Hepatocyte mitochondrial DNA mediates macrophage immune response in liver injury induced by trichloroethylene

We have previously shown that excessive activation of macrophage proinflammatory activity plays a key role in TCE-induced immune liver injury, but the mechanism of polarization is unclear. Recent studies have shown that TLR9 activation plays an important regulatory role in macrophage polarization. In the present study, we demonstrated that elevated levels of oxidative stress in hepatocytes mediate the release of mtDNA into the bloodstream, leading to the activation of TLR9 in macrophages to regulate macrophage polarization. In vivo experiments revealed that pretreatment with SS-31, a mitochondria-targeting antioxidant peptide, reduced the level of oxidative stress in hepatocytes, leading to a decrease in mtDNA release. Importantly, SS-31 pretreatment inhibited TLR9 activation in macrophages, suggesting that hepatocyte mtDNA may activate TLR9 in macrophages. Further studies revealed that pharmacological inhibition of TLR9 by ODN2088 partially blocked macrophage activation, suggesting that the level of macrophage activation is dependent on TLR9 activation. In vitro experiments involving the extraction of mtDNA from TCE-sensitized mice treated with RAW264.7 cells further confirmed that hepatocyte mtDNA can activate TLR9 in mouse peritoneal macrophages, leading to macrophage polarization. In summary, our study comprehensively confirmed that TLR9 activation in macrophages is dependent on mtDNA released by elevated levels of oxidative stress in hepatocytes and that TLR9 activation in macrophages plays a key role in regulating macrophage polarization. These findings reveal the mechanism of macrophage activation in TCE-induced immune liver injury and provide new perspectives and therapeutic targets for the treatment of OMDT-induced immune liver injury.

The role of Kupffer cell activation in immune liver damage induced by trichloroethylene associated with the IFN-γ/STAT1 signaling pathway

Trichloroethylene (TCE) is a metal detergent commonly used in industry that can enter the human body through the respiratory tract and skin, causing occupational medicamentosa-like dermatitis due to TCE (OMDT) and multiple organ damage, including liver failure. However, the pathogenesis of liver injury remains unclear. Kupffer cells (KCs) are important tissue macrophages in the body because the polarization of KCs plays a crucial role in immune-mediated liver injury. However, the mechanism of KCs polarization in TCE-induced immune liver injury has not been thoroughly elucidated. In this study, we investigated the effect of TCE-induced KCs polarization on liver function and signal transduction pathways using the TCE sensitization model developed by our group. BALB/c mouse skin was exposed to TCE for sensitization, and an increase in the expression of M1 macrophage-specific markers (CD16/CD32, iNOS), M1 macrophage-specific cytokines IL-1β, and IFN-γ, P-JAK-1 and P-STAT1 levels were also found to be dramatically increased. When using low doses of gadolinium trichloride (GdCl₃), the expression of these proteins and mRNA was significantly reduced. This phenomenon indicates that GdCl₃ blocks TCE-induced polarization of KCs and suggests that the IFN-γ/STAT1 signaling pathway may be involved in the polarization process of KCs. These findings clarify the relationship between the polarization of KCs and immune liver injury and highlight the importance of further study of immune-mediated liver injury in TCE-sensitized mice.

[The role of TNF-α/TNFR1 inhibiting autophagy of M1-type Kupffer cells in liver injury in trichloroethylene-sensitized mice]

Objective: To detect the expression levels of M1-type polarization and autophagy-related indicators in the liver of trichloroethylene (TCE) -sensitized mice, and to explore the role of liver tumor necrosis factor-α (TNF-α) and tumor necrosis factor receptor 1 (TNFR1) in regulating M1-type Kupffer cells autophagy in liver injury in TCE-sensitized mice. Methods: In November 2019, according to simple random grouping, 45 SPF grade BALB/c female mice (6-8 weeks old) were divided into 4 groups: blank control group (n=5) , solvent control group (n=5) , TCE treatment group (n=18) , TCE+R7050 (inhibitor) treatment group (n=17) . Transdermally sensitized mice, 24 h after the last challenge, the mice were divided into TCE sensitized group and TCE non-sensitized group according to the skin reaction score. The livers of mice were harvested, and the pathological changes of the livers were observed under light and electron microscopes. Western blotting was used to detect the expressions of TNF-α, TNFR1 and autophagy-related indexes. The expression of inducible nitric oxide synthase (iNOS) , a marker of M1-type Kupffer cells, was detected by immunohistochemistry, and the occurrence of autophagy in M1-type Kupffer cells was detected by immunofluorescence double-labeling method. Results: The sensitization rate of TCE treatment group was 38.9% (7/18) , and TCE+R7050 treatment group was 35.3% (6/17) , with no significant difference between the two groups (P=1.000) . Compared with the blank control group, mice in the TCE sensitized group had abnormal liver ocytes, obvious liver injury, reduced mitochondria and broken endoplasmic reticulum. Western blotting results showed that the expressions of TNF-α and TNFR1 protein in the liver of the mice in the TCE sensitized group increased, the expression of iNOS protein in M1-type Kupffer cells increased, and the expressions of autophagic microtubule-associated protein 1 light-chain 3 (LC3B) and Beclin1 protein were decreased (P<0.05) . The results of immunohistochemistry showed that iNOS was not significantly expressed in the blank control group and solvent control group, and a small amount of expression was found in the TCE non-sensitized group, the positive staining area was obvious in TCE sensitized group, and the expression of iNOS was significantly increased (P<0.05) . Immunofluorescence results showed that the iNOS protein levels in the blank control group, solvent control group and TCE non-sensitized group were lower, and only partially colocalized with P62; the colocalization of iNOS with P62 in the TCE sensitized group was significantly increased. Conclusion: TNF-α/TNFR1 signaling pathway may promote liver injury in TCE-sensitized mice by inhibiting autophagy of M1-type Kupffer cells.

[The role of ROS/TXNIP/NLRP3 pathway in the skin injury of trichloroethylene sensitized mice]

Objective: To explore the mechanism of reactive oxygen species/thioredoxin-interacting protein/nucleotide-binding oligomerization domain-like receptor 3 (ROS/TXNIP/NLRP3) pathway in the skin injury of trichloroethylene (TCE) sensitized mice. Methods: In August 2020, 40 female BALB/c mice were randomly divided into control group (n=5) , solvent control group (n=5) , TCE treatment group (n=15) and TCE+(2-(2, 2, 6, 6-Tetrameyhylpiperidin-1-oxyl-4-ylamino)-2-oxoethyl) triphenylphosphonium chloride (Mito TEMPO) treatment group (n=15) . The TCE sensitization model was established. Mice in the TCE treatment group and TCE+Mito TEMPO treatment group were divided into the sensitized positive group and the sensitized negative group according to the skin erythema and edema reactions on the back of the mice 24 h after the last stimulation. The mice were sacrificed 72 h after the last stimulation, the back skin of the mice was taken, and the skin lesions were observed. Immunohistochemistry (IHC) was used to detect the expression level of NLRP3, and the Western Blot was performed to detect the expression levels of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC) , cysteinyl aspartate specific proteinase 1 (Caspase 1) , Interleukin-1β (IL-1β) and TXNIP proteins in the skin of the mice, the reactive oxygen species (ROS) kit was used to detect the level of intracellular ROS in the back skin tissue. Results: The sensitization rates of TCE treatment group and TCE+Mito TEMPO treatment group were 40.0% (6/15) and 33.3% (5/15) , respectively, and there was no significant difference between the two groups (P>0.05) . The back skin of the mice in the TCE sensitized positive group was thickened and infiltrated by a large number of inflammatory cells. The number of mitochondria in the epidermis cells was significantly reduced, the mitochondrial crest disappeared and vacuolar degeneration occurred. TCE+Mito TEMPO sensitized positive group had less damage, more mitochondria and relatively normal cell structure. Compared with the solvent control group and corresponding sensitized negative groups, the expression levels of NLRP3, ASC, Caspase 1, IL-1β, TXNIP proteins and the content of ROS in the TCE sensitized positive group and TCE+Mito TEMPO sensitized positive group were significantly increased (P<0.05) . Compared with TCE sensitized positive group, the expression levels of NLRP3, ASC, Caspase 1, IL-1β, TXNIP proteins and the content of ROS in the TCE+Mito TEMPO sensitized positive group were significantly decreased (P<0.05) . Conclusion: ROS/TXNIP/NLRP3 pathway was activated and then encouraged the release of IL-1β, finally aggravated the TCE-induced skin injury.

