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.

Excessive oxidative stress triggers cerebrovascular and neurodegenerative diseases resulting in acute and chronic brain injury. However, the underlying mechanisms remain unknown. Levels of small heat shock protein B8 (HSPB8), which is highly expressed in the brain, are known to be significantly elevated in cerebral injury models. Exogenous HSPB8 protects the brain against mitochondrial damage. One potential mechanism underlying this protection is that HSPB8 overexpression alleviates the mitochondria-dependent pathways of apoptosis; mitochondrial biogenesis, fission, and mitophagy. Overexpression of HSPB8 may therefore have potential as a clinical therapy for cerebrovascular and neurodegenerative diseases. This review provides an overview of advances in the protective effects of HSPB8 against excessive cerebral oxidative stress, including the modulation of mitochondrial dysfunction and potent signaling pathways.

HSPB8 is a heat shock protein belonging to a family of ATP-independent stress proteins called HSPB which are present far and wide in the cells of various organisms. They are committed to protein quality control (PQC) and strive to avert protein aggregation and to procreate a pool of non-native proteins that can be swiftly folded. Their fundamental expression or stress inducibility is regulated by various cis-elements localized in the HSPB regulatory regions. In the current study we have predicted and confirmed two alternatively spliced novel transcripts of HSPB8 gene in liver, brain, and heart. These spliced variants have smaller sizes owing to smaller N terminal regions and showed remarkable changes in their cellular localization. Novel isoform (HSPB8-N1) was predicted to be majorly localized to nuclear region while the reported isoform (HSPB8) and one of the novel isoforms (HSPB8-N2) were predicted to be cytoplasmic in nature. There were many changes observed in the phosphorylation sites of the novel isoforms as well. The newly reported isoforms lack several structural motifs that are essential for various functional endeavors of the HSPB8 protein. In silico analysis of the conceptually translated protein was carried out using various bioinformatics tools to gain an understanding of their properties in order to explore their possible potential in therapeutics.

Preeclampsia (PE) is a pregnancy-specific syndrome with complex pathogenesis. The present study aimed to explore the role of heat shock protein B8 (HSPB8) and c-Myc in trophoblast cell dysfunction using a hypoxia/reoxygenation (H/R)-treated HTR8/SVneo cell model. HSPB8 expression in tissues of patients with PE was analyzed using the Gene Expression Omnibus database. Following detection of HSPB8 expression in H/R-stimulated HTR8/SVneo cells, HSPB8 was overexpressed by transfection of the gene with a HSPB8-specific plasmid. Cell Counting Kit-8, wound healing and Transwell assays were used to evaluate the proliferation, migration and invasion of HTR8/SVneo cells exposed to H/R conditions. Reactive oxygen species (ROS) were determined by 2,7-dichlorodihydrofluorescein diacetate staining. 5,5\',6,6\'-tetrachloro-1,1\',3,3\'-tetraethylbenzimidazolocarbo-cyanine iodide (JC-1) staining was applied to assess mitochondrial membrane potential. Malondialdehyde (MDA) and superoxide dismutase (SOD) levels were detected using the corresponding commercial kits. In addition, the induction of apoptosis was assessed by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. Moreover, the Biogrid database predicted that HSPB8 was bound to c-Myc, and a co-immunoprecipitation (Co-IP) assay was used to verify this interaction. Subsequently, c-Myc expression was silenced to conduct rescue experiments in HTR8/SVneo cells exposed to H/R conditions and upregulated HSPB8 expression. Notably, reduced HSPB8 expression was noted in PE tissues and H/R-stimulated HTR8/SVneo cells. HSPB8 enforced expression promoted the proliferation, migration and invasion of HTR8/SVneo cells. Moreover, H/R caused an increase in ROS and MDA levels as well as in TUNEL staining and a decrease in aggregated JC-1 fluorescence and SOD activity levels, which were restored following HSPB8 overexpression. Co-IP confirmed the interaction between HSPB8 and c-Myc. Moreover, knockdown of c-Myc expression compromised the effects of HSPB8 upregulation on trophoblast cell dysfunction following induction of H/R. Collectively, the data indicated that HSPB8 could improve mitochondrial oxidative stress by binding to c-Myc to alleviate trophoblast cell dysfunction. The findings may provide new insights into the pathogenesis of PE and highlight the role of HSPB8/c-Myc in the prevention and treatment of PE in the future.

