Heat Shock Protein HSP70 in Oxidative Stress in Apnea Patients

Forensic application of epidermal expression of HSP27 and HSP70 for the determination of wound vitality in human compressed neck skin

Estimating the age and vitality of human skin wounds is essential in forensic practice, and the use of immunohistochemical parameters in this regard remains a challenge. Heat shock proteins (HSPs) are evolutionarily conserved universal proteins that protect biological systems from various types of stress. However, its importance in forensic pathology for determining wound activation in neck compression skin remains unclear. The expression of HSP27 and HSP70 in neck skin samples was immunohistochemically examined to understand its forensic applicability in determining wound vitality. Skin samples were obtained from 45 cases of neck compression (hanging, 32 cases; strangulation, 10 cases; manual strangulation, 2 cases; other, 1 case) during forensic autopsies; intact skin from the same individual was used as a control. HSP27 expression was detected in 17.4% of keratinocytes in the intact skin samples. In the compressed region, the frequency of HSP27 expression in keratinocytes was 75.8%, which was significantly higher than that in intact skin. Similarly, HSP70 expression was 24.8% in intact skin samples and 81.9% in compressed skin samples, significantly higher in compressed skin than in intact skin samples. This increase in case compression cases may be due to the cell defence role of HSPs. From a forensic pathology perspective, the immunohistochemical examination of HSP27 and HSP70 expression in neck skin could be considered a valuable marker for diagnosing traces of antemortem compression.

Preliminary study of the intranuclear function of Sma and Mad related protein 5 gene in Litopenaeus vannamei

Litopenaeus vannamei Smad5 (LvSmad5) in cytoplasm has been proved to be involved in environmental stress response. As LvSmad5 could also locate in nucleus under specific stress, it was conjectured that LvSmad5 might participate in environmental stress response. While, the experimental evidence is still lacking. In this study, cytosolic LvSmad5 mutant or nuclear LvSmad5 mutant was expressed in Drosophila S2 cells, and then transcriptomic analysis of mentioned cells was performed using Illumina HiSeq based RNA-Seq, to reveal the function of LvSmad5 in nucleus. By comparing the two groups of cDNA libraries from S2 cells with cytosolic or nucleus LvSmad5 mutant, 86 differentially expressed genes as well as 765 differentially expressed transcripts were found. It was revealed that genes in the ER-stress response pathway, such as unfolded protein response and ER-associated degradation (ERAD) were enriched. Additionally, some kinds of metabolic reprogramming occurred in S2 cells with over-expressing nuclear LvSmad5, for significant changes in the expression of some metabolism-related genes. To test our infer that nuclear LvSmad5 was engaged in environmental stress response, homologous gene of Drosophila translocation in renal carcinoma on chromosome 8 in L.vannamei (LvTRC8) was chosen for further investigation. And studies about LvTRC8, a member of ERAD showed that it was induced by ER-stress or heat shock treatment. Suppressed the expression of LvTRC8 increased the cumulative mortality of shrimp upon stress. In some degree, these results support our speculation that nuclear LvSmad5 are involved in the environmental stress response of L. vannamei in fact.

Triflumizole Induces Developmental Toxicity, Liver Damage, Oxidative Stress, Heat Shock Response, Inflammation, and Lipid Synthesis in Zebrafish

Triflumizole (TFZ) toxicity must be investigated in the aquatic environment to understand the potential risks to aquatic species. Accordingly, the adverse effects of TFZ exposure in zebrafish were investigated. Results demonstrate that, after TFZ exposure, the lethal concentration 50 (LC50) in 3 d post-fertilization (dpf) embryos and 6 dpf larvae were 4.872 and 2.580 mg/L, respectively. The development (including pericardium edema, yolk sac retention, and liver degeneration) was apparently affected in 3 dpf embryos. Furthermore, the alanine aminotransferase (ALT) activity, superoxide dismutase (SOD) activity, catalase (CAT) activity, and malondialdehyde (MDA) content in 6 dpf larvae were significantly increased. Additionally, the expression of heat shock response genes (including hsp70, grp78, hsp90, and grp94), inflammatory genes (including p65-nfκb, il-1β, and cox2a), and lipid synthetic genes (including srebp1, fas, acc, and ppar-γ) in 3 dpf embryos was significantly increased, which was also partially observed in the intestinal cell line form Pampus argenteus. Taken together, TFZ could affect the development of zebrafish, accompanied by disturbances of oxidative stress, heat shock response, inflammation, and lipid synthesis. Our findings provide an original insight into the potential risks of TFZ to the aquatic ecosystem.

