LincRNA-p21/AIF-1/CMPK2/NLRP3 pathway promoted inflammation, autophagy and apoptosis of human tubular epithelial cell induced by urate via exosomes.

Urate nephropathy, a common complication of hyperuricemia, has garnered increasing attention worldwide. However, the exact pathogenesis of this condition remains unclear. Currently, inflammation is widely accepted as the key factor in urate nephropathy. Therefore, the aim of this study was to elucidate the interaction of lincRNA-p21/AIF-1/CMPK2/NLRP3 via exosomes in urate nephropathy. This study evaluated the effect of lincRNA-p21/AIF-1/CMPK2/NLRP3 using clinical data collected from patients with urate nephropathy and human renal tubular epithelial cells (HK2) cultured with different concentrations of urate. In clinical research section, the level of lincRNA-p21/AIF-1 in exosomes of urine in patients with hyperuricemia or urate nephropathy was found to be increased, particularly in patients with urate nephropathy. In vitro study section, the level of exosomes, inflammation, autophagy, and apoptosis was increased in HK2 cells induced by urate. Additionally, the expression of lincRNA-p21, AIF-1, CMPK2, and NLRP3 was upregulated in exosomes and HK2 cells. Furthermore, manipulating the activity of lincRNA-p21, AIF-1, CMPK2, and NLRP3 through overexpression or interference vectors regulated the level of inflammation, autophagy, and apoptosis in HK2 cells. In conclusion, the pathway of lincRNA-p21/AIF-1/CMPK2/NLRP3 contributed to inflammation, autophagy, and apoptosis of human renal tubular epithelial cell induced by urate via exosomes. Additionally, the specific exosomes in urine might serve as novel biomarkers for urate nephropathy.

Autoinhibition and relief mechanisms for MICAL monooxygenases in F-actin disassembly.

MICAL proteins represent a unique family of actin regulators crucial for synapse development, membrane trafficking, and cytokinesis. Unlike classical actin regulators, MICALs catalyze the oxidation of specific residues within actin filaments to induce robust filament disassembly. The potent activity of MICALs requires tight control to prevent extensive damage to actin cytoskeleton. However, the molecular mechanism governing MICALs' activity regulation remains elusive. Here, we report the cryo-EM structure of MICAL1 in the autoinhibited state, unveiling a head-to-tail interaction that allosterically blocks enzymatic activity. The structure also reveals the assembly of C-terminal domains via a tripartite interdomain interaction, stabilizing the inhibitory conformation of the RBD. Our structural, biochemical, and cellular analyses elucidate a multi-step mechanism to relieve MICAL1 autoinhibition in response to the dual-binding of two Rab effectors, revealing its intricate activity regulation mechanisms. Furthermore, our mutagenesis study of MICAL3 suggests the conserved autoinhibition and relief mechanisms among MICALs.

Effect of Trehalose Disaccharide on Activation of Microglia and Indices of Systemic Inflammation in an Experimental Model of Alzheimer's Disease.

In an experimental model of Alzheimer's disease in mice, oral administration of trehalose disaccharide reduces neuroinflammation assessed by the expression level of microglia activation marker Iba1 and affects the neutrophil degranulation activity. A potential anti-inflammatory effect of 4% trehalose solution associated with a decrease in the activity of leukocyte elastase in plasma was revealed.

Nesprin-2 coordinates opposing microtubule motors during nuclear migration in neurons.

Nuclear migration is critical for the proper positioning of neurons in the developing brain. It is known that bidirectional microtubule motors are required for nuclear transport, yet the mechanism of the coordination of opposing motors is still under debate. Using mouse cerebellar granule cells, we demonstrate that Nesprin-2 serves as a nucleus-motor adaptor, coordinating the interplay of kinesin-1 and dynein. Nesprin-2 recruits dynein-dynactin-BicD2 independently of the nearby kinesin-binding LEWD motif. Both motor binding sites are required to rescue nuclear migration defects caused by the loss of function of Nesprin-2. In an intracellular cargo transport assay, the Nesprin-2 fragment encompassing the motor binding sites generates persistent movements toward both microtubule minus and plus ends. Nesprin-2 drives bidirectional cargo movements over a prolonged period along perinuclear microtubules, which advance during the migration of neurons. We propose that Nesprin-2 keeps the nucleus mobile by coordinating opposing motors, enabling continuous nuclear transport along advancing microtubules in migrating cells.

