The incidence of intrahepatic cholangiocarcinoma (ICC) is steadily rising, and it is associated with a high mortality rate. Clinical samples were collected to detect the expression of HSPB8 and BAG3 in ICC tissues. ICC cells were cultured and transfected with plasmids that overexpressed or silenced specific genes to investigate the impact of gene expression alterations on cell function. qPCR and Western blot techniques were utilized to measure gene and protein expression levels. A wound healing assay was conducted to assess cell migration ability. The Transwell assay was used to assess cell invasion ability. Co-IP was used to verify the binding relationship between HSPB8 and BAG3. The effects of HSPB8 and BAG3 on lung metastasis of tumors in vivo were verified by constructing a metastatic tumor model. Through the above experiments, we discovered that the expressions of HSPB8 and BAG3 were up-regulated in ICC tissues and cells, and their expressions were positively correlated. The metastatic ability of ICC cells could be promoted or inhibited by upregulating or downregulating the expression of BAG3. Furthermore, the HSPB8-BAG3 chaperone complex resulted in the abnormal degradation of Filamin A by activating autophagy. Increased expression of Filamin A inhibits the migration and invasion of ICC cells. Overexpression of HSPB8 and BAG3 in vivo promoted the lung metastasis ability of ICC cells. The HSPB8-BAG3 chaperone complex promotes ICC cell migration and invasion by regulating CASA-mediated degradation of Filamin A, offering insights for enhancing ICC therapeutic strategies.

BACKGROUND: Clear cell renal cell carcinoma (ccRCC) remains a deadly disease with a poor prognosis. Here, we identified the ETS homologous factor (EHF) and its target Filamin-B (FLNB) as molecules related to immune evasion in ccRCC. We also explored the upstream modifier that manipulates EHF in ccRCC.
METHODS: Cell proliferation and apoptosis assay, wound healing assay, and Transwell assay were designed to analyze the effects of EHF or FLNB knockdown on the biological activity of ccRCC cells. The growth of differently treated ccRCC cells was assessed by orthotopic tumors. ccRCC cells with different treatments were co-cultured with macrophages, and the role of the lysine-specific demethylase 5B (KDM5B)/EHF/FLNB axis on macrophage polarization or ccRCC progression was characterized by detecting the expression of M2 macrophage markers in the co-culture system or tumor tissues of tumor-bearing mice.
RESULTS: The expression of EHF and FLNB was higher, while KDM5B was lower in HK2 cells than in ccRCC cells. EHF overexpression inhibited the biological behavior of ccRCC cells and tumor growth in mice. EHF activated FLNB transcription. Knockdown of FLNB supported the biological activity of ccRCC cells and tumor growth and reversed M2 macrophage polarization in tumor tissues of mice in the presence of EHF. KDM5B inhibited EHF expression by H3K4me3 demethylation, and EHF knockdown potentiated M2 macrophage polarization and tumor growth in vivo repressed by KDM5B knockdown.
CONCLUSIONS: KDM5B inhibited the expression of EHF by repressing H3K4me3 modification and the transcription of FLNB by EHF to promote immune evasion and progression of ccRCC.

Disulfidptosis, a newly recognized cell death triggered by disulfide stress, has garnered attention for its potential role in osteoporosis (OP) pathogenesis. Although sulfide-related proteins are reported to regulate the balance of bone metabolism in OP, the precise involvement of disulfidptosis regulators remains elusive. Herein, leveraging the GSE56815 dataset, we conducted an analysis to delineate disulfidptosis-associated diagnostic clusters and immune landscapes in OP. Subsequently, vertebral bone tissues obtained from OP patients and controls were subjected to RNA sequencing (RNA-seq) for the validation of key disulfidptosis gene expression. Our analysis unveiled seven significant disulfidptosis regulators, including FLNA, ACTB, PRDX1, SLC7A11, NUBPL, OXSM, and RAC1, distinguishing OP samples from controls. Furthermore, employing a random forest model, we identified four diagnostic disulfidptosis regulators including FLNA, SLC7A11, NUBPL, and RAC1 potentially predictive of OP risk. A nomogram model integrating these four regulators was constructed and validated using the GSE35956 dataset, demonstrating promising utility in clinical decision-making, as affirmed by decision curve analysis. Subsequent consensus clustering analysis stratified OP samples into two different disulfidptosis subgroups (clusters A and B) using significant disulfidptosis regulators, with cluster B exhibiting higher disulfidptosis scores and implicating monocyte immunity, closely linked to osteoclastogenesis. Notably, RNA-seq analysis corroborated the expression patterns of two disulfidptosis modulators, PRDX1 and OXSM, consistent with bioinformatics predictions. Collectively, our study sheds light on disulfidptosis patterns, offering potential markers and immunotherapeutic avenues for future OP management.

