Correlation of the levels of DNA-binding inhibitor Id3 and regulatory T cells with SLE disease severity.

E proteins, a subset of basic helix-loop-helix (bHLH) proteins, are transcription activators and their functions are inhibited by DNA-binding inhibitor (Id) 1-4. Studies have shown that Treg levels are decreased in Id3 knockout mice. Mice over-expressing Id1 in CD4 T cells possessed a greater number of regulatory T cells (Treg) and exhibited attenuated experimental autoimmune encephalomyelitis (EAE). The significance of Id proteins in human systemic lupus erythematosus (SLE) remains unclear. In this study, we systematically analyzed Id transcription in naïve, memory CD4 cells and regulatory T cells in peripheral blood mononuclear cells (PBMCs) in patients with active or inactive SLE. In parallel, Treg subsets in PBMCs were analyzed using different strategies. Id expression levels were correlated with Treg numbers as well as clinical indicators. We found that Id genes expressed in human peripheral CD4 cells were mainly Id2 and Id3. Id3 levels were significantly elevated in CD4+CD25hi T cells of patients with active SLE. Likewise, Id3 levels were positively correlated with increased CD4+FoxP3+ and CD4+Helios+FoxP3+ Treg cells in these patients. Id3 levels were found to be positively correlated with erythrocyte sedimentation rate (ESR), lupus anticoagulant (LAC), ribosomal antibody and SLE Disease Activity Index (SLEDAI) in patients with active SLE. Mice overexpressing Id1 in CD4+ T cells possessed significantly higher Treg levels in spleen and lower autoantibody concentrations in serum. Our results suggest that during the pathogenesis of SLE, up-regulation of Id3 can promote Treg differentiation to play an inhibitory effect on autoimmune responses.

Alterations in Factors Involved in Differentiation and Barrier Function in the Epithelium in Oral and Genital Lichen Planus.

Lichen planus is a chronic recurrent inflammatory disease affecting both skin and mucosa, mainly in oral and/or genital regions. Keratinocytes go through a well-regulated process of proliferation and differentiation, alterations in which may result in defects in the protective epithelial barrier. Long-term barrier impairment might lead to chronic inflammation. In order to broaden our understanding of the differentiation process in mucosal lichen planus, we mapped the expression of 4 factors known to be involved in differentiation. Biopsies were collected from oral and genital lichen planus lesions and normal controls. Altered expression of all 4 factors in epithelium from lichen planus lesions was found, clearly indicating disturbed epithelial differentiation in lichen planus lesions.

Id-1, Id-2, and Id-3 co-expression correlates with prognosis in stage I and II lung adenocarcinoma patients treated with surgery and adjuvant chemotherapy.

Inhibitors of DNA binding/inhibitors of differentiation (Id) protein family have been shown to be involved in carcinogenesis. However, the roles of Id during lung adenocarcinoma (ADC) progression remain unclear. Eighty-eight ADC samples were evaluated for Id-1,2,3 level and angiogenesis (CD 34 and VEGF microvessel density) by immunohistochemistry and morphometry. The impact of these markers was tested on follow-up until death or recurrence. A significant difference between tumor and normal tissue was found for Id-1,2,3 expression (P < 0.01). In addition, high levels of nuclear Id-1 were associated with higher angiogenesis in the tumor stroma (P < 0.01). Equally significant was the association between patients in T1-stage and low cytoplasmic Id-2, as well as patients in stage-IIb and low Id-3. High cytoplasm Id-3 expression was also directly associated to lymph nodes metastasis (P = 0.05). Patients at stages I to III, with low Id-1 and Id-3 cytoplasm histoscores showed significant long metastasis-free survival time than those with high Id-1 or Id-3 expression (P = 0.04). Furthermore, high MVD-CD34 and MVD-VEGF expression were associated with short recurrence-free survival compared to low MVD-CD34 and MVD-VEGF expressions (P = 0.04). Cox model analyses controlled for age, lymph node metastasis, and adjuvant treatments showed that nuclear Id-1, cytoplasmic Id-3, and MVD-CD34 were significantly associated with survival time. Median score for nuclear Id-1 and cytoplasmic Id-3 divided patients in two groups, being that those with increased Id-1 and Id-3 presented higher risk of death. Ids showed an independent prognostic value in patients with lung ADC, regardless of disease stage. Id-1 and Id-3 should be considered new target candidates in the development of personalized therapy in lung ADC.

ID2 and ID3 protein expression mirrors granulopoietic maturation and discriminates between acute leukemia subtypes.

