HSPD1 Supports Osteosarcoma Progression through Stabilizing ATP5A1 and thus Activation of AKT/mTOR Signaling.

Malignant transformation is concomitant with excessive activation of stress response pathways. Heat shock proteins (HSPs) are stress-inducible proteins that play a role in folding and processing proteins, contributing to the non-oncogene addiction of stressed tumor cells. However, the detailed role of the HSP family in osteosarcoma has not been investigated. Bulk and single-cell transcriptomic data from the GEO and TARGET databases were used to identify HSPs associated with prognosis in osteosarcoma patients. The expression level of HSPD1 was markedly increased in osteosarcoma, correlating with a negative prognosis. Through in vitro and in vivo experiments, we systematically identified HSPD1 as an important contributor to the regulation of proliferation, metastasis, and apoptosis in osteosarcoma by promoting the epithelial-mesenchymal transition (EMT) and activating AKT/mTOR signaling. Subsequently, ATP5A1 was determined as a potential target of HSPD1 using immunoprecipitation followed by mass spectrometry. Mechanistically, HSPD1 may interact with ATP5A1 to reduce the K48-linked ubiquitination and degradation of ATP5A1, which ultimately activates the AKT/mTOR pathway to ensure osteosarcoma progression and EMT process. These findings expand the potential mechanisms by which HSPD1 exerts biological effects and provide strong evidence for its inclusion as a potential therapeutic target in osteosarcoma.

Single turnover transient state kinetics reveals processive protein unfolding catalyzed by Escherichia coli ClpB.

Escherichia coli ClpB and Saccharomyces cerevisiae Hsp104 are AAA+ motor proteins essential for proteome maintenance and thermal tolerance. ClpB and Hsp104 have been proposed to extract a polypeptide from an aggregate and processively translocate the chain through the axial channel of its hexameric ring structure. However, the mechanism of translocation and if this reaction is processive remains disputed. We reported that Hsp104 and ClpB are non-processive on unfolded model substrates. Others have reported that ClpB is able to processively translocate a mechanically unfolded polypeptide chain at rates over 240 amino acids (aa) per second. Here, we report the development of a single turnover stopped-flow fluorescence strategy that reports on processive protein unfolding catalyzed by ClpB. We show that when translocation catalyzed by ClpB is challenged by stably folded protein structure, the motor enzymatically unfolds the substrate at a rate of ~0.9 aa s-1 with a kinetic step-size of ~60 amino acids at sub-saturating [ATP]. We reconcile the apparent controversy by defining enzyme catalyzed protein unfolding and translocation as two distinct reactions with different mechanisms of action. We propose a model where slow unfolding followed by fast translocation represents an important mechanistic feature that allows the motor to rapidly translocate up to the next folded region or rapidly dissociate if no additional fold is encountered.

Heat shock protein 22 alleviates doxorubicin-induced kidney injury by suppressing oxidative stress and apoptosis.

This study investigated the effects of heat shock protein 22 (HSP22) against doxorubicin (DOX)-induced kidney injury. Mice were randomly assigned to four groups: CON, ad-HSP22, DOX, and ad-HSP22 + DOX. Adeno-associated virus carrying the HSP22 gene (ad-HSP22) was administered via tail vein injection for four weeks, followed by intraperitoneal simulation with DOX (20 mg/kg) for another five days. Upon euthanasia, ELISA, histological staining (H&E, IHC, DHE, and TUNEL), and western blot analyses were employed to assess relevant markers. Serum biomarkers of kidney injury, SCr, and BUN, were upregulated after DOX administration but normalized with HSP22 overexpression. Pathological changes induced by DOX were also reversed by HSP22 overexpression in H&E, IHC, DHE, and TUNEL stains. DOX-induced upregulation of NOX-2 and NOX-4 and downregulation of SOD-1 and SOD-2 were reversed by HSP22 overexpression. Similarly, DOX-induced increases in Bax and decrease in Bcl-2 were attenuated by HSP22 overexpression. The study further demonstrated that the Nrf2/HO-1 signaling pathway was activated by HSP22 overexpression. In vitro experiments corroborated the findings from in vivo experiments. In conclusion, HSP22 alleviates DOX-induced kidney injury by suppressing oxidative stress and apoptosis, primarily through the activation of the Nrf2/HO-1 signaling pathway. These results suggest HSP22 as a potential therapeutic target for DOX-induced kidney injury.

