Overexpression of CLEC5A inhibits cell proliferation and metastasis and reverses epithelial-mesenchymal transition in hepatocellular carcinoma / 南方医科大学学报

OBJECTIVE@#To evaluate the effects of CLEC5A expression level on cell proliferation, migration and invasion and epithelial-mesenchymal transition (EMT) in hepatocellular carcinoma (HCC) and explore the role of CLEC5A in the tumorigenesis and progression of HCC.@*METHODS@#The expression level of CLEC5A was detected in 50 pairs of HCC and adjacent tissues using immunohistochemical staining, and its association with clinicopathological parameters of HCC patients was analyzed. Cultured HCC cell line SK-HEP-1 was transfected with a lentiviral vector overexpressing CLEC5A, and the transfection efficiency was verified using real-time fluorescence quantitative PCR and Western blotting. The changes in proliferation, migration and invasion abilities of the transfected cells were analyzed using CCK-8, 5-ethynyl-29-deoxyuridine (EdU) and Transwell assays, and EMT of the cells was determined using Western blotting.@*RESULTS@#The protein expression level of CLEC5A was significantly lower in HCC tissues than in the adjacent tissues (P < 0.001). The expression level of CLEC5A was significantly correlated with tumor size (P=0.008), tumor number (P=0.010), histological differentiation (P=0.016), microvascular invasion (P=0.024) and BCLC stage (P=0.040). In SK-HEP-1 cells, overexpression of CLEC5A obviously inhibited the cell proliferation, migration and invasion and reversed EMT phenotype of the cells.@*CONCLUSION@#CLEC5A is a potential HCC suppressor gene and may serve as a promising therapeutic target for HCC.

Evaluation of variants in IL6R, TLR3, and DC-SIGN genes associated with dengue in a sampled Colombian population / Evaluación de las variantes en los genes IL6R, TLR3 y DC-SIGN asociadas con dengue en una muestra de población colombiana

Abstract Introduction: Host genetics is recognized as an influential factor for the development of dengue disease. Objective: This study evaluated the association of dengue with the polymorphisms rs8192284 for gene IL6R, rs3775290 for TLR3, and rs7248637 for DC-SIGN. Materials and methods: Of the 292 surveyed subjects, 191 were confirmed for dengue fever and the remaining 101 were included as controls. The genotypes were resolved using polymerase chain reaction and restriction fragment length polymorphism (PCR- RFLP). In an attempt to determine the risk (Odds Ratio) of suffering dengue fever, data were analyzed using chi-square for alleles and logistic regression for both genotypes and allelic combinations. Confidence intervals were set to 95% for all tests regardless of the adjustment by either self-identification or ancestry. Results: For Afro-Colombians, the allele rs8192284 C offered protection against dengue [OR=0.425,(0.204-0.887), p=0.020]. The alleles rs7248637 A and rs3775290 A posed, respectively, an increased risk of dengue for Afro-Colombians [OR=2.389, (1.170-4.879), p=0.015] and Mestizos [OR=2.329, (1.283-4.226), p=0.005]. The reproducibility for rs8192284 C/C [OR=2.45, (1.05-5.76), p=0.013] remained after adjustment by Amerindian ancestry [OR=2.52, (1.04-6.09), p=0.013]. The reproducibility for rs3775290 A/A [OR=2.48, (1.09-5.65), p=0.033] remained after adjustment by European [OR=2.34, (1.02-5.35), p=0.048], Amerindian [OR=2.49, (1.09-5.66), p=0.035], and African ancestry [OR=2.37, (1.04-5.41), p=0.046]. Finally, the association of dengue fever with the allelic combination CAG [OR=2.07, (1.06-4.05), p=0.033] remained after adjustment by Amerindian ancestry [OR=2.16, (1.09-4.28), p=0.028]. Conclusions: Polymorphisms rs8192284 for IL6R, rs3775290 for TLR3, and rs7248637 for DC-SIGN were associated with the susceptibility to suffer dengue fever in the sampled Colombian population.

