PKCδ mediates mitochondrial ROS generation and oxidation of HSP60 to relieve RKIP inhibition on MAPK pathway for HCC progression

Clinicopathologic significance of heat shock protein 60 as a survival predictor in breast carcinoma

Background

While Heat Shock Protein 60 (HSP60) has been linked to human tumor, its clinic significance specifically in breast carcinoma is unclear. This investigation aims to retrospectively evaluate how HSP60 protein levels relate to survival outcomes among patients diagnosed with breast carcinoma.

Methods

Evaluation of 206 patients diagnosed with breast carcinoma and receiving treatment from January 2012 to April 2018, carried out retrospectively. The protein level of HSP60 in breast carcinoma determined by immunohistochemical.

Results

The study provided evidence of a distinct upregulation of HSP60 expression in breast carcinoma tumor samples in contrast to adjacent normal tissue samples. Additionally, heightened HSP60 expression was linked to advanced T stage (P = 0.046), N stage (P = 0.034), tumor metastasis (P = 0.016), pathological grading (P = 0.012), and adjuvant therapy utilization (P = 0.004). Moreover, elevated levels of HSP60 proteins exhibited a significant inverse correlation with overall survival (OS) [hazard ratio (HR) 1.598, P = 0.018] and progression-free survival (PFS) (HR 1.600, P = 0.017) among breast carcinoma patients in univariate analyses. The results of multivariate analyses highlighted HSP60 may serve as an independent predictor for both OS and PFS in breast carcinoma patients (HR 1.525, P = 0.034; HR 1.528, P = 0.033, respectively).

Conclusion

The involvement of HSP60 in breast carcinoma progression suggests its potential clinical relevance in treatment target validation and prognostic assessment of the disease.

Shirebi granules ameliorate acute gouty arthritis by inhibiting NETs-induced imbalance between immunity and inflammation

BACKGROUND

Acute gouty arthritis (AGA) is classified as 'arthritis' in traditional Chinese medicine (TCM) theory. Shirebi granules (SGs), derived from the classic prescription SiMiaoWan, exerts satisfying therapeutic efficacy in ameliorating AGA clinically. However, the underlying mechanisms of SGs against AGA remain unclarified.

METHODS

AGA-related biological processes, signal pathways and biomarker genes were mined from the GEO database through bioinformatics. SGs components were systematically recognized using the UPLC-Q-TOF-MS/MS. A correlation network was established based on the biomarker genes and the chemical components, from which the signal pathway used for further study was selected. Finally, we established an AGA model using SD rats injected with monosodium urate (MSU) in the ankle joint for experimental validation. A combination of behavioral tests, H&E, safranin O- fast green, western blotting, and immunofluorescence were employed to reveal the mechanism of action of SGs on AGA.

RESULTS

The deterioration of AGA was significantly related to the imbalance between immunity and inflammation, neutrophil chemotaxis and inflammatory factor activation. HDAC5, PRKCB, NFκB1, MPO, PRKCA, PIK3CA were identified to be the candidate targets of SGs against AGA, associated with neutrophil extracellular traps (NETs) signal pathway. Animal experiments demonstrated that SGs effectively repaired cartilage damage, blocked TLR4 activation, and inhibited the expression of NETs indicators and inflammatory factors. In addition, SGs prominently alleviated joint redness and swelling, improved joint dysfunction, inhibited inflammatory infiltration of AGA rats.

CONCLUSION

Our data reveal that SGs may effectively alleviate the disease severity of AGA by suppressing NETs-promoted imbalance between immunity and inflammation.

Molecular Chaperonin HSP60: Current Understanding and Future Prospects

Molecular chaperones are highly conserved across evolution and play a crucial role in preserving protein homeostasis. The 60 kDa heat shock protein (HSP60), also referred to as chaperonin 60 (Cpn60), resides within mitochondria and is involved in maintaining the organelle's proteome integrity and homeostasis. The HSP60 family, encompassing Cpn60, plays diverse roles in cellular processes, including protein folding, cell signaling, and managing high-temperature stress. In prokaryotes, HSP60 is well understood as a GroEL/GroES complex, which forms a double-ring cavity and aids in protein folding. In eukaryotes, HSP60 is implicated in numerous biological functions, like facilitating the folding of native proteins and influencing disease and development processes. Notably, research highlights its critical involvement in sustaining oxidative stress and preserving mitochondrial integrity. HSP60 perturbation results in the loss of the mitochondria integrity and activates apoptosis. Currently, numerous clinical investigations are in progress to explore targeting HSP60 both in vivo and in vitro across various disease models. These studies aim to enhance our comprehension of disease mechanisms and potentially harness HSP60 as a therapeutic target for various conditions, including cancer, inflammatory disorders, and neurodegenerative diseases. This review delves into the diverse functions of HSP60 in regulating proteo-homeostasis, oxidative stress, ROS, apoptosis, and its implications in diseases like cancer and neurodegeneration.

