GYY4137 ameliorates intestinal barrier injury in a mouse model of endotoxemia

Intestinal barrier injury has been reported to play a vital role in the pathogenesis of endotoxemia. This study aimed to investigate the protective effect of GYY4137, a newly synthesized H₂S donor, on the intestinal barrier function in the context of endotoxemia both in vitro and in vivo. Caco-2 (a widely used human colon cancer cell line in the study of intestinal epithelial barrier function) monolayers incubated with lipopolysaccharide (LPS) or TNF-α/IFN-γ and a mouse model of endotoxemia were used in this study. The results suggested that GYY4137 significantly attenuated LPS or TNF-α/IFN-γ induced increased Caco-2 monolayer permeability. The decreased expression of TJ (tight junction) proteins induced by LPS and the altered localization of TJs induced by TNF-α/IFN-γ was significantly inhibited by GYY4137; similar results were obtained in vivo. Besides, GYY4137 promoted the clinical score and histological score of mice with endotoxemia. Increased level of TNF-α/IFN-γ in the plasma and increased apoptosis in colon epithelial cells was also attenuated by GYY4137 in mice with endotoxemia. This study indicates that GYY4137 preserves the intestinal barrier function in the context of endotoxemia via multipathways and throws light on the development of potential therapeutic approaches for endotoxemia.

The Polymorphisms in LNK Gene Correlated to the Clinical Type of Myeloproliferative Neoplasms

Objective

LNK is an adapter protein negatively regulating the JAK/STAT cell signaling pathway. In this study, we observed the correlation between variation in LNK gene and the clinical type of myeloproliferative neoplasms (MPN).

Methods

A total of 285 MPN cases were recruited, including essential thrombocythemia (ET) 154 cases, polycythemia vera (PV) 76 cases, primary myelofibrosis (PMF) 19 cases, and chronic myeloid leukemia (CML) 36 cases. Ninety-three healthy individuals were used as normal controls. V617F mutation in JAK2 was identified by allele-specific PCR method, RT-PCR was used for the detection of BCR/ABL1 fusion gene, and mutations and variations in coding exons and their flanking sequences of LNK gene were examined by PCR-sequencing.

Results

Missense mutations of A300V, V402M, and R415H in LNK were found in 8 patients including ET (4 cases, all combined with JAK2-V617F mutation), PV (2 cases, one combined with JAK2-V617F mutation), PMF (one case, combined with JAK2-V617F mutation) and CML (one case, combined with BCR/ABL1 fusion gene). The genotype and allele frequencies of the three SNPs (rs3184504, rs111340708 and rs78894077) in LNK were significantly different between MPN patients and controls. For rs3184504 (T/C, in exon2), the T allele (p.262W) and TT genotype were frequently seen in ET, PV and PMF (P<0.01), and C allele (p.262R) and CC genotype were frequently seen in CML (P<0.01). For rs78894077 (T/C, in exon1), the T allele (p.242S) was frequently found in ET (P<0.05). For rs111340708 (TGGGGx5/TGGGGx4, in intron 5), the TGGGG x4 allele was infrequently found in ET, PMF and CML(P<0.01).

Conclusion

Mutations in LNK could be found in some of MPN patients in the presence or absence of JAK2-V617F mutation. Several polymorphisms in LNK gene may affect the clinical type or the genetic predisposition of MPN.

[Analysis of the relationship between mitochondrial DNA deletion and clinical complexity of mitochondrial disease]

OBJECTIVE

To analyze the relationship between proportion of mitochondrial DNA 4 977 bp deletion (ΔmtDNA(4977)) or copy number in blood and the clinical complexity to find the pathogenesis of mitochondrial disease.

METHODS

A total of 160 patients with mitochondrial disease and 101 healthy controls of Peking University First Hospital from December 2003 to December 2013 were collected in this study. Their peripheral blood showed no hot-point mutation which detected by polymerase chain reaction-restriction fragment length polymorphism. All the patients were divided into younger group (age<10y) and elder group (10y≤age<20y). The incidence of ΔmtDNA(4977) was detected by real-time quantitative PCR. Internal gene was used to calculate the number of mitochondrial DNA in each cell. Statistical analysis were carried out by the independent t-test, one-way ANOVA and Spearman's bivariate correlation analysis.

