Correlation between ICAM1 and VCAM1 gene polymorphisms and histopathological changes in kidney allograft biopsies

Genetic Association of ICAM-1 (rs5498) Gene Polymorphism With Susceptibility to Stage II Grade B Periodontitis: A Case-Control Study in South Indian Population

INTRODUCTION

In the contemporary perspective, periodontitis is considered a complex issue triggered and perpetuated by bacteria but strongly influenced by the way the body reacts to bacterial plaque. Recent research has indicated that variations in genes might have an impact on the development of periodontitis. This study was conducted to explore a probable link between the genetic variations in intercellular adhesion molecule-1 (ICAM-1) represented by rs5498 and the occurrence of periodontitis.  Methods: A total of 100 participants, 50 with periodontitis and 50 with periodontally healthy or mild gingivitis, were recruited for this study. Whole blood drawn from the participants was used to obtain genomic DNA. The ICAM-1 gene polymorphism (rs5498) was determined using polymerase chain reaction (PCR) amplification and digestion. The ICAM-1 gene's flanking primers were used to amp up the DNA. For statistical analysis, the genotype that was analyzed using the pattern of restriction fragment length polymorphism was recorded. The Chi-square test compared genotype and allele frequency distributions between both groups. The odds ratio with 95% confidence intervals with each individual allele or genotype was used to compute the risk. Statistical significance was established in all tests when the p-value was less than 0.05.

RESULTS

 There was no discernible difference between the genotype frequencies of patients and controls χ2df (P = 0.6065). The findings demonstrated that no significant difference was present between the two groups for homozygous or heterozygous mutant genotypes (AA vs. AG+GG; P = 0.6854). There was no discernible difference in the detected frequencies of the A allele (58% vs. 61%), G allele (42% vs. 39%), TT (16% vs. 24%), AG (40% vs. 36%), and TT genotypes in the studied groups.

CONCLUSION

According to the results of the current investigation, the ICAM-1 (rs5498) gene polymorphism is not associated with periodontitis in the population investigated.

Suppressing the activity of CXCR4 down-regulates the expression of renal fibrosis related genes in primary glomerular cells

BACKGROUND

C-X-C chemokine receptor type 4 (CXCR4) has a certain effect on renal fibrosis, and there are few specific studies in cells. We want to investigate the impact of suppressing CXCR4 activity on the expression of renal fibrosis-related genes in primary glomerular endothelial cells, mesangial cells, and podocytes.

METHODS

Immunofluorescence assays were used to determine the purity of isolated glomerular endothelial cells, mesangial cells, and podocytes. CXCR4 knockdown cell lines were established by transfecting the short hairpin (sh)RNA against CXCR4. T140 and AMD3100 were used to inhibit the activity of CXCR4. LY294002 was used to inhibit the activity of phosphoinositide 3-kinase (PI3K). The mRNA expression of CXCR4 was determined by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). The protein expression of CXCR4, collagen IV, matrix metallopeptidase (MMP)-9, PI3K, Rac1, and vascular cell adhesion protein 1 (VCAM-1) was evaluated by Western blot analysis.

RESULTS

High purity was observed on isolated primary glomerular endothelial cells and podocytes. However, the purity of isolated mesangial cells was relatively low. The mRNA expression of CXCR4 was significantly suppressed by the transfection of shRNA. Compared to control cells, the expression of CXCR4, collagen IV, MMP-9, PI3K, Rac1, and VCAM-1 were dramatically downregulated in cell lines transfected with shRNA against CXCR4. Furthermore, cell lines treated with T140, AMD3100, or LY294002 also showed downregulated expression of these proteins compared to untreated cells. No significant differences were observed in the protein expression of these proteins between control cells and cells transfected with the shRNA negative control (NC).

CONCLUSIONS

Suppressing the activity of CXCR4 downregulated the expression of renal fibrosis-related genes in primary glomerular cells, even under a non-inflammatory state.

Single Nucleotide Polymorphisms of IL-33 Gene Correlated with Renal Allograft Fibrosis in Kidney Transplant Recipients

Background

Nowadays, renal allograft survival is confined by the development of allograft fibrosis. Previous studies have reported interleukin-33 (IL-33) upregulated significantly in patients with chronic renal allograft dysfunction, and it could induce renal tubular epithelial to mesenchymal transition (EMT), which eventually contributed to renal allograft fibrosis. Our study intended to detect the underlying association between single nucleotide polymorphisms (SNPs) of IL-33 gene and renal allograft fibrosis in kidney transplant recipients.