TFIIS is required for reproductive development and thermal adaptation in barley.

KEY MESSAGE: Barley reproductive fitness and efficient heat stress adaptation requires the activity of TFIIS, the elongation cofactor of RNAPII. Regulation of transcriptional machinery and its adaptive role under different stress conditions are studied extensively in the dicot model plant Arabidopsis, but our knowledge on monocot species remains elusive. TFIIS is an RNA polymerase II-associated transcription elongation cofactor. Previously, it was shown that TFIIS ensures efficient transcription elongation that is necessary for heat stress survival in A. thaliana. However, the function of TFIIS has not been analysed in monocots. In the present work, we have generated and studied independent tfIIs-crispr-mutant barley lines. We show that TFIIS is needed for reproductive development and heat stress survival in barley. The molecular basis of HS-sensitivity of tfIIs mutants is the retarded expression of heat stress protein transcripts, which leads to late accumulation of HSP chaperones, enhanced proteotoxicity and ultimately to lethality. We also show that TFIIS is transcriptionally regulated in response to heat, supporting a conserved adaptive function of these control elements for plant thermal adaptation. In sum, our results are a step forward for the better understanding of transcriptional machinery regulation in monocot crops.

Luteolin target HSPB1 regulates endothelial cell ferroptosis to protect against radiation vascular injury.

Vascular endothelial damage due to ionizing radiation is the main pathological process of radiation injury and the main cause of damage to various organs in nuclear accidents. Ferroptosis plays an important role in ionizing radiation-induced cell death. We have previously reported that luteolin is highly resistant to ferroptosis. In the present study, body weight, microvessel count, H&E, and Masson staining results showed that luteolin rescued radial vascular injury in vivo. Cell Counting Kit 8 (CCK8), Giemsa staining clarified the anti-ferroptosis ability of luteolin with low toxicity. Malondialdehyde (MDA), superoxide dismutase (SOD), NADP+/NADPH, Fe2+ staining, dihydroethidium (DHE) and MitoTracker assays for ferroptosis-related metrics, we found that luteolin enhances human umbilical vein endothelial cells (HUVECs) antioxidant damage capacity. Drug affinity responsive target stability (DARTS), surface plasmon resonance (SPR), computer simulated docking and western blot showed that heat shock protein beta-1 (HSPB1) is one of the targets of luteolin action. Luteolin inhibits ferroptosis by promoting the protein expression of HSPB1/solute carrier family 7 member 11 (SLC7A11)/ glutathione peroxidase 4 (GPX4). In conclusion, we have preliminarily elucidated the antioxidant damage ferroptosis ability and the target of action of luteolin to provide a theoretical basis for the application of luteolin in radiation injury diseases.

Characterization of the symmetrical benzimidazole twin drug TL1228: the role as viral entry inhibitor for fighting COVID-19.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is reliably one of the largest pandemics the world has suffered in recent years. In the search for non-biological antivirals, special emphasis was placed on drug repurposing to accelerate the clinical implementation of effective drugs.The life cycle of the virus has been extensively investigated and many human targets have been identified, such as the molecular chaperone GRP78, representing a host auxiliary factor for SARS-CoV-2 entry. Here we report the inhibitor capacity of TL1228, a small molecule discovered through an in silico screening approach, which could interfere with the interaction of SARS-CoV-2 and its target cells, blocking the recognition of the GRP78 cellular receptor by the viral Spike protein. TL1228 showed in vitro the ability to reduce significantly both pseudoviral and authentic viral activity even through the reduction of GRP78/ACE2 transcript levels. Importantly, TL1228 acts in modulating expression levels of innate immunity and as inflammation markers.

