Differential contribution of M(r) 120 kDa rasGTPase-activating protein and neurofibromatosis type 1 gene product during the transition from growth phase to arrested state in human fibroblasts accompanied by a unique rasGTPase-activating activity

Production of IgG3 in MRL/Mp-lpr/lpr (MRL/lpr) lupus mice is one of the major factors to develop glomerulonephritis (GN) in these mice. To examine molecular characteristics of IgG3 responsible for GN in these mice, hybridoma clones producing IgG3 antibodies were prepared from one unmanipulated MRL/lpr mouse. Two clones, 2B11.3 and 7B6.8, were nephritogenic; that is, they caused severe glomerular lesions when injected to normal mice, moreover with a different histopathological manifestation. The 2B11.3 clone generated diffuse cell-proliferative lesions, while those induced by the 7B6.8 clone resembled wire loop lesions in human lupus nephritis. The cDNA sequence analysis of 7B6.8 antibody and the other IgG3 antibody, 1G3, non-nephritogenic, revealed that the C regions of the heavy and light kappa chains were completely the same between them. Furthermore, they were identical in deduced amino acid sequences to those from non-autoimmune BALB/c mice, indicating no allelic difference of Igh-8 between these two strains. The V regions of 2B11.3 and 7B6.8 antibodies were composed of different sets of VH, D, JH, Vk and Jk. Although both of the VH belonged to the J558 family, they seemed to use a different VH germline gene. These findings suggest that GN in MRL/lpr mice is generated by the expansion of clonally different B cells producing particular antibodies possibly with a different pathogenetic potency.     

Host modifier genes affect mouse autoimmunity induced by the lpr gene

A defect in apoptotic signal transmission through CD95 is an essential genetic mechanism for lymphoproliferation and autoimmunities in lpr or gld mice. However, disease manifestations are largely affected by the host genetic background. To identify and map such host genes modifying lpr gene effect, ie, the lpr modifier (Lprm) genes, 82 MRL/lpr x (MRL/lpr x C3H/lpr) F1 mice were subjected to immunopathological and genetical analyses. High-grade vasculitis and glomerulonephritis among backcross mice were observed in separate groups of mice. Microsatellite analysis revealed that there were two host genes affecting the occurrence of vasculitis, Lprm1 (chromosome 4) and Lprm2 (chromosome 3). A recessive MRL allele at Lprm1 enhanced vasculitis to occur in both sexes, whereas that of Lprm2 inhibited its development selectively in females. Genotype combinations of these two genes explained the severity of vasculitis in crosses of MRL/lpr and C3H/lpr mice and also the vasculitis-prone recombinant inbred strain McH5/lpr. A recessive MRL allele at Lprm3 (chromosome 14) suppressed glomerulonephritis. The weight of the spleen was increased by a recessive MRL allele at Lprm4 (chromosome 5) yielding a logarithm of odds score of 2.02 in a quantitative trait locus analysis. In contrast, the weight of axillary lymph nodes was increased by a recessive MRL allele at a locus on chromosome 2, but its presence was not supported by the quantitative trait locus analysis. The titer of anti-dsDNA autoantibody was controlled by the locus Lprm5 on chromosome 16, which had an logarithm of odds score of 3.41. Possible candidate genes for Lprm genes deduced from their map locations are discussed and compared with the autoimmunity genes reported thus far. In conclusion, autoimmune disease manifestations by the lpr mutation are affected by multiple host genes separately.     

In vitro role of IL-1 in heightened IgG, anti-DNA, and nephritogenic idiotype production by B cells derived from the murine MRL/lpr lupus model

The MRL/lpr murine model resembles human lupus both in its serologic and immunopathologic features, and is characterized by high-level IgG and autoantibody production. The precise mechanisms for this B cell hyperactivity are poorly understood. This study explored the role of IL-1 in determining high-level IgG and autoantibody production in the MRL/lpr murine lupus model by blocking IL-1 activity with a recombinant IL-1 receptor antagonist (IL-1Ra). IgG and autoantibody production (anti-DNA ab and Id-H130 activity) by B cells derived from MRL/lpr mice was significantly suppressed by treating B cell cultures with IL-1Ra. In contrast, IgG and autoantibody production by B cells derived from young MRL/lpr, MLR/++, or normal C3H/HeJ mice showed virtually no suppression with IL-1Ra. Collectively, these findings indicate that IL-1 may be an important factor in determining the heightened production of IgG, anti-DNA, and id-H130 antibody production in lupus-prone MRL/lpr mice. Furthermore, heightened IL-1 activity appears to be influenced by both age and the presence of the lpr mutation.     

