Mitochondrial chaperon TNF-receptor- associated protein 1 as a novel apoptotic regulator conferring susceptibility to Pneumocystis jirovecii pneumonia.

Molecular chaperons stabilize protein folding and play a vital role in maintaining tissue homeostasis. To this intent, mitochondrial molecular chaperons may be involved in the regulation of oxidative phosphorylation and apoptosis during stress events such as infections. However, specific human infectious diseases relatable to defects in molecular chaperons have yet to be identified. To this end, we performed whole exome sequencing and functional immune assessment in a previously healthy Asian female, who experienced severe respiratory failure due to Pneumocystis jiroveci pneumonia and non-HIV-related CD4 lymphocytopenia. This revealed that a chaperon, the mitochondrial paralog of HSP90, TRAP1, may have been involved in the patient's susceptibility to an opportunistic infection. Two rare heterozygous variants in TRAP1, E93Q, and A64T were detected. The patient's peripheral blood mononuclear cells displayed diminished TRAP1 expression, but had increased active, cleaved caspase-3, caspase-7, and elevated IL-1ß production. Transfection of A64T and E93Q variants in cell lines yielded decreased TRAP1 compared to transfected wildtype TRAP1 and re-capitulated the immunotypic phenotype of enhanced caspase-3 and caspase-7 activity. When infected with live P. jiroveci, the E93Q or A64T TRAP1 mutant expressing cells also exhibited reduced viability. Patient cells and cell lines transfected with the TRAP1 E93Q/A64T mutants had impaired respiration, glycolysis, and increased ROS production. Of note, co-expression of E93Q/A64T double mutants caused more functional aberration than either mutant singly. Taken together, our study uncovered a previously unrecognized role of TRAP1 in CD4+ lymphocytopenia, conferring susceptibility to opportunistic infections.

METTL18 functions as a Phenotypic Regulator in Src-Dependent Oncogenic Responses of HER2-Negative Breast Cancer.

Methyltransferase-like (METTL)18 has histidine methyltransferase activity on the RPL3 protein and is involved in ribosome biosynthesis and translation elongations. Several studies have reported that actin polymerization serves as a Src regulator, and HSP90 is involved in forming polymerized actin bundles. To understand the role of METTL18 in breast cancer and to demonstrate the importance of METTL18 in HER-2 negative breast cancer metastasis, we used biochemical, molecular biological, and immunological approaches in vitro (breast tumor cell lines), in vivo (tumor xenograft model), and in samples of human breast tumors. A gene expression comparison of 31 METTL series genes and 22 methyltransferases in breast cancer patients revealed that METTL18 is highly amplified in human HER2-negative breast cancer. In addition, elevated levels of METTL18 expression in patients with HER2-negative breast cancer are associated with poor prognosis. Loss of METTL18 significantly reduced the metastatic responses of breast tumor cells in vitro and in vivo. Mechanistically, METTL18 indirectly regulates the phosphorylation of the proto-oncogene tyrosine-protein kinase Src and its downstream molecules in MDA-MB-231 cells via METTL18-mediated RPL3 methylation, which is also involved in determining HSP90 integrity and protein levels. In confocal microscopy and F/G-actin assays, METTL18 was found to induce actin polymerization via HSP90. Molecular events involving METTL18, RPL3, HSP90, and actin polymerization yielded Src phosphorylated at both tyrosine 419 and tyrosine 530 with kinase activity and oncogenic functions. Therefore, it is suggested that the METTL18-HSP90-Actin-Src regulatory axis plays critical oncogenic roles in the metastatic responses of HER2-negative breast cancer and could be a promising therapeutic target.

Ischemic cardiac stromal fibroblast-derived protein mediators in the infarcted myocardium and transcriptomic profiling at single cell resolution.