Restraint Stress-Induced Neutrophil Inflammation Contributes to Concurrent Gastrointestinal Injury in Mice

Psychological stress increases risk of gastrointestinal tract diseases. However, the mechanism behind stress-induced gastrointestinal injury is not well understood. The objective of our study is to elucidate the putative mechanism of stress-induced gastrointestinal injury and develop an intervention strategy. To achieve this, we employed the restraint stress mouse model, a well-established method to study the pathophysiological changes associated with psychological stress in mice. By orally administering gut-nonabsorbable Evans blue dye and monitoring its plasma levels, we were able to track the progression of gastrointestinal injury in live mice. Additionally, flow cytometry was utilized to assess the viability, death, and inflammatory status of splenic leukocytes, providing insights into the stress-induced impact on the innate immune system associated with stress-induced gastrointestinal injury. Our findings reveal that neutrophils represent the primary innate immune leukocyte lineage responsible for stress-induced inflammation. Splenic neutrophils exhibited elevated expression levels of the pro-inflammatory cytokine IL-1, cellular reactive oxygen species, mitochondrial burden, and cell death following stress challenge compared to other innate immune cells such as macrophages, monocytes, and dendritic cells. Regulated cell death analysis indicated that NETosis is the predominant stress-induced cell death response among other analyzed regulated cell death pathways. NETosis culminates in the formation and release of neutrophil extracellular traps, which play a crucial role in modulating inflammation by binding to pathogens. Treatment with the NETosis inhibitor GSK484 rescued stress-induced neutrophil extracellular trap release and gastrointestinal injury, highlighting the involvement of neutrophil extracellular traps in stress-induced gastrointestinal inflammation. Our results suggest that neutrophil NETosis could serve as a promising drug target for managing psychological stress-induced gastrointestinal injuries.

Identification of HSPD1 as a novel invasive biomarker associated with mitophagy in pituitary adenomas

BACKGROUND

The crucial role of mitophagy in tumor progression has been recognized. Therefore, our study aimed to investigate the potential correlation between pituitary adenoma invasiveness and the mitophagy processes.

METHODS

In this study, we used transcriptomics of postoperative tissue from 32 patients and quantitative proteomics of 19 patients to screen for mitophagy-related invasion genes in pituitary adenomas. The invasive predictive value of target genes was analyzed by Lasso regression model, CytoHubba plugin and expression validation. Co-expression correlation analysis was used to identify paired proteins for target genes, and a predictive model for pituitary adenoma invasiveness was constructed by target genes and paired proteins and assessed using ROC analysis, calibration curves and DCA. GO function, pathway (GSEA or GSVA) and immune cell analysis (ssGSEA or CIBERSORT) were further utilized to explore the action mechanism of target gene. Finally, immunohistochemistry and cell function experiments were used to detect the differential expression and key roles of the target genes in pituitary adenomas.

RESULTS

Finally, Heat shock protein family D member 1 (HSPD1) was identified as a target gene. The quality of a predictive model for pituitary adenoma invasiveness consisting of HSPD1 and its paired protein expression profiles was satisfactory. Moreover, the expression of HSPD1 was significantly lower in invasive pituitary adenomas than in non-invasive pituitary adenomas. Downregulation of HSPD1 may be significantly related to invasion process, mitochondria-related pathway and immune cell regulation in pituitary adenomas.

CONCLUSION

The downregulation of HSPD1 may serve as a predictive indicator for identifying invasive pituitary adenomas.

Decoding the roles of heat shock proteins in liver cancer

Hepatocellular carcinoma (HCC) is one of the most common gastrointestinal malignancies, characterized by insidious onset and high propensity for metastasis and recurrence. Apart from surgical resection, there are no effective curative methods for HCC in recent years, due to resistance to radiotherapy and chemotherapy. Heat shock proteins (HSP) play a crucial role in maintaining cellular homeostasis and normal organism development as molecular chaperones for intracellular proteins. Both basic research and clinical data have shown that HSPs are crucial participants in the HCC microenvironment, as well as the occurrence, development, metastasis, and resistance to radiotherapy and chemotherapy in various malignancies, particularly liver cancer. This review aims to discuss the molecular mechanisms and potential clinical value of HSPs in HCC, which may provide new insights for HSP-based therapeutic interventions for HCC.

The exploration of mitochondrial-related features helps to reveal the prognosis and immunotherapy methods of colorectal cancer

BACKGROUND

Cancer cell survival, proliferation, and metabolism are all intertwined with mitochondria. However, a complete description of how the features of mitochondria relate to the tumor microenvironment (TME) and immunological landscape of colorectal cancer (CRC) has yet to be made. We performed subgroup analysis on CRC patient data obtained from the databases using non-negative matrix factorization (NMF) clustering. Construct a prognostic model using the mitochondrial-related gene (MRG) risk score, and then compare it to other models for accuracy. Comprehensive analyses of the risk score, in conjunction with the TME and immune landscape, were performed, and the relationship between the model and different types of cell death, radiation and chemotherapy, and drug resistance was investigated. Results from immunohistochemistry and single-cell sequencing were utilized to verify the model genes, and a drug sensitivity analysis was conducted to evaluate possible therapeutic medicines. The pan-cancer analysis is utilized to further investigate the role of genes in a wider range of malignancies.

METHODS AND RESULTS

We found that CRC patients based on MRG were divided into two groups with significant differences in survival outcomes and TME between groups. The predictive power of the risk score was further shown by building a prognostic model and testing it extensively in both internal and external cohorts. Multiple immune therapeutic responses and the expression of immunological checkpoints demonstrate that the risk score is connected to immunotherapy success. The correlation analysis of the risk score provide more ideas and guidance for prognostic models in clinical treatment.

CONCLUSION

The TME, immune cell infiltration, and responsiveness to immunotherapy in CRC were all thoroughly evaluated on the basis of MRG features. The comparative validation of multiple queues and models combined with clinical data ensures the effectiveness and clinical practicality of MRG features. Our studies help clinicians create individualized treatment programs for individuals with cancer.

ARID1A loss activates MAPK signaling via DUSP4 downregulation

BACKGROUND

ARID1A, a tumor suppressor gene encoding BAF250, a protein participating in chromatin remodeling, is frequently mutated in endometrium-related malignancies, including ovarian or uterine clear cell carcinoma (CCC) and endometrioid carcinoma (EMCA). However, how ARID1A mutations alter downstream signaling to promote tumor development is yet to be established.