Genetic determinants of autoimmune disease and coronary vasculitis in the MRL-lpr/lpr mouse model of systemic lupus erythematosus

MRL-lpr/lpr (MRL/lpr) mice are a model of human autoimmune disease. They exhibit a number of characteristics of systemic lupus erythematosus, including anti-DNA Abs, anti-cardiolipin Abs, immune complex-mediated vasculitis, lymphadenopathy, and severe glomerulonephritis. Although the autoimmune disorder is mediated primarily by mutation of the Fas gene (lpr), which interferes with lymphocyte apoptosis, MRL/lpr mice also have other predisposing genetic factors. In an effort to identify these additional factors, we have applied quantitative trait locus (QTL) mapping using an intercross between MRL/lpr mice and the nonautoimmune inbred strain BALB/cJ. A complete linkage map spanning the entire genome was constructed for 189 intercross progeny, and genetic loci contributing to features of the autoimmunity were identified using statistical analytic procedures. As expected, the primary genetic determinant of autoimmune disease in this cross was the Fas gene on mouse chromosome 19, exhibiting a lod score of 60. In addition, two novel loci, one on chromosome 2 (lod score, 4.3) and one on chromosome 11 (lod score, 3.1), were found to contribute to levels of anti-DNA Abs. Interestingly, the chromosome 19 and chromosome 11 QTLs, but not the chromosome 2 QTL, also exhibited associations with anti-cardiolipin Abs (lod scores, 38.4 and 2.6). We further examined the effects of these QTLs on the development of coronary vasculitis in the F2 mice. Our results indicate that the QTLs on chromosomes 11 and 19 also control the development of vasculitis, demonstrating common genetic determinants of autoantibody levels and vasculitis.     

Dysregulated cytokine expression in vivo in prediseased and diseased autoimmune-prone MRL mice

Macrophages (m?) from prediseased autoimmune-prone MRL/ + and MRL/lpr mice produce markedly decreased levels of IL-1 in vitro in response to LPS. In contrast, tissues from diseased MRL/lpr mice overexpress IL-1 in vivo. To determine whether IL-1 underproduction in the MRL strains is solely an in vitro phenomenon, we compared in vivo cytokine mRNA expression from prediseased age-matched MRL/ + and MRL/lpr mice to that from normal BALB/c and C3HeB/FeJ mice. Like m? in vitro, whole organ RNA from the spleen, liver, and kidney of MRL/ + and MRL/lpr mice showed down-regulation of IL-1 RNA following intraperitoneal injection of LPS. This abnormality in inducible IL-1 expression was present in all MRL mice, irrespective of disease stage or the presence of the lpr gene. On the other hand, only diseased MRL/lpr mice displayed elevated and constitutive expression of IL-1 in their livers and kidneys. We suggest that inducible expression is most indicative of the intrinsic, or genetic, capacity of cells to produce cytokine, whereas constitutive expression reflects extracellular disease-related inflammatory stimuli present only in the diseased MRL/lpr strains. By restricting our studies to prediseased MRL mice, we have tried to eliminate the effects of disease and to focus on the predisposing genetic background. The existence both in vitro and in vivo of a defect in inducible IL-1 expression by prediseased MRL mice suggests that the molecular abnormality underlying this defect may be a part of this predisposing background to autoimmunity.     

Efficient peripheral clonal elimination of B lymphocytes in MRL/lpr mice bearing autoantibody transgenes

Peripheral B cell tolerance was studied in mice of the autoimmune-prone, Fas-deficient MRL/ lpr.H-2(d) genetic background by introducing a transgene that directs expression of membrane-bound H-2Kb antigen to liver and kidney (MT-Kb) and a second transgene encoding antibody reactive with this antigen (3-83mu delta, anti-Kk,b). Control immunoglobulin transgenic (Ig-Tg) MRL/lpr.H-2(d) mice lacking the Kb antigen had large numbers of splenic and lymph node B cells bearing the transgene-encoded specificity, whereas B cells of the double transgenic (Dbl-Tg) MRL/lpr.H-2(d) mice were deleted as efficiently as in Dbl-Tg mice of a nonautoimmune B10.D2 genetic background. In spite of the severely restricted peripheral B cell repertoire of the Ig-Tg MRL/lpr.H-2(d) mice, and notwithstanding deletion of the autospecific B cell population in the Dbl-Tg MRL/lpr.H-2(d) mice, both types of mice developed lymphoproliferation and exhibited elevated levels of IgG anti-chromatin autoantibodies. Interestingly, Dbl-Tg MRL/lpr.H-2(d) mice had a shorter lifespan than Ig-Tg MRL/lpr.H-2(d) mice, apparently as an indirect result of their relative B cell lymphopenia. These data suggest that in MRL/lpr mice peripheral B cell tolerance is not globally defective, but that certain B cells with receptors specific for nuclear antigens are regulated differently than are cells reactive to membrane autoantigens.     