Methods

We collected blood samples from 200 renal transplant recipients for the identification of SNPs and transplanted kidney tissue samples for identifying differentially expressed genes (DEGs). Intersection of SNP-related genes and DEGs was conducted for further analysis. Relationships between these SNPs and renal allograft fibrosis were evaluated by the inheritance models. Immunohistochemical (IHC) staining and western blotting (WB) were used to detect the expression of IL-33 and the markers of EMT in human kidney tissues obtained from control and chronic renal allograft dysfunction (CAD) patients. In vitro, we detected the progressions of EMT-related markers and the levels of MAPK signaling pathway mediators after transfecting IL-33 mutant plasmids in HK2 cells.

Results

Three intersected genes including IL-33 genes were significantly expressed. IL-33 expression was validated in kidney tissues by IHC and WB. Thirty-nine IL-33-related SNPs were identified in targeted sequencing, in which 26 tagger SNPs were found by linkage disequilibrium analysis for further analysis. General linear models indicated sirolimus administration significantly influenced renal allograft fibrosis (P < 0.05), adjustment of which was conducted in the following analysis. By multiple inheritance model analyses, SNP rs10975519 of IL-33 gene was found closely related to renal allograft fibrosis (P < 0.005). Furthermore, HK2 cells transfected with mutated plasmid of rs10975519 showed stronger mobility and migration ability. Moreover, IL-33 mutant plasmids could promote the IL-33-induced EMT through the sustained activation of p38 MAPK signaling pathway in HK2 cells.

Conclusion

In our study, rs10975519 on the IL-33 gene was found to be statistically associated with the development of renal allograft fibrosis in kidney transplant recipients. This process may be related to the IL-33-induced EMT and sustained activation of p38 MAPK signaling pathway.

Deciphering key genes in cardio-renal syndrome using network analysis

Cardio-renal syndrome (CRS) is a rapidly recognized clinical entity which refers to the inextricably connection between heart and renal impairment, whereby abnormality to one organ directly promotes deterioration of the other one. Biological markers help to gain insight into the pathological processes for early diagnosis with higher accuracy of CRS using known clinical findings. Therefore, it is of interest to identify target genes in associated pathways implicated linked to CRS. Hence, 119 CRS genes were extracted from the literature to construct the PPIN network. We used the MCODE tool to generate modules from network so as to select the top 10 modules from 23 available modules. The modules were further analyzed to identify 12 essential genes in the network. These biomarkers are potential emerging tools for understanding the pathophysiologic mechanisms for the early diagnosis of CRS. Ontological analysis shows that they are rich in MF protease binding and endo-peptidase inhibitor activity. Thus, this data help increase our knowledge on CRS to improve clinical management of the disease.

IL17A and IL17F genes polymorphisms are associated with histopathological changes in transplanted kidney

Background

Interleukin 17 is a proinflammatory cytokine involved in immune response after allograft transplantation. IL-17 family of proinflammatory cytokines includes IL-17A and IL-17F. Previous studies have demonstrated that the rs2275913 IL17A and the rs11465553 IL17F gene polymorphism are associated with kidney allograft function. Because of the association between these polymorphisms and post-transplant immune response, we assume that these single nucleotide polymorphisms may affect morphological structure of transplanted kidney.

The aim of this study was to examine the association of rs2275913 IL17A and rs2397084, rs11465553 and rs763780 IL17F gene polymorphisms with histopathological changes in transplanted kidney biopsies such as: glomerulitis, tubulitis, arteritis, cell infilitration and fibrosis.

Methods

The study enrolled 82 patients after renal graft transplantation in whom a kidney biopsy was performed because of impaired graft function. The rs2397084 T > C (Glu126Gly), rs11465553 G > A (Val155Ile) and rs763780 T > C (His167Arg) polymorphisms within the IL17F gene and the rs2275913 A > G (− 197 A > G) polymorphism within the IL17A gene promoter were genotyped using TaqMan genotyping assays on a 7500 FAST Real-Time PCR System (Applied Biosystems, USA).