Vasorin (VASN) overexpression promotes pulmonary metastasis and resistance to adjuvant chemotherapy in patients with locally advanced rectal cancer.

BACKGROUND: LARC patients commonly receive adjuvant therapy, however, hidden micrometastases still limit the improvement of OS. This study aims to investigate the impact of VASN in rectal cancer with pulmonary metastasis and understand the underlying molecular mechanisms to guide adjuvant chemotherapy selection. METHODS: Sequencing data from rectal cancer patients with pulmonary metastasis from Sun Yat-sen University Cancer Center (SYSUCC) and publicly available data were meticulously analyzed. The functional role of VASN in pulmonary metastasis was validated in vivo and in vitro. Coimmunoprecipitation (co-IP), immunofluorescence, and rescue experiments were conducted to unravel potential molecular mechanisms of VASN. Moreover, VASN expression levels in tumor samples were examined and analyzed for their correlations with pulmonary metastasis status, tumor stage, adjuvant chemotherapy benefit, and survival outcome. RESULTS: Our study revealed a significant association between high VASN expression and pulmonary metastasis in LARC patients. Experiments in vitro and in vivo demonstrated that VASN could promote the cell proliferation, metastasis, and drug resistance of colorectal cancer. Mechanistically, VASN interacts with the NOTCH1 protein, leading to concurrent activation of the NOTCH and MAPK pathways. Clinically, pulmonary metastasis and advanced tumor stage were observed in 90% of VASN-positive patients and 53.5% of VASN-high patients, respectively, and VASN-high patients had a lower five-year survival rate than VASN-low patients (26.7% vs. 83.7%). Moreover, the Cox analysis and OS analysis indicated that VASN was an independent prognostic factor for OS (HR = 7.4, P value < 0.001) and a predictor of adjuvant therapy efficacy in rectal cancer. CONCLUSIONS: Our study highlights the role of VASN in decreasing drug sensitivity and activating the NOTCH and MAPK pathways, which leads to tumorigenesis and pulmonary metastasis. Both experimental and clinical data support that rectal cancer patients with VASN overexpression detected in biopsies have a higher risk of pulmonary metastasis and adjuvant chemotherapy resistance.

Concurrent de novo MACF1 mutation and inherited 16p13.11 microduplication in a preterm newborn with hypotonia, joint hyperlaxity and multiple congenital malformations: a case report.

BACKGROUND: The MACF1 gene, found on chromosome 1p34.3, is vital for controlling cytoskeleton dynamics, cell movement, growth, and differentiation. It consists of 101 exons, spanning over 270 kb. The 16p13.11 microduplication syndrome results from the duplication of 16p13.11 chromosome copies and is associated with various neurodevelopmental and physiological abnormalities. Both MACF1 and 16p13.11 microduplication have significant impacts on neural development, potentially leading to nerve damage or neurological diseases. This study presents a unique case of a patient simultaneously experiencing a de novo MACF1 mutation and a hereditary 16p13.11 microduplication, which has not been reported previously. CASE PRESENTATION: In this report, we describe a Chinese preterm newborn girl exhibiting the typical characteristics of 16.13.11 microduplication syndrome. These features include developmental delay, respiratory issues, feeding problems, muscle weakness, excessive joint movement, and multiple congenital abnormalities. Through whole-exome sequencing, we identified a disease-causing mutation in the MACF1 gene (c.15266T > C / p. Met5089Thr). Additionally, after microarray analysis, we confirmed the presence of a 16p13.11 microduplication (chr16:14,916,289 - 16,315,688), which was inherited from the mother. CONCLUSIONS: The patient's clinical presentation, marked by muscle weakness and multiple birth defects, may be attributed to both the de novo MACF1 mutation and the 16p13.11 duplication, which could have further amplified her severe symptoms. Genetic testing for individuals with complex clinical manifestations can offer valuable insights for diagnosis and serve as a reference for genetic counseling for both patients and their families.