METHODS

We used RNA-sequencing (RNA-seq) to explore transcriptomic changes in isogenic human endometrial epithelial cells after deleting ARID1A. Chromatin immunoprecipitation sequencing (ChIP-seq) was employed to assess the active or repressive histone marks on DUSP4 promoter and regulatory regions. We validated our findings using genetically engineered murine endometroid carcinoma models, human endometroid carcinoma tissues, and in silico approaches.

RESULTS

RNA-seq revealed the downregulation of the MAPK phosphatase dual-specificity phosphatase 4 (DUSP4) in ARID1A-deficient cells. ChIP-seq demonstrated decreased histone acetylation marks (H3K27Ac, H3K9Ac) on DUSP4 regulatory regions as one of the causes for DUSP4 downregulation in ARID1A-deficient cells. Ectopic DUSP4 expression decreased cell proliferation, and pharmacologically inhibiting the MAPK pathway significantly mitigated tumor formation in vivo.

CONCLUSIONS

Our findings suggest that ARID1A protein transcriptionally modulates DUSP4 expression by remodeling chromatin, subsequently inactivating the MAPK pathway, leading to tumor suppression. The ARID1A-DUSP4-MAPK axis may be further considered for developing targeted therapies against ARID1A-mutated cancers.

Mitochondrial Metabolism: A New Dimension of Personalized Oncology

Energy is needed by cancer cells to stay alive and communicate with their surroundings. The primary organelles for cellular metabolism and energy synthesis are mitochondria. Researchers recently proved that cancer cells can steal immune cells' mitochondria using nanoscale tubes. This finding demonstrates the dependence of cancer cells on normal cells for their living and function. It also denotes the importance of mitochondria in cancer cells' biology. Emerging evidence has demonstrated how mitochondria are essential for cancer cells to survive in the harsh tumor microenvironments, evade the immune system, obtain more aggressive features, and resist treatments. For instance, functional mitochondria can improve cancer resistance against radiotherapy by scavenging the released reactive oxygen species. Therefore, targeting mitochondria can potentially enhance oncological outcomes, according to this notion. The tumors' responses to anticancer treatments vary, ranging from a complete response to even cancer progression during treatment. Therefore, personalized cancer treatment is of crucial importance. So far, personalized cancer treatment has been based on genomic analysis. Evidence shows that tumors with high mitochondrial content are more resistant to treatment. This paper illustrates how mitochondrial metabolism can participate in cancer resistance to chemotherapy, immunotherapy, and radiotherapy. Pretreatment evaluation of mitochondrial metabolism can provide additional information to genomic analysis and can help to improve personalized oncological treatments. This article outlines the importance of mitochondrial metabolism in cancer biology and personalized treatments.

Investigating pathogenic SNP of PKCι in HCV-induced hepatocellular carcinoma

Hepatocellular carcinoma is a leading cause of cancer-related deaths due to its complexity in diagnosis, chemo-resistance, and aggressive nature. Identifying pathogenic single nucleotide polymorphism (SNP) in protein kinase C iota (PKCι) can be a potential biomarker in the prognosis and treatment of HCC. This study investigated the association between a SNP in PRKCI and the Pakistani population's hepatocellular carcinoma (HCC) risk. Obtained samples were first evaluated for ALT measurements and viral load quantification through reverse transcriptase-PCR. The PKCι nsSNP rs1199520604 was evaluated computationally by multiple consensus bioinformatics tools for predicting its potential deleterious effects. Its association with hepatitis C virus- (HCV) mediated HCC was then investigated through ARMS-PCR (Amplification Refractory Mutation System Polymerase Chain Reaction). SNP analysis of rs1199520604 was performed in 100 cases and 100 controls. Variant rs1199520604's homozygous T genotype is a risk factor allele for the HCV-induced HCC (odds ratio: 4.13, relative risk: 2.01, P-value < 0.0001). The heterozygous genotype is determined to protect HCV patients from HCC development (P < 0.001). The study highlighted the disease association of variant rs1199520604 with HCV-induced HCC in the Pakistani populations. This variant, after further validation through high-throughput investigation on a larger cohort, has the potential to be translated at the clinical level.

The Role of Activating Transcription Factor 3 in Metformin's Alleviation of Gastrointestinal Injury Induced by Restraint Stress in Mice

Metformin is one of the most commonly used drugs for type 2 diabetes mellitus. In addition to its anti-diabetic property, evidence suggests more potential applications for metformin, such as antiaging, cellular protection, and anti-inflammation. Studies have reported that metformin activates pathways with anti-inflammatory effects, enhances the integrity of gut epithelial tight junctions, and promotes a healthy gut microbiome. These actions contribute to the protective effect of metformin against gastrointestinal (GI) tract injury. However, whether metformin plays a protective role in psychological-stress-associated GI tract injury remains elusive. We aim to elucidate the potential protective effect of metformin on the GI system and develop an effective intervention strategy to counteract GI injury induced by acute psychological stress. By monitoring the levels of GI-nonabsorbable Evans blue dye in the bloodstream, we assessed the progression of GI injury in live mice. Our findings demonstrate that the administration of metformin effectively mitigated GI leakage caused by psychological stress. The GI protective effect of metformin is more potent when used on wild-type mice than on activating-transcription-factor 3 (ATF3)-deficient (ATF3^-/-) mice. As such, metformin-mediated rescue was conducted in an ATF3-dependent manner. In addition, metformin-mediated protection is associated with the induction of stress-induced GI mRNA expressions of the stress-induced genes ATF3 and AMP-activated protein kinase. Furthermore, metformin treatment-mediated protection of CD326⁺ GI epithelial cells against stress-induced apoptotic cell death was observed in wild-type but not in ATF3^-/- mice. These results suggest that metformin plays a protective role in stress-induced GI injury and that ATF3 is an essential regulator for metformin-mediated rescue of stress-induced GI tract injury.