Resumen Introducción. La genética del huésped se reconoce como un factor que influye en el desarrollo del dengue. Objetivo. Este estudio evaluó la asociación del dengue con los polimorfismos rs8192284 del gen IL6R, rs3775290 del TLR3 y rs7248637 del DC-SIGN. Materiales y métodos. De los 292 sujetos encuestados, en 191 se confirmó la presencia de fiebre por dengue y los restantes 101 se incluyeron como controles. Los genotipos se resolvieron mediante reacción en cadena de la polimerasa y polimorfismos en la longitud de los fragmentos de restricción (PCR-RFLP). En un intento por determinar el riesgo de sufrir dengue, los datos se analizaron mediante la prueba de ji al cuadrado para los alelos y la regresión logística para los genotipos y las combinaciones alélicas. Los intervalos de confianza se calcularon a 95 % para todas las pruebas independientemente ajustadas por autoidentificación o componente genético ancestral. Resultados. En los afrocolombianos, el alelo C rs8192284 ofreció protección contra el dengue (OR=0,425; 0,204-0,887, p=0,020). Los alelos A rs7248637 y Ars3775290 plantearon un mayor riesgo de dengue para los afrocolombianos (OR=2,389; 1,170- 4,879; p=0,015) y los mestizos (OR=2,329; 1,283-4,226: p=0,005), respectivamente. La reproducibilidad para rs8192284 C/C (OR=2,45; 1,05-5,76; p=0,013) permaneció después del ajuste por el componente genético ancestral amerindio (OR=2,52; 1,04- 6,09; p=0,013). La reproducibilidad del rs3775290 A/A (OR=2,48; 1,09-5,65; p=0,033) permaneció después del ajuste por el componente europeo (OR=2,34; 1,02-5,35; p=0,048), el amerindio (OR=2,49; 1,09- 5,66; p=0,035), y el africano (OR=2,37; 1,04- 5,41; p=0,046). Por último, la asociación del dengue con la combinación alélica CAG (OR=2,07; 1,06-4,05; p=0,033) permaneció después del ajuste por el componente genético amerindio (OR=2,16; 1,09-4,28;p=0,028). Conclusión. Los polimorfismos rs8192284 en IL6R, rs3775290 en TLR3 y rs7248637 en DC-SIGN, se asociaron con la propensión a sufrir dengue en una muestra de población colombiana.

Association between polymorphisms in the genes encoding toll-like receptors and dectin-1 and susceptibility to invasive aspergillosis: a systematic review

Abstract Invasive aspergillosis is a common fungal infection in immunocompromised individuals. Some studies have shown that toll-like receptor and dectin-1 genetic polymorphisms may alter signaling pathways, thus increasing an individual's susceptibility to invasive aspergillosis. We investigated the pertinent literature to determine whether polymorphisms in the genes encoding toll-like receptors and dectin-1 increase the susceptibility to invasive aspergillosis. This study systematically reviewed the literature using the databases PubMed/PMC, Scopus, and Web of Science using the keywords invasive aspergillosis, polymorphism, Toll-like, and Dectin-1. From the initial search, 415 studies were found and according to our inclusion and exclusion criteria, eight studies were selected. Several studies described single-nucleotide polymorphisms (SNPs) that are associated with a greater susceptibility to invasive aspergillosis. These SNPs were found in the genes that encode toll-like receptors 1, 3, 4, and 5 and the gene that encodes dectin-1; upon activation, both cellular receptors initiate a signaling cascade that can result in the production of cytokines and chemokines. Thus, our literature review uncovered a significant association between polymorphisms in the genes that encode toll-like receptors and dectin-1 and invasive aspergillosis. More studies should be performed to better understand the relationship between toll-like receptor and dectin-1 genetic polymorphisms and invasive aspergillosis susceptibility.