TNF-α/TNFR1 regulates the polarization of Kupffer cells to mediate trichloroethylene-induced liver injury

We have previously shown trichloroethylene (TCE) induced immune liver injury, and TNF-α/TNFR1 pathway as a probably mechanism underlying the immune damage, but the pathogenic mechanism is still unclear. The study aims to investigate whether TNF-α and its receptors regulate Kupffer cell polarization and downstream inflammation signaling pathways during TCE sensitization, to clarify the mechanism of TCE-mediated immune liver injury. 6-8 weeks old SPF BALB/c female mice were used to establish a TCE sensitization model. We found that in the TCE sensitization positive group, liver injury was aggravated, Kupffer cells activated and polarized to M1 type. The expression of M1 Kupffer cell marker proteins CD11c and CD16/32 increased in the TCE positive group, so did TNF-α and TNFR1 in liver. The expression of P-IKK protein, PP65 protein and P-STAT3 protein increased in the TCE sensitization positive group, and the downstream inflammatory factors IL-1β and IL-6 also increased in the TCE sensitization positive group. After using the TNFR1 inhibitor R7050, we found that M1 Kupffer cell polarization, TNF-α expression, signal pathway expression and inflammatory factors IL-1β and IL-6 expression declined, and the liver damage relieved. Briefly, the use of R7050 to inhibit TNF-α/TNFR1 changing the polarization of liver M1 Kupffer cell, thereby inhibiting the activation of related downstream signaling pathways and reducing the secretion of inflammatory factors. TNF-α/TNFR1 regulates the polarization of M1 Kupffer cells inflammatory play an important role in liver immune damage.

[Research progress on the immunological pathogenesis of occupational medicamentosa-like dermatitis due to trichloroethylene]

Occupational exposure to trichloroethylene can induce a series of immune diseases which include systemic rash, multiple system and organ damage, which are defined as occupational medicamentosa-like dermatitis due to trichloroethylene (OMLDT) . This article reviews the research progress of the role of T cell immunity, humoral immunity and complement system in the immunological pathogenesis of OMLDT to provide theoretical basis for the diagnosis and treatment of OMLDT.

[The role of epigenetic effect in the trichloroethylene toxicity]

Trichloroethylene (TCE) is a commonly used organic solvent in industry and it was classified as a Group I carcinogen by IARC, with immunotoxicity, hepatotoxicity, kidney toxicity and neurotoxicity. Increasing evidence suggests that TCE-induced autoimmune diseases and cancer are involved in epigenetic modifications. This paper summarized the mechanism of DNA methylation, histone modification and microRNA in toxicity of TCE according to the newly published articles, so as to provide new ideas for further revealing the mechanism of TCE exposure affecting health.

Identification of Key Genes for Hepatitis Delta Virus-Related Hepatocellular Carcinoma by Bioinformatics Analysis

BACKGROUND

It has been proposed that hepatitis delta virus (HDV) induces hepatic carcinogenesis by distinct molecular events compared with hepatocellular carcinoma (HCC) that is commonly induced by other hepatitis viruses. This study aimed to explore the underlying mechanism by identifying the key genes for HDV-HCC using bioinformatics analysis.

METHODS

The GSE107170 dataset was downloaded and the differentially expressed genes (DEGs) were obtained by the online tool GEO2R. Gene otology (GO) functional analyses and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed using R packages. The protein-protein interaction (PPI) network was constructed by Search Tool for the Retrieval of Interacting Genes/Proteins (STRING). Hub genes were selected by Cytoscape software according to degree algorithm. The hub genes were further validated in terms of expression and survival analysis based on public databases.

RESULTS

A total of 93 commonly upregulated genes and 36 commonly downregulated genes were found. The top 5 upregulated hub genes were TFRC, ACTR2, ARPC1A, ARPC3, and ARPC2. The top 5 downregulated hub genes were CTNNB1, CCND1, CDKN1B, CDK4, and CDKN1A. In the validation analysis, the expressions of ARPC1A, ARPC3, and CDK4 were promoted in general liver cancer samples. Higher expressions of ARPC2 and CDK4 and lower expressions of CDKN1A, CCND1, and CDKN1B were associated with worse prognosis in general HCC patients.

CONCLUSION

The present study identifies a series of key genes that may be involved in the carcinogenesis of HDV-HCC and used as prognostic factors.

[Cathepsin L mediates glomerular endothelial cell injury by cleavaging complement C3 in trichloroethylene-sensitized mice]

Objective: To observe the expressions of complement 3 (C3) and endothelial cell injury-associated proteins before and after cathepsin L (CTSL) blockade in renal injury of trichloroethylene (TCE) -sensitized mice. Methods: In June 2018, 41 SPF female BALB/c mice were divided respectively into blank control group (n=5) , vehicle control group (n=5) , TCE group (n=15) and TCE+CTSLi group (n=16) to establish trichloroethylene-sensitized mice model by pretreating the mice with intraperitoneal injection of CTSL inhibitor (CTSLi) and using TCE for the first and last challenge. According to the skin sensitization score, the mice were divided into positive group and negative group. 72 hours after the last challenge, the renal function indexes of the mice were detected, the pathological changes of mice kidneys were observed, and the glomerular C3 and endothelial cell damage-related proteins [vascular cell adhesion molecule 1 (VCAM-1) , tight junction protein 5 (Claudin-5) and Syndecan-1] expression levels were detected. Results: The sensitization rates of mice in TCE group and TCE+CTSLi group were 53.3% (8/15) and 50.0% (8/16) , respectively, and there was no significant difference between the two groups (P>0.05) . Compared with vehicle control group and the corresponding TCE negative group, the serum creatinine (CRE) and blood urea nitrogen (BUN) levels of mice in the TCE positive group was increased, while the TCE positive group were higher than the TCE+CTSLi positive group (P<0.05) . Pathological examination showed obvious vacuolar degeneration and cellular edema in the mice kidney of the TCE positive group. In the TCE+CTSLi positive group, the above pathological damage was significantly improved. Immunohistochemical results showed that the expression of glomerular C3 fragment and VCAM-1 in TCE positive group were significantly higher than that of the vehicle control and TCE negative group (P<0.05) , while TCE+CTSLi positive group was significantly lower than that of TCE positive group (P<0.05) . Western blot test results showed that the relative expression levels of Claudin-5 and Syndecan-1 protein in the mice glomeruli of TCE positive group were significantly lower than those in the vehicle control group and TCE negative group (P<0.05) . Compared with the TCE positive group, the Claudin-5 protein was increased in the kidney of the TCE+CTSLi positive group, but the difference was not statistically significant (P>0.05) , while the Syndecan-1 protein was significantly increased in the TCE+CTSLi positive group (P<0.05) . Conclusion: CTSL may mediate the glomerular structural damage by cutting complement C3, activating the complement system, damaging endothelial cell structural protein Syndecan-1 and overexpressing adhesion molecule VCAM-1 in TCE-sensitized mice. Inhibiting the expression of CTSL may be an effective way to protect the glomerular integrity of structure and function in pharmacology.

