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Updated: Jun 3, 2026
Optimizing Isolation and Purification of Murine Glomerular Mesangial Cells
Published on: March 7, 2025
Change of MAX interactor 1 expression in an anti-Thy1 nephritis model and its effect on mesangial cell proliferation
Xiaoluan Liu1, Yang Lv, Yuansheng Xie
1Department of Nephrology, Institute of Nephrology & Key Laboratory of PLA, Chinese PLA General Hospital, Beijing, China.
Background/Aims:
During the disease process of mesangial proliferative glomerulonephritis, the expression of various factors that influence mesangial proliferation is altered. MAX interactor 1 (Mxi1) antagonizes the transcription factor Myc and is believed to be a tumor suppressor. However, no studies have investigated its effect on mesangial cell proliferation.
Methods:
To investigate the effect of Mxi1 on renal mesangial cell proliferation, we established a classic rat anti-Thy1 mesangial proliferative glomerulonephritis model. Mesangial proliferation was estimated by immunohistochemical analysis of Ki67. Mxi1 expression at each time point was assessed by real-time RT-PCR and Western blot analyses. Furthermore, we altered the expression level of Mxi1 by a plasmid and siRNA to detect its effect on rat mesangial cell proliferation in vitro.
Results:
Mxi1 expression decreased significantly during the proliferative period of anti-Thy1 nephritis model and then gradually increased as proliferation declined, indicating that Mxi1 may be linked to mesangial cell proliferation. Upregulation of Mxi1 expression via plasmid transfection in vitro reduced the expression of the positive-acting cell cycle regulatory proteins cyclin B1, cyclin D1, cyclin E, CDC2 and CDK2; significantly reduced mesangial cell proliferation; reduced the percentage of S phase cells; and increased the percentage of G2/M phase cells. Inhibition of Mxi1 expression by siRNA in vitro produced the opposite effects: increased expression of cyclin B1, cyclin D1, cyclin E, CDC2 and CDK2; markedly increased cell proliferation; higher percentage of S phase cells; and dramatically lower percentage of G2/M phase cells. Transcription factor c-myc protein expression showed no obvious difference after Mxi1 plasmid and siRNA transfection. The expressions of cell cycle regulatory proteins mentioned above were negative correlated with Mxi1 expression in anti-Thy1 nephritis model.
Conclusion:
These results suggest that Mxi1 expression levels were inversely correlated with proliferation in anti-Thy1 nephritis rats and it may influence cell cycle progression and thus the rate of mesangial cell proliferation by regulating the expression of c-myc target cell cycle regulatory proteins.
Insights
MAX interactor 1 (Mxi1) expression decreases during mesangial proliferative glomerulonephritis. Upregulating Mxi1 inhibits cell proliferation, while inhibiting Mxi1 promotes it, suggesting Mxi1
Area of Science:
- Nephrology
- Cell Biology
- Molecular Biology
Background:
- Mesangial proliferative glomerulonephritis involves altered expression of factors influencing mesangial cell proliferation.
- MAX interactor 1 (Mxi1), a Myc antagonist, is a potential tumor suppressor.
- The role of Mxi1 in mesangial cell proliferation remains uninvestigated.
Purpose of the Study:
- To investigate the effect of Mxi1 on renal mesangial cell proliferation in a rat anti-Thy1 glomerulonephritis model.
- To determine the in vitro impact of Mxi1 expression levels on rat mesangial cell proliferation.
Main Methods:
- Established a rat anti-Thy1 mesangial proliferative glomerulonephritis model.
- Assessed mesangial proliferation using Ki67 immunohistochemistry.
- Quantified Mxi1 expression via real-time RT-PCR and Western blot.
- Manipulated Mxi1 levels using plasmid and siRNA in vitro to assess effects on cell proliferation.
Main Results:
- Mxi1 expression decreased during the proliferative phase of anti-Thy1 nephritis and increased as proliferation subsided.
- In vitro, Mxi1 upregulation reduced mesangial cell proliferation and altered cell cycle distribution (decreased S phase, increased G2/M phase).
- In vitro, Mxi1 inhibition increased mesangial cell proliferation and reversed cell cycle changes; c-myc protein levels were unaffected.
Conclusions:
- Mxi1 expression is inversely correlated with proliferation in anti-Thy1 nephritis.
- Mxi1 influences mesangial cell proliferation by regulating cell cycle progression.
- Mxi1 may modulate the expression of c-myc target cell cycle regulatory proteins.