RESULTS

ΔmtDNA (4977) proportion in the younger group was (2.66 ± 0.63)% and in the elder group was (3.09 ± 0.74)%, both of them were higher than that of healthy control group with the same age (the younger group: t=8.57, P<0.01; the elder group: t=4.38, P<0.01); ΔmtDNA(4977) copy number per cell in the younger group was (2.79 ± 0.50) copy and in the elder group was (2.97 ± 0.48) copy, both of them were higher than that of healthy control group with the same age (the younger group: t=4.50, P<0.01; the elder group: t=-3.67, P<0.01). The ΔmtDNA (4977) proportion was positively correlated with the complexity of the mitochondrial disease(the younger group: r=0.519, P<0.01; the elder group: r=0.772, P<0.01). The ΔmtDNA (4977) copy number per cell was positively correlated with the complexity of the mitochondrial disease(the younger group: r=0.389, P<0.01; the elder group: r=0.607, P<0.05). However, the total mtDNA copy number per cell was negatively correlated with the complexity of the mitochondrial disease (the younger group: r=-0.260, P<0.01; the elder group: r=-0.430, P<0.05).

CONCLUSIONS

The proportion or copy number of ΔmtDNA (4977) or total mtDNA copy number in blood are correlated with the complexity of mitochondrial diseases, especially the proportion of ΔmtDNA (4977).

Deletion of a 4977-bp Fragment in the Mitochondrial Genome Is Associated with Mitochondrial Disease Severity

Large deletions in mitochondrial DNA (mtDNA) may be involved in the pathogenesis of mitochondrial disease. In this study, we investigated the relationship between a 4,977-bp deletion in the mitochondrial genome (ΔmtDNA⁴⁹⁷⁷) and the severity of clinical symptoms in patients with mitochondrial disease lacking known point mutations. A total of 160 patients with mitochondrial disease and 101 healthy controls were recruited for this study. The copy numbers of ΔmtDNA⁴⁹⁷⁷ and wild-type mtDNA were determined by real-time quantitative PCR and analyzed using Spearman’s bivariate correlation analysis, t-tests, or one-way ANOVA. The overall ΔmtDNA⁴⁹⁷⁷ copy number per cell and the proportion of mtDNA⁴⁹⁷⁷ relative to the total wild-type mtDNA, increased with patient age and symptom severity. Surprisingly, the total mtDNA copy number decreased with increasing symptom severity. Our analyses revealed that increases in the proportion and total copy number of ΔmtDNA⁴⁹⁷⁷ in the blood may be associated with disease severity in patients with mitochondrial dysfunction.

Hydrogen sulfide suppresses oxidized low-density lipoprotein (ox-LDL)-stimulated monocyte chemoattractant protein 1 generation from macrophages via the nuclear factor κB (NF-κB) pathway

This study was designed to examine the role of hydrogen sulfide (H2S) in the generation of oxidized low-density lipoprotein (ox-LDL)-stimulated monocyte chemoattractant protein 1 (MCP-1) from macrophages and possible mechanisms. THP-1 cells and RAW macrophages were pretreated with sodium hydrosulfide (NaHS) and hexyl acrylate and then treated with ox-LDL. The results showed that ox-LDL treatment down-regulated the H2S/cystathionine-β-synthase pathway, with increased MCP-1 protein and mRNA expression in both THP-1 cells and RAW macrophages. Hexyl acrylate promoted ox-LDL-induced inflammation, whereas the H2S donor NaHS inhibited it. NaHS markedly suppressed NF-κB p65 phosphorylation, nuclear translocation, DNA binding activity, and recruitment to the MCP-1 promoter in ox-LDL-treated macrophages. Furthermore, NaHS decreased the ratio of free thiol groups in p65, whereas the thiol reductant DTT reversed the inhibiting effect of H2S on the p65 DNA binding activity. Most importantly, site-specific mutation of cysteine 38 to serine in p65 abolished the effect of H2S on the sulfhydration of NF-κB and ox-LDL-induced NF-κB activation. These results suggested that endogenous H2S inhibited ox-LDL-induced macrophage inflammation by suppressing NF-κB p65 phosphorylation, nuclear translocation, DNA binding activity, and recruitment to the MCP-1 promoter. The sulfhydration of free thiol group on cysteine 38 in p65 served as a molecular mechanism by which H2S inhibited NF-κB pathway activation in ox-LDL-induced macrophage inflammation.

