Biomedical subjects

Shuguang Jiang

Publications and source records attributed to Shuguang Jiang.

9 recordsLinked to original sources

PubMed2006

Myeloid lineage progenitors give rise to vascular endothelium.

Despite an important role in vascular development and repair, the origin of endothelial progenitors remains unknown. Accumulating evidence indicates that cells derived from the hematopoietic system participate in angiogenesis. However, the identity and functional role of these cells remain controversial. Here we show that vascular endothelial cells can differentiate from common myeloid progenitors and granulocyte/macrophage progenitors. Endothelial cells derived from transplanted bone marrow-derived myeloid lineage progenitors expressed CD31, von Willebrand factor, and Tie2 but did not express the hematopoietic markers CD45 and F4/80 or the pericyte markers desmin and smooth muscle actin. Lineage tracing analysis in combination with a Tie2-driven Cre/lox reporter system revealed that, in contrast to bone marrow-derived hepatocytes, bone marrow-derived endothelial cells are not the products of cell fusion. The establishment of both hematopoietic and endothelial cell chimerism after parabiosis demonstrates that circulating cells can give rise to vascular endothelium in the absence of acute radiation injury. Our findings indicate that endothelial cells are an intrinsic component of myeloid lineage differentiation and underscore the close functional relationship between the hematopoietic and vascular systems.

Animals↗

PubMed2005

In vivo genetic selection of renal proximal tubules.

Repopulation by transplanted cells can result in effective therapy for several regenerative organs including blood, liver, and skin. In contrast, cell therapies for renal diseases are not currently available. Here we developed an animal model in which cells genetically resistant to a toxic intermediate of tyrosine metabolism, homogentisic acid (HGA), were able to repopulate the damaged proximal tubule epithelium of mice with fumarylacetoacetate hydrolase (Fah) deficiency. HGA resistance was achieved by two independent mechanisms. First, Fah+ transplanted bone marrow cells produced significant replacement of damaged proximal tubular epithelium (up to 50%). The majority of bone marrow-derived epithelial cells were generated by cell fusion, not transdifferentiation. In addition to regeneration by fusion-derived epithelial cells, proximal tubular repopulation was also observed by host epithelial cells, which had lost the homogentisic acid dioxygenase gene. These data demonstrate that extensive regeneration of the renal proximal tubule compartment can be achieved through genetic selection of functional cells.

Acute Disease↗

PubMed2005

Donor marker infidelity in transgenic hematopoietic stem cells.

Transgenic marking approaches are increasingly used to evaluate the developmental potential of stem cells. However, cell fate mapping studies using different transgenic marking systems have produced conflicting results. These disparate findings may be due in part to the infidelity of donor marker gene expression. Analysis of hematopoietic stem cells (c-Kit+, Sca-1+, lineage marker- [KSL]) from a transgenic mouse (1Osb) engineered to ubiquitously express the enhanced green fluorescent protein (EGFP) reveals two distinct populations. Forty percent of KSL cells demonstrate intermediate levels of EGFP fluorescence and differentiate into subpopulations of B cells, T cells, and myeloid cells that do not express EGFP. By contrast, progeny of the remaining 60% of KSL cells are almost exclusively EGFP bright. Long-term multilineage hematopoietic reconstitution and serial transplantation experiments show that these differences in EGFP are a property of self-renewing stem cells. Furthermore, both the transgene integration site and the activation status of a cell are important determinants of EGFP expression. These results indicate that a combination of donor cell markers is required to reliably track the full differentiation potential of transgenic stem cells.

Animals↗

PubMed2004

Transplanted human bone marrow contributes to vascular endothelium.