Results

There was a significant association between the rs2275913 IL17A gene polymorphism and the grade of tubulitis, which was more severe among patients with the A allele, compared to recipients with the GG genotype (GG vs. AG + AA, P = 0.02), and with the grade of arteriolar hyaline thickening and mesangial matrix increase, which were more severe among patients with the G allele compared to recipients with the AA genotype (AA vs. AG + GG, P = 0.01 and P = 0.04, respectively). Tubular atrophy and interstitial fibrosis were more severe among individuals with the C allele at the rs763780 IL17F gene polymorphism (TT vs. TC, P = 0.09 and P = 0.017, respectively). However, it should be taken into account that the statistical significance was achieved without correction for multiple testing, and no significant association would remain significant after such correction.

Conclusions

The results of this study may suggest a possible association between the rs2275913 IL17A and rs2275913 IL17A gene polymorphisms and some histopathological changes in transplanted kidney biopsies.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1308-z) contains supplementary material, which is available to authorized users.

Comparative Assessment of uNGAL, uNAG and Cystatin C As Early Biomarkers in Renal Post-Transplant Patients

Urinary neutrophil gelatinase-associated lipocalin (uNGAL), urinary N-acetyl-bd-glucosaminidase (NAG), urinary α1-microglobulin/creatinine ratio and cystatin C have been suggested as potential early markers of delayed graft function (DGF) following kidney transplantation. We conducted a prospective study in 50 consecutive kidney transplant recipients to evaluate serial changes of these biomarkers within the first week after transplantation and assess their performance in predicting DGF (dialysis requirement during initial post-transplant week) and graft function throughout the first year. Urine samples were collected on post-transplantation days 0, 1, 2, 4, and 7. Statistical analysis: Linear mixed and multivariable regression models, receiver-operating characteristic (ROC), and areas under ROC curves were used. At all-time points, mean urinary NGAL levels were significantly higher in patients developing DGF. Shortly after transplantation (3-6 h), uNGAL and uNAG values were higher in DGF recipients (on average +242 ng/mL; NAG – 6.8 U/mmol creatinine, considering mean dialysis time of 4.1 years) and rose further in the following days, contrasting with prompt function recipients. On Day-1 uNGAL levels accurately predicted DGF (AUC-ROC = 0.93), with a performance higher than serum creatinine (AUC-ROC = 0.76), and similar to cystatin C (AUC-ROC = 0.95). Multivariable analyses revealed that uNGAL levels at days 4 and 7 were strongly associated with one-year serum creatinine level. Urinary NGAL, serum cystatin C is an early marker of graft injury and is independently associated with dialysis requirement within one week after transplantation and one-year graft function.

Telomere Length Assessment for Prediction of Organ Transplantation Outcome. Future or Failure: A Review of the Literature

Telomeres are located at each end of eukaryotic chromosomes. Their functional role is genomic stability maintenance. The protective role of telomeres depends on various factors, including number of nucleotides repeats, telomere-binding proteins, and telomerase activity. Organ transplantation is the preferred replacement therapy in the case of chronic kidney disease and the only possibility of sustaining recipients’ life in the case of advanced liver failure. While the prevalence of acute rejection is constantly decreasing, prevention of transplanted organ long-term function loss is still challenging. It has been demonstrated that post-transplant stressors accelerate aging of the allografts manifested through telomere shortening.

The aim of this paper was to evaluate the importance of telomere length assessment for prediction of organ transplantation outcome. Literature review included the 10 most important studies regarding linkage between allograft function and telomere erosion, including 2 of our own reports.

Telomere length assessment is useful to predict organ transplantation outcome. The importance of telomere length as a prediction marker depends on the analyzed material. To obtain reliable results, both graft cells (donor material) and lymphocytes (recipient material) should be examined. In the case of kidney transplantation, assessment of telomere length in the early post-transplant period allows prediction of the long-term function of the transplanted organ. To increase the accuracy of transplantation outcome prediction, telomere length assessment should be combined with evaluation of other aging biomarkers, like CDKN2A (p16). Large-scale clinical studies regarding telomere length measurement, including genome wide association analysis introducing relevant genetic factors, are needed for the future.

Novel surgical techniques, regenerative medicine, tissue engineering and innovative immunosuppression in kidney transplantation

On the 60th anniversary of the first successfully performed renal transplantation, we summarize the historical, current and potential future status of kidney transplantation. We discuss three different aspects with a potential significant influence on kidney transplantation progress: the development of surgical techniques, the influence of regenerative medicine and tissue engineering, and changes in immunosuppression. We evaluate the standard open surgical procedures with modern techniques and compare them to less invasive videoscopic as well as robotic techniques. The role of tissue engineering and regenerative medicine as a potential method for future kidney regeneration or replacement and the interesting search for novel solutions in the field of immunosuppression will be discussed. After 60 years since the first successfully performed kidney transplantation, we can conclude that the greatest achievements are associated with the development of surgical techniques and with planned systemic immunosuppression.