This article focuses on screening the major secreted proteins by the ischemia-challenged cardiac stromal fibroblasts (CF), the assessment of their expression status and functional role in the post-ischemic left ventricle (LV) and in the ischemia-challenged CF culture and to phenotype CF at single cell resolution based on the positivity of the identified mediators. The expression level of CRSP2, HSP27, IL-8, Cofilin-1, and HSP90 in the LV tissues following coronary artery bypass graft (CABG) and myocardial infarction (MI) and CF cells followed the screening profile derived from the MS/MS findings. The histology data unveiled ECM disorganization, inflammation and fibrosis reflecting the ischemic pathology. CRSP2, HSP27, and HSP90 were significantly upregulated in the LV-CABG tissues with a concomitant reduction ion LV-MI whereas Cofilin-1, IL8, Nrf2, and Troponin I were downregulated in LV-CABG and increased in LV-MI. Similar trends were exhibited by ischemic CF. Single cell transcriptomics revealed multiple sub-phenotypes of CF based on their respective upregulation of CRSP2, HSP27, IL-8, Cofilin-1, HSP90, Troponin I and Nrf2 unveiling pathological and pro-healing phenotypes. Further investigations regarding the underlying signaling mechanisms and validation of sub-populations would offer novel translational avenues for the management of cardiac diseases.

TRMT10C-mediated m7G modification of circFAM126A inhibits lung cancer growth by regulating cellular glycolysis.

The N7-methylguanosine (m7G) modification and circular RNAs (circRNAs) have been shown to play important roles in the development of lung cancer. However, the m7G modification of circRNAs has not been fully elucidated. This study revealed the presence of the m7G modification in circFAM126A. We propose the novel hypothesis that the methyltransferase TRMT10C mediates the m7G modification of circFAM126A and that the stability of m7G-modified circFAM126A is reduced. circFAM126A is downregulated in lung cancer and significantly inhibits lung cancer growth both in vitro and in vivo. The expression of circFAM126A correlates with the stage of lung cancer and with the tumour diameter, and circFAM126A can be used as a potential molecular target for lung cancer. The molecular mechanism by which circFAM126A increases HSP90 ubiquitination and suppresses AKT1 expression to regulate cellular glycolysis, ultimately inhibiting the progression of lung cancer, is elucidated. This study not only broadens the knowledge regarding the expression and regulatory mode of circRNAs but also provides new insights into the molecular mechanisms that regulate tumour cell metabolism and affect tumour cell fate from an epigenetic perspective. These findings will facilitate the development of new strategies for lung cancer prevention and treatment.

Thermal Adaptations in Animals: Genes, Development, and Evolution.

Thermal adaptation to environmental temperature is a driving force in animal evolution. This chapter presents thermal adaptation in ectotherms and endotherms from the perspective of developmental biology. In ectotherms, there are known examples of temperature influencing morphological characteristics, such as seasonal color change, melanization, and sex determination. Furthermore, the timing of embryonic development also varies with environmental temperature. This review will introduce the cellular and molecular mechanisms underlying temperature-dependent embryogenesis. The evolution of thermal adaptation in endotherms is also important for survival in cold climates. Recent genome-wide studies have revealed adaptive mutations in the genomes of extant humans as well as extinct species such as woolly mammoths and Neanderthals. These studies have shown that single-nucleotide polymorphisms in physiologically related genes (e.g., CPT1A, LRP5, THATA, PRKG1, and FADS1-3) allow humans to live in cold climates. At the end of this chapter, we present the remaining questions in terms of genetic assimilation, heat shock protein Hsp90, and embryonic development.

A transcriptional enhancer regulates cardiac maturation.

Cardiomyocyte maturation is crucial for generating adult cardiomyocytes and the application of human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs). However, regulation at the cis-regulatory element level and its role in heart disease remain unclear. Alpha-actinin 2 (ACTN2) levels increase during CM maturation. In this study, we investigated a clinically relevant, conserved ACTN2 enhancer's effects on CM maturation using hPSC and mouse models. Heterozygous ACTN2 enhancer deletion led to abnormal CM morphology, reduced function and mitochondrial respiration. Transcriptomic analyses in vitro and in vivo showed disrupted CM maturation and upregulated anabolic mammalian target for rapamycin (mTOR) signaling, promoting senescence and hindering maturation. As confirmation, ACTN2 enhancer deletion induced heat shock protein 90A expression, a chaperone mediating mTOR activation. Conversely, targeting the ACTN2 enhancer via enhancer CRISPR activation (enCRISPRa) promoted hPSC-CM maturation. Our studies reveal the transcriptional enhancer's role in cardiac maturation and disease, offering insights into potentially fine-tuning gene expression to modulate cardiomyocyte physiology.

TRAP1 modulates mitochondrial biogenesis via PGC-1α/TFAM signalling pathway in colorectal cancer cells.