Deinococcus radiodurans-derived membrane vesicles protect HaCaT cells against H2O2-induced oxidative stress via modulation of MAPK and Nrf2/ARE pathways

BACKGROUND

Deinococcus radiodurans is a robust bacterium that can withstand harsh environments that cause oxidative stress to macromolecules due to its cellular structure and physiological functions. Cells release extracellular vesicles for intercellular communication and the transfer of biological information; their payload reflects the status of the source cells. Yet, the biological role and mechanism of Deinococcus radiodurans-derived extracellular vesicles remain unclear.

AIM

This study investigated the protective effects of membrane vesicles derived from D. radiodurans (R1-MVs) against H₂O₂-induced oxidative stress in HaCaT cells.

RESULTS

R1-MVs were identified as 322 nm spherical molecules. Pretreatment with R1-MVs inhibited H₂O₂-mediated apoptosis in HaCaT cells by suppressing the loss of mitochondrial membrane potential and reactive oxygen species (ROS) production. R1-MVs increased the superoxide dismutase (SOD) and catalase (CAT) activities, restored glutathione (GSH) homeostasis, and reduced malondialdehyde (MDA) production in H₂O₂-exposed HaCaT cells. Moreover, the protective effect of R1-MVs against H₂O₂-induced oxidative stress in HaCaT cells was dependent on the downregulation of mitogen-activated protein kinase (MAPK) phosphorylation and the upregulation of the nuclear factor E2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway. Furthermore, the weaker protective capabilities of R1-MVs derived from ΔDR2577 mutant than that of the wild-type R1-MVs confirmed our inferences and indicated that SlpA protein plays a crucial role in R1-MVs against H₂O₂-induced oxidative stress.

CONCLUSION

Taken together, R1-MVs exert significant protective effects against H₂O₂-induced oxidative stress in keratinocytes and have the potential to be applied in radiation-induced oxidative stress models.

Inhibition of Histone H3K18 Acetylation-Dependent Antioxidant Pathways Involved in Arsenic-Induced Liver Injury in Rats and the Protective Effect of Rosa roxburghii Tratt Juice

Arsenic is a common environmental toxicant. Long-term arsenic exposure can induce various types of liver injury, but the underlying mechanism remains unclear, so effective prevention and treatment measures are unknown. This study aims to explore the mechanism of arsenic-induced rat liver injury based on the histone H3K18 acetylation-dependent antioxidant pathway and to identify the role of a medicinal and edible resource, Rosa roxburghii Tratt juice, in combating it. Hepatic steatosis and inflammatory cell infiltration were observed in rats exposed to different doses of NaAsO₂ using histopathological measurement. Increased 8-OHdG and MDA in liver tissue corroborated hepatic oxidative damage. We further found that a reduction in H3K18ac in the liver showed a dose-response relationship, with an increase in the NaAsO₂ treatment dose, and it was remarkably associated with increased 8-OHdG and MDA. The results of ChIP-qPCR identified that the decreased enrichment of H3K18ac in promoters of the Hspa1a and Hspb8 genes culminated in the inhibition of the genes' expression, which was found to be involved in the aggravation of hepatic oxidative damage induced by arsenic. Notably, Rosa roxburghii Tratt juice was found to reduce 8-OHdG and MDA in the liver, thereby alleviating the histopathological lesions induced by arsenic, which was modulated by recovering the H3K18ac-dependent transcriptional activation of the Hspa1a and Hspb8 genes. Taken together, we provide a novel epigenetics insight into clarifying the mechanism of arsenic-induced liver injury and its rescue by Rosa roxburghii Tratt juice.

Mitochondrial immune regulation and anti-tumor immunotherapy strategies targeting mitochondria

Cancer cells adapt to increasing energy and biosynthetic demands by reprogramming their metabolic pathways. Mitochondria are important organelles for the metabolic reprogramming of tumor cells. In addition to supplying energy, they play crucial roles in the survival, immune evasion, tumor progression, and treatment resistance of the hypoxic tumor microenvironment (TME) in cancer cells. With the development of the life sciences, scientists have gained an in-depth understanding of immunity, metabolism, and cancer, and numerous studies have emphasized that mitochondria are essential for tumor immune escape and the regulation of immune cell metabolism and activation. Moreover, recent evidence suggests that targeting the mitochondria-related pathway with anticancer drugs can initiate the killing of cancer cells by increasing the ability of cancer cells to be recognized by immune cells, tumor antigen presentation ability, and the anti-tumor function of immune cells. This review discusses the effects of mitochondrial morphology and function on the phenotype and function of immune cells under normal and TME conditions, the effects of mitochondrial changes in tumors and microenvironments on tumor immune escape and immune cell function, and finally focuses on the recent research progress and future challenges of novel anti-tumor immunotherapy strategies targeting mitochondria.

Knockdown of heat shock protein family D member 1 (HSPD1) promotes proliferation and migration of ovarian cancer cells via disrupting the stability of mitochondrial 3-oxoacyl-ACP synthase (OXSM)

BACKGROUND

Heat shock protein 60 (HSP60) is essential for the folding and assembly of newly imported proteins to the mitochondria. HSP60 is overexpressed in most types of cancer, but its association with ovarian cancer is still in dispute. SKOV3 and OVCAR3 were used as experimental models after comparing the expression level of mitochondrial HSP60 in a normal human ovarian epithelial cell line and four ovarian cancer cell lines.