The inhibitors of DNA binding (ID) inhibit basic helix-loop-helix transcription factors and thereby guide cellular differentiation and proliferation. To elucidate the involvement of IDs in hematopoiesis and acute leukemias (AL), we analyzed ID2 and ID3 expression in hematopoiesis and leukemic blasts in bone marrow biopsies (BMB). BMB of healthy stem cell donors (n = 19) and BMB of patients with acute myeloid leukemia (AML) with myelodysplasia-related changes (AML-MD; n = 19), de novo AML (n = 20), B-acute lymphoblastic leukemia (B-ALL) (n = 23), T-ALL (n = 19), were immunohistochemically stained for ID2 and ID3 expression. The expression patterns were evaluated and quantified for each hematopoietic lineage and each leukemia subtype. In normal BMB, immature granulopoiesis showed weak ID2 and strong ID3 expression, which was lost during maturation (p < 0.001). Erythropoiesis remained negative for ID2/3 (p < 0.001). ID2/3 expression differed between immature granulopoiesis and leukemic blasts (p < 0.001). Moreover, differential ID2/3 expression was seen between AL subgroups: AML, especially AML-MD, had more ID2- (p < 0.001) and ID3-positive (p < 0.001) blasts than ALL. We show a comprehensive in situ picture of ID2/3 expression in hematopoiesis and AL. Morphologically, ID2/3 proteins seem to be involved in the granulopoietic maturation. Importantly, the distinct ID2/3 expression patterns in AL indicate a specific deregulation of ID2/3 in the various types of AL and may support subtyping of AL.

Inhibitor of differentiation proteins do not influence prognosis of biliary tract cancer.

AIM: To investigate the expression and clinical relevance of inhibitor of differentiation (ID) proteins in biliary tract cancer. METHODS: ID protein expression was analyzed in 129 samples from patients with advanced biliary tract cancer (BTC) (45 extrahepatic, 50 intrahepatic, and 34 gallbladder cancers), compared to normal controls and correlated with clinical an pathological parameters. RESULTS: ID1-3 proteins are frequently overexpressed in all BTC subtypes analyzed. No correlation between increased ID protein expression and tumor grading, tumor subtype or treatment response was detected. Survival was influenced primary tumor localization (extrahepatic vs intrahepatic and gall bladder cancer, OS 1.5 years vs 0.9 years vs 0.7 years, P = 0.002), by stage at diagnosis (OS 2.7 years in stage I vs 0.6 years in stage IV, P < 0.001), resection status and response to systemic chemotherapy. In a multivariate model, ID protein expression did not correlate with clinical prognosis. Nevertheless, there was a trend of shorter OS in patients with loss of cytoplasmic ID4 protein expression (P = 0.076). CONCLUSION: ID protein expression is frequently deregulated in BTC but does not influence clinical prognosis. Their usefulness as prognostic biomarkers in BTC is very limited.

Humoral factors released from human periodontal ligament cells influence calcification and proliferation in human bone marrow mesenchymal stem cells.

BACKGROUND: Transplantation of bone marrow mesenchymal stem cells (MSCs) is believed to be a new modality for periodontal tissue regeneration. However, little is known about the factors that influence the functions of the transplanted MSCs. Periodontal ligament cells may be implicated in regulating MSC functions. METHODS: To examine the effect of humoral factors (HFs) produced by human periodontal ligament (HPL) cells on human MSC (hMSC) gene expression, hMSCs were cocultured separately with HPL cells. The gene expression of the hMSCs was analyzed by microarray. Moreover, the effect of conditioned medium (CM) from cultures of HPL cells (CM-HPL cells) on the proliferation and mineralizing capacity of hMSCs was examined. RESULTS: Thirty-five genes whose expressions were upregulated more than two-fold and 32 genes whose expressions were downregulated more than two-fold were identified in hMSCs cocultured separately with HPL cells. CM-HPL cells prevented calcification in hMSCs cultured with bone morphogenetic protein-2 but not dexamethasone. CM-HPL cells stimulated cell proliferation in hMSCs, whereas CM from culture of human osteoblasts did not influence the proliferation. CONCLUSIONS: To the best of our knowledge, this is the first study on the global gene expression of MSCs cocultured with periodontal ligament cells. A particular humoral factor released from periodontal ligament cells is suggested to affect differentiation and proliferation in MSCs.

ID genes mediate tumor reinitiation during breast cancer lung metastasis.

The establishment of distant metastases depends on the capacity of small numbers of cancer cells to regenerate a tumor after entering a target tissue. The mechanisms that confer this capacity remain to be defined. Here we identify a role for the transcriptional inhibitors of differentiation Id1 and Id3 as selective mediators of lung metastatic colonization in the triple negative [TN, i.e., lacking expression of estrogen receptor and progesterone receptor, and lacking Her2 (human epidermal growth factor receptor 2) amplification] subgroup of human breast cancer. Although broad expression of Id1 has recently been documented in tumors of the rare metaplastic subtype, here we report that rare Id1-expressing cells are also present in the more common TN subset of human breast tumors but not in other subtypes. We also provide evidence that Id1 expression is enriched in clinically obtained hormone receptor negative lung metastases. Functional studies demonstrate that Id1 and its closely related family member Id3 are required for tumor initiating functions, both in the context of primary tumor formation and during metastatic colonization of the lung microenvironment. In vivo characterization of lung metastatic progression reveals that Id1 and Id3 facilitate sustained proliferation during the early stages of metastatic colonization, subsequent to extravasation into the lung parenchyma. These results shed light on the proliferative mechanisms that initiate metastatic colonization, and they implicate Id1 and Id3 as mediators of this malignant function in the TN subgroup of breast cancers.