Immune protective, stress indicators, antioxidant, histopathological status, and heat shock protein gene expression impacts of dietary Bacillus spp. against heat shock in Nile tilapia, Oreochromis niloticus.

This research evaluated the efficacy of mixed Bacillus strains probiotic supplements in mitigating acute thermal-induced stress in Nile tilapia (Oreochromis niloticus). Three experimental fish groups involved 135 Nile tilapia (49 ± 2 g); one control (no added probiotics), 0.5, and 1% of selected Bacillus strains (B. subtilis, B. licheniformis, and B. pumilus) for 58 days. After the feeding period, growth parameters, immunological parameters, stress biochemical markers, and antioxidant parameters in addition to genes related to stress and histopathological changes in fish, were assessed; subsequently subjected to heat shock at 36 ± 0.5 ◦C for 2 h. Before the heat challenge, our results exhibited a marked increase in the growth efficacy (P < 0.05), lower marked serum levels of triglycerides and cholesterol, and tissue malondialdehyde (MDA) levels along with significantly increased superoxide dismutase (SOD) and catalase (CAT) enzymes activity in fish-fed Bacillus probiotic at 0.5% concerning the control group (P < 0.05). There were no significant changes in the serum levels of glucose, cortisol, lactate, phagocytic activity, respiratory burst (ROS), total immunoglobulin Ig, alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), total protein, albumin, globulin, uric acid, urea, creatinine, as well as HSP70, GST, and GPx mRNA expression in most of the probiotic groups compared to the control group (P > 0.05). When Nile tilapia was exposed to heat stress, supplementation with Bacillus probiotic in the diet significantly decreased most of the indices related to serum biochemical (ALT (P < 0.01; P < 0.001), AST (P < 0.01), LDH (P < 0.01), urea (P < 0.05), and creatinine (P < 0.01)), triglycerides (P < 0.001; (P < 0.01)), cholesterol (P < 0.01; (P < 0.05)), glucose (P < 0.001), and cortisol (P < 0.01; (P < 0.05)), with tissue oxidative stress MDA levels (P < 0.05), and HSP70 mRNA expression (P < 0.01; P < 0.001), aligned with the stressed control group. In addition, a notable upsurge in the total protein, albumin, globulin, phagocytic and ROS activities, and total Ig, as well as the enzymatic antioxidant ability (SOD, CAT) (P < 0.01), with GST and GPx mRNA expression (P < 0.05; P < 0.01), were shown in fish-fed Bacillus spp. post-exposure compared with the stressed control group. Besides, no histopathological alterations were revealed in the spleen and brain of fish pre- and post-heat exposure. According to our findings, diet supplementation of Bacillus species has the potential to combat the suppressive effects of heat shock in Nile tilapia.

The middle domain of Hsp104 can ensure substrates are functional after processing.

Molecular chaperones play a central role in protein disaggregation. However, the molecular determinants that regulate this process are poorly understood. Hsp104 is an AAA+ ATPase that disassembles stress granules and amyloids in yeast through collaboration with Hsp70 and Hsp40. In vitro studies show that Hsp104 processes different types of protein aggregates by partially translocating or threading polypeptides through the central pore of the hexamer. However, it is unclear how Hsp104 processing influences client protein function in vivo. The middle domain (MD) of Hsp104 regulates ATPase activity and interactions with Hsp70. Here, we tested how MD variants, Hsp104A503S and Hsp104A503V, process different protein aggregates. We establish that engineered MD variants fail to resolve stress granules but retain prion fragmentation activity required for prion propagation. Using the Sup35 prion protein, our in vitro and in vivo data indicate that the MD variants can disassemble Sup35 aggregates, but the disaggregated protein has reduced GTPase and translation termination activity. These results suggest that the middle domain can play a role in sensing certain substrates and plays an essential role in ensuring the processed protein is functional.

Sestrin2 serves as a scaffold protein to maintain cardiac energy and metabolic homeostasis during pathological stress.

