Effects of Mitophagy on Regulatory T Cell Function in Patients With Myasthenia Gravis

Abstract

This study was conducted to determine whether regulatory T cells (CD4 + CD25 + T, Tregs) show abnormal mitophagy as well as the function of Tregs in patients with myasthenia gravis (MG). Methods: CD4 + T cells and CD4 + CD25 + Treg cells were obtained from 15 patients with MG (MG group) and 15 controls (N group). Tregs from the MG group were subjected to rapamycin-induced culture for 48 h (Rapa group) and 3-methyladenine-induced culture for 48 h (3-MA group). The levels of mitophagy in Tregs were then observed through electron and confocal microscopy. Expression of the autophagy-related protein LC3-II was detected by western blotting, and mitochondrial function in each group was evaluated by flow cytometry. Inhibition of Treg cell proliferation was detected by flow cytometry. Results: Mitophagy in the MG group was lower than that in the N group; it was higher in the Rapa group compared to that in the MG group and lowered in the 3-MA group than in the MG group. Expression of the autophagy-related protein LC3-II was lower in the MG group than in the N group, higher in the Rapa group than in the MG group, and lower in the 3-MA group than in the MG group. The mitochondrial membrane potential was lower in the MG group compared to that in the N group; it was higher in the Rapa group than in the MG group and lowered in the 3-MA group than in the MG group. Inhibition of Treg proliferation was lower in the MG group than in the N group; it was higher in the Rapa group than in the MG group and lowered in the 3-MA group than in the MG group. Conclusion: The decreased mitochondrial membrane potential and mitophagy in Tregs in the MG group may be related to a decreased inhibition of Treg proliferation. The mitochondrial membrane potential was increased after adding the autophagy agent Rapa to enhance mitophagy, and the proliferation inhibition function of Tregs was also enhanced. The autophagy agent 3-MA down-regulated mitophagy, which decreased the mitochondrial membrane potential and inhibitory effect of Tregs. These results reveal the possible cellular immune mechanism of Treg dysfunction in MG.

Organelle Crosstalk Regulators Are Regulated in Diseases, Tumors, and Regulatory T Cells: Novel Classification of Organelle Crosstalk Regulators

“…Recent reports showed that the MT membrane potential and the proliferation inhibition function of CD4 + Foxp3 + Treg from patients with myasthenia gravis are enhanced by autophagy inducing agent rapamycin and suppressed by phosphoinositide 3-kinase (PI3 kinase) and autophagy inhibitor 3-methyladenine (3-MA) ( 102 ) and that during autoimmune conditions, Treg function alterations associate with MT oxidative stress, dysfunctional mitophagy, and enhanced DNA damage and cell death ( 103 , 104 ). We hypothesized that the expressions of OCRGs are modulated in CD4 + CD25 high FOXP3 + Treg in comparison with those of CD4 + CD25 − T effector cell controls.…”

Redefining Autoimmune Disorders’ Pathoetiology: Implications for Mood and Psychotic Disorders’ Association with Neurodegenerative and Classical Autoimmune Disorders

“…Raised cerebrospinal fluid and plasma indicants of autophagy and mitophagy, including PINK1 and parkin, are evident in the active phase of relapse remitting multiple sclerosis, with autophagy inhibition enhancing myelination, highlighting that the enhancement, as well as the suppression, of mitophagy are aspects of 'autoimmune' disorders [53]. Dysregulated mitophagy is evident in many classical 'autoimmune' disorders, including rheumatoid arthritis [54], SLE [55], T1DM [56], myasthenia gravis [57] and autoimmune hepatitis [58], as well as in suspected 'autoimmune' conditions, such as endometriosis [59], and neurodegenerative conditions [60]. Notably, alterations in mitochondrial function and mitophagy are not always evident in cells classically associated with these conditions, but in cells relevant to wider intercellular interactions, including immune cell mitochondria, as evident in Treg in myasthenia gravis [57].…”

“…Dysregulated mitophagy is evident in many classical 'autoimmune' disorders, including rheumatoid arthritis [54], SLE [55], T1DM [56], myasthenia gravis [57] and autoimmune hepatitis [58], as well as in suspected 'autoimmune' conditions, such as endometriosis [59], and neurodegenerative conditions [60]. Notably, alterations in mitochondrial function and mitophagy are not always evident in cells classically associated with these conditions, but in cells relevant to wider intercellular interactions, including immune cell mitochondria, as evident in Treg in myasthenia gravis [57]. Such data implicate a 'microenvironment' of diverse interacting cells with their mitochondrial function dynamically shaped via alterations in the mitochondrial function of other 'microenvironment' cells, paralleling the dynamic intercellular interactions occurring within the tumor microenvironment [61], and as recently proposed for T1DM [17].…”

The Effect of CCCP on Mitophagy in CD4+CD25+ Regulatory T Cells in Human Peripheral Blood

“…The use of immunosuppressive Tregs for therapeutic purposes is of great interest to researchers because of their great potential in the treatment of autoimmune diseases, prevention of transplant rejection, and tumor immunotherapy [7][8][9] . Previous research in our research group showed that the abnormal mitophagy in peripheral blood Treg cells in patients with myasthenia gravis (MG) [10] . In this research, the autophagy state of mitochondria was changed In Vitro by using different CCCP concentrations in Tregs.…”