Genetic characterisation of Langerin gene in human immunodeficiency virus-1-infected women from Bahia, Brazil

Studies on human genetic variations are a useful source of knowledge about human immunodeficiency virus (HIV)-1 infection. The Langerin protein, found at the surface of Langerhans cells, has an important protective role in HIV-1 infection. Differences in Langerin function due to host genetic factors could influence susceptibility to HIV-1 infection. To verify the frequency of mutations in the Langerin gene, 118 samples from HIV-1-infected women and 99 samples from HIV-1-uninfected individuals were selected for sequencing of the promoter and carbohydrate recognition domain (CRD)-encoding regions of the Langerin gene. Langerin promoter analysis revealed two single nucleotide polymorphisms (SNPs) and one mutation in both studied groups, which created new binding sites for certain transcription factors, such as NFAT5, HOXB9.01 and STAT6.01, according to MatInspector software analysis. Three SNPs were observed in the CRD-encoding region in HIV-1-infected and uninfected individuals: p.K313I, c.941C>T and c.983C>T. This study shows that mutations in the Langerin gene are present in the analysed populations at different genotypic and allelic frequencies. Further studies should be conducted to verify the role of these mutations in HIV-1 susceptibility.

Expression of non-TLR pattern recognition receptors in the spleen of BALB/c mice infected with Plasmodium yoelii and Plasmodium chabaudi chabaudi AS

The spleen plays a crucial role in the development of immunity to malaria, but the role of pattern recognition receptors (PRRs) in splenic effector cells during malaria infection is poorly understood. In the present study, we analysed the expression of selected PRRs in splenic effector cells from BALB/c mice infected with the lethal and non-lethal Plasmodium yoelii strains 17XL and 17X, respectively, and the non-lethal Plasmodium chabaudi chabaudi AS strain. The results of these experiments showed fewer significant changes in the expression of PRRs in AS-infected mice than in 17X and 17XL-infected mice. Mannose receptor C type 2 (MRC2) expression increased with parasitemia, whereas Toll-like receptors and sialoadhesin (Sn) decreased in mice infected with P. chabaudi AS. In contrast, MRC type 1 (MRC1), MRC2 and EGF-like module containing mucin-like hormone receptor-like sequence 1 (F4/80) expression decreased with parasitemia in mice infected with 17X, whereas MRC1 an MRC2 increased and F4/80 decreased in mice infected with 17XL. Furthermore, macrophage receptor with collagenous structure and CD68 declined rapidly after initial parasitemia. SIGNR1 and Sn expression demonstrated minor variations in the spleens of mice infected with either strain. Notably, macrophage scavenger receptor (Msr1) and dendritic cell-associated C-type lectin 2 expression increased at both the transcript and protein levels in 17XL-infected mice with 50% parasitemia. Furthermore, the increased lethality of 17X infection in Msr1 -/- mice demonstrated a protective role for Msr1. Our results suggest a dual role for these receptors in parasite clearance and protection in 17X infection and lethality in 17XL infection.

CCR2, MCP-1, SDF-1α & DC-sign gene polymorphisms in HIV-1 infected patients with & without tuberculosis.

Background & objectives: Variability in the clinical outcome of persons exposed to and infected with HIV-1 and tuberculosis (TB) is determined by multiple factors including host genetic variations. The aim of the present study was to find out whether chemokine, chemokine receptor and DC-SIGN gene polymorphisms were associated with susceptibility or resistance to HIV and HIV-TB in south India. Methods: CCR2 V64I (G/A), monocyte chemoattractant protein-1 (MCP-1) -2518 A/G, stromal cell derived factor-1α (SDF-1α) 3’UTR G/A and DC-SIGN gene polymorphisms were studied by polymerase chain reaction based methods in HIV-1 infected patients without TB (n=151), with pulmonary TB (PTB) (n=81) and extrapulmonary TB (n=31), 155 PTB patients without HIV and 206 healthy controls. Results: The genotype frequencies of CCR2 V64I, MCP-1 -2518 and DC-SIGN polymorphisms did not differ significantly between the study groups. A significantly increased frequency of GG genotype of SDF-1α polymorphism was observed among HIV+PTB+ patients compared to healthy controls (P=0.009, Pc=0.027). Interpretation & conclusions: Our data suggest that GG genotype of SDF-1α 3’UTR polymorphism may be associated with susceptibility to PTB in HIV-1 infected patients. A better understanding of genetic factors that are associated with TB could help target preventive strategies to those HIV patients likely to develop tuberculosis.