Recent evidence indicates that bone marrow is a source of endothelial progenitor cells that are mobilized into the peripheral blood in response to cytokines or tissue injury. Previously, we showed that functional endothelial cells (ECs) can be clonally derived from phenotypically defined hematopoietic stem cells. To determine the EC potential of human bone marrow and peripheral blood stem cells, blood vessels in sex-mismatched transplant recipients were evaluated. EC outcomes were identified by using a combination of immunohistochemistry and XY interphase FISH. Donor-derived ECs were detected in the skin and gut of transplant recipients with a mean frequency of 2% and could readily be distinguished from CD45-expressing hematopoietic stem cells. None of the >4,000 ECs examined had more than two sex chromosomes, consistent with an absence of cell fusion. Y chromosome signals were not detected in sex-matched female recipients, excluding the vertical transmission of male cells. None of the recipients evaluated before hematopoietic engraftment demonstrated donor-derived ECs, indicating a close linkage between the recovery of hematopoiesis and EC outcomes. Transplantable bone marrow-derived endothelial progenitor cells may represent novel therapeutic targets for hematopoietic and vascular disease.

Biopsy↗

PubMed2003

Transplanted adult hematopoietic stems cells differentiate into functional endothelial cells.

During early embryogenesis, blood vessels and hematopoietic cells arise from a common precursor cell, the hemangioblast. Recent studies have identified endothelial progenitor cells in the peripheral blood, and there is accumulating evidence that a subset of these cells is derived from precursors in the bone marrow. Here we show that adult bone marrow-derived, phenotypically defined hematopoietic stem cells (c-kit+, Sca-1+, lineage-) give rise to functional endothelial cells. With the exception of the brain, donor-derived cells are rapidly integrated into blood vessels. Durably engrafted endothelial cells express CD31, produce von Willebrand factor, and take up low-density lipoprotein. Analysis of DNA content indicates that donor-derived endothelial cells are not the products of cell fusion. Self-renewal of stem cells with hematopoietic and endothelial cell potential was revealed by serial transplantation studies. The clonal origin of both hematopoietic and endothelial cell outcomes was established by the transfer of a single cell. These results suggest that adult bone marrow-derived hematopoietic stem cells may serve as a reservoir for endothelial cell progenitors.

Animals↗

PubMed2002

Crucial role of CCL3/MIP-1alpha in the recurrence of autoimmune anterior uveitis induced with myelin basic protein in Lewis rats.

In this study, we examined the role of CCL2/MCP-1, CCL3/MIP-1alpha, CCL4/MIP-1beta, and CCL5/RANTES during recurrent anterior uveitis (RAU). LEW rats injected with myelin basic protein (MBP) developed experimental autoimmune encephalomyelitis (EAE) and associated anterior uveitis (AU), which was mediated by CD4(+) T cells. After recovery, rats become resistant to EAE but developed RAU. Rats reinjected with MBP developed RAU without EAE. The chemokines tested were detected in the eye at RAU accelerated onset, increased as the disease progressed, and fell as clinical signs improved. At the same time, in the spinal cords of rats, these chemokines were still detected but at reduced levels. Administration of anti-MIP-1alpha neutralizing antibodies resulted in almost complete suppression of clinical RAU and significant reduction of inflammatory cell recruitment into the iris. Anti-MIP-1beta and anti-MCP-1 antibodies were effective in suppression of RAU but to lesser degree. Treatment with anti-RANTES antibodies was not effective in protecting against the recurrent development of the disease. In the eyes, the message for CCR1 and CCR5 was considerably elevated prior to the onset of AU and decreased after treatment with anti-chemokine antibodies. Our results suggest a crucial role of CCL3/MIP-1alpha in the development of RAU in Lewis rats. In addition, CCL2/MCP-1 and CCL4/MIP-1beta may also play a role in immunopathogenesis of RAU.

Animals↗

PubMed2002

Phenotypes of T cells infiltrating the eyes in autoimmune anterior uveitis associated with EAE.

