Background. Mitochondrial dysfunctions play a pivotal role in cerebral ischemia‐reperfusion (I/R) injury. Although mitochondrial transplantation has been recently explored for the treatment of cerebral I/R injury, the underlying mechanisms and fate of transplanted mitochondria are still poorly understood. Methods. Mitochondrial morphology and function were assessed by fluorescent staining, electron microscopy, JC‐1, PCR, mitochondrial stress testing, and metabolomics. Therapeutic effects of mitochondria were evaluated by cell viability, reactive oxygen species (ROS), and apoptosis levels in a cellular hypoxia‐reoxygenation model. Rat middle cerebral artery occlusion model was applied to assess the mitochondrial therapy in vivo. Transcriptomics was performed to explore the underlying mechanisms. Mitochondrial fate tracking was implemented by a variety of fluorescent labeling methods. Results. Neuro‐2a (N2a) cell‐derived mitochondria had higher mitochondrial membrane potential, more active oxidative respiration capacity, and less mitochondrial DNA copy number. Exogenous mitochondrial transplantation increased cellular viability in an oxygen‐dependent manner, decreased ROS and apoptosis levels, improved neurobehavioral deficits, and reduced infarct size. Transcriptomic data showed that the differential gene enrichment pathways are associated with metabolism, especially lipid metabolism. Mitochondrial tracking indicated specific parts of the exogenous mitochondria fused with the mitochondria of the host cell, and others were incorporated into lysosomes. This process occurred at the beginning of internalization and its efficiency is related to intercellular connection. Conclusions. Mitochondrial transplantation may attenuate cerebral I/R injury. The mechanism may be related to mitochondrial component separation, altering cellular metabolism, reducing ROS, and apoptosis in an oxygen‐dependent manner. The way of isolated mitochondrial transfer into the cell may be related to intercellular connection.

To evaluate the macular microstructure repair and explore the factors related to those changes and visual improvement after vitrectomy for idiopathic macular hole (IMH). Totally 19 eyes of 18 IMH patients who underwent macular hole (MH) surgery were evaluated with best-corrected visual acuity (BCVA) and spectral-domain optical coherence tomography (SD-OCT) images. All 19 eyes closed at 6mo postoperatively. BCVA was observed gradually improved (P<0.001), with subretinal fluid (SRF) gradually absorbed (P=0.021) and the rate of external limiting membrane (ELM) defects gradually decreased (P=0.011) with follow-up time. Poorer postoperative logMAR BCVA correlated with larger MH minimum diameter (P<0.001), larger MH basal diameter (P=0.008), longer symptom duration (P=0.002) and poorer preoperative logMAR BCVA (P=0.010). More improvement in BCVA correlated only with poorer preoperative in logMAR BCVA (P=0.002). The earlier reconstruction of ELM was associated with smaller MH basal diameter (P=0.022) and shorter symptom duration (P=0.008). In conclusion, smaller basal diameter of MH and shorter symptom duration were key factors in earlier reconstruction of ELM.

Background: Intracerebral hemorrhage (ICH) is a devastating subtype of stroke, in which neuroinflammation and blood–brain barrier (BBB) disruption are secondary pathophysiological events that drive progressive brain injury. Histone lysine demethylase JMJD3 (Jumonji C domain-containing protein 3) is a master epigenetic switch governing inflammatory signaling; however, its participation in ICH-induced vascular disruption and its possible mechanism remain elusive. Objective: To examine the expression patterns of JMJD3 in the context of ICH and to evaluate the therapeutic potential of its specific inhibitor, GSK-J4, in attenuating neuroinflammation and BBB disruption in a murine ICH model. Methods: Hemin treatment of a mouse C8-D1A astrocytic cell line was used to develop an in vitro ICH model. The transcript level of the Jmjd3 gene and its correlation with pro-inflammatory signaling were analyzed with or without GSK-J4 pretreatment. ICH in vivo was created experimentally in adult male C57BL/6 mice through stereotactic striatal injection of collagenase IV, and the mice were randomly assigned to sham, ICH + vehicle, and ICH + GSK-J4 (30 mg/kg intraperitoneally (i.p.), every other day starting three days before ICH) groups. At three days post-ICH, ipsilateral brain tissues were collected to detect JMJD3 cellular localization, pro-inflammatory mediator levels, tight junction protein expression, BBB ultrastructure, and hematoma volume. White matter integrity and neuronal recovery were assessed on day 7, and sensorimotor function was assessed longitudinally on days 1, 3, 5, 7, and 14. Results: Jmjd3 gene transcription was upregulated in hemin-treated astrocytes and correlated positively with IL-6 pro-inflammatory signaling activation. In vivo, the co-localization of JMJD3 with the astrocytic identifier glial fibrillary acidic protein (GFAP) was markedly increased in the area adjacent to the hematoma at three days post-ICH. GSK-J4 administration significantly suppressed the pro-inflammatory signaling cascade by decreasing the levels of inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α), and matrix metalloproteinase-9 (MMP-9), enhanced brain vascular structural and functional integrity by upregulating tight junction proteins zonula occludens protein-1 (ZO-1) and claudin-5, improved BBB ultrastructural integrity, and decreased hematoma volume at three days post-ICH. Furthermore, GSK-J4 administration promoted white matter integrity (increased myelin basic protein [MBP] expression) and neuronal recovery (increased neuron-specific nuclear protein [NeuN] expression) at seven days post-ICH and significantly improved the performance of ICH mice in sensorimotor behavioral tests. Conclusions: Astrocytic JMJD3 is upregulated following ICH and promotes neuroinflammation, which in turn mediates BBB disruption. Pharmacological inhibition of JMJD3 by GSK-J4 attenuates neuroinflammation and subsequent BBB damage, accelerates hematoma resolution, and promotes histological and functional recovery after ICH, likely by downregulating MMP-9 expression. These findings identify astrocytic JMJD3 as a novel epigenetic therapeutic target for acute ICH.