Bladder cancer (BCa) stands as a significant malignancy within the genitourinary system. Notably, heat shock proteins (HSPs) exhibit elevated expression in cells subjected to environmental stresses and have been linked to the progression of many human malignancies. Among these, the functional implications and specific mechanism of HSPB8 in BCa have yet to be fully explored. In this study, we measured HSPB8 expression in both BCa tissues and various cell lines, further delving into its influence on cellular behaviors. Our observations pinpoint an upregulation of HSPB8 in BCa, a trend strongly associated with more advanced clinical manifestations. Suppressing HSPB8 exhibited marked reductions in cell proliferation and migration capabilities, while simultaneously amplifying apoptosis and inducing cell cycle arrest. Reinforcing these findings, our in vivo analyses using mouse models showed similar trends. Notably, upon HSPB8 knockdown, levels of specific proteins including eNOS (S1177), Hsp27 (S78/S82), PRAS40(T246), RSK1/2(S221/S227), and STAT3 (S727) decreased, with Hsp27 (S78/S82) and PRAS40(T246) experiencing the most profound drops. Furthermore, the application of an HSP27 inhibitor effectively reversed the phenotypes caused by increased HSPB8 expression. Collectively, our results suggest that elevated HSPB8 expression could act as a potential prognostic marker for BCa, and targeting HSPB8 might open new therapeutic avenues for treating this malignancy.

Dexmedetomidine (Dex) is reported to play a neuroprotective role in Alzheimer\'s disease (AD). However, the specific mechanism remains unclear. Figure out the underlying molecular mechanism of Dex regulating nerve cell apoptosis in the AD model. The AD model in vitro was established after SH-SY5Y cells were treated with Aβ1 - 42 at (10 μM) for 24 h. The interaction among UPF1, lncRNA SNHG14, and HSPB8 was verified by RIP assay. Cell viability, apoptosis, the level of genes, and proteins were detected by CCK-8 assay, flow cytometry, Western blot, and qRT-PCR, respectively. Dex downregulated lncRNA SNHG14 level and inhibited apoptosis of nerve cells. LncRNA SNHG14 overexpression reversed the inhibitory effect of Dex on nerve cell apoptosis in the AD model. LncRNA SNHG14 attenuated HSPB8 mRNA stability by recruiting UPF1. HSPB8 overexpression inhibited apoptosis of nerve cells in the AD model. Moreover, HSPB8 knockdown reversed the inhibitory effect of Dex on nerve cell apoptosis in the AD model. Our study demonstrated that Dex promoted HSPB8 expression via inhibiting the lncRNA SNHG14/UPF1 axis to inhibit nerve cell apoptosis in AD.

Recently, uncontrolled actin polymerization has been recognized as an initiator of early-onset blood-brain barrier (BBB) rupture. Here, using in vitro models, we found that after oxygen-glucose deprivation/reperfusion (OGD/R), endothelial overexpression of HSPB8 suppressed aberrant actin polymerization and thus preserved the integrity of BBB. We further investigated the mechanisms of HSPB8 in the control of actin assembly. HSPB8 suppressed the RhoA/ROCK2/p-MLC signaling pathway in bEnd.3 cells and the RhoA activator abrogated the inhibitory action of HSPB8 on actin reorganization after OGD/R. In addition, endothelial autophagic flux was impaired after OGD/R. This effect was attenuated by HSPB8 overexpression. Autophagy inhibition partially reversed the effect of HSPB8 on the RhoA/ROCK2/p-MLC pathway. Taken together, the present study revealed that the restoration of autophagic flux by overexpressing HSPB8, via the inhibition of the RhoA/ROCK2/p-MLC signaling pathway, reverses the aggregation of endothelial cytoskeleton actin, eventually alleviating OGD/R-induced BBB injury.