RESULTS

Low HSPD1 (Heat Shock Protein Family D (HSP60) Member 1) expression was associated with unfavorable prognosis in ovarian cancer patients. Knockdown of HSPD1 significantly promoted the proliferation and migration of ovarian cancer cells. The differentially expressed proteins after HSPD1 knockdown were enriched in the lipoic acid (LA) biosynthesis and metabolism pathway, in which mitochondrial 3-oxoacyl-ACP synthase (OXSM) was the most downregulated protein and responsible for lipoic acid synthesis. HSP60 interacted with OXSM and overexpression of OXSM or LA treatment could reverse proliferation promotion mediated by HSPD1 knockdown.

CONCLUSIONS

HSP60 interacted with OXSM and maintained its stability. Knockdown of HSPD1 could promote the proliferation and migration of SKOV3 and OVCAR3 via lowering the protein level of OXSM and LA synthesis.

EF-24 inhibits TPA-induced cellular migration and MMP-9 expression through the p38 signaling pathway in cervical cancer cells

Diphenyl difluoroketone (EF-24), a synthetic curcumin analog, has enhanced bioavailability over curcumin. EF-24 acts more powerful bioactivity for anti-inflammatory and anti-cancer activity. However, the effects and mechanism of EF-24 on cervical cancer has not been fully investigated. Herein, this study evaluated the effects of EF-24 on TPA-induced cellular migration of cervical cancer. The results showed that EF-24 substantially reduced the cellular migration and cellular invasion of the HeLa and SiHa cells. Moreover, gelatin zymography, western blotting analyses and real-time PCR revealed that EF-24 suppressed Matrix metalloproteinase-9 (MMP-9) activity, protein expression and mRNA levels. Mechanistically, EF-24 inhibited the phosphorylation of the p38 signaling pathway. In conclusion, EF-24 inhibited TPA-induced cellular migration and cellular invasion of cervical cancer cell lines through modulating MMP-9 expression via downregulating signaling p38 pathway and EF-24 may have potential to serve as a chemopreventive agent of cervical cancer.

Genetic Analysis of Platelet-Related Genes in Hepatocellular Carcinoma Reveals a Novel Prognostic Signature and Determines PRKCD as the Potential Molecular Bridge

BACKGROUND

Hepatocellular carcinoma (HCC) belongs to a representative lethality gastrointestinal malignancy, and comprehensive management of HCC remains intractable at present on account of its invasive biological feature that is easy to relapse and early metastasis. The intimate connection between platelets and tumor progression has been widely reported, and platelet-related indicators are also used in the clinical practice of carcinoma. This work is designed to investigate the significance of platelet-related genes in the prognostic prediction of patients with HCC and their potential role in the cross-talk between HCC cells and platelets in the tumor microenvironment.

METHODS

By integrating the RNA-seq data and clinicopathological information of HCC patients, we extracted prognosis-associated platelet-related genes based on the univariate cox analysis and further established a relevant prognostic signature via the lasso cox regression analysis, and two independent HCC cohorts were used as external validation. Multiple bioinformatics methods were utilized to explore the underlying functional discrepancy between different risk groups classified by the risk model. And in vitro proliferation, invasion, and migration assays were conducted to investigate the effect of platelet stimulation on HCC cells' viability and motility, and flow cytometric analysis was exerted to demonstrate the influence of HCC cells on platelet activation.

RESULTS

A novel platelet-related risk model was developed and patients both in the training and testing cohorts were divided into distinct risk subgroups according to the median risk score. It was observed that the high-risk status was closely associated with poor prognosis and worse clinicopathological parameters. Meanwhile, an obvious discrepancy in the constitution of the immune microenvironment also indicated that distinct immune status might be a potential determinant affecting prognosis as well as immunotherapy reactiveness. Moreover, in vitro experiments demonstrated that PRKCD could act as a molecular bridge between tumor cells and platelets, which could either participate in regulating tumor malignant phenotype or mediating platelet activation.

CONCLUSIONS

In brief, this work reveals a novel platelet-related risk signature for prognostic evaluation of HCC patients and confirms that PRKCD is a key messenger in HCC cell-platelet interaction and plays a crucial role in mediating platelet-induced tumor progression.

Protein Kinase C (PKC) Isozymes as Diagnostic and Prognostic Biomarkers and Therapeutic Targets for Cancer

Protein kinase C (PKC) is a large family of calcium- and phospholipid-dependent serine/threonine kinases that consists of at least 11 isozymes. Based on their structural characteristics and mode of activation, the PKC family is classified into three subfamilies: conventional or classic (cPKCs; α, βI, βII, and γ), novel or non-classic (nPKCs; δ, ε, η, and θ), and atypical (aPKCs; ζ, ι, and λ) (PKCλ is the mouse homolog of PKCι) PKC isozymes. PKC isozymes play important roles in proliferation, differentiation, survival, migration, invasion, apoptosis, and anticancer drug resistance in cancer cells. Several studies have shown a positive relationship between PKC isozymes and poor disease-free survival, poor survival following anticancer drug treatment, and increased recurrence. Furthermore, a higher level of PKC activation has been reported in cancer tissues compared to that in normal tissues. These data suggest that PKC isozymes represent potential diagnostic and prognostic biomarkers and therapeutic targets for cancer. This review summarizes the current knowledge and discusses the potential of PKC isozymes as biomarkers in the diagnosis, prognosis, and treatment of cancers.