Metabolic rewiring promotes cancer cell adaptation to a hostile microenvironment, representing a hallmark of cancer. This process involves mitochondrial function and is mechanistically linked to the balance between mitochondrial biogenesis (MB) and mitophagy. The molecular chaperone TRAP1 is overexpressed in 60-70% of human colorectal cancers (CRC) and its over-expression correlates with poor clinical outcome, being associated with many cancer cell functions (i.e. adaptation to stress, protection from apoptosis and drug resistance, protein synthesis quality control, metabolic rewiring from glycolysis to mitochondrial respiration and vice versa). Here, the potential new role of TRAP1 in regulating mitochondrial dynamics was investigated in CRC cell lines and human CRCs. Our results revealed an inverse correlation between TRAP1 and mitochondrial-encoded respiratory chain proteins both at transcriptional and translational levels. Furthermore, TRAP1 silencing is associated with increased mitochondrial mass and mitochondrial DNA copy number (mtDNA-CN) as well as enhanced MB through PGC-1α/TFAM signalling pathway, promoting the formation of new functioning mitochondria and, likely, underlying the metabolic shift towards oxidative phosphorylation. These results suggest an involvement of TRAP1 in regulating MB process in human CRC cells. KEY MESSAGES: TRAP1 inversely correlates with protein-coding mitochondrial gene expression in CRC cells and tumours. TRAP1 silencing correlates with increased mitochondrial mass and mtDNA copy number in CRC cells. TRAP1 silencing favours mitochondrial biogenesis in CRC cells.

Association analysis of HSP90AA1 polymorphism with thermotolerance in tropically adapted Indian crossbred cattle.

Raising cattle is a lucrative business that operates globally but is confronted by many obstacles, such as thermal stress, which results in substantial monetary losses. A vital role of heat shock proteins (HSPs) is to protect cells from cellular damage. HSP90 is a highly prevalent, extremely adaptable gene linked to physiological resilience in thermal stress. This study aimed to find genetic polymorphisms of the HSP90AA1 gene in Karan Fries cattle and explore their relationship to thermal tolerance and production traits. One SNP (g.3292 A > C) was found in the Intron 8 and three SNPs loci (g.4776 A > G, g.5218T > C and g.5224 A > C) were found in the exon 11 of 100 multiparous Karan Fries cattle. The association study demonstrated that the SNP1-g.3292 A > C was significantly (P < 0.01) linked to the variables respiratory rate (RR), heat tolerance coefficient (HTC) and total milk yield (TMY (kg)) attributes. There was no significant correlation identified between any of the other SNP sites (SNP2-g.4776 A > G; SNP3-g.5218T > C; SNP4-g.5224 A > C) with the heat tolerance and production attributes in Karan Fries cattle. Haploview 4.2 and SHEsis software programs were used to analyse pair linkage disequilibrium and construct haplotypes for HSP90AA1. Association studies indicated that the Hap3 (CATA) was beneficial for heat tolerance breeding in Karan Fries cattle. In conclusion, genetic polymorphisms and haplotypes in the HSP90AA1 were associated with thermal endurance attributes. This relationship can be utilized as a beneficial SNP or Hap marker for genetic heat resistance selection in cow breeding platforms.

Hsp90aa1/JUN/Ccl2 regulatory axis mediates migration and differentiation of NSPCs, promoting the onset and progression of early post-ischemic stroke epilepsy.

Early-onset epilepsy following ischemic stroke is a severe neurological condition, the pathogenesis of which remains incompletely understood. Recent studies suggest that Neural stem/progenitor cells (NSPCs) play a crucial role in the disease process, yet the precise molecular mechanisms regulating NSPCs have not been thoroughly investigated. This study utilized single-cell transcriptome sequencing and bioinformatics analysis to identify disease-related genes, which were subsequently validated in both in vitro and in vivo experiments. The findings revealed that Hsp90aa1 (heat shock protein 90 kDa alpha, class A member 1), Jun proto-oncogene (JUN), and CC Motif Ligation 2 (Ccl2) constitute an important regulatory axis influencing the migration and differentiation of NSPCs, potentially impacting the onset and progression of early-onset epilepsy post-ischemic stroke. Additionally, the expression of Hsp90aa1 was found to influence the likelihood of seizure occurrence and the severity of brain ischemia.

Activity-based protein profiling and global proteome analysis reveal MASTL as a potential therapeutic target in gastric cancer.