Cauliflower-shaped lesions on a young woman's vulva

A 20-year-old young woman with cauliflower-shaped lesions on her vulva was misdiagnosed as condyloma acuminatum. Further evaluation revealed positive serological tests for syphilis. On histological examination, and numerous plasma cells were seen to infiltrate the dermis heavily. The cauliflower-shaped lesions on vulva completely disappeared after benzathine penicillin treatment. Cauliflower-shaped lesions are a rare manifestation of secondary syphilis.

Kupffer cell inactivation ameliorates immune liver injury via TNF-α/TNFR1 signal pathway in trichloroethylene sensitized mice

METHODS

36 female BALB/c mice were selected and randomly divided the mice into four groups. We established a BALB/c mouse model of TCE sensitization and pretreatment with GdCl3 (40 mg/kg) by intraperitoneal injection during the during the 17th and 19th days.

RESULTS

We found F4/80, the marker of Kupffer cell, was increased in TCE positive group. GdCl3 treatment successfully blocked the activation of Kupffer cell. TNF-α was increased significantly in liver of TCE sensitized mice and decreased significantly when low-dose GdCl3 was used. We found TNF receptor 1 (TNFR1) was increased significantly and GdCl3 treatment resumed the expression of TNFR1 to normal level, as well as the F4/80, TNF-α and TNFR1 mRNA. We also found both caspase-8 and caspase-3 increased in TCE positive group and decreased in TCE + GdCl3 positive group. The number of apoptotic cells in TCE sensitized mice increased by TUNEL staining, and GdCl3 treatment alleviated this increase. Some cells showed edema and inflammatory cell aggregation in liver of TCE positive group, while in the TCE + GdCl3 positive group, the cytoplasm became loose and vacuole-like degeneration occurred.

CONCLUSION

Our study unveils cross-talk between Kupffer cell activation and TNFR1 which mediate apoptosis in liver of TCE sensitized mice.

Kupffer cell depletion attenuates IL-6/STAT3 mediates hepatocyte apoptosis in immunological liver injury of trichloroethylene sensitized mice

Trichloroethylene (TCE) induced TCE hypersensitivity syndrome which makes immune injuries in multi-system. The multiple organ damage included skin, liver, kidney and so on. The main manifestations of liver injuries were apoptosis and edema of hepatocytes. In our previous research, we found the activation of Kupffer cells (KCs) which increased IL-6 can aggravate liver cell apoptosis in TCE sensitized mice. However, the mechanism of IL-6 in liver damages induced by TCE was not clear. This study explored the function of IL-6/STAT3 signal pathway on the TCE induced apoptosis of liver cell. We established a TCE sensitized BALB/c mouse model with a KCs inhibitor GdCl₃, we found that the expressions of ALT and AST in TCE sensitization positive mice were higher than other mice, and the expressions of apoptosis-related proteins were up-regulated in TCE sensitization positive mice, GdCl₃ could alleviate this process. Meanwhile, GdCl₃ could significantly decrease the expressions of IL-6/STAT3 proteins. All in all, the activation of KCs can increase the expression of IL-6, IL-6R and phosphorylate STAT3, induces hepatocyte apoptosis, and participates in immunity damage of liver which induced by TCE.

[Effect of complement C5a on the expression of MCP-1 and NGAL in immune kidney injury of trichloroethylene sensitized mice]

Objective: To explore the possible role of C5a in the pathogenesis of renal injury in TCE- sensitized mice, to analyze the impact of expression of neutrophil gelatinase-associated lipocalin (NGAL) and monocyte chemotactic protein-1 (MCP-1) in the presence or absence of C5a receptor antagonist (C5aRA) pretreatment. Methods: A total of 50 female specific pathogens free(SPF) BALB/c mice were randomly divided into blank control group (n=5) , solvent control group (n=5) , TCE group (n=20) , and TCE+C5aRA group (n= 20) . After one week for adaptive feeding, a mouse model of TCE-induced skin sensitization was established by treating with 50% TCE and 30% TCE in turn. The mice in solvent control group accept same reagents without TCE and the mice in blank control group underwent nothing. In TCE +C5aRA group, except for the TCE solution treatment, mice were intraperitoneally injected with 0.5 mg/kg C5aRA solution at the time of challenge. And the skin erythema and edema reaction were scored 24 h after the last challenge. The mice were divided into sensitization positive group and sensitization negative group according to the scoring result. The mice were aseptically sacrificed 72 h after the last challenge to obtain the kidneys. The structural damage of kidney was observed after histopathological staining. The levels of NGAL and MCP-1 mRNA and proteins were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) , respectively. Results: The sensitization rate of mice in TCE group and TCE+C5aRA group was 45.0% (9/20) and 40.0% (8/20) , respectively. No skin lesions was found in the mice of blank control group and solvent control group. The results of histopathological staining showed that the TCE sensitization positive mice showed renal tubular dilatation, vacuolar degeneration of renal tubular epithelial cells, and infiltration of interstitial cells. The pathological damage of the kidney in TCE sensitization positive group was mild, and no inflammatory cell infiltration was seen. The data of qRT-PCR showed that the expression levels of NGAL and MCP-1 mRNA in the TCE sensitization positive group were significantly increased than in solvent control group and TCE sensitization negative group (P<0.05) , while the levels of NGAL and MCP-1 mRNA in TCE+C5aRA sensitization positive group were decreased than TCE sensitization positive group (P <0.05) . The results of IHC showed that the expression levels of NGAL and MCP-1 in TCE protein sensitization positive group were significantly higher than those in solvent control group and TCE sensitization negative group (P<0.05) . After C5aRA pretreatment, the expression levels of NGAL and MCP-1 protein were decreased than the mice in TCE sensitization positive group (P<0.05) . Conclusion: The regulation of C5a on the expression of MCP-1 and NGAL may participate in TCE- induced mice kidney damage, and pharmacological inhibition of C5a seems to be an effective way to protect the kidney injury in TCE-sensitized mice.

Inflammatory kidney injury in trichloroethylene hypersensitivity syndrome mice: Possible role of C3a receptor in the accumulation of Th17 phenotype

Trichloroethylene (TCE) is a common organic solvent which can cause TCE hypersensitivity syndrome (THS) in exposure workers. THS is an adverse skin disorder with severe inflammatory kidney damage. Complement C3a receptor (C3aR) acts as a specific receptor for the key complement cleavage product C3a and involves multiple inflammatory responses, but the role of C3aR in TCE induced kidney inflammatory injury remains unknown. In this study, BALB/c mouse model of skin sensitization induced by TCE was set up in the presence or absence of C3aR antagonist (C3aRA). Kidney pathology and renal function, expression of inflammatory mediators and C3aR, changes in Th17 cell numbers, and activation of signal transducer and activator of transcription 3 (STAT3) in the kidney were examined. TCE sensitization produced histopathological and functional damage to the kidney, accompanied by increased levels of interleukin (IL-) 1β, IL-6, and IL-23. Local accumulation of Th17 cells and enhanced phosphorylation of STAT3 were also seen in the impaired kidney in TCE sensitization-positive mice. C3aR was mainly located in the impaired glomerulus and upregulated in TCE sensitization-positive mice. C3aRA pretreatment alleviated the structural and functional kidney damage and the inflammatory cytokine and Th17 responses by TCE sensitization, and specifically reduced the phosphorylation of STAT3. Together, our results demonstrate that C3aR signaling promotes the inflammatory responses and regulates the accumulation of Th17 phenotype via phosphorylation of STAT3 in TCE sensitization induced inflammatory kidney damage. C3aR may serve as a potential therapeutic target in TCE sensitization mediated kidney injury.

