrome type-dependent：yin-nourishing formulas （Zengye Chengqi Tang， Tongbian Tang） mainly regulate the ERK/AQP axis； yang-warming formulas （Jichuan Jian） target both ERK/JNK and anti-apoptosis； heat-clearing formulas （Sanren Tang） focus on p38/NF-κB anti-inflammation. A single drug can simultaneously cover multiple aspects including water metabolism， inflammation， barrier function， apoptosis， and intestinal motility.Current relevant studies still have limitations such as mechanisms mostly remaining at the correlational level and a lack of disease-syndrome integrated research models. Future studies should combine specific inhibitors or gene knockout to identify core targets， establish disease-syndrome integrated STC models， and use network pharmacology and molecular docking techniques to deeply analyze the fine mechanism of “component-target-phenotype”， so as to provide high-quality evidence for the precise regulation of the MAPK signaling pathway by TCM in the intervention of STC.

In the context of burgeoning economic trade, there has been a remarkable increase in the number of ships travelling between domestic and international ports. Inbound and outbound cargo ships, cruise liners, ferries, and other types of vessels have emerged as critical vehicles for the dispersal of vector organisms and the spread of infectious disease agents. Public health concerns associated with these vessels represent a significant threat to human welfare. In this paper, we comprehensively review the hazards posed by vector organisms on ships, the latest advances in prevention and control strategies, and proposes appropriate countermeasures. The aim is to provide effective guidance for the prevention and control of public health security issues caused by ship-borne vector organisms.

Objective This study aimed to investigate the genetic diversity, differentiation, and population structure of Aedes albopictus across different geographical regions in Shandong Province, and to explore the relationship between genetic diversity and geographical distribution. Methods Between July and August 2024, ten Ae. albopictus populations were sampled from seven cities in Shandong Province. Genomic DNA was extracted from individual mosquitoes, and the mitochondrial cytochrome c oxidase subunit I(COⅠ)gene was amplified using PCR and sequenced. The obtained sequences were verified using BLAST and analyzed with MAFFT, MEGA 11, DnaSP v6.12, Arlequin 3.5, PopART 1.7, STRUCTURE 2.3.4 and the R packages adegenet and vegan to assess genetic diversity and population structure. Results A total of 229 COⅠ sequences(662 bp) was obtained, revealing ten variable sites with no insertions or deletions. The overall base composition showed an AT bias of 67.7%. Haplotype analysis identified 11 haplotypes, with Hap2 being the dominant and most widely distributed haplotype across all populations. Neutrality tests showed significant population expansion only in the Rizhao population. Mantel testing result revealed that geographical distance does not significantly impede gene flow. Overall, genetic differentiation among populations was low, indicating frequent gene flow. When combined with additional samples from Shanghai, Fujian, Guangdong, Yunnan, Hainan and Guangxi, STRUCTURE, UPGMA and DAPC analyses revealed two primary genetic clusters of Ae. albopictus. Conclusions Ae. albopictus populations in Shandong Province exhibit frequent gene flow, low genetic differentiation, and relatively low overall genetic diversity. However, the Rizhao population showed signs of recent expansion, highlighting the need for enhanced surveillance and targeted control measures in this area.

ObjectiveTo investigate the novel post-translational modifications (PTMs) of SnRK2.6, a central component in the abscisic acid (ABA) signaling pathway, such as SUMOylation, and to establish a foundation for revealing the physiological functions and molecular mechanisms of SnRK2.6 regulated by these new modifications. MethodsThe interaction between SnRK2.6 and the SUMO E3 ligase SIZ1, as well as members of the SUMO protease family, was examined using yeast two-hybrid and in vitro pull-down assays. An in vitro SUMOylation system in Escherichia coli was utilized to determine whether SnRK2.6 undergoes SUMOylation. Mass spectrometry, combined with site-directed mutagenesis of candidate lysine residues, was employed to identify potential SUMOylation sites on SnRK2.6. In vitro de-SUMOylation assays were performed to assess whether SUMO proteases interacting with SnRK2.6 could catalyze the removal of SUMO moieties from modified SnRK2.6. The protein stability of SnRK2.6 was assessed in a cell-free degradation assay using bacterial-purified SnRK2.6 incubated with total protein extracts from Col and siz1 mutant seedlings. To dissect the genetic relationship between SnRK2.6 and SIZ1, stomatal aperture assays were performed under ABA treatment using snrk2.6, siz1, and snrk2.6 siz1 double mutant plants. ResultsSnRK2.6 physically interacts with SIZ1 and the SUMO protease ESD4, with the binding domains localized to the C-terminal region of SIZ1 and the N-terminal region of ESD4, respectively. SnRK2.6 was found to be SUMOylated, exhibiting two distinct high-molecular-mass bands ranging from 70 to 100 ku, indicative of modified forms. Bioinformatics analysis predicted four putative SUMOylation sites on lysine residues K57, K63, K142, and K190. Mass spectrometry identified three SUMOylation sites on K63, K142, and K174. However, individual or combinatorial point mutations on these sites had minimal impact on the pattern or intensity of SUMOylation signals, suggesting that these residues may not be responsible for the SUMOylation on SnRK2.6. Instead, such mutations only weaken the protein stability or accelerate the protein mobility of SnRK2.6. Therefore, the exact SUMOylation sites on SnRK2.6 remain unidentified. In de-SUMOylation experiments, incubation of GST-ESD4 with SUMOylated SnRK2.6 for 1-2 h led to the near-complete disappearance of both SUMOylated bands. In contrast, neither the GST control nor the catalytically inactive mutant GST-ESD4^C448S exhibited any de-SUMOylation activity. In protein turnover experiments, SnRK2.6 exhibited markedly enhanced half-life in siz1 compared with Col, indicating that SIZ1-dependent SUMOylation promotes SnRK2.6 turnover. Phenotypically, snrk2.6 mutants were completely insensitive to ABA-induced stomatal closure; siz1 mutants displayed pronounced hypersensitivity; and the snrk2.6 siz1 double mutant phenocopied snrk2.6—showing no significant response to ABA beyond that of the snrk2.6 mutant. These data indicate that SIZ1 acts as a negative regulator of ABA-triggered stomatal closure and SnRK2.6 functions as a positive regulator, and the inhibitory activity of SIZ1 is strictly dependent on SnRK2.6, placing SnRK2.6 genetically upstream of SIZ1 in the ABA signaling pathway. ConclusionSnRK2.6 undergoes SUMOylation, although the specific SUMOylation sites have not been defined. SnRK2.6 is dynamically regulated by reversible SUMOylation—catalyzed by SIZ1 and reversed by ESD4—which controls its protein stability. SUMOylation acts as a destabilizing signal for SnRK2.6, and SIZ1 exerts its negative effect on ABA-triggered stomatal closure probably through promoting SnRK2.6 degradation via SUMOylation. These findings uncover SUMOylation as a critical regulatory layer fine-tuning SnRK2.6 abundance in ABA signaling.