The effects of red LED light on pig sperm function rely upon mitochondrial electron chain activity rather than on a PKC-mediated mechanism

While irradiation with red LED light has been reported to modulate sperm function in different mammalian species, the mechanisms underlying their response are poorly understood. This work sought to provide new insights into whether this effect relies on a direct action upon mitochondrial electron chain and/or on PKC-linked mechanisms such as those related to opsins. For this purpose, pig semen was light-stimulated for 1, 5 or 10 min in the presence/absence of antimycin A, an inhibitor of the mitochondrial electron chain, or PKC 20–28^® (PKCi), a PKC inhibitor. Antimycin A completely blocked the effects of light at all the performed irradiation patterns. This effect was linked to a complete immobility of sperm, which was accompanied with a significant (p < 0.05) drop in several markers of mitochondrial activity, such as JC-1 staining and O₂ consumption rate. Antimycin A, however, did not affect intracellular ATP levels, intramitochondrial calcium, total ROS, superoxides or cytochrome C oxidase (CCO) activity. In the case of PKCi, it did also counteract the effects of light on motility, O₂ consumption rate and CCO activity, but not to the same extent than that observed for antimycin A. Finally, the effects observed when sperm were co-incubated with antimycin A and PKCi were similar to those observed with antimycin A alone. In conclusion, red LED light acts on sperm function via a direct effect on mitochondrial electron chain. Additionally, light-activated PKC pathways have a supplementary effect to that observed in the electron chain, thereby modulating sperm parameters such as motility and CCO activity.

Targeted Anti-Mitochondrial Therapy: The Future of Oncology

Like living organisms, cancer cells require energy to survive and interact with their environment. Mitochondria are the main organelles for energy production and cellular metabolism. Recently, investigators demonstrated that cancer cells can hijack mitochondria from immune cells. This behavior sheds light on a pivotal piece in the cancer puzzle, the dependence on the normal cells. This article illustrates the benefits of new functional mitochondria for cancer cells that urge them to hijack mitochondria. It describes how functional mitochondria help cancer cells’ survival in the harsh tumor microenvironment, immune evasion, progression, and treatment resistance. Recent evidence has put forward the pivotal role of mitochondria in the metabolism of cancer stem cells (CSCs), the tumor components responsible for cancer recurrence and metastasis. This theory highlights the mitochondria in cancer biology and explains how targeting mitochondria may improve oncological outcomes.

PKCα and PKCδ: Friends and Rivals

PKC comprises a large family of serine/threonine kinases that share a requirement for allosteric activation by lipids. While PKC isoforms have significant homology, functional divergence is evident among subfamilies and between individual PKC isoforms within a subfamily. Here, we highlight these differences by comparing the regulation and function of representative PKC isoforms from the conventional (PKCα) and novel (PKCδ) subfamilies. We discuss how unique structural features of PKCα and PKCδ underlie differences in activation and highlight the similar, divergent, and even opposing biological functions of these kinases. We also consider how PKCα and PKCδ can contribute to pathophysiological conditions and discuss challenges to targeting these kinases therapeutically.

Nanodiamond-Induced Thrombocytopenia in Mice Involve P-Selectin-Dependent Nlrp3 Inflammasome-Mediated Platelet Aggregation, Pyroptosis and Apoptosis

Nanodiamond (ND) has been developed as a carrier to conduct various in vivo diagnostic and therapeutic uses. Safety is one of the major considerations, while the hemocompatibility of ND is not clearly addressed. Here we found that, compared to the other sizes of ND with relatively inert properties, treatments of 50 nm ND induced stronger platelet aggregation, platelet pyroptosis, apoptosis and thrombocytopenia in mice. Blockage treatments of soluble P-selectin, reactive oxygen species (ROS), and Nlrp3 inflammasome inhibitors markedly suppressed such adverse effects, suggesting ND-induced platelet activation and pyroptosis involves surface P-selectin-mediated enhancement of mitochondrial superoxide levels and Nlrp3 inflammasome activation. In addition, challenges of NDs induced less platelet pyroptosis and displayed less thrombocytopenia in P-selectin (Selp^-/-), Nlrp3 (Nlrp3^-/-) and caspase-1 (Casp1^-/-) mutants, as compared to the wild type mice. Blockers of P-selectin, ROS, and Nlrp3 inflammasome pathways could be considered as antidotes for ND induced platelet activation and thrombocytopenia.

Multiple subcellular localizations and functions of protein kinase Cδ in liver cancer

Protein kinase Cδ (PKCδ) is a member of the PKC family, and its implications have been reported in various biological and cancerous processes, including cell proliferation, cell death, tumor suppression, and tumor progression. In liver cancer cells, accumulating reports show the bi-functional regulation of PKCδ in cell death and survival. PKCδ function is defined by various factors, such as phosphorylation, catalytic domain cleavage, and subcellular localization. PKCδ has multiple intracellular distribution patterns, ranging from the cytosol to the nucleus. We recently found a unique extracellular localization of PKCδ in liver cancer and its growth factor-like function in liver cancer cells. In this review, we first discuss the structural features of PKCδ and then focus on the functional diversity of PKCδ based on its subcellular localization, such as the nucleus, cell surface, and extracellular space. These findings improve our knowledge of PKCδ involvement in the progression of liver cancer.

Activating Transcription Factor 3 Protects against Restraint Stress-Induced Gastrointestinal Injury in Mice

Psychological stress increases the risk of gastrointestinal (GI) tract diseases, which involve bidirectional communication of the GI and nerves systems. Acute stress leads to GI ulcers; however, the mechanism of the native cellular protection pathway, which safeguards tissue integrality and maintains GI homeostasis, remains to be investigated. In a mouse model of this study, restraint stress induced GI leakage, abnormal tight junction protein expression, and cell death of gut epithelial cells. The expression of activating transcription factor 3 (ATF3), a stress-responsive transcription factor, is upregulated in the GI tissues of stressed animals. ATF3-deficient mice displayed an exacerbated phenotype of GI injuries. These results suggested that, in response to stress, ATF3 is part of the native cellular protective pathway in the GI system, which could be a molecular target for managing psychological stress-induced GI tract diseases.

