Anti-Thy-1 Antibody-mediated Complement-dependent Cytotoxicity is Regulated by the Distribution of Antigen, Antibody and Membrane Complement Regulatory Proteins in Rats

Ameliorating role of microRNA-378 carried by umbilical cord mesenchymal stem cells-released extracellular vesicles in mesangial proliferative glomerulonephritis

BACKGROUND

Mesenchymal stem cells (MSCs) and their released extracellular vesicles (Evs) have shown protective effects against kidney diseases. This study aims to study the functions of umbilical cord MSCs-released Evs (ucMSC-Evs) and their implicated molecules in mesangial proliferative glomerulonephritis (MsPGN).

METHODS

A rat model of MsPGN was induced by anti-Thy-1.1, and rat mesangial cells (rMCs) HBZY-1 were treated with PDGF-BB/DD to mimic MsPGN condition in vitro. Rats and cells were treated with different doses of ucMSC-Evs, and then the pathological changes in renal tissues and proliferation of rMCs were determined. Differentially expressed microRNAs (miRNAs) after Evs treatment were screened by microarray analysis. The interactions among miR-378, PSMD14, and TGFBR1 were analyzed. Gain- and loss-of function studies of miR-378 and PSMD14 were performed to explore their effects on tissue hyperplasia and rMC proliferation and their interactions with the TGF-β1/Smad2/3 signaling pathway.

RESULTS

The ucMSC-Evs treatment ameliorated mesangial hyperplasia and fibrosis in rat renal tissues and suppressed the aberrant proliferation of rMCs in a dose-dependent manner. miR-378 was the most upregulated miRNA in tissues and cells after ucMSC-Evs treatment. miR-378 directly targeted PSMD14, and PSMD14 maintained the stability of TGFBR1 through deubiquitination modification, which led to TGF-β1/Smad2/3 activation. Either miR-378 knockdown or PSMD14 overexpression diminished the protective functions of ucMSC-Evs by activating the TGF-β1/Smad2/3 signaling pathway.

CONCLUSION

UcMSC-Evs ameliorate pathological process in MsPGN through the delivery of miR-378, which suppresses PSMD14-mediated TGFBR1 stability and inactivates the TGF-β1/Smad2/3 signaling pathway to reduce tissue hyperplasia and rMC proliferation. Video abstract.

Mesangial cells regulate the single nephron GFR and preserve the integrity of the glomerular filtration barrier: An intravital multiphoton microscopy study

AIM

The intraglomerular mesangial cells are located between the glomerular capillaries. Here we hypothesized that mesangial cells regulate the single nephron glomerular filtration rate (snGFR) and that mesangial cells support the integrity of the glomerular filtration barrier.

METHODS

We assessed the function of mesangial cells in vivo by multiphoton microscopy. Mesangial cells were depleted in Munich Wistar Froemter rats using the Thy1.1 antibody model.

RESULTS

The Thy1.1 antibody caused the cell-specific loss of 82 ± 3% of mesangial cells. After mesangial cell depletion, the baseline snGFR was reduced to 12.0 ± 1.2 vs 32.4 ± 3.2 nL/min in controls. In control rats, the snGFR decreased after angiotensin II infusion by 61 ± 3% (P = .004), whereas it remained unchanged in Thy1.1-treated rats. The changes in the snGFR after angiotensin II infusion in control rats were accompanied by the marked rotation of the capillary loops within Bowman's space. This phenomenon was absent in anti-Thy1.1-treated rats. The glomerular sieving coefficient (GSC_A ) for albumin, used as a measure of the integrity of the glomerular filtration barrier, was low in control rats (0.00061 ± 0.00004) and increased after angiotensin II infusion (0.00121 ± 0.00015). In Thy1.1-treated rats, the GSC was elevated (0.0032 ± 0.00059) and did not change in response to angiotensin II. Electron microscopy revealed the increased thickness of the glomerular basement membrane after mesangial cell depletion.

CONCLUSION

Our data suggest that mesangial cells actively contribute to the regulation of the snGFR. Furthermore, mesangial cells are crucially involved in maintaining the integrity of the glomerular filtration barrier, in part by modulating the thickness of the glomerular basement membrane.

HUANGKUISIWUFANG inhibits pyruvate dehydrogenase to improve glomerular injury in anti-Thy1 nephritis model

ETHNOPHARMACOLOGICAL RELEVANCE

Huangkuisiwufang (HKSWF) is composed of Abelmoschus manihot (L.) Medik., Astragalus mongholicus, Polygonum cuspidatum, Curcuma longa L. Abelmoschus Manihot (L.) Medik. has been widely used for the treatment of chronic renal disease, oral ulcers and burn in China for centuries (Committee of the Pharmacopoeia of PR China, 2010). Abelmoschus manihot (L.) Medik., Polygonum cuspidatum, Curcuma longa L. have been mainly applied in folk medicine for their therapeutic effects on diabetes, cancer, heart disease and other diseases.

