bims-mitrat 2025-04-06 papers

Exp Physiol. 2025 Mar 31.

Mitochondrial transplantation combined with mitoquinone and melatonin: A survival strategy against myocardial reperfusion injury in aged rats.

Behnaz Mokhtari, Mitra Delkhah, Reza Badalzadeh, Samad Ghaffari.

Myocardial ischaemia-reperfusion (IR) injury poses a severe threat to cardiac health, particularly in the ageing population, where susceptibility to such damage is significantly heightened owing to age-related declines in mitochondrial function, thus highlighting mitochondria as crucial targets for innovative therapies. The aim of this study was to investigate the combined modality therapy involving mitochondrial transplantation and the mitochondrial boosters mitoquinone and melatonin to address myocardial IR injury in aged rats. A total of 54 male Wistar rats, aged 22-24 months, were randomly divided into groups that either received IR injury or not, and were subjected to various treatments, both individually and in combination. Myocardial IR injury was induced by temporarily blocking and reopening the left anterior descending coronary artery. Mitoquinone was given intraperitoneally for 14 days prior to ischaemia, while melatonin and isolated mitochondria were administered intraperitoneally and intramyocardially, respectively, at the onset of reperfusion. Finally, we evaluated changes in haemodynamic indices, creatine kinase-MB levels, mitochondrial function endpoints and the expression of mitochondrial biogenesis genes, including sirtuin 1 (SIRT-1), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and nuclear respiratory factor 2 (NRF-2). The triple therapy enhanced myocardial function, decreased creatine kinase-MB levels and improved mitochondrial function along with the expression of mitochondrial biogenesis genes in aged IR rats. This combined approach elicited significant cardioprotection in comparison to single or dual therapies. The triple therapy provided substantial cardioprotection in aged rat hearts by improving mitochondrial function and biogenesis through enhanced SIRT-1/PGC-1α/NRF-2 profiles, suggesting a promising strategy for mitigating IR injury in elderly patients.

Keywords: ageing; combined modality therapy; melatonin; mitochondria; mitoquinone; myocardial ischaemia–reperfusion

DOI: https://doi.org/10.1113/EP092292

Mol Ther. 2025 Apr 03. pii: S1525-0016(25)00260-6. [Epub ahead of print]

An engineered mitoCBE facilitates efficient mitochondrial DNA editing and modified mitochondrial transfer.

Jie Liu, Jun Chen, Shisheng Huang, Junfan Guo, Xiangyang Li, Ying Yan, Ruijing Chen, Guanglei Li, Ming Liu, Jiao Wei, Xingxu Huang, Yunbo Qiao.

Double-stranded DNA (dsDNA) cytosine deaminase DddA orthologs from multiple types of bacteria have been fused with TALE system for mitochondrial DNA (mtDNA) base editing, while the efficiencies remain limited and its nuclear off-targeting activity cannot be ignored yet. Here we identified a DddA ortholog from Burkholderia gladioli (BgDddA) and generated nuclear or mitochondrial DNA cytosine base editors (mitoCBEs), exhibiting higher C•G-to-T•A editing frequencies compared to canonical DdCBE, and fusion with transactivator Rta remarkably improved editing efficiencies by up to 6.4-fold at non-TC targets. Referring to DddA11, we further introduced six substitutions into BgDddA and generated mitoCBE3.2, which efficiently induced disease-associated mtDNA mutations in mouse and human cell lines at both TC and non-TC targets with efficiency reaching up to 99.2%. Using mitoCBE3.2, single clones containing homoplasmic mtDNA mutations or premature stop codons associated with human diseases were generated, and the functions of these mutations have been evaluated upon the treatment of ROS inducers. Importantly, mitochondria harboring these homoplasmic mutations were transplanted into wildtype cells, enabling precise base conversions, without risk of nuclear gene off-targets. Thus, we have engineered an efficient mitoCBE using BgDddA, facilitating mitochondrial disease modeling and potential mutation correction with the aid of mitochondrial transplantation.

DOI: https://doi.org/10.1016/j.ymthe.2025.03.051

Theriogenology. 2025 Mar 29. pii: S0093-691X(25)00140-2. [Epub ahead of print]240 117414

Cryopreservation of sturgeon egg mitochondria and their replacement in germline: A novel strategy for maternal genetic preservation in sturgeons.

Linan Gao, Roman Franěk, Martin Pšenička.

Nearly all sturgeon species are critically endangered, necessitating the development of innovative approaches to preserve their genetic diversity and support population recovery. Unlike sperm, the cryopreservation of fish eggs or embryos remains technically unscalable because of the inherent structural and compositional barriers. Mitochondria are abundant in germ plasm and indispensable in the formation of primordial germ cells (PGCs). Transplanting isolated mitochondria into the vegetal pole of sturgeon embryos, where germ plasm is located, represents a promising conservation strategy. The transplanted mitochondria integrate into the germ plasm and are subsequently incorporated into the germline. Considering seasonality and long generation intervals of sturgeon reproduction, a reliable method for long-term storage of sturgeon egg mitochondria would be advantageous. This study optimized the cryopreservation of sturgeon egg-derived mitochondria, with subsequent validation of mitochondria structural and functional integrity. Various concentrations of dimethyl sulfoxide (DMSO), glycerol, and bovine serum albumin (BSA), combined with different freezing protocols were tested. Mitochondria functionality was assessed through four keys indicators: adenosine triphosphate synthesis, reactive oxygen species production, mitochondrial membrane potential, and integrity. For the first time, we demonstrated that sturgeon egg mitochondria can be successfully cryopreserved, recovered using transplantation and incorporated into the germline. Therefore, we restored maternal germplasm in sturgeon embryos. This work establishes a vital technological advance for conservation biology, offering an alternative approach to preserving and restoring maternal genetic information, which is currently unachievable through other methods in fish. Future research can leverage mitochondrial applications to advance germline preservation, surrogate reproduction, fertility enhancement, and reproductive biotechnology in aquaculture species.

Keywords: Cryopreservation; Egg mitochondria; Maternal genetic; Mitochondrial transplantation; Sturgeon conservation

DOI: https://doi.org/10.1016/j.theriogenology.2025.117414