Mosaicism in von Hippel-Lindau disease with severe renal manifestations

von Hippel-Lindau (VHL) disease is an inheritable multisystem tumor syndrome characterized by multiple benign and malignant tumors affecting multiple organs. VHL is the result of a germline mutation in the VHL tumor suppressor gene. Molecular genomic analysis routinely confirms the clinical diagnosis. However, the use of molecular diagnostic methods can often be insufficient for the detection of mosaic germline VHL mutations, making the diagnosis of some cases of VHL difficult. Here, we report the case of a VHL mosaic patient with bilateral renal lesions in the absence of other VHL-associated lesions. A VHL mutation was not originally detected by routine molecular testing. Nonetheless, the detection of a heterozygous c.194C>G (p.Ser65Trp) VHL mutation in the patient's daughter prompted further genetic assessment and eventually resulted in the finding of a mosaic c.194C>G (p.Ser65Trp) VHL mutation in the patient. The mutation rate was 18.8 ± 3.84% in peripheral leukocytes. As the frequency of VHL mosaicism remains underdetermined, the possibility of a diagnosis of mosaic VHL should be considered in patients with both typical and atypical VHL-associated manifestations.

MicroRNA expression patterns in the bovine mammary gland are affected by stage of lactation

The objective of this work was to determine the expression pattern of microRNA (miR) associated with cellular proliferation, lipid metabolism, and innate immunity in dairy cow mammary gland tissue at different stages of lactation. The expression of miR-10a, miR-15b, miR-16, miR-21, miR-31, miR-33b, miR-145, miR-146b, miR-155, miR-181a, miR-205, miR-221, and miR-223 was studied by real-time reverse-transcription PCR in tissue (n=7/stage) harvested via repeated biopsies during the dry period (-30 d prepartum), the fresh period (7 d postpartum), and early lactation (30 d postpartum). Except for miR-31, all miR studied increased in expression between the dry and fresh periods. Among those upregulated, the expression of miR-221 increased further at early lactation, suggesting a role in the control of endothelial cell proliferation or angiogenesis, whereas the expression of miR-223 decreased at early lactation but to a level that was greater than in the dry period, suggesting it could play a role in the mammary response to pathogens soon after parturition. The expression of miR-31, a hormonally regulated miR that inhibits cyclin gene expression, was greater at early lactation compared with the dry period. From a metabolic standpoint, the consistent upregulation of miR-33b during early lactation compared with the dry period suggests that this miR may exert some control over lipogenesis in mammary tissue. Overall, results indicate that expression of miR associated with transcriptional regulation of genes across diverse biological functions is altered by stage of lactation. The specific roles of these miR during lactation will require further research.

Exome sequencing reveals mutations in TRPV3 as a cause of Olmsted syndrome

Olmsted syndrome (OS) is a rare congenital disorder characterized by palmoplantar and periorificial keratoderma, alopecia in most cases, and severe itching. The genetic basis for OS remained unidentified. Using whole-exome sequencing of case-parents trios, we have identified a de novo missense mutation in TRPV3 that produces p.Gly573Ser in an individual with OS. Nucleotide sequencing of five additional affected individuals also revealed missense mutations in TRPV3 (which produced p.Gly573Ser in three cases and p.Gly573Cys and p.Trp692Gly in one case each). Encoding a transient receptor potential vanilloid-3 cation channel, TRPV3 is primarily expressed in the skin, hair follicles, brain, and spinal cord. In transfected HEK293 cells expressing TRPV3 mutants, much larger inward currents were recorded, probably because of the constitutive opening of the mutants. These gain-of-function mutations might lead to elevated apoptosis of keratinocytes and consequent skin hyperkeratosis in the affected individuals. Our findings suggest that TRPV3 plays essential roles in skin keratinization, hair growth, and possibly itching sensation in humans and selectively targeting TRPV3 could provide therapeutic potential for keratinization or itching-related skin disorders.

Family history of von Hippel-Lindau disease was uncommon in Chinese patients: suggesting the higher frequency of de novo mutations in VHL gene in these patients

Von Hippel-Lindau (VHL) disease is an autosomal dominant familial cancer syndrome caused by germline mutations in VHL tumor suppressor gene. It is characterized by hemangioblastoma in central nervous system and retina, renal cell carcinoma or cyst, pheochromocytoma, pancreatic cyst and tumor, endolymphatic-sac tumor, and papillary cystadenoma in epididymis and broad ligament. Here, we used PCR-direct sequencing and universal primer quantitative fluorescent multiplex PCR (UPQFM-PCR) to detect VHL mutations in 16 patients clinically diagnosed with VHL disease. PCR-direct sequencing detected 12 germline mutations (75%, 12/16), in which a novel mutation of c.451A>T/p.Ile151Phe found in one proband had not been reported previously. UPQFM-PCR found two large deletions (12.5%, 2/16). The two remaining patients carried non-typical disease-causing mutations, including one silent mutation (c.481C>A/p.Arg161Arg) and one mutation in 3'-UTR (c.642+70C>A). Remarkably, 56.3% (9/16) probands did not have family history of VHL disease, suggesting the higher frequency of de novo mutations in Chinese patients. We also summarized Chinese VHL disease patients with VHL mutation findings published in the literature to provide information about the spectrum of VHL mutations in Chinese VHL disease patients.