AIM OF THE STUDY

We aimed to investigate the renoprotective function of HKSWF in anti-Thy nephritis model and clarify the relevant mechanisms.

MATERIALS AND METHODS

One week after the model of glomerulonephritis created by injecting anti-thymocyte serum (ATS), rats were treated with Huangkui capsule, enalapril or HKSWF by gavage for a period of 8 weeks. The therapeutic effect was evaluated by detection of proteinuria, plasma creatine, blood urea nitrogen (BUN), podocyte injury, glomerular accumulation of extracellular matrix (ECM) and the markers of oxidative stress and renal fibrosis. RNA Sequencing (RNA-seq), KEGG and western blotting analysis were performed to indicate the signaling pathway involved in the therapeutic effect of HKSWF.

RESULTS

Nephritic rats presented the increase of BUN, serum creatinine (Scr), proteinuria, podocyte damage, glomerular fibrosis, Ang II type 1 receptor (AT1R), and the reduction of creatinine clearance (Ccr). In contrast, application of HKSWF to nephritic rats decreased the levels of BUN and proteinuria, promoted mesangial cell recovery and improved oxidative stress level and podocyte injury. KEGG analysis revealed that pyruvate metabolism was the most significantly upregulated pathway in rats treated with HKSWF compared to disease control group. Increased pyruvate dehydrogenase and PAI-1 caused by nephritis was inhibited by HKSWF interposition. Furthermore, dichloroacetate sodium (DCA), an agonist of pyruvate dehydrogenase, could stimulate PAI-1 expression, which was suppressed by HKSWF.

CONCLUSION

Chinese herbal preparation HKSWF has remarkable curative effects on glomerulonephritis animals. HKSWF attenuates pyruvate dehydrogenase to improve glomerular injury.

Recombinant human IgG1 based Fc multimers, with limited FcR binding capacity, can effectively inhibit complement-mediated disease

There is a lack of effective targeted therapies for the treatment of complement dependent diseases. We developed two recombinant Fc multimers, G207 and G211, with limited ability to interact with low/moderate affinity FcγRs, but with high avidity for C1q. These drugs effectively inhibited complement dependent cytotoxicity (CDC) in vitro, and prevented the deposition of C1q, C3b and MAC, on the surface of Ab-opsonized cells. Importantly, these inhibitory effects were both C1q dependent and independent. In order to determine the biologic relevance of our findings, we evaluated the clinical efficacy of these drugs in three different animal models, acute RBC hemolysis, anti-Thy-1 nephritis and passive Heymann's nephropathy (PHN), in which disease pathophysiology relies preferentially on complement activation. While G207 was protective in the anti-Thy-1 nephritis and PHN models, G211 was protective in all of the models tested and could effectively treat PHN. In the anti-Thy-1 nephritis model, G211 prevented the characteristic histologic changes associated with the disease and limited glomerular deposition of C3. Collectively, these data suggest that "complement preferential" Fc multimers offer a novel approach to the treatment of complement mediated diseases.

Therapeutic antibodies: their mechanisms of action and the pathological findings they induce in toxicity studies

Antibodies can swiftly provide therapeutics to target disease-related molecules discovered in genomic research. Antibody engineering techniques have been actively developed and these technological innovations have intensified the development of therapeutic antibodies. From the mid-1990’s, a series of therapeutic antibodies were launched that are now being used in clinic. The disease areas that therapeutic antibodies can target have subsequently expanded, and antibodies are currently utilized as pharmaceuticals for cancer, inflammatory disease, organ transplantation, cardiovascular disease, infection, respiratory disease, ophthalmologic disease, and so on. This paper briefly describes the modes of action of therapeutic antibodies. Several non-clinical study results of the pathological changes induced by therapeutic antibodies are also presented to aid the future assessment of the toxic potential of an antibody developed as a therapeutic.

Expression of Membrane Complement Regulatory Proteins Crry and CD55 in Normal Rats

Some anticancer therapeutic antibodies are designed to act through complement-dependent cytotoxicity (CDC). It has been reported that there are many membrane complement regulatory proteins (mCRPs) that inhibit CDC. In the present study, we examined the expression of two mCRPs, the complement receptor 1-related gene/protein Y (Crry) and the decay-accelerating factor CD55, in three normal rats by immunohistochemistry. Crry and CD55 were detected widely in rat organs and tissues. Crry was found mainly in the urinary, digestive, respiratory, immunohematopoietic, circulatory and neuroendocrine systems. CD55 was found in the urinary, digestive and neuroendocrine systems. However, the two molecules were expressed in separate cells within the same organ. These results suggest that the distribution of mCRPs is related to the strict regulation of CDC activation in these organs and tissues and that the two molecules have a nonoverlapping expression pattern, a fact indicating specific roles in CDC regulation.