OBJECTIVE: To analyze the clinical phenotype and genetic basis of a Chinese pedigree affected with Otopalatodigital syndrome type 1 (OPD1).
METHODS: A pedigree which was evaluated at the Department of Endocrinology, General Hospital of the Central Theater Command on December 3, 2020 was selected as the study subject. Clinical phenotype and genetic features of the proband were analyzed. Whole exome sequencing was employed to screen for genetic variants in the proband, and Sanger sequencing was used to verify the candidate variants in the proband\'s mother, uncle, maternal aunt, and paternal aunt. Pathogenicity analysis was also conducted for the candidate variants.
RESULTS: The proband, a 16-year-old male, had shown distinctive facial features including mildly prominent eyebrows, down-slanting palpebral fissures, hypertelorism, and depressed nasal bridge. Additionally, he had clubbing of bilateral thumbs and big toes, and central type diabetes insipidus. Genetic sequencing revealed that he has harbored a heterozygous c.586C>T (p.R196W) missense variant of the FLNA gene (NM_001110556.2), which was also carried by his mother and uncle. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), this variant was classified as likely pathogenic (PM1+PM2_Supporting+PP2+PP3+PS4 Supporting).
CONCLUSIONS: The heterozygous c.586C>T (p.R196W) variant of the FLNA gene probably underlay the pathogenesis in this OPD1 family. The central type diabetes insipidus in the proband may represent a newly discovered phenotype of OPD1. Above finding has contributed crucial information for the comprehensive understanding of the clinical manifestations and pathogenic mechanisms of OPD1.

OBJECTIVE: This study aimed to evaluate the associations between disulfidptosis related genes-SLC3A2, SLC7A11 and FLNB polymorphisms and risk of autoimmune thyroiditis (AIT).
METHODS: Six SNPs in the SLC3A2, SLC7A11 and FLNB were genotyped in 650 AIT cases and 650 controls using a MassARRAY platform.
RESULTS: Minor alleles of SLC3A2-rs12794763, rs1059292 and FLNB-rs839240 might lead to a higher risk of AIT (p < 0.001), while SLC7A11-rs969319-C allele tends to decrease the risk of the disease (p = 0.006). Genetic model analysis showed that SLC3A2-rs12794763, SLC3A2-rs1059292 and FLNB-rs839240 polymorphisms were risk factors for AIT (p < 0.001); while SLC7A11-rs969319 showed a protective role for the disease in all genetic models (p < 0.005). Stratification analysis showed that SLC3A2-rs1059292 and rs12794763 were correlated with higher risk of AIT regardless of sex (p < 0.05). Moreover, FLNB-rs839240 exhibited higher risk of disease only in females (p < 0.05). By contrast, SLC7A11-rs969319 showed a protective role only in females (p < 0.05).
CONCLUSIONS: Our results shed new light on the association between disulfidptosis-related genes and AIT risk.

OBJECTIVE: To explore the genetic basis for a patient with Dilated cardiomyopathy.
METHODS: A patient admitted to Beijing Anzhen Hospital Affiliated to Capital Medical University in April 2022 was selected as the study subject. Clinical data and family history of the patient was collected. Targeted exome sequencing was carried out. Candidate variant was verified by Sanger sequencing and bioinformatic analysis based on guidelines of the American College of Medical Genetics and Genomics (ACMG).
RESULTS: DNA sequencing revealed that the patient has harbored a heterozygous c.5044dupG frameshift variant of the FLNC gene. Based on the ACMG guidelines, the variant was predicted to be likely pathogenic (PVS1+PM2_Supporting+PP4).
CONCLUSIONS: The heterozygous c.5044dupG variant of the FLNC gene probably underlay the pathogenesis in this patient, which has provided a basis for the genetic counseling for his family.

In resting platelets, the 17 th domain of filamin a (FLNa17) constitutively binds to the platelet membrane glycoprotein Ibα (GPIbα) at its cytoplasmic tail (GPIbα-CT) and inhibits the downstream signal activation, while the binding of ligand and blood shear force can activate platelets. To imitate the pull force transmitted from the extracellular ligand of GPIbα and the lateral tension from platelet cytoskeleton deformation, two pulling modes were applied on the GPIbα-CT/FLNa17 complex, and the molecular dynamics simulation method was used to explore the mechanical regulation on the affinity and mechanical stability of the complex. In this study, at first, nine pairs of key hydrogen bonds on the interface between GPIbα-CT and FLNa17 were identified, which was the basis for maintaining the complex structural stability. Secondly, it was found that these hydrogen bonding networks would be broken down and lead to the dissociation of FLNa17 from GPIbα-CT only under the axial pull force; but, under the lateral tension, the secondary structures at both terminals of FLNa17 would unfold to protect the interface of the GPIbα-CT/FLNa17 complex from mechanical damage. In the range of 0~40 pN, the increase of pull force promoted outward-rotation of the nitrogen atom of the 563 rd phenylalanine (PHE 563-N) at GPIbα-CT and the dissociation of the complex. This study for the first time revealed that the extracellular ligand-transmitted axial force could more effectively relieve the inhibition of FLNa17 on the downstream signal of GPIbα than pure mechanical tension at the atomic level, and would be useful for further understanding the platelet intracellular force-regulated signal pathway.
静息血小板中细丝蛋白a的17号结构域（FLNa17）可组成型结合到血小板膜糖蛋白Ibα（GPIbα）的胞质尾部（GPIbα-CT），抑制下游信号活化，而配体的结合和血流剪切力可激活血小板。为模拟来自GPIbα胞外配体向胞内传递的正向拉力及血小板细胞骨架形变传递的侧向张力，本文在GPIbα-CT/FLNa17复合物上施加两种受力模式，采用分子动力学模拟方法探究机械力对该复合物亲和力及力学稳定性的调控。本研究首先识别出GPIbα-CT与FLNa17接触面上的9对关键氢键是维持复合物结构稳定的基础。其次，发现仅正向拉力作用下，这些氢键作用网络才会发生断裂，并导致复合物的最终解离；而侧向张力下，FLNa17两端的二级结构会解折叠以保护复合物接触面不受机械力破坏。在0～40 pN范围内，正向拉力的增加促使GPIbα-CT氨基酸序列中第563位的苯丙氨酸的氮原子（PHE 563-N）的外旋和复合物解离概率的提高。本研究首次在原子层面揭示胞外配体传递的正向拉力可更有效解除FLNa17对GPIbα下游信号的抑制，为深入理解力调控的血小板胞内信号通路提供参考。.