BACKGROUND: Gastric cancer (GC) is a prevalent malignancy with limited therapeutic options for advanced stages. This study aimed to identify novel therapeutic targets for GC by profiling HSP90 client kinases. METHODS: We used mass spectrometry-based activity-based protein profiling (ABPP) with a desthiobiotin-ATP probe, combined with sensitivity analysis of HSP90 inhibitors, to profile kinases in a panel of GC cell lines. We identified kinases regulated by HSP90 in inhibitor-sensitive cells and investigated the impact of MASTL knockdown on GC cell behavior. Global proteomic analysis following MASTL knockdown was performed, and bioinformatics tools were used to analyze the resulting data. RESULTS: Four kinases-MASTL, STK11, CHEK1, and MET-were identified as HSP90-regulated in HSP90 inhibitor-sensitive cells. Among these, microtubule-associated serine/threonine kinase-like (MASTL) was upregulated in GC and associated with poor prognosis. MASTL knockdown decreased migration, invasion, and proliferation of GC cells. Global proteomic profiling following MASTL knockdown revealed NEDD4-1 as a potential downstream mediator of MASTL in GC progression. NEDD4-1 was also upregulated in GC and associated with poor prognosis. Similar to MASTL inhibition, NEDD4-1 knockdown suppressed migration, invasion, and proliferation of GC cells. CONCLUSIONS: Our multi-proteomic analyses suggest that targeting MASTL could be a promising therapy for advanced gastric cancer, potentially through the reduction of tumor-promoting proteins including NEDD4-1. This study enhances our understanding of kinase signaling pathways in GC and provides new insights for potential treatment strategies.

17-AAG Induces Endoplasmic Reticulum Stress-mediated Apoptosis in Breast Cancer Cells, Possibly Through PERK/eIF2α Up-regulation.

BACKGROUND/AIM: Breast cancer is the most predominant type of cancer affecting women worldwide and the current therapeutic treatment for breast cancer patients is not adequately effective. This study aimed to investigate the mechanism of 17-AAG, a heat shock protein (HSP90) inhibitor, as a treatment for inducing breast cancer cell apoptosis. MATERIALS AND METHODS: The pharmacology network was employed to examine the correlation of 17-AAG with the gene expression profiles of breast cancer, obtained by Gene Expression Profiling Interactive Analysis (GEPIA). MTT and flow cytometry were utilized to investigate cell proliferation and cell apoptosis, respectively. Dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay and western blot analysis were employed to examine the correlation between cellular oxidant levels and protein expression. Immunofluorescence staining was utilized to confirm the protein localization and assess DNA damage. RESULTS: The pharmacological network analysis revealed that HSP90 serves as the common target connecting 17-AAG and breast cancer genes. Treatment with 17-AAG significantly increased cell apoptosis. Moreover, the treatment resulted in up-regulation of cellular oxidant levels and PERK/eIF2α expression. In line with these, protein localization after treatment revealed an increase in DNA damage, correlating with higher ER stress levels. Furthermore, GEPIA demonstrated that PERK and eIF2α expression were significantly higher in breast invasive carcinoma compared to other tumor types. CONCLUSION: HSP90 emerges as a potential target for inducing apoptosis in breast cancer cells by disrupting protein homeostasis in the endoplasmic reticulum, possibly through PERK/eIF2α up-regulation. 17-AAG, an HSP90 inhibitor, may therefore potentially hold an alternative therapeutic strategy for breast cancer treatment.

Plastid HSP90C C-terminal extension region plays a regulatory role in chaperone activity and client binding.

HSP90Cs are essential molecular chaperones localized in the plastid stroma that maintain protein homeostasis and assist the import and thylakoid transport of chloroplast proteins. While HSP90C contains all conserved domains as an HSP90 family protein, it also possesses a unique feature in its variable C-terminal extension (CTE) region. This study elucidated the specific function of this HSP90C CTE region. Our phylogenetic analyses revealed that this intrinsically disordered region contains a highly conserved DPW motif in the green lineages. With biochemical assays, we showed that the CTE is required for the chaperone to effectively interact with client proteins PsbO1 and LHCB2 to regulate ATP-independent chaperone activity and to effectuate its ATP hydrolysis. The CTE truncation mutants could support plant growth and development reminiscing the wild type under normal conditions except for a minor phenotype in cotyledon when expressed at a level comparable to wild type. However, higher HSP90C expression was observed to correlate with a stronger response to specific photosystem II inhibitor DCMU, and CTE truncations dampened the response. Additionally, when treated with lincomycin to inhibit chloroplast protein translation, CTE truncation mutants showed a delayed response to PsbO1 expression repression, suggesting its role in chloroplast retrograde signaling. Our study therefore provides insights into the mechanism of HSP90C in client protein binding and the regulation of green chloroplast maturation and function, especially under stress conditions.