TAGLN2 induces resistance signature ISGs by activating AKT-YBX1 signal with dual pathways and mediates the IFN-related DNA damage resistance in gastric cancer.

Recently, various cancer types have been identified to express a distinct subset of Interferon-stimulated genes (ISGs) that mediate therapy resistance. The mechanism through which cancer cells maintain prolonged Interferon stimulation effects to coordinate resistance remains unclear. Our research demonstrated that aberrant upregulation of TAGLN2 is associated with gastric cancer progression, and inhibiting its expression renders gastric cancer cells more susceptible to chemotherapy and radiation. We uncovered a novel role for TAGLN2 in the upregulation of resistance signature ISGs by enhancing YBX1-associated ssDNA aggregation and cGAS-STING pathway activation. TAGLN2 modulates YBX1 by recruiting c-Myc and SOX9 to YBX1 promoter region and directly interacting with AKT-YBX1, thereby enhancing YBX1 phosphorylation and nuclear translocation. Significantly, targeted downregulation of key proteins, inhibition of the TAGLN2-YBX1-AKT interaction (using Fisetin or MK2206) or disruption of the cGAS-STING pathway substantially reduced ssDNA accumulation, subsequent ISGs upregulation, and therapy resistance. The combination of Cisplatin with MK2206 displayed a synergistic effect in the higher TAGLN2-expressing xenograft tumors. Clinical analysis indicated that a derived nine-gene set effectively predicts therapeutic sensitivity and long-term prognosis in gastric cancer patients. These findings suggest that TAGLN2, YBX1 and induced ISGs are novel predictive markers for clinical outcomes, and targeting this axis is an attractive therapeutic sensitization strategy.

Cyclase-associated protein (CAP) inhibits inverted formin 2 (INF2) to induce dendritic spine maturation.

The morphology of dendritic spines, the postsynaptic compartment of most excitatory synapses, decisively modulates the function of neuronal circuits as also evident from human brain disorders associated with altered spine density or morphology. Actin filaments (F-actin) form the backbone of spines, and a number of actin-binding proteins (ABP) have been implicated in shaping the cytoskeleton in mature spines. Instead, only little is known about the mechanisms that control the reorganization from unbranched F-actin of immature spines to the complex, highly branched cytoskeleton of mature spines. Here, we demonstrate impaired spine maturation in hippocampal neurons upon genetic inactivation of cyclase-associated protein 1 (CAP1) and CAP2, but not of CAP1 or CAP2 alone. We found a similar spine maturation defect upon overactivation of inverted formin 2 (INF2), a nucleator of unbranched F-actin with hitherto unknown synaptic function. While INF2 overactivation failed in altering spine density or morphology in CAP-deficient neurons, INF2 inactivation largely rescued their spine defects. From our data we conclude that CAPs inhibit INF2 to induce spine maturation. Since we previously showed that CAPs promote cofilin1-mediated cytoskeletal remodeling in mature spines, we identified them as a molecular switch that control transition from filopodia-like to mature spines.

Structural basis for coupling of the WASH subunit FAM21 with the endosomal SNX27-Retromer complex.

Endosomal membrane trafficking is mediated by specific protein coats and formation of actin-rich membrane domains. The Retromer complex coordinates with sorting nexin (SNX) cargo adaptors including SNX27, and the SNX27-Retromer assembly interacts with the Wiskott-Aldrich syndrome protein and SCAR homolog (WASH) complex which nucleates actin filaments establishing the endosomal recycling domain. Crystal structures, modeling, biochemical, and cellular validation reveal how the FAM21 subunit of WASH interacts with both Retromer and SNX27. FAM21 binds the FERM domain of SNX27 using acidic-Asp-Leu-Phe (aDLF) motifs similar to those found in the SNX1 and SNX2 subunits of the ESCPE-1 complex. Overlapping FAM21 repeats and a specific Pro-Leu containing motif bind three distinct sites on Retromer involving both the VPS35 and VPS29 subunits. Mutation of the major VPS35-binding site does not prevent cargo recycling; however, it partially reduces endosomal WASH association indicating that a network of redundant interactions promote endosomal activity of the WASH complex. These studies establish the molecular basis for how SNX27-Retromer is coupled to the WASH complex via overlapping and multiplexed motif-based interactions required for the dynamic assembly of endosomal membrane recycling domains.

