Forensic Research Progress on Postural Asphyxia.

In recent years, the increase in the number of cases of postural asphyxia has gradually attracted the attention and discussion of forensic scientists domestically and internationally, but a systematic, comprehensive and recognized expert consensus and identification standard has not been established at home and abroad. This paper reviews the case characteristics, occurrence, mechanism of death, and identification criteria of postural asphyxia, to provide reference for future research.

NKG2D Enhances Double-Negative T Cell Regulation of B Cells.

Numerous studies reported a small subpopulation of TCRαß+CD4-CD8- (double-negative) T cells that exert regulatory functions in the peripheral lymphocyte population. However, the origin of these double-negative T (DNT) cells is controversial. Some researchers reported that DNT cells originated from the thymus, and others argued that these cells are derived from peripheral immune induction. We report a possible mechanism for the induction of nonregulatory CD4+ T cells to become regulatory double-negative T (iDNT) cells in vitro. We found that immature bone marrow dendritic cells (CD86+MHC-II- DCs), rather than mature DCs (CD86+MHC-II+), induced high levels of iDNT cells. The addition of an anti-MHC-II antibody to the CD86+MHC-II+ DC group significantly increased induction. These iDNT cells promoted B cell apoptosis and inhibited B cell proliferation and plasma cell formation. A subgroup of iDNT cells expressed NKG2D. Compared to NKG2D- iDNT cells, NKG2D+ iDNT cells released more granzyme B to enhance B cell regulation. This enhancement may function via NKG2D ligands expressed on B cells following lipopolysaccharide stimulation. These results demonstrate that MHC-II impedes induction, and iDNT cells may be MHC independent. NKG2D expression on iDNT cells enhanced the regulatory function of these cells. Our findings elucidate one possible mechanism of the induction of peripheral immune tolerance and provide a potential treatment for chronic allograft rejection in the future.

Overexpression of anillin is related to poor prognosis in patients with hepatocellular carcinoma.

BACKGROUND: Anillin (ANLN) is required for tumor growth. It has been proven that knockdown of ANLN effectively reduces the occurrence of hepatocellular carcinoma (HCC) in transgenic mice. However, the functional role of ANLN in HCC patients remains to be elucidated. METHODS: Both microarray and TCGA project were used for the analyses of ANLN expression and regulation in HCC. The effect of ANLN on proliferation and cell cycle was detected by CCK-8, colony formation assay and flow cytometry. ANLN expression was measured by immunohistochemistry. Correlation between ANLN expression and clinicopathological features was assessed by Pearson Chi-square test and 5-year overall survival after liver resection was evaluated by Kaplan-Meier method. RESULTS: Increased copy number, decreased methylation levels in the CpG island and upregulated histone hypermethylation of ANLN were found in HCC. Knockdown of ANLN inhibited proliferation and induced G2/M phase arrest in SMMC-7721 cells. ANLN was mainly expressed in the nucleus and showed significantly higher expression levels in cancerous tissues than those in paired adjacent tissues. Moreover, nuclear ANLN expression levels in HCC metastases were significantly higher than those in primary HCC. The results of Cox proportional hazards regression model suggested that ANLN nuclear expression in HCC was an independent risk factor for poor 5-year overall survival of patients after liver resection. CONCLUSIONS: ANLN is a potential therapeutic target for HCC. Patients with nuclear ANLN overexpression in HCC tissue may need adjuvant therapy after liver resection.

Paradoxical effects of cellular senescence-inhibited gene involved in hepatocellular carcinoma migration and proliferation by ERK pathway and mesenchymal-like markers.

BACKGROUND: Cellular senescence-inhibited gene (CSIG) strongly prolongs the progression of replicative senescence. However, roles and mechanisms of CSIG in tumor progression have not been studied widely. METHODS: Roles of CSIG in migration and proliferation of SMMC7721 and Huh7 cells were analyzed by transwell or cell viability assays, respectively. Tumorigenicity assays were used to study whether CSIG knockdown could affect SMMC7721 proliferation in vivo. Next, Western blotting and RT-PCR were preformed to evaluate the effects of CSIG on P-ERK cascade and epithelial mesenchymal transformation markers. Then, the location and expression of CSIG protein was detected by immunofluorescence and Western blotting, respectively. Finally, the Cancer Genome Atlas dataset was used to analyze CSIG mRNA levels in hepatocellular carcinoma (HCC) and adjacent non-tumor tissues. RESULTS: In this study, we found that CSIG overexpression promoted SMMC7721 cell migration, and CSIG knockdown suppressed tumorigenicity of SMMC7721 cells. In contrast to expectation, CSIG up-regulation could significantly inhibit Huh7 cell growth and migration. CSIG could promote P-ERK activation and levels of mesenchymal-like markers in SMMC7721 cells, whereas CSIG suppressed P-ERK activation and levels of mesenchymal-like markers in Huh7 cells. CSIG protein was located in nucleoli as well as nucleoplasm of SMMC7721 cells, whereas CSIG protein was mainly expressed in the nucleoli rather than nucleoplasm of Huh7 cells. Finally, due to individual differences, raised or down-regulated trends of CSIG in HCC as compared with adjacent non-tumor tissues are different among various patient populations. CONCLUSION: In summary, these results indicate that CSIG might play different roles in SMMC7721 and Huh7 cells through regulating P-ERK pathway and mesenchymal-like markers. The differential distribution of CSIG might be an important factor that causes its different functions in SMMC7721 and Huh7 cells. CSIG might play different roles in various patient populations.

New function for Escherichia coli xanthosine phophorylase (xapA): genetic and biochemical evidences on its participation in NAD(+) salvage from nicotinamide.

BACKGROUND: In an effort to reconstitute the NAD(+) synthetic pathway in Escherichia coli (E. coli), we produced a set of gene knockout mutants with deficiencies in previously well-defined NAD(+)de novo and salvage pathways. Unexpectedly, the mutant deficient in NAD(+) de novo and salvage pathway I could grow in M9/nicotinamide medium, which was contradictory to the proposed classic NAD(+) metabolism of E. coli. Such E. coli mutagenesis assay suggested the presence of an undefined machinery to feed nicotinamide into the NAD(+) biosynthesis. We wanted to verify whether xanthosine phophorylase (xapA) contributed to a new NAD(+) salvage pathway from nicotinamide. RESULTS: Additional knockout of xapA further slowed down the bacterial growth in M9/nicotinamide medium, whereas the complementation of xapA restored the growth phenotype. To further validate the new function of xapA, we cloned and expressed E. coli xapA as a recombinant soluble protein. Biochemical assay confirmed that xapA was capable of using nicotinamide as a substrate for nicotinamide riboside formation. CONCLUSIONS: Both the genetic and biochemical evidences indicated that xapA could convert nicotinamide to nicotinamide riboside in E. coli, albeit with relatively weak activity, indicating that xapA may contribute to a second NAD(+) salvage pathway from nicotinamide. We speculate that this xapA-mediated NAD(+) salvage pathway might be significant in some bacteria lacking NAD(+) de novo and NAD(+) salvage pathway I or II, to not only use nicotinamide riboside, but also nicotinamide as precursors to synthesize NAD(+). However, this speculation needs to be experimentally tested.