Cardiovascular diseases (CVDs) are a leading cause of morbidity and mortality worldwide. Metabolic imbalances and pathological stress often contribute to increased mortality. Sestrin2 (Sesn2) is a stress-inducible protein crucial in maintaining cardiac energy and metabolic homeostasis under pathological conditions. Sesn2 is upregulated in response to various stressors, including oxidative stress, hypoxia, and energy depletion, and mediates multiple cellular pathways to enhance antioxidant defenses, promote autophagy, and inhibit inflammation. This review explores the mechanisms through which Sesn2 regulates these pathways, focusing on the AMPK-mTORC1, Sesn2-Nrf2, and HIF1α-Sesn2 pathways, among others. We can identify the potential therapeutic targets for treating CVDs and related metabolic disorders by comprehending these complex mechanisms. Sesn2's unique ability to respond thoroughly to metabolic challenges, oxidative stress, and inflammation makes it a promising prospect for enhancing cardiac health and resilience against pathological stress.

Acute exposure to mercury drives changes in gene expression in Drosophila melanogaster.

OBJECTIVE: We quantified the effect of acute exposure to a high dosage of inorganic mercury on gene expression in Drosophila melanogaster using RNA-sequencing of whole adult females. RESULTS: We found 119 genes with higher gene expression following treatment (including all 5 Drosophila metallothionine genes and a number of heat shock protein genes), and 31 with lower expression (several of which are involved in egg formation). Our results highlight biological processes and genetic pathways impacted by exposure to this toxic metal, and provide motivation for future studies to understand the genetic basis of response to mercury.

Inhibition of neutrophil swarming by type I interferon promotes intracellular bacterial evasion.

Listeria monocytogenes (LM) possesses the ability to breach multiple barriers and elicit intricate immune responses. However, there remains a lack of explicit understanding regarding how LM evades innate immune surveillance within the body. Here, we utilized liver intravital imaging to elucidate the dynamic process of LM during infection in the liver. We discovered that LM can rapidly escape from Kupffer cells (KCs) through listeriolysin O (LLO) and proliferate within hepatocytes. Upon LM exposure to the hepatic sinusoids, neutrophils rapidly aggregate at the site of infection. Subsequently, LM can induce type I interferon (IFN-I) production primarily in the spleen, which acts systemically on neutrophils to hamper their swarming by deactivating the ERK pathway, thus evading neutrophil-mediated eradication. Furthermore, our findings suggest that virus-induced IFN-I suppresses neutrophil swarming, and COVID-19 patients exhibit impaired neutrophil aggregation function. In conclusion, our findings provide compelling evidence demonstrating that intracellular bacteria represented by LM can hijack host defense mechanisms against viral infections to evade immune surveillance. Additionally, impaired neutrophil swarming caused by IFN-I is one of the significant factors contributing to the increased susceptibility to bacterial infections following viral infections.

The endoplasmic reticulum protein HSPA5/BiP is essential for decidual transformation of human endometrial stromal cells.

Decidualization denotes the process of inflammatory reprogramming of endometrial stromal cells (EnSC) into specialized decidual cells (DC). During this process, EnSC are subjected to endoplasmic reticulum (ER) stress as well as acute cellular senescence. Both processes contribute to the proinflammatory mid-luteal implantation window and their dysregulation has been implicated in reproductive failure. Here, we evaluated the link between ER stress, decidual differentiation and senescence. In-silico analysis identified HSPA5 gene, codifying the ER chaperone BiP, as a potentially critical regulator of cell fate divergence of decidualizing EnSC into anti-inflammatory DC and pro-inflammatory senescent decidual cells (snDC). Knockdown of HSPA5 in primary EnSC resulted both in decreased expression of DC marker genes and attenuated induction of senescence associated ß-galactosidase activity, a marker of snDC. Stalling of the decidual reaction upon HSPA5 knockdown was apparent at 8 days of differentiation and was preceded by the upregulation of ER stress associated proteins IRE1α and PERK. Further, HSPA5 knockdown impaired colony-forming unit activity of primary EnSC, indicative of loss of cellular plasticity. Together, our results point to a key role for HSPA5/BiP in decidual transformation of EnSCs and highlight the importance of constraining ER stress levels during this process.