Comparative Analysis of Breast Cancer Metabolomes Highlights Fascin's Central Role in Regulating Key Pathways Related to Disease Progression.

Omics technologies provide useful tools for the identification of novel biomarkers in many diseases, including breast cancer, which is the most diagnosed cancer in women worldwide. We and others have reported a central role for the actin-bundling protein (fascin) in regulating breast cancer disease progression at different levels. However, whether fascin expression promotes metabolic molecules that could predict disease progression has not been fully elucidated. Here, fascin expression was manipulated via knockdown (fascinKD+NORF) and rescue (fascinKD+FORF) in the naturally fascin-positive (fascinpos+NORF) MDA-MB-231 breast cancer cells. Whether fascin dysregulates metabolic profiles that are associated with disease progression was assessed using untargeted metabolomics analyses via liquid chromatography-mass spectrometry. Overall, 12,226 metabolic features were detected in the tested cell pellets. Fascinpos+NORF cell pellets showed 2510 and 3804 significantly dysregulated metabolites compared to their fascinKD+NORF counterparts. Fascin rescue (fascinKD+FORF) revealed 2710 significantly dysregulated cellular metabolites compared to fascinKD+NORF counterparts. A total of 101 overlapped cellular metabolites between fascinKD+FORF and fascinpos+NORF were significantly dysregulated in the fascinKD+NORF cells. Analysis of the significantly dysregulated metabolites by fascin expression revealed their involvement in the metabolism of sphingolipid, phenylalanine, tyrosine, and tryptophan biosynthesis, and pantothenate and CoA biosynthesis, which are critical pathways for breast cancer progression. Our findings of fascin-mediated alteration of metabolic pathways could be used as putative poor prognostic biomarkers and highlight other underlying mechanisms of fascin contribution to breast cancer progression.

Actomyosin organelle functions of SPIRE actin nucleators precede animal evolution.

An important question in cell biology is how cytoskeletal proteins evolved and drove the development of novel structures and functions. Here we address the origin of SPIRE actin nucleators. Mammalian SPIREs work with RAB GTPases, formin (FMN)-subgroup actin assembly proteins and class-5 myosin (MYO5) motors to transport organelles along actin filaments towards the cell membrane. However, the origin and extent of functional conservation of SPIRE among species is unknown. Our sequence searches show that SPIRE exist throughout holozoans (animals and their closest single-celled relatives), but not other eukaryotes. SPIRE from unicellular holozoans (choanoflagellate), interacts with RAB, FMN and MYO5 proteins, nucleates actin filaments and complements mammalian SPIRE function in organelle transport. Meanwhile SPIRE and MYO5 proteins colocalise to organelles in Salpingoeca rosetta choanoflagellates. Based on these observations we propose that SPIRE originated in unicellular ancestors of animals providing an actin-myosin driven exocytic transport mechanism that may have contributed to the evolution of complex multicellular animals.

Genetic Insights into Skeletal Malocclusion: The Role of the FBN3 rs7351083 SNP in the Romanian Population.

Background and Objectives: irregularities in the growth and development of the jawbones can lead to misalignments of maxillary and mandibular structures, a complex condition known as skeletal malocclusion, one of the most common oral health problems. Skeletal malocclusions, particularly Class II and Class III, can significantly affect facial appearance, chewing efficiency, speech, and overall oral health, often requiring orthodontic treatment or surgery to correct. These dentofacial anomalies are influenced by genetic and environmental factors and exhibit diverse phenotypic expressions. Materials and Methods: in this study, we investigated the correlation between the rs7351083 SNP of the FBN3 gene that encodes a member of the fibrillin protein family and malocclusion risk in a group of 57 patients from Romania. Results: the results shed light on the relationship between the selected genetic marker and the investigated dentofacial disorder, revealing a positive association between the reference allele (A) and Class II and that the alternate allele (G) is associated with Class III. Conclusions: cephalometric analysis revealed no significant differences among genotypes, suggesting that while genetic factors are implicated in malocclusion, they may not directly affect cephalometric parameters or that the sample size was too small to detect these differences. The discovery of an A > T transversion in one individual with a Class II deformity underscores the genetic diversity within the population and the necessity of comprehensive genotyping to uncover rare genetic variants that might influence craniofacial development and the risk of malocclusion. This study highlights the need for larger studies to confirm these preliminary associations.

