The Role of Membrane Protein ATAD3A in The Mitochondrial Quality Control / 生物化学与生物物理进展

Mitochondrial quality control plays an important role in maintaining homeostasis of mitochondrial network and normal function of mitochondria. ATPase family AAA domain-containing protein 3A (ATAD3A) is one of the mitochondrial membrane proteins involved in the regulation of mitochondrial structure and function, mitochondrial dynamics, mitophagy and other important biological processes. Recent studies show that ATAD3A not only interacts with Mic60/Mitofilin and mitochondrial transcription factor A (TFAM) to maintain mitochondrial cristae morphology and oxidative phosphorylation, but also interacts with dynamin-related protein 1 (Drp1) to positively/negatively regulate mitochondrial fission. In addition, ATAD3A serves as a bridging factor between the translocase of the outer mitochondrial membrane (TOM) complex and translocase of the inner mitochondrial membrane (TIM) complex to facilitate the import of PTEN-induced putative kinase protein 1 (PINK1) into mitochondria and its processing displays a pro-autophagic or anti-autophagic activity. This article reviews the role and mechanism of ATAD3A in regulating mitochondrial quality control. Firstly, as an inner mitochondrial membrane protein, ATAD3A is involved in maintaining the stability of mitochondrial crista structure, and its gene deletion or mutation will cause the loss and breakage of crista. Secondly, ATAD3A is also involved in maintaining mitochondrial respiratory function and mitochondrial nucleoid homeostasis, and its gene deletion or mutation can reduce the activity of mitochondrial respiratory chain complex and enhance the size and movement of nucleoid. Thirdly, ATAD3A participates in the negative regulation of mitochondrial fusion, but its role in mitochondrial fission may dependent on specific cell types, as it can promote and/or inhibit the mitochondrial fission by increasing and/or decreasing phosphorylation or oligomerization of Drp1. Finally, ATAD3A can interact with mitophagy-related proteins (e.g. PINK1, autophagy/beclin-1 regulator 1 (AMBRA1), acylglycerol kinase (AGK)) to enhance/reduce PINK1-Parkin-dependent mitophagy.

Artemisia argyi extract subfraction exerts an antifungal effect against dermatophytes by disrupting mitochondrial morphology and function / 中国天然药物

Artemisia argyi (A. argyi), a plant with a longstanding history as a raw material for traditional medicine and functional diets in Asia, has been used traditionally to bathe and soak feet for its disinfectant and itch-relieving properties. Despite its widespread use, scientific evidence validating the antifungal efficacy of A. argyi water extract (AAWE) against dermatophytes, particularly Trichophyton rubrum, Trichophyton mentagrophytes, and Microsporum gypseum, remains limited. This study aimed to substantiate the scientific basis of the folkloric use of A. argyi by evaluating the antifungal effects and the underlying molecular mechanisms of its active subfraction against dermatophytes. The results indicated that AAWE exhibited excellent antifungal effects against the three aforementioned dermatophyte species. The subfraction AAWE6, isolated using D101 macroporous resin, emerged as the most potent subfraction. The minimum inhibitory concentrations (MICs) of AAWE6 against T. rubrum, M. gypseum, and T. mentagrophytes were 312.5, 312.5, and 625 μg·mL-1, respectively. Transmission electron microscopy (TEM) results and assays of enzymes linked to cell wall integrity and cell membrane function indicated that AAWE6 could penetrate the external protective barrier of T. rubrum, creating breaches ("small holes"), and disrupt the internal mitochondrial structure ("granary"). Furthermore, transcriptome data, quantitative real-time PCR (RT-qPCR), and biochemical assays corroborated the severe disruption of mitochondrial function, evidenced by inhibited tricarboxylic acid (TCA) cycle and energy metabolism. Additionally, chemical characterization and molecular docking analyses identified flavonoids, primarily eupatilin (131.16 ± 4.52 mg·g-1) and jaceosidin (4.17 ± 0.18 mg·g-1), as the active components of AAWE6. In conclusion, the subfraction AAWE6 from A. argyi exerts antifungal effects against dermatophytes by disrupting mitochondrial morphology and function. This research validates the traditional use of A. argyi and provides scientific support for its anti-dermatophytic applications, as recognized in the Chinese patent (No. ZL202111161301.9).