Terminal complement complex C5b-9 reduced megalin and cubilin-mediated tubule proteins uptake in a mouse model of trichloroethylene hypersensitivity syndrome

Trichloroethylene (TCE), a commonly used industrial solvent and degreasing agent, is known to cause trichloroethylene hypersensitivity syndrome (THS) with multi-system damage, including skin, liver and kidney. Clinical evidence have shown that the kidney injury occurs in THS and our previous studies suggested that the terminal complement complex C5b-9 deposited in impaired renal tubules induced by TCE with unclear mechanisms. In the present study, we questioned whether activation of the complement system with renal deposition of C5b-9 contributes to TCE-induced kidney injury in THS. We established a BALB/c mouse model of TCE sensitization with or without pretreatment of exogenous CD59, a C5b-9 inhibitory protein. H&E staining, PAS staining, and biochemical detection of urinary proteins were performed to assess renal function. Deposition of C5b-9 and expression of CD59 were evaluated by immunohistochemistry. Sub-lytic effects of C5b-9 in tubular epithelial cells were assessed by lactate dehydrogenase (LDH) cytotoxicity assay. Expression of endocytosis receptors megalin and cubilin on proximal tubules were assessed by immunofluorescence and qRT-PCR. We found that TCE sensitization induced structural and functional changes of renal tubules in mice, associated with the deposition of sub-lytic C5b-9 on proximal tubular epithelial cells. TCE sensitization decreased proximal tubule uptake of filtered proteins and renal expression of megalin and cubilin, phenotypes that were attenuated by pretreatment with exogenous CD59. Overall, our findings reveal a novel mechanism underlying sub-lytic C5b-9 acting on megalin and cubilin, contributes to the renal tubules damage by TCE exposure.

Dietary Fat Intake and the Risk of Skin Cancer: A Systematic Review and Meta-Analysis of Observational Studies

We conducted a meta-analysis to evaluate the association between fat intake and the risk of three major types of skin cancer including basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and cutaneous malignant melanoma (CMM). A comprehensive search of PubMed and EMBASE was performed to identify all relevant observational studies published up to December 1, 2018. Specific odds ratio (OR) or relative risk (RR) estimates for the highest versus the lowest intake of dietary fat and 95% confidence intervals (CI) from the included studies were pooled using random effect model. Three prospective cohort studies (175,675 participants and 30,915 BCC cases, 4,106 SCC cases and 1,638 CMM cases) and nine case-control studies (328 BCC cases, 493 SCC cases, 1,547 CMM cases and 2,660 controls) were identified. The pooled results indicated that dietary consumption of total fat and saturated fat were not associated with three major types of skin cancer. High consumption of monounsaturated fat was significantly associated with a decreased risk of BCC (RR: 0.90, 95% CI: 0.85-0.96) and high level of polyunsaturated fat intake was potentially positively associated with SCC (RR: 1.19, 95% CI: 1.06-1.33). Our findings should be confirmed by further evidence from well-designed and large-scale prospective cohort studies.

Complement regulatory protein CD59a plays a protective role in immune liver injury of trichloroethylene-sensitized BALB/c mice

Trichloroethylene (TCE) is a major occupational and environmental chemical compound which causes occupational dermatitis medicamentosa-like of TCE with severe liver damage. Our previous studies showed that complement activation was a newly recognized mechanism for TCE-induced liver damage. The objective of this study was to explore the role of the key complement regulatory protein, CD59a, in TCE-induced immune liver injury. We firstly evaluated the changes of CD59a expression in liver tissue and then investigated if the changes were associated with membrane attack complex (MAC) formation, nuclear factor kappa B (NF-κB) activation and liver damage in BALB/c mice model of TCE-induced skin sensitization in the absence or presence of soluble recombinant rat CD59-Cys. The results showed that low expression of CD59a accompanied by MAC deposition in the liver of TCE-sensitized BALB/c mice, which was consistent in time. In addition, activation of NF-κB pathway, upregulation of inflammatory cytokine and liver damage also occured. Additional experiment showed that recombinant rat sCD59-Cys alleviated inflammation and liver damage in TCE-sensitized BALB/c mice. Moreover, recombinant rat sCD59-Cys reduced MAC formation and inhibited NF-κB activation measured by P-IκBα and nuclear NF-κB p65 in the liver of TCE-sensitized BALB/c mice. In conclusion, recombinant rat sCD59-Cys plays a protective role in immune liver injury of TCE-sensitized BALB/c mice.

Viral mimic polyinosine-polycytidylic acid potentiates liver injury in trichloroethylene-sensitized mice - Viral-chemical interaction as a novel mechanism

Occupational trichloroethylene (TCE) exposure can induce hypersensitivity dermatitis and severe liver injury. Recently, several clinical investigations indicate that viral infection, such as human herpesvirus-6, is associated with hepatic dysfunction in patients with TCE-related generalized skin disorders. However, whether viral infection potentiates TCE-induced liver injury remains unknown. This study aimed to explore the contribution of viral infection to the development of TCE-sensitization-induced liver injury in BALB/c mice. Female BALB/c mice were randomly assigned into four groups: solvent control group (n = 20), TCE group (n = 80), poly(I:C) group (n = 20) and combination of TCE and poly(I:C) (poly(I:C)+TCE) group (n = 80). Poly(I:C) (50 μg) was i.p. administrated. TCE and poly(I:C)+TCE groups were further divided into sensitization and non-sensitization subgroup. Complement 3 and C3a protein levels, and complement factors were measured. Combination treatment significantly enhanced TCE-induced liver injury, decreased complement 3, but increased C3a in serum and liver tissues in sensitization group. These changes were not correlated with the hepatic complement 3 transcription. Moreover, combination treatment specifically promoted complement factor B, but not factor D and factor H expressions. These data provide first evidence that poly(I:C) potentiates liver injury in BALB/c mouse model of TCE-sensitization. Upregulated C3a and factor B contributes to the poly(I:C) action in TCE-induced liver injury. This new mode of action may explain increased risk of chemical-sensitization induced tissue damage by viral infection.

Extra green light induced ZnO ultraviolet lasing enhancement assisted by Au surface plasmons

We observed the dramatic enhancement of the intrinsic spontaneous and stimulated emission as well as the ensuing suppression of defect-related green emission in Au-decorated ZnO microrods. A series of spectral experiments and theoretical analysis demonstrated an electron transfer assisted process by surface plasmon (SP) resonant coupling between the Au nanoparticles and ZnO. The mechanism indicates an approach to enhance the UV emission of ZnO through an extra excitation of visible light similar to that for the defect emission of ZnO. Based on the coupling mechanism, the externally enhanced ultraviolet lasing was further improved from 1.5 to 2.8-fold by adjusting the pumping power of the green light intensity in the Au/ZnO hybrid cavity. This research not only further confirms the SPR-assisted electron transfer process but also offers an approach to improve the intrinsic UV emission even for heavily-defected ZnO through visible light excitation via a nonlinear process.