Developmental dysplasia of the hip (DDH), characterized by acetabular deformity that manifests from loose ligaments to complete dislocation of the hip, can cause notable pain and dysfunction and lead to hip dislocation, secondary fractures, scoliosis, and osteoarthritis of hip. Variants in FLNA may produce a spectrum of malformations in multiple organs, especially the skeleton. This study aimed to identify the genetic etiologies of DDH patients and provide genetic testing information for further diagnosis and treatment of DDH. We recruited a Chinese woman with DDH and her family members. Whole-exome sequencing was used to identify the patient\'s genetic etiologies. Protein models were used to analyze the pathogenic mechanism of the identified variants. A novel variant (c.3493T>G, p.C1165G) of FLNA was detected. The structural models of the mutant FLNA protein indicated that the variant would lose its sulfhydryl side chain and destroy the attraction between benzene rings and sulfhydryl. We reported a novel variant (c.3493T>G, p.C1165G) of FLNA in a Chinese woman with DDH. Our research outcome enriches the gene pool for hip dysplasia and emphasizes the pathogenicity of sulfhydryl side chain disruption in FLNA.

The filamin C (FLNC) was hypothesized to be colocalized with its certain binding partners in pork tissues and calpain as well as caspase was assumed responsible for the postmortem degradation of FLNC. Therefore, the specific distribution of pork FLNC and its degradation pattern during postmortem aging were investigated in this study. The longissimus thoracis muscles from 12 pigs were removed from the carcasses and then aged at 4 °C for 1, 6, 12, 24, 72, and 168 h, respectively. The FLNC signals appeared to localize in subsarcolemmal areas by cross-sectional images, while the localization was found surrounding the myofibrils at the level of the Z-discs in longitudinal sections. FLNC displayed a highly overlapped spatial colocalization with actin or integrin. Western blot results showed that the intact 290 kDa FLNC was rapidly degraded to produce an approximately 280 kDa band. An almost overlapped distribution pattern was observed between FLNC and μ-calpain or caspase-3 in porcine skeletal muscle cells. Moreover, both the μ-calpain inhibitor and the caspase-3 inhibitor could inhibit the degradation of FLNC in porcine LT muscles during postmortem aging.

Prolonged exposure to arsenic can cause nonalcoholic steatohepatitis (NASH). The NOD-like receptor protein 3 (NLRP3) inflammasome plays an essential role in the process of NASH. However, the mechanism by which arsenic promotes NLRP3 expression remains unclear. Three-month NaAsO2 gavage led to the nuclear factor-κB (NF-κB) signaling pathway activation and NASH. Additionally, NaAsO2 upregulated the level of Filamin A (FLNA) and pyroptosis, thereby activating the NLRP3 inflammasome in SD rat liver. Using FLNA siRNA, NASH-associated inflammation and pyroptosis were clearly mitigated by reducing activation of the NLRP3 inflammasome. Furthermore, arsenic treatment facilitated activation of the NF-κB signaling pathway and promoted p-p65 translocation into the nucleus. Chromatin immunoprecipitation (Ch-IP) assay indicated that FLNA promoted p65 binding to the NLRP3 gene and upregulated the transcription of NLRP3, ultimately leading to pyroptosis and NASH. Our findings indicate that FLNA and pyroptosis are strongly associated with NASH induced by NaAsO2. Collectively, the findings of this study indicated that FLNA mediates NF-κB signaling pathway-induced activation of the NLRP3 inflammasome and ultimately activates pyroptosis and NASH upon NaAsO2 exposure. This information may be useful for improving therapeutic strategies against arsenic-induced NASH.