Up-regulated Complement 3 Production by Toll-like receptor 9/ Transforming Growth Factor-Beta 1/Complement 3 Pathway in Whole Blood Cells of Lupus Thrombocytopenia

TGF-β as a Key Modulator of Astrocyte Reactivity: Disease Relevance and Therapeutic Implications

Astrocytes are essential for normal brain development and functioning. They respond to brain injury and disease through a process referred to as reactive astrogliosis, where the reactivity is highly heterogenous and context-dependent. Reactive astrocytes are active contributors to brain pathology and can exert beneficial, detrimental, or mixed effects following brain insults. Transforming growth factor-β (TGF-β) has been identified as one of the key factors regulating astrocyte reactivity. The genetic and pharmacological manipulation of the TGF-β signaling pathway in animal models of central nervous system (CNS) injury and disease alters pathological and functional outcomes. This review aims to provide recent understanding regarding astrocyte reactivity and TGF-β signaling in brain injury, aging, and neurodegeneration. Further, it explores how TGF-β signaling modulates astrocyte reactivity and function in the context of CNS disease and injury.

N-Acetyl-L-Cysteine Potentially Inhibits Complement Activation in Transplantation-Associated Thrombotic Microangiopathy

Transplant-associated thrombotic microangiopathy (TA-TMA) has a high mortality rate and lacks effective treatments. We searched the GEO database and analyzed RNA-seq data and whole-genome sequencing data from patients' blood samples. We identified N-acetyl-L-cysteine (NAC) as a possible therapeutic target for TA-TMA. In vitro experiments showed that NAC reduced complement activation and VWF multimerization in HUVECs. We also treated a 36-year-old female TA-TMA patient with NAC. Hemoglobin, platelet counts, lactate dehydrogenase levels, and sC5b-9 levels and schistocytes were normalized after using NAC. It shows that NAC may be an effective drug to improve TA-TMA symptoms by inhibiting complement activation.

Microarray-based analysis of renal complement components reveals a therapeutic target for lupus nephritis

Background

Screening abnormal pathways and complement components in the kidneys of patients with lupus nephritis (LN) and NZB/W mice may help to identify complement-related therapeutic targets for LN.

Methods

KEGG and GO enrichment assays were used to analyze kidney microarray data of LN patients and NZB/W mice. Immunohistochemistry and immunofluorescence assays were used to measure renal expression of complement-related proteins and TGFβ1. Cytokines were measured using RT-qPCR and ELISA.

Results

We screened the renal pathogenic pathways present in LN patients and NZB/W mice and selected the complement activation pathway for further study. The results indicated greater renal expression of C1qa, C1qb, C3, C3aR1, and C5aR1 at the mRNA and protein levels. C3 appeared to be a key factor in LN and the renal signaling downstream of C1 was inhibited. There were significant correlations between the expression of TGFβ1 and C3. Analysis of primary cell cultures indicated that TGFβ1 promoted the expression of C3 and that a TGFβ1 antagonist decreased the levels of C3 and C3aR. TGFβ1 inhibition significantly inhibited the deposition of complement-related factors in the kidneys of NZB/W mice.

Conclusions

At the onset of LN, there are significant increases in the renal levels of C3 and other complement pathway-related factors in patients with LN and NZB/W mice. C3 may lead to albuminuria and participate in the pathogenesis of LN. TGFβ1 promotes C3 synthesis, and TGFβ1 inhibition may block the progression of LN by inhibiting the synthesis of C3 and other complement components.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02605-9.

Immunotherapeutic effects of allogeneic mesenchymal stem cells on systemic lupus erythematosus

Mesenchymal stem cells have been applied to treat graft versus host disease as they have immunosuppressive ability and can overcome the major histocompatibility complex-histocompatibility barrier. The potential of allogeneic mesenchymal stem cells in treating systemic lupus erythematosus (SLE) was investigated in this study. MRL/lpr mice which can develop acquired SLE-like phenotypes were selected as an animal model. Mesenchymal stem cells obtained from green fluorescent protein-transgenic ICR mice were infused into MRL/lpr mice at either the early or late stage of disease. The dosage was 1 × 10⁶/mice per infusion. Mice were stratified into six groups including negative controls and those receiving one, two, three, four or five doses at 2-weekly intervals. The phenotypes were monitored regularly. After treatment, the spleen CD3⁺CD4^-CD8^- T and CD19⁺ B cells of two-dose mesenchymal stem cell-treated mice were significantly lower than those of the phosphate-buffered saline control. In terms of reducing the severity of SLE such as hair loss, skin ulcers, proteinuria and anti-dsDNA level, mesenchymal stem cells given at the early stage responded better and mice receiving two doses of mesenchymal stem cells performed better than those receiving either a lower dose (one dose) or higher doses (three, four or five doses). In conclusion, early treatment and an optimal dose of mesenchymal stem cells can effectively suppress the murine SLE model.