Efficient growth suppression and apoptosis in human laryngeal carcinoma cell line HEP-2 induced by an adeno-associated virus expressing human FAS ligand

BACKGROUND

Apoptosis induced by Fas/FasL system has been proposed as a gene therapy methold for various cancers.

METHODS

We used adeno-associated virus-expressing enhanced green fluorescent protein (EGFP)-human FasL (AAV-EGFP-hFasL) to deliver FasL into Hep-2 cells, cytotoxicity was detected by MTS assay , apoptosis was confirmed by flow cytometry. We also treated the xenograft of Hep-2 tumor in nude mice with intratumoral injection of AAV-EGFP-hFasL. The size of the xenograft, the apoptosis in the xenograft, and the survival rate of the inoculated mice were then evaluated.

RESULTS

Hep-2 cells infected with AAV-EGFP-hFasL showed increased apoptosis rate and killing effect compared with AAV-EGFP-infected cells. In addition intratumoral injections of AAV-EGFP-hFasL into Hep-2 xenografts induced significant growth suppression of tumors.

CONCLUSION

Our findings suggest that the introduction of FasL into head and neck squamous cell carcinoma may induce significant apoptosis, and adeno-associated virus may be a useful vehicle for gene therapy.

Fas ligand gene transfer effectively induces apoptosis in head and neck cancer cells

CONCLUSION

Fas ligand (FasL) gene therapy may provide a new efficient therapeutic model for head and neck squamous cell cancer (HNSCC). Acid ceramidase (AC) may not play an important role in the sensitivity of HNSCC cell lines to Fas-induced apoptosis.

OBJECTIVES

The aims of this study were to investigate the efficacy of FasL gene therapy for HNSCC in vitro and to determine whether the expression of AC in different kinds of HNSCC cell lines is related to the sensitivity of HNSCC cell lines to Fas-mediated apoptotic induction.

METHODS

Three HNSCC cell lines (Hep-2, MMSI, and SCCVII) were transfected with pEGFP-FasL, a plasmid containing a modified human FasL gene fused to enhanced green fluorescent protein (GFP). pEGFP-C1, a plasmid containing the GFP gene alone, was used as a control. Cell death was observed by fluorescence imaging and quantified using a tetrazolium-based (MTS) assay. SCCVII cells were analyzed by flow cytometry to determine the presence of apoptotic induction. Hep-2 and MMSI cells were evaluated by quantitative real-time PCR to evaluate the expression of AC.

RESULTS

Transfection of pEGFP-FasL plasmid was shown to be able to induce cell death, the sensitivity of Fas-mediated apoptosis in HNSCC was different, and the level of AC did not correlate with the sensitivity of HNSCC cells to Fas-induced apoptosis.

New mutations in the transglutaminase 1 gene in three families with lamellar ichthyosis

BACKGROUND

Autosomal recessive lamellar ichthyosis (LI) is a severe skin disorder characterized by generalized hyperkeratosis. Gene mutation in transglutaminase 1 (TGM1), which mediates cross-links in the formation of the cell envelope during terminal differentiation of epidermis, has been identified as a cause of LI.

OBJECTIVES

To determine mutations of TGM1 gene in three Chinese families with LI.

METHODS

The TGM1 gene was sequenced to identify disease-causing mutations in the three families with LI. One of the results was confirmed by using reverse transcriptase PCR and in situ hybridization. An in situ transglutaminase (TGase) 1 assay was performed to estimate TGase 1 activity in the patients' skin.

RESULTS

Four novel mutations of keratinocyte TGase1 (Q203X, D254N, R687H and IVS4 + 1G-->T) were found in the three families. No TGase 1 mRNA was detected in patient skin using RT-PCR and in situ hybridization, and the in situ TGase assay showed that there was no or decreased TGase 1 activity in patient skin.

CONCLUSIONS

Our findings suggest that four novel mutations in TGM1 gene result in decrease or absence of TGase activity in the skin and, as a consequence, cause the phenotype of LI.