PURPOSE: Lewis rats immunized with myelin basic protein (MBP) develop experimental autoimmune encephalomyelitis (EAE) and associated anterior uveitis (AU), which recurs. The goal was to analyze cellular activation markers and adhesion molecules of T cells that infiltrate the eyes and spinal cord during acute and recurrent AU in actively and passively induced diseases simultaneously in the same animals. METHODS: EAE-AU was induced in Lewis rats by immunization with MBP in CFA, or by adoptive transfer of MBP-specific T-cell lines, and the signs of clinical EAE and AU was scored. Cells isolated from the iris-ciliary body were tested by flow cytometry for expression of CD4, CD8, CD45RC, T-cell receptor (TCR) Vbeta8.2, alpha4 integrin, L-selectin, CD44, and CD134. RESULTS: Ocular T cells showed a significantly higher expression of CD62L (l-selectin) than did T cells in the spinal cord. In addition, a much lower percentage of infiltrating CD8(+) T cells was found in the eyes during AU. In passive transfer experiments, T-cell lines derived from acute and recurrent uveitis showing similar phenotypes differing in specificities but possessed the capacity of inducing both AU and EAE. Pretreatment of rats with effector CD4(+) T cell before MBP immunization did not induce suppression of EAE or AU. However, pretreatment with regulatory CD8(+) T cells significantly reduced the severity and duration of both EAE and AU. CONCLUSIONS: T cells recruited into the inflamed eyes or central nervous system (CNS) are mainly activated/memory T cells expressing different levels of L-selectin. Regulatory CD8(+) T cells may contribute to the susceptibility of the eye to recurrent AU. The differences in phenotypes of T cells recruited simultaneously to two different organs suggest that microenvironment also plays a role in determining lymphocyte homing.

Adoptive Transfer↗

PubMedDate not supplied

Cryptic MBP epitope 1-20 is inducing autoimmune anterior uveitis without EAE in Lewis rats.

Lewis rats immunized with myelin basic protein (MBP) developed experimental autoimmune encephalomyelitis (EAE) and associated anterior uveitis (AU). Although several cryptic epitopes of MBP have strong encephalitogenic and uveitogenic properties, the peptide corresponding to the MBP residues 1-20 was uniquely capable of inducing AU without EAE. In this study, we showed that acetylation of the N-terminal amino acid did not produce encephalitogenicity, did not enhance uveitogenicity, and did not improve T cell proliferation in Lewis rats. The cytokine production profile induced by MBP(1-20) immunization was consistent with a Th1 response. In MBP-injected rats and in peptide-injected rats, the frequency of the IFN-gamma-secreting cells in MBP(69-89)-stimulated T cells was significantly higher than the frequency of IFN-gamma-secreting cells in MBP(1-20)-stimulated T cells. However, similar numbers of IFN-gamma-producing specific cells were found in the eyes of MBP(69-89) and MBP(1-20) immunized rats. In these rats, the iris-infiltrating cells consisted of a much higher percentage of CD4(+) T cells expressing L-selectin (CD62L) than did those cells found in the spinal cord. The results demonstrate that MBP(1-20) is immunogenic and uveitogenic, although it induced only weak proliferation and weak Th1 reaction. The fact that T cells with the same specificity have different effects on target organs suggested that, in the eye and spinal cord, a distinct mechanism might mediate the recruitment of cells to these organs.

Acetylation↗

PubMedDate not supplied

Alcohol consumption during murine acquired immunodeficiency syndrome accentuates heart pathology due to coxsackievirus.

Alcohol, especially after prolonged and excessive consumption, results in marked alteration of host immunity and increased susceptibility to infection. To determine whether ethanol consumption exacerbates coxsackievirus B3 cardiomyopathy during murine acquired immunodeficiency syndrome (AIDS), female C57BL/6 mice were infected with LP-BM5 retrovirus and administered 40% ethanol both in water and in solid agar-based form. Cardiac histopathology was semi-quantitatively assessed for lesion severity and induced production of splenocyte: interleukin (IL)-2, IL-4, IL-6, tumour necrosis factor-alpha and interferon-gamma were determined. Ethanol consumption during murine retrovirus infection increased coxsackievirus-induced myocarditis in 85% of the animals and also exacerbated the lesion severity. Mice infected with retrovirus and co-infected with coxsackievirus showed significant heart lesions. Retrovirus infection suppressed Th1 responses, causing cytokine dysregulation and immunosuppression, which facilitated coxsackievirus-induced myocarditis. Our data suggest that ethanol consumption heightens the cytokine imbalance to favour a Th2 response by enhancing Th2 and/or by suppressing Th1 function. In conclusion, murine AIDS facilitated severe cardiotoxicity during coxsackievirus infection, while non-retrovirus-infected mice were resistant. These effects were accentuated by ethanol consumption.

Administration, Oral↗