RKIP Pleiotropic Activities in Cancer and Inflammatory Diseases: Role in Immunity

Simple Summary

The human body consists of tissues and organs formed by cells. In each cell there is a switch that allows the cell to divide or not. In contrast, cancer cells have their switch on which allow them to divide and invade other sites leading to death. Over two decades ago, Doctor Kam Yeung, University of Toledo, Ohio, has identified a factor (RKIP) that is responsible for the on/off switch which functions normally in healthy tissues but is inactive or absent in cancers. Since this early discovery, many additional properties have been ascribed to RKIP including its role in inhibiting cancer metastasis and resistance to therapeutics and its role in modulating the normal immune response. This review describes all of the above functions of RKIP and suggesting therapeutics to induce RKIP in cancers to inhibit their growth and metastases as well as inhibit its activity to treat non-cancerous inflammatory diseases.

Abstract

Several gene products play pivotal roles in the induction of inflammation and the progression of cancer. The Raf kinase inhibitory protein (RKIP) is a cytosolic protein that exerts pleiotropic activities in such conditions, and thus regulates oncogenesis and immune-mediated diseases through its deregulation. Herein, we review the general properties of RKIP, including its: (i) molecular structure; (ii) involvement in various cell signaling pathways (i.e., inhibition of the Raf/MEK/ERK pathway; the NF-kB pathway; GRK-2 or the STAT-3 pathway; as well as regulation of the GSK3Beta signaling; and the spindle checkpoints); (iii) regulation of RKIP expression; (iv) expression’s effects on oncogenesis; (v) role in the regulation of the immune system to diseases (i.e., RKIP regulation of T cell functions; the secretion of cytokines and immune mediators, apoptosis, immune check point inhibitors and RKIP involvement in inflammatory diseases); and (vi) bioinformatic analysis between normal and malignant tissues, as well as across various immune-related cells. Overall, the regulation of RKIP in different cancers and inflammatory diseases suggest that it can be used as a potential therapeutic target in the treatment of these diseases.

Identification of the function and regulatory network of circ_009773 in DNA damage induced by nanoparticles of neodymium oxide

The health hazards of nanoparticles of neodymium oxide (NPs-Nd₂O₃) have aroused public concern in recent years. Exposure to NPs-Nd₂O₃ can change the level of reactive oxygen species (ROS) that cause DNA damage and alter whole transcriptome expression profiles for micro (mi)RNA, circular (circ)RNA, long noncoding (lnc)RNA, and mRNA. However, there have been no reports to our knowledge about the role of circRNAs in DNA damage caused by NPs-Nd₂O₃. In our study, we analyzed the circRNA expression profile of human bronchial epithelial cells(16HBE)exposed to 40 μg/ml NPs-Nd₂O₃. Our results indicated that exposure produced 1025 up-regulated and 890 down-regulated circRNAs. Real-time quantitative polymerase chain reaction (qRT-PCR) was applied to verify some of the significantly changed circRNAs and demonstrated that circ_009773 was apparently down-regulated. Through exploration of its host gene function, we found that circ_009773 may be related to DNA damage. Functional experiments found that circ_009773 regulated NPs-Nd₂O₃-induced DNA damage in 16HBE cells. A circ_009773-associated competing endogenous (ce)RNA network was constructed based on one differentially expressed (DE) circRNA, 74 DE miRNAs and 208 DE mRNAs. Module analysis identified hub genes related to DNA damage and repair and a protein-protein interaction (PPI) network was created.

Regulation on tumor metastasis by Raf kinase inhibitory protein: New insight with reactive oxygen species signaling

Targeted therapy aiming at the metastatic signal pathway, such as that triggered by receptor tyrosine kinase (RTK), for the prevention of tumor progression is promising. However, RTK-based targeted therapy frequently suffered from drug resistance due to the co-expression of multiple growth factor receptors that may raise compensatory secondary signaling and acquired mutations after treatment. One alternative strategy is to manipulate the common negative regulators of the RTK signaling. Among them, Raf kinase inhibitory protein (RKIP) is highlighted and focused on this review. RKIP can associate with Raf-1, thus suppressing the downstream mitogen-activated protein kinase (MAPK) cascade. RKIP also negatively regulates other metastatic signal molecules including NF-κB, STAT3, and NOTCH1. In general, RKIP achieves this task via associating and blocking the activity of the critical molecules on upstream of the aforementioned pathways. One novel RKIP-related signaling involves reactive oxygen species (ROS). In our recent report, we found that PKCδ-mediated ROS generation may interfere with the association of RKIP with heat shock protein 60 (HSP60)/MAPK complex via oxidation of HSP60 triggered by the tumor promoter 12-O-tetradecanoyl-phorbol-13-acetate. The departure of RKIP may impact the downstream MAPK in two aspects. One is to trigger the Mt→cytosol translocation of HSP60 coupled with MAPKs. The other is to change the conformation of HSP60, favoring more efficient activation of the associated MAPK by upstream kinases in cytosol. It is worthy of investigating whether various RTKs capable of generating ROS can drive metastatic signaling via affecting RKIP in the same manner.