RNA sequencing comparing centenarian and middle-aged women lymphoblastoid cell lines identifies age-related dysregulated expression of genes encoding selenoproteins, heat shock proteins, CD99, and BID.

Women typically live longer than men, and constitute the majority of centenarians. We applied RNA-sequencing (RNA-seq) of blood-derived lymphoblastoid cell lines (LCLs) from women aged 60-80 years and centenarians (100-105 years), validated the RNA-seq findings by real-time PCR, and additionally measured the differentially expressed genes in LCLs from young women aged 20-35 years. Top RNA-seq genes with differential expression between the age groups included three selenoproteins (GPX1, SELENOW, SELENOH) and three heat shock proteins (HSPA6, HSPA1A, HSPA1B), with the highest expression in LCLs from young women, indicating that young women are better protected from oxidative stress. The expression of two additional genes, BID encoding BH3-interacting domain death agonist and CD99 encoding CD99 antigen, showed unique age dependence, with similar expression levels in young and centenarian women while exhibiting higher and lower expression levels, respectively, in LCLs from women aged 60-80 years compared with the two other age groups. This age-related differential expression of BID and CD99 suggests elevated inflammation susceptibility in middle-aged women compared with either young or centenarian women. Our findings, once validated with human peripheral blood mononuclear cells and further cell types, may lead to novel healthy aging diagnostics and therapeutics.

The role of heat shock proteins in HIV-1 pathogenesis: a systematic review investigating HSPs-HIV-1 correlations and interactions.

Background: The human immunodeficiency virus (HIV) pandemic is a global health emergency. Studies suggest a connection between heat shock proteins (HSPs) and HIV-1 infection pathogenesis. This systematic review aims to summarize HSPs' role in HIV-1 infection pathogenesis. Materials and Methods: A systematic literature search was undertaken across the National Library of Medicine (MEDLINE-PubMed), Science Direct, Web of Science, Scopus, SpringerLink, Sage, ProQuest, and Google Scholar databases, using related keywords to synthesize the HSPs' role in HIV-1 infection pathogenesis. This literature review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and the protocol was registered in the Open Science Framework (OSF) database under DOI 10.17605/OSF.IO/VK3DJ. Results: A database search revealed 3,332 articles, with 14 in vitro studies analysing the interaction between HSPs and HIV-1 across different cell types. HSPs are involved in HIV-1 infection through direct interactions and indirect responses to cellular stress, including HSP40, HSP70, HSPBP1, and HSP90. The study explores HSP interactions at various stages of the viral life cycle, including entry, uncoating, replication, transmission, and latency reactivation. Conclusion: HSPs are crucial for the HIV lifecycle and immune response, offering the potential for new therapeutic strategies. Further research is needed to understand the clinical significance and target potential.

Silicon Modifies Photosynthesis Efficiency and hsp Gene Expression in European Beech (Fagus sylvatica) Seedlings Exposed to Drought Stress.

Background: Climate change is leading to severe and long-term droughts in European forest ecosystems. can have profound effects on various physiological processes, including photosynthesis, gene expression patterns, and nutrient uptake at the developmental stage of young trees. Objectives: Our study aimed to test the hypothesis that the application of silica (SiO2) influences photosynthetic efficiency and gene expression in 1- to 2-year-old Fagus sylvatica (L.) seedlings. Additionally, we aimed to assess whether silicon application positively influences the structural properties of leaves and roots. To determine whether the plant physiological responses are genotype-specific, seedlings of four geographically different provenances were subjected to a one-year evaluation under greenhouse conditions. Methods: We used the Kruskal-Wallis test followed by Wilcoxon's test to evaluate the differences in silicon content and ANOVA followed by Tukey's test to evaluate the physiological responses of seedlings depending on treatment and provenance. Results: Our results showed a significantly higher Si content in the roots compared with the leaves, regardless of provenance and treatment. The most significant differences in photosynthetic performance were found in trees exposed to Si treatment, but the physiological responses were generally nuanced and provenance-dependent. Expression of hsp70 and hsp90 was also increased in leaf tissues of all provenances. These results provide practical insights that Si can improve the overall health and resilience of beech seedlings in nursery and forest ecosystems, with possible differences in the beneficial role of silicon application arising from the large differences in wild populations of forest tree species.