The immune response in trichloroethylene hypersensitivity syndrome: A review

Trichloroethylene (TCE) has been used for a variety of industrial and consumer cleaning purposes because of its ability to dissolve organic substances. The multisystem injuries include those of skin, liver, and kidney, which are defined as TCE hypersensitivity syndrome (THS). THS is a serious occupational health issue. However, the mechanism of immune dysfunction leading to organ injury is poorly understood. Many studies reveal that skin lesions and organ injury caused by TCE are consistent with type IV hypersensitivity, also called delayed hypersensitivity, mediated by T cells. However, many researchers found T cell-mediated type IV hypersensitivity could not account for the pathogenesis of THS fully. Humoral immunity, including immunoglobulins and complement activation, may also play a possible role in THS pathogenesis. This review will describe the history, current understanding, and future research directions of the mechanism of THS.

[Role of complement regulatory protein CD55 in the liver immune injury of trichloroethylene-sensitized mice]

Objective: To explore the expression of CD55 in liver tissue of trichloroethylene-sensitized mice and discuss the role of CD55 in the liver immune injury of trichloroethylene-sensitized mice. Methods: 6-8 weeks specific pathogen free female BALB/c were randomly divided into blank control group, solvent control group and TCE treatment group to establish BALB/c mice sensitized model. According to mouse skin sensitization reaction score, TCE treatment mice were divided into sensitized and non-sensitized group at 24 h after the last challenge. At 48 h after the last challenge, the blood and aseptic livers were collected. The level of serum ALT was tested by automatic biochemical analyzer and pathology of the liver was observed. C5b-9 deposition was studied by immunohistochemistry (IHC) . CD55 protein expression level in liver tissue was studied by immunohistochemistry and Western blotting. The expression of CD55 mRNA in liver tissue was detected by qRT-PCR. Results: Liver function test result showed level of serum ALT in TCE sensitized group was significantly higher than solvent control group and TCE non-sensitized group (P<0.05) . There was ballooning degeneration and necrosis of liver cells in TCE sensitized group. IHC demonstrated that TCE sensitized group had obviously increased content of C5b-9 but had reduced content of CD55 compared with solvent control group and TCE non-sensitized group (P<0.05) . Western blotting also showed that TCE sensitized group had lower expression of CD55 than solvent control group and TCE non-sensitized group (P<0.05) . qRT-PCR showed that CD55 mRNA expression level in liver tissue of TCE sensitized group was apparently lower than solvent control group and TCE non-sensitized group (P<0.05) . Conclusion: Complement activation may be involved in TCE-induced liver injury, and the expression change of complement regulatory protein CD55 may play essential role in the process.

[The effect of complement C3a receptor antagonist in the kidney immune injury in trichloroethylene-sensitized mice]

Objective: To explore the effect of complement C3 a-C3a receptor in the kidney immune inju-ry in trichloroethylene-sensitized mice by using C3a receptor specific antagonist C3aRA and discuss the patho-genesis of kidney injury in occupational dermatitis medicamentosa-like of trichloroethylene (ODMLT) . Methods: 42 female 6~8 weeks old BALB/c mice of specific pathogen free were randomly divided into blank control group (5) , solvent control group (5) , TCE treatment group (16) and TCE+C3aRA treatment group (16) . The TCE treat-ment group and TCE+C3aRA treatment group were further divided into the sensitized group and the non-sensi-tized group according to the skin sensitization test score. Renal function was detected by biochemical detection kit; expression of C3aR in kidney tissue was detected by qPCR; expression of IL-1β and TNF-α protein were de-tected by immunohistochemical. Results: Compared with solvent control group and corresponding non-sensitized group, CRE and BUN in TCE sensitized group and TCE + C3aRA sensitized group were significantly increased (P<0.05) . Compared with TCE sensitized group, CRE and BUN in TCE+C3aRA sensitized group were signifi-cantly decreased (P<0.05) . Compared with solvent control group and TCE non-sensitized group, the expression level of C3aR gene in kidney tissue in TCE sensitized group was significantly increased (P<0.05) . There was a large number of IL-1β and TNF-α protein expression in kidney tissue in TCE sensitized group and TCE+C3aRA sensitized group. Compared with the TCE sensitized group, the expression level of IL-1β and TNF-α protein in kidney tissue in TCE+C3aRA sensitized group was significantly decreased (P<0.05) . Conclusion: C3a-C3aR may be involved in the kidney immune injury in TCE sensitized mice, C3aRA has a protective effect on the kid-ney immune injury in TCE sensitized mice.

Plasma Kallikrein-Kinin system mediates immune-mediated renal injury in trichloroethylene-sensitized mice

Trichloroethylene (TCE) is a major environmental pollutant. An immunological response is a newly-recognized mechanism for TCE-induced kidney damage. However, the role of the plasma kallikrein-kinin system (KKS) in immune-mediated kidney injury has never been examined. This study aimed to explore the role of the key components of the KKS, i.e. plasma kallikrein (PK), bradykinin (BK) and its receptors B1R and B2R, in TCE-induced kidney injury. A mouse model of skin sensitization was used to explore the mechanism of injury with or without a PK inhibitor PKSI. Kidney function was evaluated by measuring blood urea nitrogen (BUN) and creatinine (Cr) in conjunction with histopathologic characterization. Plasma BK was determined by ELISA; Renal C5b-9 membrane attack complex was evaluated by immunohistochemistry. Expression of BK and PK in the kidney was detected by immunofluorescence. mRNA and protein levels of B1R and B2R were assessed by real-time qPCR and Western blot. As expected, numerous inflammatory cell infiltration and tubular epithelial cell vacuolar degeneration were observed in TCE-sensitized mice. Moreover, serum BUN and Cr and plasma BK were increased. In addition, deposition of BK, PK and C5b-9 were observed and B1R and B2R mRNA and proteins levels were up-regulated. Pre-treatment with PKSI, a highly selective inhibitor of PK, alleviated TCE-induced renal damage. In addition, PKSI attenuated TCE-induced up-regulation of BK, PK and its receptors and C5b-9. These results provided the first evidence that activation of the KKS contributed to immune-mediated renal injury induced by TCE and also helped to identify the KKS as a potential therapeutic target for mitigating chemical sensitization-induced renal damage.

[Role of kallikrein kinin system activation in kidney injury induced by trichloroethylene sensitized mice]

OBJECTIVE

Through testing the expression of complement C3 fragment C3b and iC3b, C5b-9 as well as indexes of KKS before and after using kallikrein-kinin system inhibitor PKSI-527, observing the relevant between KKS and complement system, we preliminary study on the mechanism how KKS works on the renal injury of sensitized mice model induced by trichloroethylene.

METHODS

Female BALB/c mice (6~8 weeks) were randomly divided into blank control group (5), TCE treated group (15), PKSI-527+TCE treated group (15). Mice were sensitized with TCE in the 1,3,7,10 days, the first and the last challenge were on day 17 and 19. 24h before every challenge, mice in PKSI-527+TCE group were treated with intraperitoneal injection of KKS inhibitor PKSI-527 inhibitor (50mg/kg). Mice were killed 72h after the last challenge. The function of kidney in mice were detected and kidney B1R, B2R expression were detected using real-time quantitative PCR, mice kidney complement C3 fragments C3b, iC3b and C5b-9 deposition were also detected by chemoimmunology.