HSP60 Regulates Lipid Metabolism in Human Ovarian Cancer

Accumulating evidence demonstrates that cancer is an oxidative stress-related disease, and oxidative stress is closely linked with heat shock proteins (HSPs). Lipid oxidative stress is derived from lipid metabolism dysregulation that is closely associated with the development and progression of malignancies. This study sought to investigate regulatory roles of HSPs in fatty acid metabolism abnormality in ovarian cancer. Pathway network analysis of 5115 mitochondrial expressed proteins in ovarian cancer revealed various lipid metabolism pathway alterations, including fatty acid degradation, fatty acid metabolism, butanoate metabolism, and propanoate metabolism. HSP60 regulated the expressions of lipid metabolism proteins in these lipid metabolism pathways, including ADH5, ECHS1, EHHADH, HIBCH, SREBP1, ACC1, and ALDH2. Further, interfering HSP60 expression inhibited migration, proliferation, and cell cycle and induced apoptosis of ovarian cancer cells in vitro. In addition, mitochondrial phosphoproteomics and immunoprecipitation-western blot experiments identified and confirmed that phosphorylation occurred at residue Ser70 in protein HSP60, which might regulate protein folding of ALDH2 and ACADS in ovarian cancers. These findings clearly demonstrated that lipid metabolism abnormality occurred in oxidative stress-related ovarian cancer and that HSP60 and its phosphorylation might regulate this lipid metabolism abnormality in ovarian cancer. It opens a novel vision in the lipid metabolism reprogramming in human ovarian cancer.

PKCδ/MAPKs and NF-κB Pathways are Involved in the Regulation of Ingenane-Type Diterpenoids from Euphorbia neriifolia on Macrophage Function

PURPOSE

Euphorbia neriifolia Linn. has important medicinal value in the treatment of ulcers, tumors, inflammation, chronic respiratory troubles, and so on. Although many ingredients with anti-inflammatory activity have been discovered and isolated from the Euphorbia neriifolia, the current research still cannot explain its multivariate effects on the immune response. This article aims to introduce two Ingenane-type diterpenoids from Euphorbia neriifolia with macrophage regulatory effects and to investigate the mechanism of their action.

METHODS

The stem bark of E. neriifolia was extracted with various separation methods to obtain ingenane-type diterpenoids. The RAW264.7 cells were treated with lipopolysaccharide (LPS, 1 μg/mL) to establish an inflammatory cell model. The cell viability was detected by MTT assay. The secretion of PGE2, TNF-α, IL-1β, and IL-6 was tested with ELISA. The levels of iNOS, COX-2, IκBα, JNK, ERK, p38, p-IκBα, p-JNK, p-ERK, and p-p38 in cells were detected by Western blotting. The translocation of nuclear factor-kappa B (NF-κB)/p65 subunit were evaluated by Immunofluorescence staining.

RESULTS

Ingenane-type diterpenoids, eurifoloid A (Euri A) and a new compound euphorneroid E (Euph E), were isolated from the EtOAc fraction of E. neriifolia stem bark extracts. Euph E and Euri A exhibited significant inhibition on the levels of pro-inflammatory mediators NO, IL-1β, IL-6, and iNOS on LPS-induced macrophage RAW264.7. Cellular signaling pathway studies showed that they prevented the degradation of IκBα and the translocation of NF-κB/p65 subunit. Furthermore, the production of PGE2, TNFα, and COX-2 was dramatically increased under the influence of the compounds, which were closely related to the phosphorylation of protein kinase C δ (PKCδ) and activation of mitogen-activated protein kinase (MAPKs) signaling pathway.

CONCLUSION

These results demonstrated that Euph E and Euri A exhibited multidirectional regulation on cytokines and immune function of macrophages, in addition to a good anti-inflammatory activity, and which was closely related to the regulation of PKCδ/MAPKs and NF-κB signal pathways.

Dengue Virus Envelope Protein Domain III Induces Nlrp3 Inflammasome-Dependent NETosis-Mediated Inflammation in Mice

Abnormal immune responses and cytokine storm are involved in the development of severe dengue, a life-threatening disease with high mortality. Dengue virus-induced neutrophil NETosis response is associated with cytokine storm; while the role of viral factors on the elicitation of excessive inflammation mains unclear. Here we found that treatments of dengue virus envelope protein domain III (EIII), cellular binding moiety of virion, is sufficient to induce neutrophil NETosis processes in vitro and in vivo. Challenges of EIII in inflammasome Nlrp3-/- and Casp1-/- mutant mice resulted in less inflammation and NETosis responses, as compared to the wild type controls. Blockages of EIII-neutrophil interaction using cell-binding competitive inhibitor or selective Nlrp3 inflammasome inhibitors OLT1177 and Z-WHED-FMK can suppress EIII-induced NETosis response. These results collectively suggest that Nlrp3 inflammsome is a molecular target for treating dengue-elicited inflammatory pathogenesis.

Exposure to Dengue Envelope Protein Domain III Induces Nlrp3 Inflammasome-Dependent Endothelial Dysfunction and Hemorrhage in Mice

Typically occurring during secondary dengue virus (DENV) infections, dengue hemorrhagic fever (DHF) causes abnormal immune responses, as well as endothelial vascular dysfunction, for which the responsible viral factor remains unclear. During peak viremia, the plasma levels of virion-associated envelope protein domain III (EIII) increases to a point at which cell death is sufficiently induced in megakaryocytes in vitro. Thus, EIII may constitute a virulence factor for endothelial damage. In this study, we examined endothelial cell death induced by treatment with DENV and EIII in vitro. Notably, pyroptosis, the major type of endothelial cell death observed, was attenuated through treatment with Nlrp3 inflammasome inhibitors. EIII injection effectively induced endothelial abnormalities, and sequential injection of EIII and DENV-NS1 autoantibodies induced further vascular damage, liver dysfunction, thrombocytopenia, and hemorrhage, which are typical manifestations in DHF. Under the same treatments, pathophysiological changes in the Nlrp3 inflammasome–deficient mice were notably reduced compared with those in the wild-type mice. These results suggest that the Nlrp3 inflammasome constitutes a potential therapeutic target for treating DENV-induced hemorrhage in DHF.