Characterisation of Saccharomyces cerevisiae ARO8 and ARO9 genes encoding aromatic aminotransferases I and II reveals a new aminotransferase subfamily

It is known that lpr mice develop systemic lymphadenopathy and lupus erythematosus-like autoimmune disease that are associated with the accumulation of CD4- CD8- (double-negative; DN) CD3+ B220+ abnormal T cells as well as normal mature CD4+ or CD8+ single-positive (SP) CD3+ T cells. In order to clarify the role of B cells in the lymphoproliferation and autoimmunity of lpr mice, we created B-cell-deficient C57BL/6 (B6) lpr mice (B6lpr/lpr microMT/microMT) by crossing B6lpr/lpr mice with B6 microMT/microMT mice in which the B-cell development was arrested at pre-B stage owing to a targeted disruption of the immunoglobulin mu heavy-chain gene locus. In the B-cell-deficient B6-lpr mice, both lymphadenopathy and splenomegaly were markedly suppressed. Although the accumulation of both CD3+ B220- SP normal T cells and CD3+ B220+ DN abnormal T cells was inhibited in the B-cell-deficient lpr mice, the decrease in numbers of CD3+ B220- SP normal T cells occurred more strikingly than that of the CD3+ B220+ DN abnormal T cells. Glomerulonephritis did not develop in the B-cell-deficient lpr mice over 40 weeks. The present results indicate that the B cells thus play a crucial role in the extensive proliferation of normal CD3+ B220- mature SP T cells rather than the accumulation of abnormal DN T cells.     

Effect of cyclic AMP level reduction on human neutrophil responses to formylated peptides

In an attempt to elucidate the mechanism of development of organ-specific autoimmune lesions resembling human Sj?gren's syndrome of MRL/lpr mice, we have analyzed local cytokine gene expressions and organ-specific autoantibody production in vivo. We have demonstrated that a major proportion of T cells bearing CD4 and V(beta)8 molecules are essentially responsible for triggering the autoimmunity in the salivary glands of MRL/lpr mice. The local cytokine gene expressions including interferon(IFN)-gamma, IL-12(p40) mRNAs were observed during the course of murine Sjogren's syndrome in MRL/lpr autoimmune strain. In particular, a high level of local expressions of IL-12 mRNA was detected earlier in the proinflammatory stage of autoimmune lesions. A significant level of local expression of MHC class-II(I-Ak) mRNA was detected before the onset of inflammatory lesions in the salivary glands, and I-Ak-positive epithelial duct cells were frequently observed in the salivary glands of MRL/lpr mice. In addition, we found the salivary gland-specific autoantibody in sera from MRL/lpr mice with early phase of autoimmune lesions by immunoblot analysis. These results suggest that cytokine gene stimulation and autoantibody production are essentially involved in the development of organ-specific autoimmune lesions in Sj?gren's syndrome of MRL/lpr mice.     

A new strategy for treatment of autoimmune diseases in chimeric resistant MRL/lpr mice