RESULTS

Compared with blank control group, all indexes expressions in the solvent control group have no significant change. Compared with the solvent control group, BUN、Cr level and B1R、B2R level have an significant increase (P< 0.05) in TCE sensitized group and PKSI-527+TCE sensitized group; There is a sharp decrease in PKSI-527+TCE sensitized group compared to TCE sensitized group(P< 0.05).

CONCLUSION

The renal damage in the TCE sensitization mouse model may aggravated by upregulate complement system followed by the activation of kallikrein-kinin system.

Association of glutathione S-transferase pi (GSTP1) Ile105Val polymorphism with the risk of skin cancer: a meta-analysis

Numerous epidemiological studies have evaluated the association of Glutathione S-transferase P1 (GSTP1) Ile105Val polymorphism with the risk of skin cancer. However, the results remain inconclusive. To derive a more precise estimation of the association between the GSTP1 Ile105Val polymorphism and skin cancer risk, a meta-analysis was performed. A comprehensive search was conducted to identify the eligible studies. We used odds ratios (ORs) with 95 % confidence intervals (CIs) to assess the association of GSTP1 Ile105Val polymorphism with skin cancer risk. Thirteen case-control studies in nine articles, which included a total of 1504 cases and 2243 controls. Overall, we found that GSTP1 Ile105Val polymorphism was not associated with skin cancer risk. Furthermore, subgroup analysis by histological types showed that GSTP1 Ile105Val polymorphism was associated with risks of malignant melanoma under the dominant model (Val/Val + Val/Ile vs. Ile/Ile: OR 1.230, 95 % CI 1.017-1.488, P = 0.033). However, lack of association between GSTP1 Ile105Val polymorphism and BCC and SCC risk in all genetic models. Our meta-analysis suggested that the GSTP1 Ile105Val polymorphism might be associated with increased risk of malignant melanoma in Caucasian population.

Bleomycin-induced epithelial-mesenchymal transition in sclerotic skin of mice: possible role of oxidative stress in the pathogenesis

Epithelial-mesenchymal transition (EMT) derived myofibroblasts are partly responsible for the increased collagen synthesis and deposition that occur in tissue fibrosis; however EMT occurrence in skin fibrosis and its mechanism remain unknown. The aim of this study was to investigate whether epithelial cells undergo EMT and determine the role of oxidative stress in this process. BALB/c mice were subcutaneously injected with bleomycin (BLM) or phosphate buffer saline (PBS) into the shaved back daily for 2, 3, and 4weeks. Skin collagen deposition was evaluated by histopathology and Western blotting. EMT characteristics in the skin were determined by histopathology and immunofluorescent staining for E-cadherin and vimentin, which were further evaluated by Western blotting and reverse transcriptase polymerase chain reaction (RT-PCR). To investigate the role of oxidative stress in EMT, the antioxidant N-acetylcysteine (NAC) was intraperitoneally (100mg/kg body weight/day) injected daily for 3weeks. The epithelial suprabasal cells were detached from the basement membrane zone (BMZ) in the sclerotic skin treated with BLM. Immunofluorescent staining indicated vimentin-positive epithelial cells frequently occurring in the thickened epidermis of BLM-treated mice. Western blotting and RT-PCR showed that the expression of E-cadherin was significantly decreased but that of vimentin significantly increased in the skin treated with BLM. NAC attenuated BLM induced oxidative damage, changes in E-cadherin and vimentin expressions and collagen deposition in the sclerotic skin of mice. This study provides the first evidence that BLM induces the EMT of the epithelial cells superficial to the basement membrane zone in the skin fibrosis. Oxidative stress may contribute, at least in part, to BLM induced EMT and skin fibrosis in mice.

[Effect of trichloroethylene intake via drinking water on Th17 cells in BALB/c mice]

OBJECTIVE

This study aimed to investigate the effect of trichloroethylene (TCE) intake via drinking water on Th17 cells in mice.

METHODS

Forty eight six weeks old female BALB/c mice were divided into blank control, vehicle control, 2.5 mg/ml TCE and 5.0 mg/ml TCE groups by random number table (12 mice each group), and exposed to TCE by drinking water. On the 14(th), 28(th), 56(th), 84(th) days, blood were collected and assayed for IL-17, IL-6, and TGF-β concentration in serum through ELISA. Animals were killed and spleen biopsies were taken sterility. The proportion of Th17 cells among CD4(+) T cells and RORγt mRNA expression level in spleen were measured by FCM and real-time PCR.

RESULTS

In 2.5 mg/ml TCE and 5.0 mg/ml TCE group mice, Th17 cells/CD4(+) T cells in spleen were (3.46 ± 0.32)% and (5.45 ± 0.45)% on day 14, (3.47 ± 0.33)% and (4.10 ± 0.39)% on day 84, which were significantly higher than those for solvent control group at the same time point ((2.15 ± 0.20)%, (2.16 ± 0.35)%, respectively) (P < 0.01). RORγt mRNA expression levels were (1.870 ± 0.084) and (1.965 ± 0.060) on 14 day, (1.998 ± 0.079) and (2.028 ± 0.073) on day 56, which were also significantly higher than those for solvent control group at the same time point (1.77 ± 0.04 and 1.75 ± 0.09, respectively) (P < 0.05). IL-17 concentrations in serum were (32.28 ± 5.38) and (34.47 ± 5.02) pg/ml on day 14, and (34.87 ± 5.48) and (41.94 ± 6.19) pg/ml on day 28, which were significantly higher than those for solvent control group at the same time point((21.57 ± 5.23), (22.11 ± 5.11) pg/ml). IL-6 concentration in serum were (43.07 ± 6.71) and (47.86 ± 8.52) pg/ml on day14, (41.32 ± 7.04) and (46.74 ± 9.33) pg/ml on day 56, which were significantly higher than solvent control group at the same time point ((7.56 ± 7.71) and (28.26 ± 7.22) pg/ml). TGF-β concentration were (17.48 ± 3.06) and (18.93 ± 3.12) pg/ml on day 14, which did not show significant difference from solvent control group ((15.25 ± 2.95) pg/ml). Correlation analysis showed that IL-6 in serum were significantly positively correlated with the proportion of Th17 cells among CD4(+) T cells and RORγt expression level in spleen (r = 0.741, 0.765, P < 0.01).

CONCLUSION

TCE might promote the differentiation of Th17 cells and increase IL-17 secretion by inducing IL-6 and up-regulating RORγt expression together with TGF-β.

Association analyses identify six new psoriasis susceptibility loci in the Chinese population

We extended our previous genome-wide association study for psoriasis with a multistage replication study including 8,312 individuals with psoriasis (cases) and 12,919 controls from China as well as 3,293 cases and 4,188 controls from Germany and the United States and 254 nuclear families from the United States. We identified six new susceptibility loci associated with psoriasis in the Chinese study containing the candidate genes ERAP1, PTTG1, CSMD1, GJB2, SERPINB8 and ZNF816A (combined P < 5 × 10⁻⁸) and replicated one locus, 5q33.1 (TNIP1-ANXA6), previously reported (combined P = 3.8 × 10⁻²¹) in the European studies. Two of these loci showed evidence for association in the German study at ZNF816A and GJB2 with P = 3.6 × 10⁻³ and P = 7.9 × 10⁻³, respectively. ERAP1 and ZNF816A were associated with type 1 (early onset) psoriasis in the Chinese Han population (test for heterogeneity P = 6.5 × 10⁻³ and P = 1.5 × 10⁻³, respectively). Comparisons with the results of previous GWAS of psoriasis highlight the heterogeneity of disease susceptibility between the Chinese and European populations. Our study identifies new genetic susceptibility factors and suggests new biological pathways in psoriasis.