Structural Basis for the Interaction between the Ezrin FERM-Domain and Human Aquaporins.

The Ezrin/Radixin/Moesin (ERM) family of proteins act as cross-linkers between the plasma membrane and the actin cytoskeleton. This mechanism plays an essential role in processes related to membrane remodeling and organization, such as cell polarization, morphogenesis and adhesion, as well as in membrane protein trafficking and signaling pathways. For several human aquaporin (AQP) isoforms, an interaction between the ezrin band Four-point-one, Ezrin, Radixin, Moesin (FERM)-domain and the AQP C-terminus has been demonstrated, and this is believed to be important for AQP localization in the plasma membrane. Here, we investigate the structural basis for the interaction between ezrin and two human AQPs: AQP2 and AQP5. Using microscale thermophoresis, we show that full-length AQP2 and AQP5 as well as peptides corresponding to their C-termini interact with the ezrin FERM-domain with affinities in the low micromolar range. Modelling of the AQP2 and AQP5 FERM complexes using ColabFold reveals a common mode of binding in which the proximal and distal parts of the AQP C-termini bind simultaneously to distinct binding sites of FERM. While the interaction at each site closely resembles other FERM-complexes, the concurrent interaction with both sites has only been observed in the complex between moesin and its C-terminus which causes auto-inhibition. The proposed interaction between AQP2/AQP5 and FERM thus represents a novel binding mode for extrinsic ERM-interacting partners.

Cyclosporine A Protects Podocytes by Regulating Transgelin in Adriamycin-Induced Podocyte Injury.

INTRODUCTION: The calcineurin inhibitor cyclosporine A (CsA) has been shown to effectively reduce proteinuria. However, its precise mechanism is still not fully understood. Our previous study showed that CsA reduced proteinuria by directly stabilizing the foot process (FP) cytoskeletal structure via cofilin-1, suggesting that synaptopodin, a podocyte-specific actin protein, is not the sole target of CsA in podocytes. METHODS: In this study, we established an adriamycin (ADR)-induced nephropathy rat model and a cultured podocyte injury model. We employed Western blotting and immunofluorescence techniques to assess the expression and distribution of transgelin, Krüppel-like factor-4 (KLF-4), nephrin, and synaptopodin. RESULTS: We observed a significant increase in proteinuria levels accompanied by loss of normal FP structure in the ADR-induced nephropathy rat model. The levels of the actin cross-linking protein transgelin were increased significantly, while those of the podocyte-specific molecules nephrin and synaptopodin were decreased in vivo. Treatment with CsA effectively reduced proteinuria while restoring FP effacement stability in ADR-induced nephropathy models and restoring the expression of transgelin, nephrin, and synaptopodin both in vivo and in vitro. Furthermore, CsA treatment dose-dependently decreased transgelin levels while significantly increasing KLF-4 expression in injured podocytes. In addition, CsA failed to downregulate transgelin when KLF-4 was specifically knocked down. CONCLUSION: Our findings suggest that CsA protects against podocyte injury by downregulating abnormally high levels of transgelin via upregulation of KLF-4 expression.

Shaping Drosophila eggs: unveiling the roles of Arpc1 and cpb in morphogenesis.