A new strategy for the treatment of autoimmune diseases in chimeric resistant MRL/lpr mice is established. The strategy includes injection of cyclophosphamide (CY), fractionated irradiation (5 Gy x 2), bone grafts (to recruit stromal cells), and two transplantations of whole bone marrow cells (WBMCs) from allogeneic normal C57BL/6 mice (CY/2X/Bone/2BMT). MRL/lpr mice, thus treated, survived more than 40 weeks (1 mouse survived for >40 weeks, 7 for >50 weeks, and 4 for >60 weeks after these treatments). Immunohistological studies showed that the mice were completely free from both lymphadenopathy and autoimmune diseases such as systemic lupus erythematosis and rheumatoid arthritis. The levels of autoantibodies (IgM/IgG rheumatoid factors and IgM/IgG anti-ssDNA antibodies [Abs]) in the treated mice decreased to those in the normal mice. In addition, successful cooperation among T cells, B cells, and antigen-presenting cells (APCs) was observed. Abnormal T cells with immunophenotypes of B220+/Thy-1+/CD3+/CD4-/CD8- present in untreated MRL/lpr mice disappeared, and the hematolymphoid cells of the treated mice were of donor origin. However, the mice that had been irradiated with 8.5 Gy and then reconstituted with T-cell-depleted BMCs plus bone grafts died within 2 weeks due to the side effect of irradiation. The depletion of CD8+ cells (not CD4+ cells) from WBMCs resulted in graft failure; 60% of the recipient mice, thus treated, died within 2 weeks, and all recipients died by 15 weeks. Furthermore, limiting dilution assays showed that approximately more than 0.5% of T cells contained in the BMCs are necessary not only for engraftment of BMCs but also for long-term disease-free survival of the recipients. In contrast, recipients that had received CD4-depleted BMCs with CY plus fractionated irradiation (5Gy x 2) survived for more than 40 weeks without showing graft-versus-host reaction (GVHR). This indicates that CD8(+)cells in the BMCs are essential for the successful engraftment of the donor-type hematolymphoid cells.     

Solitary pancreas allografts. The role of percutaneous biopsy and standardized histologic grading of rejection

Murine models such as NZB/W F1, NZB.H-2bm12 and MRL.lpr/lpr mice have provided greater insight into the pathogenic mechanisms of lupus. To understand further the roles of T cells and cytokines in the pathogenesis of murine lupus, 11 cloned anti-DNA antibodies augmenting autoreactive T cell lines were derived from NZB/W F1 mice. All these autoreactive cells responded to syngeneic splenic cells and helped syngeneic B cells to produce anti-DNA antibodies, especially the IgG antibody. Ten out of 11 autoreactive T cell lines expressed neither CD4 nor CD8 cell surface markers on their surface. In addition, the cytokine production pattern of these autoreactive T cell lines was predominantly of type 0 (Th0) or type 2 T helper cells (Th2). To further investigate the role of accessory molecules in the activation of these autoreactive T cell lines, expression of IL-2R and heat-stable antigen (HSA) on these autoreactive T cells was analysed. Results suggest that the HSA played a critical role in the activation and function of these double-negative cloned autoreactive T cells.     

Mycophenolate mofetil suppresses autoimmunity and mortality in the female NZB x NZW F1 mouse model of systemic lupus erythematosus

OBJECTIVE: To examine the effects of the immunosuppressant, mycophenolate mofetil (MM), on autoimmunity, glomerulonephritis, and mortality in the female NZB x NZW F1 (B/W) mouse model of systemic lupus erythematosus (SLE). METHODS: The development of murine lupus was assessed during the lifespan of 10 female B/W mice given 200 mg/kg/day of MM compared to 10 female B/W mice given vehicle. At 6 week intervals, mice were examined for weight change, albuminuria, antibodies to DNA, and IgG immunoglobulin levels. Morbidity and mortality were assessed daily. In a parallel study, MM treated and control B/W mice were examined at 18 weeks of age for splenocyte phenotype and adhesion molecule expression, as well as antibody titers and in vitro cytokine production in response to immunization with dinitrophenyl-keyhole limpet hemocyanin (DNP-KLH). RESULTS: The administration of MM was well tolerated without apparent side effects. Weight gain in MM treated and control mice was identical through 36 weeks of age. In the treatment group, MM suppressed the development of albuminuria and anti-DNA antibodies compared to the control animals. There were no significant differences between groups in serum concentrations of total IgG. At 60 weeks of age survival in the MM treated group was 100% compared to 10% in the control group. MM did not alter the percentages of CD4, CD8, or IgM positive splenocytes; however, the percentage of CD4+ T lymphocytes expressing very late antigen 4 and intercellular adhesion molecule 1 was reduced. MM inhibited the antibody response to DNP-KLH immunization in vivo; however, in vitro cytokine production in response to KLH was not suppressed. CONCLUSION: MM suppressed the development of autoimmunity and prolonged lifespan in the female B/W mouse model of SLE. Suppression of autoimmunity was achieved without obvious side effects or altered CD4:CD8 T cell ratios. MM may be a useful primary or adjunctive therapy in human SLE.     

The urine of SLE patients contains antibodies that bind to the laminin component of the extracellular matrix

Direct immunofluorescence of tissues derived from patients affected with SLE demonstrates antibodies bound to the extracellular matrix (ECM). In the present work we have tested whether such antibodies are found in the serum and urine of lupus patients and mice. We found that the urine of patients with active SLE and of MRL/lpr/lpr mice contains antibodies that bind ECM and that a major target for these antibodies is the 200 kDa light chain of laminin which is one of the matrix components. The level of the anti-ECM, anti-laminin antibodies correlates with disease activity.     