Comparative study of synonymous codon usage variations between the nucleocapsid and spike genes of coronavirus, and C-type lectin domain genes of human and mouse

Coronaviruses (CoVs) are single-stranded RNA viruses which contain the largest RNA genomes, and severe acute respiratory syndrome coronavirus (SARS-CoV), a newly found group 2 CoV, emerged as infectious disease with high mortality rate. In this study, we compared the synonymous codon usage patterns between the nucleocapsid and spike genes of CoVs, and C-type lectin domain (CTLD) genes of human and mouse on the codon basis. Findings indicate that the nucleocapsid genes of CoVs were affected from the synonymous codon usage bias than spike genes, and the CTLDs of human and mouse partially overlapped with the nucleocapsid genes of CoVs. In addition, we observed that CTLDs which showed the similar relative synonymous codon usage (RSCU) patterns with CoVs were commonly derived from the human chromosome 12, and mouse chromosome 6 and 12, suggesting that there might be a specific genomic region or chromosomes which show a more similar synonymous codon usage pattern with viral genes. Our findings contribute to developing the codon-optimization method in DNA vaccines, and further study is needed to determine a specific correlation between the codon usage patterns and the chromosomal locations in higher organisms.

Differential gene expression profiles of human monocyte-derived antigen presenting cells in response to Penicillium marneffei: roles of DC-SIGN (CD209) in fungal cell uptake.

DNA microarray technology was used to determine the gene expression profile of human monocyte-derived macrophages (hMDMs) after stimulation by Penicillium marneffei yeast. The expression levels of 175 macrophage genes were found to be altered by a minimum of two-fold in magnitude following 4 hours of P. marneffei exposure. Among those, 41 genes were upregulated in activated hMDMs while 134 genes were downregulated. Real-time PCR and RT-PCR were performed to further examine gene expression associated with the inflammatory response. Increased levels of TNF-alpha and IL-1 beta gene expression in both hMDMs and human monocyte-derived dendritic cells (hMoDCs) were observed after stimulation by P. marneffei yeast. Furthermore, the genes encoding T-bet, IL-6 and ICAM-1 were also upregulated in hMDMs. Functional analysis of the adhesion of P. marneffei to dendritic cell-specific intercellular adhesion molecule-3 grabbing non-integrin (DC-SIGN, CD209) was performed in hMoDCs since the microarray data revealed an increased expression of DC-SIGN in activated hMDMs. We found that DC-SIGN-Fc bound preferentially to P. marneffei yeast rather than to conidia. Moreover, an anti-DC-SIGN monoclonal antibody inhibited the binding of P. marneffei yeast to hMoDCs, but did not inhibit endocytosis of P. marneffei yeast. The mannose receptor, on the other hand, was important in both adhesion and phagocytosis. These results suggest that P. marneffei may exploit DC-SIGN as a receptor to facilitate the systemic spread of infection. Taken together, our study demonstrates the usefulness of microarray technology in generating valuable expression data to permit conventional immunologic investigations of host-fungal interactions.

Overexpression of SOX9 in mouse embryonic stem cells directs the immediate chondrogenic commitment

Mouse embryonic stem (mES) cells are capable of undergoing chondrogenesis in vitro. To enhance this process, the human SOX9 (hSOX9) cDNA was delivered into mES cells and the clones overexpressing hSOX9 (denoted as mES-hSOX9 cells) were verified by Western blot analysis. The transcripts of collagen IIA (a juvenile form), aggrecan and Pax1 were expressed in mES-hSOX9 cells grown on feeder layers, suggesting the immediate effect of exogenous SOX9 on chondrogenesis. However, SOX9 overexpression did not affect the cell cycle distribution in undifferentiated mES cells. Upon differentiation, collagen IIB (an adult form) was detected in day 3 immature embryoid bodies. In addition, the overexpression of exogenous SOX9 significantly induced transcriptional activity driven by SOX9 binding site. Taken together, we for the first time demonstrated that constitutive overexpression of exogenous SOX9 in undifferentiated mES cells might have dual potentials to induce both chondrogenic commitment and growth capacity in the undifferentiated status.