Effects of ovarian varicose vein on mitochondrial structure, malondialdehyde and prooxidants: antioxidants balance in rat ovaries / Efectos de las venas ováricas varicosas sobre la estructura mitocondrial, niveles de malondialdehído y balance prooxidantes: antioxidantes en ovarios de ratas

Oxidative stress is increased in varicose veins. Many studies have implicated oxidative stress in the pathogenesis of infertility causing diseases of the female reproductive tract. The aim of this study was to determine whether varicocele can cause raised levels of reactive oxygen species and denaturation of mitochondrial structure in ovaries of female rats or not. In each experimental study, 15 weaning-age female rats were divided equally in 3 groups: Unilateral Varicose Vein (A), Sham (B) and Control (C) groups. Mitochondrial structure and malondialdehyde levels as a product of lipid peroxidation and Prooxidants-Antioxidants Balance were evaluated 60 days after intervention in proestrus stage. Comparisons between groups were made by the measured test. After 2 months, our results showed that mitochondrial structure ultra-structurally was denatured with histologic examination, malondialdehyde and prooxidants-antioxidants balance levels of left ovaries increased significantly in varicocele group compared to control and sham groups (P0.05). In the right side, malondialdehyde increased significantly, but in prooxidants-antioxidants balance levels, there is no significant differences between groups. The data of control and sham groups were the same. These findings may support the concept that increased levels of malondialdehyde and PAB in varicocele may cause negative effects on fertility, so using antioxidants maybe useful.

El estrés oxidativo aumenta en las venas varicosas. Diversas investigaciones han implicado al estrés oxidativo en la patogénesis de las enfermedades que causan la infertilidad del tracto reproductivo femenino. El objetivo de este estudio fue determinar si el varicocele puede provocar niveles de especies reactivas del oxígeno y la desnaturalización de la estructura mitocondriales en los ovarios de ratas. En cada estudio experimental, cinco ratas hembras en edad de destete se dividieron por igual en 3 grupos: Várices unilateral (A), simulado (B) y control (C). La estructura mitocondrial y los niveles de malondialdehído como un producto de la peroxidación lipídica y el balance pro-oxidantes-antioxidantes (BPA) se evaluaron 60 días después de la intervención en la etapa proestro. Las comparaciones entre grupos se realizaron mediante la prueba de medición. Después de 2 meses, observamos que la estructura mitocondrial se desnaturalizó ultraestructuralmente, los niveles malondialdehído y el balance prooxidantes-antioxidantes de los ovarios izquierdos aumentaron significativamente en el grupo A en comparación con los grupos B y C (P0.05). En el lado derecho, los niveles de malondialdehído aumentaron significativamente, pero el BPA, no mostró diferencias significativas entre los grupos. Los datos de los grupos B y C eran los mismos. Estos hallazgos pueden apoyar el concepto de que el aumento de niveles de malondialdehído y BPA en presencia de varicocele, puede causar efectos negativos sobre la fertilidad, por tanto el uso de antioxidantes puede resultar útil.

Effect of preconditioning with pioglitazone on ischemia reperfusion/hypoxia reoxygenation-induced mitochondrial structure and membrane potential in rats / 中国病理生理杂志

AIM:To observe the effect of preconditioning with pioglitazone on ischemia reperfusion/hypoxia reoxygenation-induced mitochondrial ultramicro-structure and membrane potential in rats. METHODS: Sprague-Dawley rats were randomly divided into four groups: sham-operated (SO) group, ischemia reperfusion (IR) group, pioglitazone preconditioning group (Pio-P) and 5-HD+pioglitazone (5-HD+Pio) group. Apart from the SO group, IR, Pio-P and 5-HD+Pio groups were subjected to 30 min ischemia and 4 h reperfusion. The heart was quickly removed for observing the structure of mitochondria and measurement of the apoptosis index (AI) by TUNEL. Primary cultured cardiomyocytes of Sprague-Dawley rats were divided into control, hypoxic reoxygenation (HR) and different concentrations of Pio-P group. JC-1 staining flowcytometry was adopted to examine mitochondrial membrane potential (?m). RESULTS: The injury of mitochondrial structure in IR group was severer than that in Pio-P group, while the difference between 5-HD+Pio group and IR group was not evident. Flameng score in Pio-P group(1.62?0.60) was significantly lower than that in IR group (2.75?1.09), P0.05). CONCLUSION: Pioglitazone protects the heart from ischemia reperfusion/ hypoxia reoxygenation injury evidenced by improving mitochondrial ultrastructure and lessening the loss of mitochondrial membrane potential, and decreasing apoptosis. The cardioprotective effects can be inhibited by the blocker of mitochondrial ATP-sensitive potassium channels.