Transcriptome analysis reveals the early resistance of zebrafish larvae to oxidative stress

Oxidative stress is one of most common environmental stresses encountered by fish, especially during their fragile larval stage. More and more studies are aimed at understanding the antioxidant defense mechanism of fish larvae. Herein we characterized the early resistance of zebrafish larvae to oxidative stress and investigated the underlying transcriptional regulations using RNA-seq. We found that pre-exposure of zebrafish larvae to 2 mM H₂O₂ for 1 or 3 h significantly improved their survival under higher doses of H₂O₂ (3 mM), suggesting the antioxidant defenses of zebrafish larvae were rapidly built under pre-exposure of H₂O₂. Comparative transcriptome analysis showed that 310 (185 up and 125 down) and 512 (331 up and 181 down) differentially expressed genes were generated after 1 and 3 h of pre-exposure, respectively. KEGG enrichment analysis revealed that protein processing in endoplasmic reticulum is a highly enriched pathway; multiple genes (e.g., hsp70.1, hsp70.2, and hsp90aa1.2) encoding heat shock proteins in this pathway were sharply upregulated presumably to correct protein misfolding and maintaining the cellular normal functions during oxidative stress. More importantly, the Keap1/Nrf2 system-mediated detoxification enzyme system was significantly activated, which regulates the upregulation of target genes (e.g., gstp1, gsr, and prdx1) to scavenger reactive oxygen species, thereby defending against apoptosis. In addition, the MAPK, as a transmitter of stress signals, was activated, which may play an important role in activating antioxidant system in the early stages of oxidative stress. Altogether, these findings demonstrate that zebrafish larvae rapidly establish resistance to oxidative stress, and this involves changes in protein processing, stress signal transmission, and the activation of detoxification pathways.

Hypoxia-Induced Intracellular and Extracellular Heat Shock Protein gp96 Increases Paclitaxel-Resistance and Facilitates Immune Evasion in Breast Cancer

BACKGROUNDS

Hypoxia contributes to cancer progression, drug resistance and immune evasion in various cancers, including breast cancer (BC), but the molecular mechanisms have not been fully studied. Thus, the present study aimed to investigate this issue.

METHODS

The paclitaxel-sensitive BC (PS-BC) cells were administered with continuous low-dose paclitaxel treatment to establish paclitaxel-resistant BC (PR-BC) cells. Exosomes were isolated/purified by using the commercial kit, which were observed by Transmission electron microscopy (TEM). Cell viability was measured by MTT assay, cell apoptosis was determined by flow cytometer (FCM). Gene expressions were respectively measured by Real-Time qPCR, Western Blot and immunofluorescence staining assay. The peripheral mononuclear cells (PBMCs) derived CD8⁺ T cells were obtained and co-cultured with gp96-containing exosomes, and cell proliferation was evaluated by EdU assay. ELISA was employed to measure cytokine secretion in CD8⁺ T cells' supernatants.

RESULTS

HSP gp96 was significantly upregulated in the cancer tissues and plasma exosomes collected from BC patients with paclitaxel-resistant properties. Also, continuous low-dose paclitaxel treatment increased gp96 levels in the descendent PR-BC cells and their exosomes, in contrast with the parental PS-BC cells. Upregulation of gp96 increased paclitaxel-resistance in PS-BC cells via degrading p53, while gp96 silence sensitized PR-BC cells to paclitaxel treatments. Moreover, PR-BC derived gp96 exosomes promoted paclitaxel-resistance in PS-BC cells and induced pyroptotic cell death in the CD8⁺ T cells isolated from human peripheral blood mononuclear cells (pPBMCs). Furthermore, we noticed that hypoxia promoted gp96 generation and secretion through upregulating hypoxia-inducible factor 1 (HIF-1), and hypoxia increased paclitaxel-resistance and accelerated epithelial-mesenchymal transition (EMT) in PS-BC cells.

CONCLUSIONS

Hypoxia induced upregulation of intracellular and extracellular gp96, which further degraded p53 to increase paclitaxel-sensitivity in BC cells and activated cell pyroptosis in CD8⁺ T cells to impair immune surveillance.