The Drosophila egg chamber (EC) starts as a spherical tissue at the beginning. With maturation, the outer follicle cells of EC collectively migrate in a direction perpendicular to the anterior-posterior axis, to shape EC from spherical to ellipsoidal. Filamentous actin (F-actin) plays a significant role in shaping individual migratory cells to the overall EC shape, like in every cell migration. The primary focus of this article is to unveil the function of different Actin Binding Proteins (ABPs) in regulating mature Drosophila egg shape. We have screened 66 ABPs, and the genetic screening data revealed that individual knockdown of Arp2/3 complex genes and the "capping protein ß" (cpb) gene have severely altered the egg phenotype. Arpc1 and cpb RNAi mediated knockdown resulted in the formation of spherical eggs which are devoid of dorsal appendages. Studies also showed the role of Arpc1 and cpb on the number of laid eggs and follicle cell morphology. Furthermore, the depletion of Arpc1 and cpb resulted in a change in F-actin quantity. Together, the data indicate that Arpc1 and cpb regulate Drosophila egg shape, F-actin management, egg-laying characteristics and dorsal appendages formation.

Expression and molecular insights of lima1 in cholangiocarcinoma.

Lim Domain and Actin Binding protein1 (lima1) influence cancer cell function. Thus far, functional role of lima1 in cholangiocarcinoma remains unknown. We used public databases, in vitro experiments, and multi-omics analysis to investigate the Lima1 in cholangiocarcinoma. Our results showed that lima1 expression is significantly upregulated and high levels of lima1 are significantly associated with vascular invasion in cholangiocarcinoma. Furthermore, lima1 knocking out inhibits the RBE cell invasion. Multi-omics data suggest that lima1 affect a broad spectrum of cancer related pathways, promoting tumor progression and metastatic ability in cholangiocarcinoma. This study provides insights into molecular associations of lima1 with tumorigenesist and establishes a preliminary picture of the correlation network in cholangiocarcinoma.

The expression and clinical significance of CFAP65 in colon cancer.

BACKGROUND: CFAP65 (cilia and flagella associated protein 65) is a fundamental protein in the development and formation of ciliated flagella, but few studies have focused on its role in cancer. This study aimed to investigate the prognostic significance of CFAP65 in colon cancer. METHODS: The functionally enriched genes related to CFAP65 were analyzed through the Gene Ontology (GO) database. Subsequently, CFAP65 expression levels in colon cancer were evaluated by reverse transcription and quantitative polymerase chain reaction (RT-qPCR) and immunoblotting in 20 pairs of frozen samples, including tumors and their matched paratumor tissue. Furthermore, protein expression of CFAP65 in 189 colon cancer patients were assessed via immunohistochemical staining. The correlations between CFAP65 expression and clinical features as well as long-term survival were statistically analyzed. RESULTS: CFAP65-related genes are significantly enriched on cellular processes of cell motility, ion channels, and GTPase-associated signaling. The expression of CFAP65 was significantly higher in colon cancer tissue compared to paratumor tissue. The proportion of high expression and low expression of CFAP65 in the clinical samples of colon cancer were 61.9% and 38.1%, respectively, and its expression level was not associated with the clinical parameters including gender, age, tumor location, histological differentiation, tumor stage, vascular invasion and mismatch repair deficiency. The five-year disease-free survival rate of the patients with CFAP65 low expression tumors was significantly lower than that those with high expression tumors (56.9% vs. 72.6%, P = 0.03), but the overall survival rate has no significant difference (69% vs. 78.6%, P = 0.171). The cox hazard regression analysis model showed that CFAP65 expression, tumor stage and tumor location were independent prognostic factors. CONCLUSIONS: In conclusion, we demonstrate CFAP65 is a potential predictive marker for tumor progression in colon cancer.

TGFß1 Regulates Cellular Composition of In Vitro Cardiac Perivascular Niche Based on Cardiospheres.

The cardiac perivascular niche is a cellular microenvironment of a blood vessel. The principles of niche regulation are still poorly understood. We studied the effect of TGFß1 on cells forming the cardiac perivascular niche using 3D cell culture (cardiospheres). Cardiospheres contained progenitor (c-Kit), endothelial (CD31), and mural (αSMA) cells, basement membrane proteins (laminin) and extracellular matrix proteins (collagen I, fibronectin). TGFß1 treatment decreased the length of CD31+ microvasculature, VE cadherin protein level, and proportion of NG2+ cells, and increased proportion of αSMA+ cells and transgelin/SM22α protein level. We supposed that this effect is related to the stabilizing function of TGFß1 on vascular cells: decreased endothelial cell proliferation, as shown for HUVEC, and activation of mural cell differentiation.