Proteome signatures reveal homeostatic and adaptive oxidative responses by a putative co-chaperone, Wos2, to influence fungal virulence determinants in cryptococcosis.

The increasing prevalence of invasive fungal pathogens is dramatically changing the clinical landscape of infectious diseases, posing an imminent threat to public health. Specifically, Cryptococcus neoformans, the human opportunistic pathogen, expresses elaborate virulence mechanisms and is equipped with sophisticated adaptation strategies to survive in harsh host environments. This study extensively characterizes Wos2, an Hsp90 co-chaperone homolog, featuring bilateral functioning for both cryptococcal adaptation and the resulting virulence response. In this study, we evaluated the proteome and secretome signatures associated with wos2 deletion in enriched and infection-mimicking conditions to reveal Wos2-dependent regulation of the oxidative stress response through global translational reprogramming. The wos2Δ strain demonstrates defective intracellular and extracellular antioxidant protection systems, measurable through a decreased abundance of critical antioxidant enzymes and reduced growth in the presence of peroxide stress. Additional Wos2-associated stress phenotypes were observed upon fungal challenge with heat shock, osmotic stress, and cell membrane stressors. We demonstrate the importance of Wos2 for intracellular lifestyle of C. neoformans during in vitro macrophage infection and provide evidence for reduced phagosomal replication levels associated with wos2Δ. Accordingly, wos2Δ featured significantly reduced virulence within impacting fungal burden in a murine model of cryptococcosis. Our study highlights a vulnerable point in the fungal chaperone network that offers a therapeutic opportunity to interfere with both fungal virulence and fitness.IMPORTANCEThe global impact of fungal pathogens, both emerging and emerged, is undeniable, and the alarming increase in antifungal resistance rates hampers our ability to protect the global population from deadly infections. For cryptococcal infections, a limited arsenal of antifungals and increasing rates of resistance demand alternative therapeutic strategies, including an anti-virulence approach, which disarms the pathogen of critical virulence factors, empowering the host to remove the pathogens and clear the infection. To this end, we apply state-of-the-art mass spectrometry-based proteomics to evaluate the impact of a recently defined novel co-chaperone, Wos2, toward cryptococcal virulence using in vitro and in vivo models of infection. We explore global proteome and secretome remodeling driven by the protein and uncover the novel role in modulating the fungal oxidative stress response. Complementation of proteome findings with in vitro infectivity assays demonstrated the protective role of Wos2 within the macrophage phagosome, influencing fungal replication and survival. These results underscore differential cryptococcal survivability and weakened patterns of dissemination in the absence of wos2. Overall, our study establishes Wos2 as an important contributor to fungal pathogenesis and warrants further research into critical proteins within global stress response networks as potential druggable targets to reduce fungal virulence and clear infection.

eHSP90α in front-line therapy in EGFR exon 19 deletion and 21 Leu858Arg mutations in advanced lung adenocarcinoma.

PURPOSE: Extracellular heat shock protein 90 AA1(eHSP90α) is intricately linked to tumor progression and prognosis. This study aimed to investigate the difference in the value of eHSP90α in post-treatment response assessment and prognosis prediction between exon 19 deletion(19DEL) and exon 21 Leu858Arg(L858R) mutation types in lung adenocarcinoma(LUAD). METHODS: We analyzed the relationship between the expression of eHSP90α and clinicopathological features in 89 patients with L858R mutation and 196 patients with 19DEL mutation in LUAD. The Kaplan-Meier survival curve was used to determine their respective cut-off values and analyze the relationship between eHSP90α expression and the survival time of the two mutation types. The area under the curve (AUC) was used to evaluate the diagnostic performance of biomarkers. Then, the prognostic model was developed using the univariate-Cox multivariate-Cox and LASSO-multivariate logistic methods. RESULTS: In LUAD patients, eHSP90α was positively correlated with carcinoembryonic antigen(CEA), carbohydrate antigen 125(CA125), and carbohydrate antigen 153(CA153). The truncated values of eHSP90α in L858R and 19DEL patients were 44.5 ng/mL and 40.8 ng/mL, respectively. Among L858R patients, eHSP90α had the best diagnostic performance (AUC = 0.765), and higher eHSP90α and T helper cells(Th cells) expression were significantly related to shorter overall survival(OS) and worse treatment response. Also, high eHSP90a expression and short progression-free survival(PFS) were significantly correlated. Among 19DEL patients, CEA had the best diagnostic efficacy (AUC = 0.734), and CEA and Th cells were independent prognostic factors that predicted shorter OS. Furthermore, high CA125 was significantly associated with short PFS and poor curative effect. CONCLUSIONS: eHSP90α has a better prognostic value in LUAD L858R patients than 19DEL, which provides a new idea for clinical diagnosis and treatment.