Trichloroethylene induce nitric oxide production and nitric oxide synthase mRNA expression in cultured normal human epidermal keratinocytes

Trichloroethylene (TCE), a major chemical hazard during occupational exposure, can cause obvious skin lesions, including irritant reactions and dermatitis. Nitric oxide (NO) synthesized by nitric oxide synthase (NOS) is involved in a broad array of pathogenesis of skin inflammatory and immune responses. To understand the mechanisms of TCE-induced dermatoxicity, we investigated the effects of TCE on NO production and NOS mRNA expression in cultured normal human epidermal keratinocytes (NHEK). Cells were treated with TCE (0 mM, 0.125 mM, 0.25 mM, 0.5 mM, 1.0 mM, 2.0 mM) for 4 h, and then incubated for 12 h, 24 h, 48 h and 72 h. At each given time point, NO production were evaluated indirectly by measuring nitrite plus nitrate concentration in the culture medium using Griess reaction, as well as cell viability determined by MTT test, iNOS and cNOS activities assayed with a NOS activity detecting kit. The expression of iNOS and cNOS mRNA was detected using RT-PCR. TCE decreases cell viability and enhance NO production from NHEK in concentration- and time-dependent manner. Aminoguanidine (AG), an inhibitor of NOS, can prevent NO production and cell viability decrease in NHEK by TCE induced. Change to NO production was accompanied by increased activities of both types of NOS, but the iNOS activity accounted mainly for the TCE-induced NO production. RT-PCR detection showed that NHEK expressed both iNOS and cNOS mRNA by TCE exposure. Whereas a concentration- and time-dependent up-regulation of the mRNA expression was observed for iNOS and cNOS following TCE exposure, changes to iNOS were more marked. These results suggest that TCE caused increase in NO production, attributed to activation of iNOS as well as cNOS, and expression of iNOS and cNOS mRNA. These cellular changes may contribute to the pathological and physiological features of TCE-induced erythema and skin inflammation.

[Effects of TCE and PCE on cultured human keratinocyte lipid peroxidation and protective effect of vitamin E on it]

OBJECTIVE

To explore the different concentrations of trichloroethylene (TCE) or perchloroethylene (PCE) induced cultured normal human epidermal keratinocyte (KC) lipid peroxidation and protective effect of Vitamin E on it.

METHODS

KC derived from 3 or more donors were pooled together and cultured with K-SFM. Neutral Red Uptake Assay was used to determine the IC50 of TCE or PCE, and then different concentrations of TCE or PCE were administered for culturing KC; 0.5 mmol/L TCE or 0.2 mmol/L PCE and different concentrations of Vitamin E were used to determine the protective effect of Vitamin E. After 4 hours' culture, kits were used to determine cellular MDA, SOD and ROS level.

RESULTS

Treatment of KC with different concentrations of TCE or PCE showed significant dose-related variations in lipid peroxidation, with the higher concentration, higher level of MDA, ROS and lower activity of SOD displayed in this study. Vitamin E 10 - 200 mmol/L dose-dependently attenuated MDA and ROS level, and increased SOD activities.

CONCLUSION

TCE or PCE can induce the lipid peroxidation in cultured KC and Vitamin E protects it from TCE- or PCE-induced peroxidation.

[Relationship of nitric oxide with the apoptosis of keratinocytes]

Nitric oxide (NO) is a kind of free radical, also is a signaling molecule, which universally distributed in the tissues of organism. NO play important role in the dermato-, cardia-, encephalo-, hepat- and immunological regulation on the physio- and patho- situation. Recently studying show that NO can bifunctionally regulate the apoptosis of keratinocytes, which play an important role in the occurrence and development of many skin diseases. However, the regulatory mechanism still can't be completely elucidated at present time. In this review, we are reviewing the recent investigation progress on the apoptosis of keratinocytes and some diseases of skin that related to the regulating disturbance of NO.

The effect of mizolastine on expression of vascular endothelial cell growth factor, tumour necrosis factor-alpha and keratinocyte-derived chemokine in murine mast cells, compared with dexamethasone and loratadine

It has been shown that many antihistamines may have anti-inflammatory activity in addition to being H1 antagonists. Mizolastine (MIZ), a novel antihistamine, might also have anti-angiogenesis properties. In this study, we investigated the influence of MIZ on proangiogenesis factors, vascular endothelial cell growth factor (VEGF), tumour necrosis factor (TNF)-alpha and keratinocyte-derived chemokine (KC) in murine mast cells by using ELISA and RT-PCR, as compared with dexamethasone (DEX) and loratadine (LOR). Our results show that MIZ is effective in the inhibition of KC, VEGF and TNF-alpha release induced by an IgE-dependent mechanism, in a time- and dose-dependent manner. The differences between the inhibitory effects of the three drugs on these proangiogenic factors were rather subtle. Semiquantitative analysis using RT-PCR showed that the three drugs significantly reduced VEGF165, VEGF120, TNF-alpha and KC mRNA expression. Statistical results revealed that the effect of DEX on VEGF165 mRNA was different from that of MIZ or LOR (P < 0.01) and the differences between the three drugs on VEGF120, TNF-alpha and KC mRNA were not statistically significant (P > 0.05). These findings raise the possibility that MIZ can mediate anti-angiogenesis activity and that the effect may depend not only on the inhibition on the levels of cytokine proteins but also at the mRNA level.

Cytotoxicity of trichloroethylene and perchloroethylene on normal human epidermal keratinocytes and protective role of vitamin E

Trichloroethylene (TCE) and perchloroethylene (PERC), the most common alkenyl halides, have been extensively used in industry, and can cause skin damage. To evaluate their cytotoxic potential on skin, the effects of these agents on the normal human epidermal keratinocytes (NHEK) were investigated. Their action on cell viability, membrane integrity and lipid peroxidation (LPO) was assessed by neutral red uptake (NRU) assay, lactate dehydrogenase (LDH) release test and measurement of malondialdehyde (MDA) levels and superoxide dismutase (SOD) activity. In addition, the protective effect of antioxidatant vitamin E on the cytotoxicity was also studied. Incubation of NHEK with various concentrations (0.01-31.6 mM) of TCE or PERC caused a dose-dependent decrease in cell viability, with 80% reduction at 31.6 mM. NR50 values from the cytotoxicity assay was found to be 4.53 and 2.16 mM for TCE and PERC, respectively. A time- and concentration- dependent release of LDH were observed at 1, 2, 3, 4 h after cells were exposed to different doses of TCE or PERC. These agents also caused an increase of MDA, whilst an inhibition of SOD activity, in a concentration-dependent manner. Pre-treatment of the cells with vitamin E at 10-200 mM dose-dependently attenuated the cytotoxic effect of TCE or PERC. Pre-treatment with vitamin E also reversed subsequent TCE or PERC-induced release of LDH, elevation of lipid peroxidation and decline of anti-oxidant enzyme activities. These results suggest that TCE and PERC could induce cytotoxicity to NHEK associated with oxidative stress and antioxidatant vitamin E could effectively protect NHEK from TCE- or PERC-induced cytotoxicity, which may be associated to the superoxide scavenging effect and enhancement of anti-oxidant enzyme activities.

