Expression of MUC2 and MUC4 proteins and cytokines: early markers of intestinal graft rejection

Whole Exome Sequencing to Find Candidate Variants for the Prediction of Kidney Transplantation Efficacy

INTRODUCTION

Kidney transplantation is the optimal treatment strategy for some end-stage renal disease (ESRD); however, graft survival and the success of the transplantation depend on several elements, including the genetics of recipients. In this study, we evaluated exon loci variants based on a high-resolution Next Generation Sequencing (NGS) method.

METHODS

We evaluated whole-exome sequencing (WES) of transplanted kidney recipients in a prospective study. The study involved a total of 10 patients (5 without a history of rejection and 5 with). About five milliliters of blood were collected for DNA extraction, followed by whole-exome sequencing based on molecular inversion probes (MIPs).

RESULTS

Sequencing and variant filtering identified nine pathogenic variants in rejecting patients (low survival). Interestingly, in five patients with successful kidney transplantation, we found 86 SNPs in 63 genes 61 were variants of uncertain significance (VUS), 5 were likely pathogenic, and five were likely benign/benign. The only overlap between rejecting and non-rejecting patients was SNPs rs529922492 in rejecting and rs773542127 in non-rejecting patients' MUC4 gene.

CONCLUSIONS

Nine variants of rs779232502, rs3831942, rs564955632, rs529922492, rs762675930, rs569593251, rs192347509, rs548514380, and rs72648913 have roles in short graft survival.

Cytokine stimulation of MUC4 expression in human female reproductive tissue carcinoma cell lines and endometrial cancer

MUC4, a transmembrane glycoprotein, interferes with cell adhesion, and promotes EGFR signaling in cancer. Studies in rat models have demonstrated steroid hormonal regulation of endometrial MUC4 expression. In this study, qRT-PCR screening of mouse tissues determined that Muc4 mRNA also was robustly expressed in mouse uteri. Previous studies from our labs have demonstrated MUC4 mRNA was expressed at levels <1% of MUC1 mRNA in human endometrium and endometriotic tissue. Multiple human endometrial adenocarcinoma cell lines were assayed for MUC4 mRNA expression revealing extremely low basal expression in the Ishikawa, RL-95-2, AN3CA, and KLE lines. Moderate to high expression was observed in HEC50 and HEC-1A cells. MUC4 mRNA expression was not affected by progesterone and/or estrogen treatment, but was greatly stimulated at both mRNA and protein levels by proinflammatory cytokines (IFN-γ and TNF-α), particularly when used in combination. In endometrial tissue, MUC4 mRNA levels did not change significantly between normal or cancerous samples; although, a subset of patients with grade 1 and 2 tumors displayed substantially higher expression. Likewise, immunostaining of human endometrial adenocarcinoma tissues revealed little to no staining in many patients (low MUC4), but strong staining in some patients (high MUC4) independent of cancer grade. In cases where staining was observed, it was heterogeneous with some cells displaying robust MUC4 expression and others displaying little or no staining. Collectively, these observations demonstrate that while MUC4 is highly expressed in the mouse uterus, it is not a major mucin in normal human endometrium. Rather, MUC4 is a potential marker of endometrial adenocarcinoma in a subset of patients.

MUC4 as a diagnostic marker in cancer

BACKGROUND

Mucins are high molecular mass glycoproteins whose role in diagnosis, prognosis and therapy is being increasingly recognized owing to their altered expression in a variety of carcinomas. MUC4, a membrane-bound mucin encoded by a gene located on chromosome locus 3q29, is aberrantly expressed in several cancers including those of the bile duct, breast, colon, esophagus, ovary, lung, prostate, stomach and pancreas.

OBJECTIVE

This review considers the potential use of the MUC4 expression pattern in the diagnosis and prognosis of various cancers.

RESULTS/CONCLUSION

MUC4 expression is a specific marker of epithelial tumors and its expression correlates positively with the degree of differentiation in several cancers. Importantly, MUC4 has emerged as a specific marker of dysplasia, being expressed in the earliest dysplastic lesions preceding several malignancies, including lethal pancreatic cancer. The presence of MUC4-specific antibodies in the serum and of the transcript in peripheral blood mononuclear cells of cancer patients raises the possibility of it emerging as a new diagnostic biomarker for bedside application in high-risk individuals and those with established cancer.

