Single-cell RNA Sequencing Analysis Reveals The Relationship Of Bone Marrow And Osteopenia In Type 1 Diabetic Mice

Objective:Type 1 diabetes(T1D)is a multifactorial autoimmune disease,and osteopenia is a severe complication.Broad knowledge about the genetics,epidemiology,and clinical management of T1D has been achieved,but the cell varieties in the bone marrow and the relationship with osteopenia during T1D remain poorly understood.We aimed to present a profile of the bone marrow cells and reveal the relationship of bone marrow and osteopenia in type 1 diabetic miceMethods:T1D model was established with streptozotocin(STZ).The whole bone marrow cells from femurs and tibias of healthy(group C)and T1D mice(group D)were collected for single-cell RNA sequencing analysis.Single-cell flow cytometry and immunohistochemistry were performed to confirmed the changes in BM-neutrophil(Cxcr2~+,Ly6g~+)and B lymphocyte(Cd19~+).X-ray and micro-CT were performed to detect bone mineral density(BMD).The correlation between the ratio of BM-neutrophils/B lymphocytes and osteopenia in T1D mice was analyzed by nonparametric Spearman correlation analysis.Results:The bone marrow cells in both groups C and D were divided into 12 clusters.There were 249 differentially expressed genes(DEGs).The diversity of CD45+immune cells between groups C and D were greatly affected.There was a large increase in the proportion of bone marrow neutrophils and a large decrease in the proportion of B lymphocytes in group D.X-ray and Micro-CT analyses confirmed that osteopenia occurred in group D mice.The results of single-cell flow cytometry and correlation analysis showed that the ratio of BM-neutrophils/B lymphocytes was negatively correlated with osteopenia in T1D mice(p<0.05).Conclusion:A single-cell RNA sequencing analysis revealed the profile and heterogeneity of bone marrow immune cells in T1D mice for the first time.The ratio of BM-neutrophils/B lymphocytes was negatively correlated with osteopenia in T1D mice,which may contribute to a better understanding of the treatment of T1D and the prevention of T1D-induced osteopenia.