Selection for robust metabolism in domesticated yeasts is driven by adaptation to Hsp90 stress.

Protein folding both promotes and constrains adaptive evolution. We uncover this surprising duality in the role of the protein-folding chaperone heat shock protein 90 (Hsp90) in maintaining the integrity of yeast metabolism amid proteotoxic stressors within industrial domestication niches. Ethanol disrupts critical Hsp90-dependent metabolic pathways and exerts strong selective pressure for redundant duplications of key genes within these pathways, yielding the classical genomic signatures of beer and bread domestication. This work demonstrates a mechanism of adaptive canalization in an ecology of major economic importance and highlights Hsp90-dependent variation as an important source of phantom heritability in complex traits.

SENP1-Mediated HSP90ab1 DeSUMOylation in Cardiomyocytes Prevents Myocardial Fibrosis by Paracrine Signaling.

Myocardial infarction (MI) triggers a poor ventricular remodeling response, but the underlying mechanisms remain unclear. Here, the authors show that sentrin-specific protease 1 (SENP1) is downregulated in post-MI mice and in patients with severe heart failure. By generating cardiomyocyte-specific SENP1 knockout and overexpression mice to assess cardiac function and ventricular remodeling responses under physiological and pathological conditions. Increased cardiac fibrosis in the cardiomyocyte-specific SENP1 deletion mice, associated with increased fibronectin (Fn) expression and secretion in cardiomyocytes, promotes fibroblast activation in response to myocardial injury. Mechanistically, SENP1 deletion in mouse cardiomyocytes increases heat shock protein 90 alpha family class B member 1 (HSP90ab1) SUMOylation with (STAT3) activation and Fn secretion after ventricular remodeling initiated. Overexpression of SENP1 or mutation of the HSP90ab1 Lys72 ameliorates adverse ventricular remodeling and dysfunction after MI. Taken together, this study identifies SENP1 as a positive regulator of cardiac repair and a potential drug target for the treatment of MI. Inhibition of HSP90ab1 SUMOylation stabilizes STAT3 to inhibit the adverse ventricular remodeling response.

GRK2 is critical for the cleavage of the porcine embryo by regulating HSP90 and the AKT pathway.

In brief: GRK2 deficiency disrupts the early embryonic development in pigs. The regulation of GRK2 on HSP90 and AKT may also play an important role during embryo development and tumor formation. Abstract: Among the family of GPCR kinases (GRKs) that regulate receptor phosphorylation and signaling termination, G-protein-coupled receptor kinase 2 (GRK2) binds to HSP90 in response to hypoxia or other stresses. In this study, we investigated the effects of GRK2 knockdown and inhibition on porcine embryonic development from the zygote stage. Immunofluorescence and western blotting were used to determine the localization and expression, respectively, of GRK2 and related proteins. First, GRK2 and p-GRK2 were expressed in both the cytoplasm and membrane and co-localized with HSP90 on the membrane. The mRNA level of GRK2 increased until the 8C-morula stage, suggesting that GRK2 may play an essential role during the early development of the porcine embryos. GRK2 knockdown reduced porcine embryo development capacity and led to significantly decreased blastocyst quality. In addition, inhibition of GRK2 also induced poor ability of embryo development at an early stage, indicating that GRK2 is critical for embryonic cleavage in pigs. Knockdown and inhibition of GRK2 reduced HSP90 expression, AKT activation, and cAMP levels. Additionally, GRK2 deficiency increased LC3 expression, suggesting enhanced autophagy during embryo development. In summary, we showed that GRK2 binds to HSP90 on the membrane to regulate embryonic cleavage and AKT activation during embryonic development in pigs.