Epithelial lineages of the small intestine have unique patterns of GATA expression

The ability of the GATA family of factors to interact with numerous other factors, co-factors, and repressors suggests that they may play key roles in tissues and cells where they are expressed. Adult mouse small intestine has been shown to express GATA-4, GATA-5, and GATA-6, where they have been implicated in the activation of a number of intestinal genes. Determination of which GATA factor(s) are involved in a specific function in tissues expressing multiple family members has proven difficult. The immunohistochemical analysis presented here demonstrate that within the mouse small intestine GATA-4/-5/-6 are found to be uniquely distributed among the various differentiated lineages of the intestinal epithelium. Among differentiated cells GATA-4 is found only in the villous enterocytes. GATA-5 is absent from enterocytes, but was found in the remaining lineages: goblet, Paneth and enteroendocrine. Additionally, high levels of GATA-6 are found in only one of these differentiated cell types, the enteroendocrine lineage. The observed distribution suggests that the GATA factors may have distinct roles in lineage allocation, lineage maintenance, and/or terminal differentiation events in small intestine.

Intragraft distribution of lymphocytes expressing β7 integrins after small bowel transplantation in mice

Lymphocytes with activated beta7 integrins (alphaEbeta7 and alpha4beta7) contribute to inflammatory reactions in the small bowel. Since the selective recruitment of lymphocytes to the lymphoid compartments of the small bowel is controlled by distinct adhesion molecule interactions, a compartment-dependent use of beta7 integrins may influence the rejection response within intestinal transplants. To further delineate the nature of beta7 integrin-mediated graft infiltration, we analysed their expression on T lymphocytes in the heterotopically transplanted small bowel of BALB/c and C57BL/6 mice. Lymphocytes isolated from the epithelium, lamina propria (LP), Peyer's patches (PP), and mesenteric lymph nodes (MLN) were analysed by three-color fluorescence flow cytometry using monoclonal antibodies (mAb) to integrin the subunits, lymphocyte markers, and MHC I of the donor and recipient strains. On postoperative day 5 (POD) after allogeneic small bowel transplantation (SBT), 43% of intraepithelial lymphocytes (IEL) and 63% of LP, 93% of MLN, and 93% of PP lymphocytes were of host origin. In the MLN and PP of allografts, a major infiltrating lymphocyte population consisted of CD8+ cells with increased expression of alpha4beta7 and decreased expression of L-selectin, an adhesion molecule profile characteristic of intestinal effector cell phenotypes. An increase in alpha4beta7 levels was also found on CD8+ host lymphocytes in the LP. The integrin profile of a number of host IEL suggests an ongoing transition from the phenotype of graft infiltrating lymphocytes with high levels of alpha4beta7 and low levels of alphaepsilonbeta7 to that of resident IEL with high levels of alphaepsilonbeta7 and low levels of alpha4beta7. The importance of beta7-mediated lymphocyte trafficking to the graft is attested by the significant reduction in the host lymphocyte population in the LP, PP, and epithelium following the administration of a beta7-blocking mAb to allograft recipients. In conclusion, while the infiltration patterns of lymphocytes may vary between the lymphoid compartments of intestinal allografts, host CD8+ lymphocytes with high levels of alpha4beta7 constitute a major effector cell population that affects the entire graft.

Histological changes in the gastric mucosa after Helicobacter pylori eradication

BACKGROUND AND AIM

Correa described a stepwise model of changes in the gastric mucosa after Helicobacter pylori infection, from the normal gastric epithelium to chronic gastritis, atrophy, intestinal metaplasia, dysplasia and adenocarcinoma. The aim of this study is to assess the reversibility of these mucosal changes after H. pylori eradication.

METHODS

The study sample consisted of 89 patients who underwent at least two gastric biopsies from 1990 to 2000, with a positive finding for H. pylori in the first and a negative finding in the second. Specimens were evaluated for acute and chronic inflammation, lymphoid aggregates, proliferation, mucosal atrophy, intestinal metaplasia, dysplasia, and MUC5AC and MUC6 expression using histochemical and immunohistochemical methods.