OBJECTIVE: The critical roles of eukaryotic elongation factor 1alpha-2 (EEF1A2) and heat shock protein B8 (HSPB8) in the carcinogenesis and progression of cancers have been well documented. However, the regulatory role of EEF1A2/HSPB8 in the development of gastric cancer (GC) have not been fully understood. This study was aimed at clarifying the biological effects of EEF1A2/HSPB8 on the malignant behaviors of GC cells and to investigate the molecular mechanism underlying the involvement of EEF1A2/HSPB8 in GC.
METHODS: In the present work, expression differences of EEF1A2 and HSPB8 in GC cells were detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot assay. Cell counting kit -8 (CCK-8), 5-ethynyl-2\'-deoxyuridine (EdU) staining, wound healing and transwell assays were employed to detect the proliferation, migration and invasion of GC cells. In addition, tube formation assay was adopted to assess in vitro angiogenesis of HUVECs incubated with the conditioned media (CM) of GC cells. Moreover, the interaction between EEF1A2 and HSPB8 was predicted from BioGrid database and analyzed through co-immunoprecipitation (Co-IP).
RESULTS: The present research revealed that EEF1A2 and HSPB8 were highly expressed in GC cell lines. EEF1A2 knockdown markedly suppressed the proliferation, migration and invasion of GC cells as well as in vitro angiogenesis. Furthermore, it was verified that EEF1A2 interacted with HSPB8 and positively regulated HSPB8 expression. Overexpression of HSPB8 reversed the suppressive effects of EEF1A2 knockdown on GC cell proliferation, migration, invasion and in vitro angiogenesis.
CONCLUSIONS: In conclusion, EEF1A2 could act as an oncogene in the development of GC via promoting HSPB8 expression.

Sepsis-associated encephalopathy (SAE) is associated with a higher risk of cognitive deficits; however, its potential mechanisms are still unknow. Recently, researches show that HSPB8, a family of small heat shock proteins, affects cognitive function and ameliorates sepsis-induced dysfunction. However, the role of HSPB8 in SAE-associated cognitive impairment has not been elucidated. In this study, we found that HSPB8 expression was up-regulated in the brain of mice with lipopolysaccharide-induced sepsis. HSPB8 overexpression alleviated cognitive decline in SAE mice. In addition, exogenous HSPB8 exerts neuroprotective effects and salvages synaptic function via regulating NRF1/TFAM-induced mitochondrial biogenesis and DRP1-mediate mitochondrial fission in a lipopolysaccharide-induced mouse model. Furthermore, HSPB8 overexpression inhibits IBA1 and NLRP3 activation in the SAE model. Overexpression of HSPB8 may be an efficient treatment for relieving SAE-related cognitive decline.

Amyotrophic lateral sclerosis (ALS) is a neuronal degenerative condition identified via a build-up of mutant aberrantly folded proteins. The native folding of polypeptides is mediated by molecular chaperones, preventing their pathogenic aggregation. The mutant protein expression in ALS is linked with the entrapment and depletion of chaperone capacity. The lack of a thorough understanding of chaperones\' involvement in ALS pathogenesis presents a significant challenge in its treatment. Here, we review how the accumulation of the ALS-linked mutant FUS, TDP-43, SOD1, and C9orf72 proteins damage cellular homeostasis mechanisms leading to neuronal loss. Further, we discuss how the HSP70 and DNAJ family co-chaperones can act as potential targets for reducing misfolded protein accumulation in ALS. Moreover, small HSPB1 and HSPB8 chaperones can facilitate neuroprotection and prevent stress-associated misfolded protein apoptosis. Designing therapeutic strategies by pharmacologically enhancing cellular chaperone capacity to reduce mutant protein proteotoxic effects on ALS pathomechanisms can be a considerable advancement. Chaperones, apart from directly interacting with misfolded proteins for protein quality control, can also filter their toxicity by initiating strong stress-response pathways, modulating transcriptional expression profiles, and promoting anti-apoptotic functions. Overall, these properties of chaperones make them an attractive target for gaining fundamental insights into misfolded protein disorders and designing more effective therapies against ALS.