Immunophenotypical Characterization of Macrophages in Rat Bleomycin-Induced Scleroderma

Abstract

Scleroderma is a skin disorder characterized by persistent fibrosis. Macrophage properties influencing cutaneous fibrogenesis remain to be fully elucidated. In this rat (F344 rats) model of scleroderma, at 1, 2, 3, and 4 weeks after initiation of daily subcutaneous injections of bleomycin (BLM; 100 ml of 1 mg/ml daily), skin samples were collected for histological and immunohistochemical evaluations. Immunohistochemically, the numbers of cells reacting to ED1 (anti-CD68; phagocytic activity) and ED2 (anti-CD163; inflammatory factor production) began to increase at week 1, peaked at week 2, and decreased thereafter. In contrast, the increased number of cells reacting to OX6 (anti-MHC class II molecules) was seen from week 2 and remained elevated until week 4. aSmooth muscle actin-positive myofibroblasts were increased for 4 weeks. Double labeling revealed that galectin-3, a regulator of fibrogenic factor TGF-b1, was expressed in CD68þ, CD163þ, and MHC class IIþ macrophages and myofibroblasts. mRNA expression of TGF-b1, as well as MCP-1 and CSF-1 (both macrophage function modulators), were significantly elevated at weeks 1 to 4. This study shows that the increased number of macrophages with heterogeneous immunophenotypes, which might be induced by MCP-1 and CSF-1, could participate in the sclerotic lesion formation, presumably through increased fibrogenic factors such as galectin-3 and TGF-b1; the data may provide useful information to understand the pathogenesis of the human scleroderma condition.

CSF-1–dependant donor-derived macrophages mediate chronic graft-versus-host disease

“…Cutaneous macrophage infiltration has been suggested to be associated with refractory aGVHD and poor prognosis (16). Alternatively, activated macrophages (CD163 + ) have been previously shown to be present in both humans (17) and rats with systemic sclerosis (18). Additionally, macrophages displaying an M2 phenotype are present in the skin (19) and lungs of patients with systemic sclerosis (20).…”

Participation of bone morphogenetic protein (BMP)-6 and osteopontin in cisplatin (CDDP)-induced rat renal fibrosis

“…2). TGF-␤1 is well known to be an inducer of myofibroblasts from the progenitors, and its expression is increased in organs undergoing fibrogenesis (Golbar et al, 2011;Golbar et al, 2013;Juniantito et al, 2013;Kang et al, 2007;Liu, 2006). TGF-␤1 mRNA expression was increased in the present CDDP-induced kidney lesions.…”

The expression and function of galectins in skin physiology and pathology

“…In a rat model of bleomycininduced scleroderma, immunohistochemical staining of skin lesions showed that galectin-3 could be expressed in CD68 + , CD163 + , and MHC class II + macrophages and myofibroblasts. [37] Human studies showed galectin-3 serum levels were significantly decreased in patients with early stage diffuse cutaneous SSc than in normal control. However, galectin-3 serum levels were higher in SSc patients with digital ulcers/elevated right ventricular systolic pressure than in patients without these signs.…”

“…The profibrotic function of galectin‐3 in fibrosis development in different organs, including liver, lung, heart, kidney, and blood vessels, was mentioned (reviewed in ). In a rat model of bleomycin‐induced scleroderma, immunohistochemical staining of skin lesions showed that galectin‐3 could be expressed in CD68 + , CD163 + , and MHC class II + macrophages and myofibroblasts . Human studies showed galectin‐3 serum levels were significantly decreased in patients with early stage diffuse cutaneous SSc than in normal control.…”

“…Lower serum gal-1 in SSc patients with digital vasculopathy [35,[37][38][39][40] Gal-3 expression in macrophages/myofibroblasts in bleomycin-induced rat scleroderma Gal-1 promotes wound healing through ROS production [43,45,[47][48][49][52][53][54] Gal-3 promotes keratinocyte migration through regulating intracellular EGFR trafficking Gal-3 promotes re-epithelization but not the gross wound healing Gal-7 overexpressing in the basal epidermal keratinocytes impairs intercellular cohesion and impaired keratinocyte migration Gal-7 is increased in wounded epidermis, promotes keratinocyte migration, re-epithelization but is suppressed by high glucose (Continues) was barely found in biopsies of malignant melanoma. Galectin-7 overexpression in B16F1 melanoma cells reduced cell motility, increased resistance to apoptosis and EGR-1 (early growth response protein 1) expression, but was insufficient to affect the tumor growth.…”