Cell-to-cell interaction is required to induce proteinuria in in situ immune complex glomerulonephritis

This experiment was performed to study the roles of intercellular adhesion molecule-1 (ICAM-1), lymphocyte function-associated antigen-1 (LFA-1), and another adhesion molecule, selectin, in the development of cationized antigen-induced in situ immune complex glomerulonephritis (CAICGN). CAICGN was induced in preimmunized rats by perfusing cationized human immunoglobulin G (CaIgG) through the left kidney. Albuminuria developed within 2 days of CaIgG perfusion and peaked around day 7. Marked polymorphonuclear leukocyte (PMN) infiltration was observed in the glomeruli 1 hour after CaIgG perfusion, but the infiltrate resolved by day 7. Immunofluorescent studies disclosed linear deposition of rat IgG and C3 along glomerular capillary walls 1 hour after CaIgG perfusion. Treatment with monoclonal antibodies (mAbs) to both ICAM-1 and LFA-1, as well as with a sulfatide, a ligand of L- and P-selectin, started within 2 days after CaIgG perfusion completely suppressed the development of proteinuria without affecting the glomerular deposition of immunoreactants. Although sulfatide attenuated the PMN response 1 hour after CaIgG perfusion, ICAM-1 and LFA-1 mAb treatment did not alter PMN infiltration. Treatment with ICAM-1 and LFA-1 mAbs started on day 5, or treatment with sulfatide started on day 4, after CaIgG perfusion did not affect albuminuria. These findings suggest that adhesion molecules play an important role in the development of proteinuria in CAICGN. The contribution of these molecules was evident for only a short interval after the induction of nephritis, when a significant infiltration of PMNs was observed.     

Genotype effects on the antioxidant enzymes activity and mRNA expression in liver and kidney tissues of autoimmune-prone MRL/MpJ-lpr/lpr mice

Congeneic pairs of MRL/lpr and MRL/++ (+/+) mice differ in incidence of autoantibodies, lymphoproliferative disease and survival, characteristics that are linked to immunological abnormalities. MRL/lpr mice have a significantly shorter life span compared to +/+ mice. Because a weak antioxidant defense and an increased generation of free radicals are generally implicated in the severity of many autoimmune disease, the present study was undertaken to compare the influence of genotype on lipid composition, lipid peroxidation and expression of mRNA, and activity of antioxidant enzymes such as catalase (CAT), glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) in the livers and kidneys of these mice. The expression of SOD, GSH-Px and CAT mRNAs was significantly higher (P < 0.05) in the livers of +/+ mice, while in the kidneys only SOD expression was found significantly higher in +/+ mice when compared to MRL/lpr mice. Further, the activity of cytosolic SOD and GSH-Px was also found significantly higher (P < 0.001) in the livers of +/+ mice. Both livers and kidneys of MRL/lpr mice exhibited significantly higher levels of arachidonic acid (20:4(n-6)), significantly higher generation of thiobarbituric acid reactive substances (TBARS) and higher estimated peroxidation index than the +/+ mice. In addition, the MRL/lpr mice had higher levels of serum anti-cardiolipin antibodies. In summary, the results from the present study indicate that besides several immune-related abnormalities, the MRL/lpr mice may exhibit their inability to cope with oxidative stress due to a poor antioxidant defense system.(ABSTRACT TRUNCATED AT 250 WORDS)     

Mice defective in Fas are highly susceptible to Leishmania major infection despite elevated IL-12 synthesis, strong Th1 responses, and enhanced nitric oxide production

MRL/MP-lpr/lpr (MRL/lpr) mice have a single mutation (lpr) of the fas apoptosis gene. The mutant mice developed significantly smaller lesions than the wild-type mice at the earlier stage of infection with the intracellular protozoan parasite Leishmania major. However, while all the wild-type mice achieved complete lesion resolution, the disease in the mutant mice progressed inexorably. The mutant mice had more IL-12 and nitrite/nitrate in the serum than wild-type mice following infection. Lymphoid cells from infected MRL/lpr mice produced more IFN-gamma but less IL-4 and IL-5 than cells from MRL-+/+ mice. Peritoneal macrophages from the mutant mice also produced more IL-12 and NO after stimulation with LPS. Thus, Fas expression is essential for resistance against leishmaniasis, and Fas-mediated apoptosis may form an integral part of the Th1-mediated microbicidal function.     