Evaluation of ICAM-1 and VCAM-1 Gene Polymorphisms in Patients with Periodontal Disease

BACKGROUND We aimed to investigate the potential genetic relationships between the polymorphisms of gene rs5498 ICAM-1 and rs1041163 VCAM-1 and chronic periodontitis in a Chinese population within Heilongjiang. MATERIAL AND METHODS Genomic DNA was extracted from oral mucosa cells of 584 periodontal patients and 182 healthy individuals. Genotyping of the rs5498 ICAM-1 and rs1041163 VCAM-1 gene polymorphisms was performed with the Multiplex SNaPshot technique. RESULTS Statistically significant associations were identified between the chronic periodontal patients and the controls in the gene polymorphisms of rs5498 ICAM-1 (P=0.007) and rs1041163 VCAM-1 (P=0.029). The distribution of rs5498 (P=0.029) and rs1041163 (P=0.049) differed significantly across the mild, moderate, and severe groups of periodontitis. CONCLUSIONS Our findings indicate that ICAM-1 rs5498 and VCAM-1 rs1041163 polymorphisms contribute to chronic periodontitis, and ICAM-1 rs5498 and VCAM-1 rs1041163 gene polymorphisms might be associated with periodontitis severity in the Heilongjiang Chinese population. Further studies should be conducted to determine whether these polymorphisms could be used as biomarkers of periodontitis.

IL2-IL21 gene cluster polymorphism is not associated with allograft function after kidney transplantation

BACKGROUND

Cytokines are key mediators of the immune response after transplantation. The interleukin (IL)-2 cytokine family, which includes IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21, is of particular interest because of its importance in the allogenic response. The aim of this study was to examine the association between the rs6822844 gene polymorphism in the IL2-IL21 region and allograft function after kidney transplantation.

METHODS

The study enrolled 270 Caucasian kidney allograft recipients (166 males and 104 females, mean age 47.63 ± 12.96 years). Following parameters were recorded in each case: recipient's age, delayed graft function (DGF), occurrence and number of episodes of acute rejection (AR), and chronic allograft dysfunction (CAD). Genotyping of the rs6822844 IL2-IL21 cluster gene polymorphism was performed using real-time PCR assay.

RESULTS

There were no statistically significant differences in the genotypes and alleles of the rs6822844 IL2-IL21 cluster gene polymorphism among patients with DGF (p = 0.72), AR (p = 0.69) and CAD (p = 0.77), or in creatinine concentrations 1, 3, 6, 12, 24 or 36 months after transplantation (p = 0.46, p = 0.58, p = 0.6, p = 0.72, p = 0.7, p = 0.76, respectively).

CONCLUSION

It seems that the rs6822844 IL2-IL21 gene cluster polymorphism is of little importance in allograft function after kidney transplantation.

Impacts of ICAM-1 gene polymorphisms on urothelial cell carcinoma susceptibility and clinicopathologic characteristics in Taiwan

Intercellular adhesion molecule (ICAM)-1, a cell adhesion molecule, is reportedly overexpressed in several cancers and may contribute to tumorgenesis and metastasis. The current study explored the effect of ICAM-1 gene polymorphisms on the susceptibility of developing urothelial cell carcinoma (UCC) and the clinicopathological status. A total of 558 participants, including 279 healthy people and 279 patients with UCC, were recruited for this study. Four single-nucleotide polymorphisms of the ICAM-1 gene were assessed by a real-time polymerase chain reaction with the TaqMan assay. After adjusting for other covariants, the individuals carrying at least one G allele at ICAM-1 rs5498 had a 1.603-fold risk of developing UCC than did wild-type (AA) carriers. Furthermore, UCC patients who carried at least one G allele at rs5498 had a higher invasive stage risk (p < 0.05) than did patients carrying the wild-type allele. In conclusion, the rs5498 polymorphic genotypes of ICAM-1 might contribute to the prediction of susceptibility to and pathological development of UCC. This is the first study to provide insight into risk factors associated with ICAM-1 variants in carcinogenesis of UCC in Taiwan.