Miconazole induces aneuploidy-mediated tolerance in Candida albicans that is dependent on Hsp90 and calcineurin.

Antifungal resistance and antifungal tolerance are two distinct terms that describe different cellular responses to drugs. Antifungal resistance describes the ability of a fungus to grow above the minimal inhibitory concentration (MIC) of a drug. Antifungal tolerance describes the ability of drug susceptible strains to grow slowly at inhibitory drug concentrations. Recent studies indicate antifungal resistance and tolerance have distinct evolutionary trajectories. Superficial candidiasis bothers millions of people yearly. Miconazole has been used for topical treatment of yeast infections for over 40 years. Yet, fungal resistance to miconazole remains relatively low. Here we found different clinical isolates of Candida albicans had different profile of tolerance to miconazole, and the tolerance was modulated by physiological factors including temperature and medium composition. Exposure of non-tolerant strains with different genetic backgrounds to miconazole mainly induced development of tolerance, not resistance, and the tolerance was mainly due to whole chromosomal or segmental amplification of chromosome R. The efflux gene CDR1 was required for maintenance of tolerance in wild type strains but not required for gain of aneuploidy-mediated tolerance. Heat shock protein Hsp90 and calcineurin were essential for maintenance as well as gain of tolerance. Our study indicates development of aneuploidy-mediated tolerance, not resistance, is the predominant mechanism of rapid adaptation to miconazole in C. albicans, and the clinical relevance of tolerance deserves further investigations.

miR-15a targets the HSP90 co-chaperone Morgana in chronic myeloid leukemia.

Morgana is a ubiquitous HSP90 co-chaperone protein coded by the CHORDC1 gene. Morgana heterozygous mice develop with age a myeloid malignancy resembling human atypical myeloid leukemia (aCML), now renamed MDS/MPN with neutrophilia. Patients affected by this pathology exhibit low Morgana levels in the bone marrow (BM), suggesting that Morgana downregulation plays a causative role in the human malignancy. A decrease in Morgana expression levels is also evident in the BM of a subgroup of Philadelphia-positive (Ph+) chronic myeloid leukemia (CML) patients showing resistance or an incomplete response to imatinib. Despite the relevance of these data, the mechanism through which Morgana expression is downregulated in patients' bone marrow remains unclear. In this study, we investigated the possibility that Morgana expression is regulated by miRNAs and we demonstrated that Morgana is under the control of four miRNAs (miR-15a/b and miR-26a/b) and that miR-15a may account for Morgana downregulation in CML patients.

Molecular insights into programmed cell death in esophageal squamous cell carcinoma.

Background: Esophageal squamous cell carcinoma (ESCC) is a deadly type of esophageal cancer. Programmed cell death (PCD) is an important pathway of cellular self-extermination and is closely involved in cancer progression. A detailed study of its mechanism may contribute to ESCC treatment. Methods: We obtained expression profiling data of ESCC patients from public databases and genes related to 12 types of PCD from previous studies. Hub genes in ESCC were screened from PCD-related genes applying differential expression analysis, machine learning analysis, linear support vector machine (SVM), random forest and Least Absolute Shrinkage and Selection Operator (LASSO) regression analysis. In addition, based on the HTFtarget and TargetScan databases, transcription factors (TFs) and miRNAs interacting with the hub genes were selected. The relationship between hub genes and immune cells were analyzed using the CIBERSORT algorithm. Finally, to verify the potential impact of the screened hub genes on ESCC occurrence and development, a series of in vitro cell experiments were conducted. Results: We screened 149 PCD-related DEGs, of which five DEGs (INHBA, LRRK2, HSP90AA1, HSPB8, and EIF2AK2) were identified as the hub genes of ESCC. The area under the curve (AUC) of receiver operating characteristic (ROC) curve of the integrated model developed using the hub genes reached 0.997, showing a noticeably high diagnostic accuracy. The number of TFs and miRNAs regulating hub genes was 105 and 22, respectively. INHBA, HSP90AA1 and EIF2AK2 were overexpressed in cancer tissues and cells of ESCC. Notably, INHBA knockdown suppressed ECSS cell migration and invasion and altered the expression of important apoptotic and survival proteins. Conclusion: This study identified significant molecules with promising accuracy for the diagnosis of ESCC, which may provide a new perspective and experimental basis for ESCC research.