Mitochondria transfer in tissue homeostasis and diseases

Mitochondria serve as the essential powerhouse for virtually all eukaryotic cells and have been implicated in other crucial functions in both physiological and disease contexts. As cytoplasmic organelles, mitochondria are segregated and transported from parent to daughter cells during division or differentiation, a process known as vertical mitochondria transfer (VMT). A growing body of literature indicates that various cell types can export mitochondria for delivery to developmentally unrelated cell types without division, a process termed horizontal mitochondria transfer (HMT). In this review, we summarize current understanding of the modes of mitochondria transfer and illustrate the phenomenon of HMT across different tissue backgrounds, including the immune, cardiovascular, respiratory, hepatic, renal, musculoskeletal, adipose, and reproductive systems. Moreover, updated applications and functions of mitochondria transfer are discussed. Additionally, we also highlight the therapeutic potential of mitochondria transfer in current preclinical and clinical trials for inherited mitochondrial diseases, cancer, wound healing, and injuries of the respiratory and central nervous systems.