Central T cell tolerance in lupus-prone mice: influence of autoimmune background and the lpr mutation

Lupus-prone mice develop a systemic autoimmune disease that is dependent upon the B cell help provided by autoreactive alphabeta CD4+ T cells. Since autoreactive T cells with high affinity for self peptides are normally deleted in the thymus, their presence in these mice suggests the possibility that intrathymic negative selection may be defective. Here, we directly compared central T cell tolerance in response to a conventional peptide Ag in lupus-prone MRL/MpJ mice with a nonautoimmune strain using an MHC class II-restricted TCR transgene. Our results did not demonstrate any defects after Ag exposure in the induction of intrathymic deletion of immature CD4+ CD8+ thymocytes, in TCR down-regulation, or in the number of apoptotic thymocytes in MRL/MpJ compared with nonautoimmune mice. Furthermore, we found that the lpr mutation had no influence upon the Ag-induced thymic deletion of immature thymocytes. These data support the notion that T cell autoreactivity in MRL/MpJ mice is caused by defects in peripheral control mechanisms.     

MRL/lpr and MRL+/+ macrophage DNA synthesis in the absence and the presence of colony-stimulating factor-1 and granulocyte-macrophage colony-stimulating factor

Macrophage accumulation and proliferation as well as altered macrophage properties have been observed in autoimmune MRL mice. To determine whether there might be innate differences in the proliferative responses, we examined the DNA synthesis responses of peritoneal macrophages and macrophages derived in vitro from bone marrow precursors (bone marrow-derived macrophages (BMM)). Murine peritoneal exudate macrophages normally require the addition of macrophage CSF (CSF-1) to enter cell cycle in vitro. In contrast, we have found that many thioglycollate-induced adherent peritoneal macrophages, but not resident peritoneal macrophages, from both MRL/lpr and MRL+/+ mice atypically underwent DNA synthesis even in the absence of added CSF-1. They also responded very well to granulocyte-macrophage CSF. These findings may help to explain the appearance of increased macrophage numbers in MRL lesions. In contrast to a previous report, it was found that MRL/lpr and MRL+/+ BMM did not have an enhanced response to CSF-1 and that modulation of CSF-1 receptor expression was not more rapid in MRL BMM. We also found no evidence for abnormal CSF-1 internalization and degradation or for the lpr mutation to have any enhanced effect on BMM survival in the absence of CSF-1. TNF-alpha lowered the DNA synthesis response to CSF-1 of MRL/lpr BMM rather than enhanced it, as has been reported. Our data suggest that the enhanced accumulation of macrophages in the MRL/lpr kidney cannot be explained by a proposed model of enhanced responsiveness of MRL/lpr BMM to CSF-1, including a contribution by TNF-alpha.     

Centralis superior raphe, reticularis pontis nuclei, and sleep-wakefulness cycle in cats

It has been reported that circumferential mesangial interposition (CMI) is an important morphological feature suggesting the progression of glomerulosclerosis in glomerular disease. The relation between CMI and its associated lesions was investigated in various renal diseases by electron microscopy. In 276 patients, of whom the glomeruli were observed by electron microscopy, CMI was observed non-specifically in 48 patients with various glomerular diseases (IgA nephropathy, 11; non-IgA glomerulonephritis, 1; membranoproliferative glomerulonephritis, 8; membranous nephropathy, 5; lupus glomerulonephritis, 12; toxemia of pregnancy, 2; diabetic nephropathy, 7; mitomycin nephropathy, 1; and Seckel's dwarfism patients, 1). The glomeruli with CMI showed a marked increase in mesangial matrix, as well as various grades of mesangial cell proliferation. Mesangiolysis associated with subendothelial widening was observed in a lesion of CMI in most cases. This phenomenon appears to be an initial alteration that conducts proliferated cells to the peripheral portion of a capillary loop. Localized severe thinning of the glomerular basement membrane was frequently combined with CMI, particularly in IgA nephropathy patients. Endothelial cells were occasionally interposed into the widened subendothelial space. Subendothelial deposits were noticed in the CMI lesion, particularly in MPGN patients. In conclusion, in the process of glomerulosclerosis progression in various glomerular diseases, lytic and edematous changes initially occur in the mesangio-subendothelial system (mesangiolysis and subendothelial widening), then proliferating mesangial cells extend into the widened space (between GBM and endothelial cells), and reach the peripheral portion of a capillary loop.