ESRP1-mediated biogenesis of circPTPN12 inhibits hepatocellular carcinoma progression by PDLIM2/ NF-κB pathway.

BACKGROUND: Emerging evidence indicates the pivotal involvement of circular RNAs (circRNAs) in cancer initiation and progression. Understanding the functions and underlying mechanisms of circRNAs in tumor development holds promise for uncovering novel diagnostic indicators and therapeutic targets. In this study, our focus was to elucidate the function and regulatory mechanism of hsa-circ-0003764 in hepatocellular carcinoma (HCC). METHODS: A newly discovered hsa-circ-0003764 (circPTPN12) was identified from the circbase database. QRT-PCR analysis was utilized to assess the expression levels of hsa-circ-0003764 in both HCC tissues and cells. We conducted in vitro and in vivo experiments to examine the impact of circPTPN12 on the proliferation and apoptosis of HCC cells. Additionally, RNA-sequencing, RNA immunoprecipitation, biotin-coupled probe pull-down assays, and FISH were employed to confirm and establish the relationship between hsa-circ-0003764, PDLIM2, OTUD6B, P65, and ESRP1. RESULTS: In HCC, the downregulation of circPTPN12 was associated with an unfavorable prognosis. CircPTPN12 exhibited suppressive effects on the proliferation of HCC cells both in vitro and in vivo. Mechanistically, RNA sequencing assays unveiled the NF-κB signaling pathway as a targeted pathway of circPTPN12. Functionally, circPTPN12 was found to interact with the PDZ domain of PDLIM2, facilitating the ubiquitination of P65. Furthermore, circPTPN12 bolstered the assembly of the PDLIM2/OTUD6B complex by promoting the deubiquitination of PDLIM2. ESRP1 was identified to bind to pre-PTPN12, thereby fostering the generation of circPTPN12. CONCLUSIONS: Collectively, our findings indicate the involvement of circPTPN12 in modulating PDLIM2 function, influencing HCC progression. The identified ESRP1/circPTPN12/PDLIM2/NF-κB axis shows promise as a novel therapeutic target in the context of HCC.

Unveiling the role of TAGLN2 in glioblastoma: From proneural-mesenchymal transition to Temozolomide resistance.

Glioblastoma (GBM) presents a daunting challenge due to its resistance to temozolomide (TMZ), a hurdle exacerbated by the proneural-to-mesenchymal transition (PMT) from a proneural (PN) to a mesenchymal (MES) phenotype. TAGLN2 is prominently expressed in GBM, particularly in the MES subtype compared to low-grade glioma (LGG) and the PN subtype. Our research reveals TAGLN2's involvement in PMT and TMZ resistance through a series of in vitro and in vivo experiments. TAGLN2 knockdown can restrain proliferation and invasion, trigger DNA damage and apoptosis, and heighten TMZ sensitivity in GBM cells. Conversely, elevating TAGLN2 levels amplifies resistance to TMZ in cellular and intracranial xenograft mouse models. We demonstrate the interaction relationship between TAGLN2 and ERK1/2 through co-immunoprecipitation (Co-IP) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) spectrometry analysis. Knockdown of TAGLN2 results in a decrease in the expression of p-ERK1/2, whereas overexpression of TAGLN2 leads to an increase in p-ERK1/2 expression within the nucleus. Subsequently, the regulatory role of TAGLN2 in the expression and control of MGMT has been demonstrated. Finally, the regulation of TAGLN2 by NF-κB has been validated through chromatin immunoprecipitation and ChIP-PCR assays. In conclusion, our results confirm that TAGLN2 exerts its biological functions by interacting with the ERK/MGMT axis and being regulated by NF-κB, thereby facilitating the acquisition of promoting PMT and increased resistance to TMZ therapy in glioblastoma. These results provide valuable insights for the advancement of targeted therapeutic approaches to overcome TMZ resistance in clinical treatments.