Efficacy and safety of mesenchymal stem cell-derived microvesicles in mouse inflammatory arthritis
Shixiong Wei1, Chenyang Lu2, Sujia Li3
1Department of Rheumatology and Clinical Immunology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, NO. 1 Shuai Fu Yuan, Wang Fu Jing street, Beijing 100730, China; Department of Rheumatology & Department of Rheumatology and Immunology, West China Hospital, Sichuan University, No.37 Guoxue xiang Wuhou District, Chengdu City, Sichuan Province 610041, China.
Objective:
To determine the effective and safe intravenous doses of mesenchymal stem cells (MSCs)-derived microvesicles (MVs) and to elucidate the possible causes of death in mice receiving high-dose MVs.
Methods:
MVs were isolated from human MSCs by gradient centrifugation. Mice with collagen-induced arthritis were treated with different doses of intravenous MVs or MSCs. Arthritis severity, white blood cell count, and serum C-reactive protein levels were measured. To assess the safety profile of MSCs and MVs, mice were treated with different doses of MSCs and MVs, and LD50 was calculated. Mouse lungs and heart were assessed by live fluorescence imaging, histopathological measurements, and immunohistochemistry to explore the possible causes of death. Serum concentrations of cTnT, cTnI, and CK-MB were determined by ELISA. With the H9C2 cardiomyocyte cell line, cellular uptake of MVs was observed using confocal microscopy and cell toxicity was assessed by CCK-8 and flow cytometry.
Results:
Intravenous treatment with MSCs and MVs alleviated inflammatory arthritis, while high doses of MSCs and MVs were lethal. Mice receiving a maximum dose of MSCs (0.1 mL of MSCs at 109/mL) died immediately, while mice receiving a maximum dose of MVs (0.1 mL of MVs at 1012/mL) exhibited tears, drooling, tachycardia, shortness of breath, unbalanced rollover, bouncing, circular crawling, mania, and death. Some mice died after exhibiting convulsions and other symptoms. All mice died shortly after injecting the maximum dose of MSCs. Histologically, mice receiving high doses of MSCs frequently developed pulmonary embolism, while those receiving high doses of MVs died of myocardial infarction. Consistently, the serum levels of cTnT, cTnI, and CK-MB were significantly increased in the MVs-treated group (P < 0.05). The LD50 of intravenous MVs was 1.60 × 1012/kg. Further, MVs could enter the cell. High doses of MVs induced cell apoptosis, though low concentrations of MVs induced cell proliferation.
Conclusions:
Appropriate dosages of MVs and MSCs are effective treatments for inflammatory arthritis while MVs and MSCs overdose is unsafe by causing cardiopulmonary complications.
Insights
Mesenchymal stem cells (MSCs)-derived microvesicles (MVs) effectively treat arthritis but high doses are lethal. Overdosing on MVs or MSCs can cause fatal cardiopulmonary complications in mice.
Area of Science:
- Biomedical Science
- Regenerative Medicine
- Cell Therapy
Background:
- Mesenchymal stem cells (MSCs) and their derived microvesicles (MVs) show therapeutic potential.
- Determining safe and effective intravenous dosage is crucial for clinical translation.
Purpose of the Study:
- To establish effective and safe intravenous doses of MSCs-derived MVs.
- To investigate the causes of mortality in mice receiving high-dose MVs or MSCs.
Main Methods:
- MVs isolated from human MSCs via gradient centrifugation.
- Arthritis severity, blood markers, and LD50 determined in mice treated with varying MVs/MSCs doses.
- Cardiopulmonary tissues analyzed via imaging and histology; cardiac markers measured.
- In vitro studies assessed MV cellular uptake and toxicity in H9C2 cardiomyocytes.
Main Results:
- Both MSCs and MVs alleviated inflammatory arthritis.
- High doses of MSCs and MVs proved lethal, causing pulmonary embolism and myocardial infarction, respectively.
- LD50 for intravenous MVs was 1.60 × 10^12/kg; high doses induced apoptosis, while low doses promoted proliferation.
Conclusions:
- Appropriate dosages of MSCs-derived MVs and MSCs are effective for inflammatory arthritis.
- Overdosing on MVs or MSCs is unsafe, leading to severe cardiopulmonary complications.