QRICH1 suppresses pediatric T-cell acute lymphoblastic leukemia by inhibiting GRP78.

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy that commonly affects children and adolescents with a poor prognosis. The terminal unfolded protein response (UPR) is an emerging anti-cancer approach, although its role in pediatric T-ALL remains unclear. In our pediatric T-ALL cohort from different centers, a lower QRICH1 expression was found associated with a worse prognosis of pediatric T-ALL. Overexpression of QRICH1 significantly inhibited cell proliferation and stimulated apoptosis of T-ALL both in vitro and in vivo. Upregulation of QRICH1 significantly downregulated 78 KDa glucose-regulated protein (GRP78) and upregulated CHOP, thus activating the terminal UPR. Co-overexpression of GRP78 in T-ALL cells overexpressing QRICH1 partially reverted the inhibited proliferation and stimulated apoptosis. QRICH1 bound to the residues Asp212 and Glu155 of the nucleotide-binding domain (NBD) of GRP78, thereby inhibiting its ATP hydrolysis activity. In addition, QRICH1 was associated with endoplasmic reticulum (ER) stress in T-ALL, and overexpression of QRICH1 reversed drug resistance. Overall, low QRICH1 expression is an independent risk factor for a poor prognosis of pediatric T-ALL. By inhibiting GRP78, QRICH1 suppresses pediatric T-ALL.

Heat shock proteins as hallmarks of cancer: insights from molecular mechanisms to therapeutic strategies.

Heat shock proteins are essential molecular chaperones that play crucial roles in stabilizing protein structures, facilitating the repair or degradation of damaged proteins, and maintaining proteostasis and cellular functions. Extensive research has demonstrated that heat shock proteins are highly expressed in cancers and closely associated with tumorigenesis and progression. The "Hallmarks of Cancer" are the core features of cancer biology that collectively define a series of functional characteristics acquired by cells as they transition from a normal state to a state of tumor growth, including sustained proliferative signaling, evasion of growth suppressors, resistance to cell death, enabled replicative immortality, the induction of angiogenesis, and the activation of invasion and metastasis. The pivotal roles of heat shock proteins in modulating the hallmarks of cancer through the activation or inhibition of various signaling pathways has been well documented. Therefore, this review provides an overview of the roles of heat shock proteins in vital biological processes from the perspective of the hallmarks of cancer and summarizes the small-molecule inhibitors that target heat shock proteins to regulate various cancer hallmarks. Moreover, we further discuss combination therapy strategies involving heat shock proteins and promising dual-target inhibitors to highlight the potential of targeting heat shock proteins for cancer treatment. In summary, this review highlights how targeting heat shock proteins could regulate the hallmarks of cancer, which will provide valuable information to better elucidate and understand the roles of heat shock proteins in oncology and the mechanisms of cancer occurrence and development and aid in the development of more efficacious and less toxic novel anticancer agents.

Gandouling ameliorates liver injury in Wilson's disease through the inhibition of ferroptosis by regulating the HSF1/HSPB1 pathway.