RESULTS

The average time between biopsies was 23.15 +/- 26.30 months. There was a significant decrease in acute and chronic inflammation scores, from 1.48 +/- 1.10 to 0.23 +/- 0.63 and from 2.67 +/- 0.68 to 1.44 +/- 1.04, respectively (P < 0.001), and in a number of lymphoid follicles, from 42.68% to 21.95% of cases (P < 0.008). The number of glands increased from 39.08 +/- 16.67/mm to 48.86 +/- 17.93/mm after eradication (P = 0.062). Intestinal metaplasia was found in 17.07% of the cases, with no change over time. Dysplasia appeared in one case 2 years after eradication. In 27 patients, the Ki67 labeling index decreased significantly after eradication, while MUC5AC and MUC6 expression increased.

CONCLUSION

Our findings, although not conclusive for arrest of the malignant potential, support the importance of H. pylori eradication in the prevention of gastric cancer.

Viral interleukin-10-engineered autologous hematopoietic stem cell therapy: a novel gene therapy approach to prevent graft rejection

The Epstein-Barr virus-encoded protein BCRF1 (viral interleukin [vIL]-10) is a biologically active homologue of cellular interleukin (IL)-10. In this study, a novel gene therapy approach to prolong allograft survival was designed. Autologous (syngeneic) hematopoietic progenitor/stem cell-enriched (HSC; lineage(-ve)) population derived from CBA/J mouse bone marrow were transduced with retrovirus encoding vIL-10 gene (vIL-10-HSC), ex vivo; vIL-10-HSC were injected (4-6 x 10(6) cells intravenously) into lethally (9.5 Gy) or sublethally (4 Gy) irradiated CBA/J mice. Six weeks after vIL-10-HSC administration, vascular heterotopic heart (C57BL/6) transplantation was performed. Ex vivo, the vIL-10-HSC produced 5.4 +/- 0.5 ng of vIL-10 protein/2 x 10(5) cells per 24 hr. In vivo, serum vIL-10 production was 187 +/- 205 pg/ml during 3-10 weeks after vIL-10-HSC administration. Cardiac allograft survival was prolonged (p < 0.004) in lethally (71 +/- 40 days) and sublethally (114 +/- 15 days) irradiated mice that received vIL-10-HSC compared to controls that received unengineered (UE) HSC or vector DNA-engineered HSC (12-16 days). However, secondary skin graft (C57BL/6) survival was not prolonged in cardiac allograft-tolerant animals. In the vIL-10-HSC-administered group, graft histopathology demonstrated mild arteritis/venulitis (grade 0.7) and rejection (grade 1.0). Intragraft expression of costimulatory molecules (B7.1, B7.2), cytokines (IL-2, IL-4, mIL-10, interferon [IFN]-gamma), and inducible nitric oxide synthase (iNOS) molecules was markedly lower in vIL-10-HSC-treated tolerant grafts that survived more than 100 days compared to vector DNA-HSC- or UE-HSC-treated controls. Furthermore, T lymphocytes derived from vIL-10-HSC-treated tolerant recipients demonstrated hyporeactivity to donor antigens in mixed lymphocyte cultures. Administration of autologous vIL-10-engineered HSC prior to organ transplantation prolonged cardiac allograft survival significantly.

Intragraft heat shock protein-60 expression after small bowel transplantation in the mouse

The time course of heat shock protein 60 (hsp 60) expression after intestinal transplantation in syngeneic and allogeneic combination was correlated with the degree of rejection. Hsp 60 expression was assessed by immunostaining; rejection degree was established by histologic examination on posttransplantation days 1, 3, 6, and 8. No signs of rejection occurred in syngeneic grafts at any time. In the allogeneic setting, rejection was absent in all but 1 case on postoperative day 3. Three days later moderate rejection was evident based on focal crypt destruction and focal mucosal ulceration, whereas at postoperative day 8 extensive mucosal sloughing was the dominant feature, consistent with advanced rejection. Hsp 60 remained undetectable in the syngeneic setting at all times. In allografts, hsp 60 was initially expressed on posttransplant day 3, increasing synchronously with the progression of rejection at days 6 and 8. Hsp 60 expression was localized almost exclusively to the crypt area and the lower third of the villi. In conclusion, the rejection of murine allogeneic intestinal grafts is characterized by a progressive expression of hsp 60 in the epithelium.