Exposure to acrylonitrile induced DNA strand breakage and sex chromosome aneuploidy in human spermatozoa

To explore acrylonitrile (ACN)-induced DNA strand breakage and sex chromosome aneuploidy in human spermatozoa, semen parameters were examined among 30 acrylonitrile-exposed workers according to WHO laboratory manual for the examination of human sperm. DNA strand breakage of sperm cells was investigated among 30 ACN-exposed workers using single cell gel electrophoresis (SCGE). The frequency of sex chromosome aneuploidy in sperm cells was analyzed among nine ACN-exposed workers using fluorescence in situ hybridization (FISH). The geometrical mean of sperm density was 75 x 10(6)ml(-1) in exposure group, significantly lower than 140 x 10(6)ml(-1) in the control. The geometrical mean of sperm number per ejaculum was 205 x 10(6) in exposure group, significantly lower than 280 x 10(6) in the control. The rates of comet sperm nuclei were 28.7% in exposure group, significantly higher than 15.0% in the control. Mean tail length was 9.8 microm in exposure group, longer than 4.3 microm in the control. The frequency of sex chromosome disomy was 0.69% in exposure group, significantly higher than 0.35% in the control. XY-bearing sperm was the most common sex chromosome disomy, with an average rate of 0.37% in exposure group, and 0.20% in the control. XX- and YY-bearing sperm accounted for an additional 0.09 and 0.23% in exposure group, and 0.05 and 0.10% in the control. The results indicate that ACN affect semen quality among ACN-exposed workers. ACN or its metabolites could induce reproductive defects as an in vivo multipotent genotoxic agent by inducing DNA strand breakage and sex chromosome non-disjunction in spermatogenesis.

The associations among semen quality, oxidative DNA damage in human spermatozoa and concentrations of cadmium, lead and selenium in seminal plasma

To explore the associations among semen quality, oxidative DNA damage in human spermatozoa and concentrations of cadmium, lead and selenium in seminal plasma, 56 non-smoking subjects were asked to collect semen by masturbation into a sterile wide-mouth metal-free plastic container after 3 days of abstinence. The conventional semen parameters were analysed. The concentrations of Cd, Pb and Se in seminal plasma were detected using atomic absorption spectrophotometer. 8-OHdG levels in sperm DNA were measured using HPLC-EC. The results showed that the geometric mean concentrations of Cd, Pb and Se were 0.78, 7.8 and 51.4 microg/l, respectively. The geometric mean of 8-OHdG/10(6) dG was 51.4 (95% CI: 21.5-123.0). A significant inverse correlation exists between Cd and sperm density (r=-0.28, P<0.05), and between Cd and sperm number per ejaculum (r=-0.27, P<0.05). In contrast, there was a significantly positive correlation between Se and sperm density (r=0.50, P<0.01), between Se and sperm number (r=0.49, P<0.01), between Se and sperm motility (r=0.40, P<0.01), and between Se and sperm viability (r=0.38, P<0.01). No statistically significant correlation was observed between Pb and semen quality. A significant inverse correlation was observed between 8-OHdG and sperm density (r=-0.34, P<0.01), between 8-OHdG and sperm number per ejaculum (r=-0.30, P<0.01), and 8-OHdG and sperm viability (r=-0.24, P<0.05). 8-OHdG was significantly correlated with Cd in seminal plasma (r=0.55, P<0.01). A significant but weak positive correlation was found between 8-OHdG and Pb concentration in seminal plasma (r=0.28, P<0.05). In contract, a significant inverse correlation was observed between 8-OHdG and Se concentration in seminal plasma (r=-0.40, P<0.01). The results indicate that Cd in seminal plasma could affect semen quality and oxidative DNA damage in human spermatozoa. Se could protect against oxidative DNA damage in human sperm cells. Pb did not appear to have any association with the semen quality when concentration of Pb in seminal plasma was below 10 microg/l.

Glyceroglycolipids from Serratula strangulata

The rhizomes of Serratula strangulata yielded three glyceroglycolipids, i.e. 1,2-di-O-(9Z,12Z,15Z-octadecatrienoyl)-3-O-(6-amine-6-deoxy-alpha-D-glucosyl)-glycerol, 1,2-di-O-(9Z,12Z,15Z-octadecatrienoyl)-3-O-(6-p-hydroxy-phenyl-propionamido-6-deoxy-alpha-D-glucosyl)-glycerol and 1,2-di-O-(9Z,12Z,15Z-octadecatrienoyl)-3-O-[alpha-D-glucose(1-6)-beta-D-allose]-glycerol, as well as a known sesquiterpene lactone and three known phytoecdysones. Their structures were elucidated on the basis of spectral data, especially by 2D NMR spectroscopic methods and chemical conversion. These compounds exhibited significant antibacterial and antitumor activities.

Eudesmanolides, aromatic derivatives, and other constituents from Carpesium cernuum

A new eudesmanolide 13-hydroxy-4 alpha H-eudesman-5,7(11)-dien-12,8 beta-olide (1) and a new aromatic derivative 3-methyl-8-acetoxy-9,10-diisobutanoyloxy-p-cymene (6), along with ten known compounds were isolated from the roots of Carpesium cernuum L. Their structures were elucidated by spectral methods (IR, EIMS, FAB-MS, 1D and 2D NMR). Compound 2, 3 and compound 10 exhibited moderate antibacterial activity against Bacillus subtilis, Escherichia coli and Staphylococcus aureus.

New antimicrobial mono- and sesquiterpenes from Soroseris hookeriana subsp. erysimoides

A new monoterpene and a new guaianolide were isolated from the aerial parts of the Tibetan medicinal plant Soroseris hookeriana subsp. erysimoides (Asteraceae), in addition to (1R,4R,5R)-5-hydroxybornan-2-one 5-O-beta-D-glucopyranoside, beta-sitosterol, daucosterol, diosmetin, isoluteolin, p-methoxybenzoic acid, isovanillic acid, two phenylmethanol derivatives (vanilioloside and phenylmethanol glucopyranoside), and five guaianolides [3 beta,8 beta-dihyroxyguaia-4(15),10(14),11(13)-triene-12,6 alpha-olide, dentalactone, 10 alpha-hydroxy-8-deoxy-10,14-dihydrodeacylcinaropicrin, glucozaluzanin C and 8-epideacylcinaropicrin glucoside]. By a combination of spectroscopic methods (IR, EI-MS, 1H- and 13C-NMR, and DEPT), the structure of the new guaianolide was established as 3 beta,8 beta-dihydroxy-11 alpha H-guaia-4(15),10(14)-diene-12,6 alpha-olide, and that of the new monoterpene as (1R,4R,5R)-5-benzoyloxybornan-2-one. The antimicrobial activity of all isolates except the two sterols were measured using Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Candida albicans, Aspergillus niger, and Trichophyton rubrum as test microorganisms. The new guaianolide was shown to be equally active (MIC: 50 micrograms/ml) against E. coli, B. subtilis and A. niger. The new monoterpene inhibited exclusively the growth of B. subtilis with MIC at 25 micrograms/ml. p-Methoxybenzoic acid and isovanillic acid were inhibitory against A. niger (MIC: 25 micrograms/ml), the latter being also active against B. subtilis with MIC at 25 micrograms/ml. The flavonoids diosmetin and isoluteolin almost equally inhibited the growth of B. subtilis (MIC: 25 micrograms/ml) and the human pathgenic fungus T. rubrum (MIC: 50 micrograms/ml).

Nor-lignan and sesquiterpenes from Cremanthodium ellisii

A nor-lignan and two sesquiterpenes, along with six known compounds, have been isolated from the medicinal plant Cremanthodium ellisii. Their structures were determined on the basis of spectral evidence, especially 2D NMR (1H-1H COSY, HMQC, HMBC).