Ferroptosis, an iron-dependent form of cell death, plays a crucial role in the progression of liver injury in Wilson's disease (WD). Gandouling (GDL) has emerged as a potential therapeutic agent for preventing and treating liver injury in WD. However, the precise mechanisms by which GDL mitigates ferroptosis in WD liver injury remain unclear. In this study, we discovered that treating Toxic Milk (TX) mice with GDL effectively decreased liver copper content, corrected iron homeostasis imbalances, and lowered lipid peroxidation levels, thereby preventing ferroptosis and improving liver injury. Bioinformatics analysis and machine learning algorithms identified Hspb1 as a pivotal regulator of ferroptosis. GDL treatment significantly upregulated the expression of HSPB1 and its upstream regulatory factor HSF1, thereby activating the HSF1/HSPB1 pathway. Importantly, inhibition of this pathway by NXP800 reversed the protective effects of GDL on ferroptosis in the liver of TX mice. In conclusion, GDL shows promise in alleviating liver injury in WD by inhibiting ferroptosis through modulation of the HSF1/HSPB1 pathway, suggesting its potential as a novel therapeutic agent for treating liver ferroptosis in WD.

Recruitment of USP10 by GCS1 to deubiquitinate GRP78 promotes the progression of colorectal cancer via alleviating endoplasmic reticulum stress.

BACKGROUND: Long-term accumulation of misfolded proteins leads to endoplasmic reticulum (ER) stress in colorectal cancer (CRC). However, the precise pathways controlling the decision between survival and apoptosis in CRC are unclear. Therefore, in this study, we investigated the function and molecular mechanism of glucosidase I (GCS1) in regulating ER stress in CRC. METHODS: A public database was used to confirm the expression level of GCS1 in CRC and normal tissues. Clinical samples from our center were used to confirm the mRNA and protein expression levels of GCS1. Cell proliferation, migration, invasion, and apoptosis assays revealed the biological role of GCS1. Immunohistochemical techniques were used to evaluate the expression of key proteins in subcutaneous implanted tumors in nude mice, which provided further evidence for the biological function of GCS1 in promoting cancer in vivo. The results of coimmunoprecipitation-mass spectrometry analysis and immunofluorescence colocalization analysis the interaction between GCS1 and GRP78. In addition, the mechanism of action of USP10, GRP78, and GCS1 at the post- translational level was investigated. Finally, a tissue microarray was used to examine the connection between GCS1 and GRP78 expression and intracellular localization of these proteins using immunohistochemistry and immunofluorescence. RESULTS: The experimental results revealed that GCS1 was substantially expressed in CRC, with higher expression indicating a worse prognosis. Thus, GCS1 can enhance the proliferation and metastasis while inhibiting the apoptosis of CRC cells both in vivo and in vitro. Mechanistically, GCS1 binds to GRP78, recruits USP10 for deubiquitination of GRP78 to promote its degradation, and decreases ER stress-mediated apoptosis, increasing CRC cell proliferation and metastasis. CONCLUSIONS: In summary, GCS1 stimulates CRC growth and migration and reduces ER stress-mediated apoptosis via USP10-mediated deubiquitination of GRP78. Our findings identify a possible therapeutic target for CRC.

m6A-activated BACH1 exacerbates ferroptosis by epigenetic suppression HSPB1 in severe acute pancreatitis.

Severe acute pancreatitis (SAP) is characterized by acute inflammation of the pancreas. The transcription factor BTB and CNC homology 1 (BACH1) has been implicated in various biological processes, including oxidative stress, apoptosis, and cell cycle regulation. However, its involvement in the pathogenesis of SAP remains relatively understudied. In the present work, our data demonstrated that BACH1 level was significantly increased in SAP patients, cellular, and animal models, while heat shock protein B1 (HSPB1) expression was weakened. Mechanistic assays validated that BACH1 acted as a transcriptional inhibitor of HSPB1. Moreover, HPDE6-C7 cells were stimulated with cerulein (Cer) and LPS to mimic the pathological stages of SAP in vitro. Depletion of BACH1 remarkably improved cell survival and alleviated the oxidative stress, ferroptosis, and inflammatory responses in SAP cell models. However, these changes were dramatically reversed upon co-inhibition of HSPB1. Animal findings confirmed that loss of BACH1 decreased pancreatic injury, inflammatory responses, and ferroptosis, but these effects were weakened by HSPB1 silence. Overall, these findings elucidate that the overexpression of BACH1 favors the ferroptosis and inflammation by transcriptionally inhibiting HSBP1, thereby exacerbating SAP progression.