Biology subjects

Salehi, F.

Publications and source records attributed to Salehi, F..

3 recordsLinked to original sources

bioRxiv2026

Epigenetic dysregulation of Th2 cytokine genes in MuSK myasthenia gravis and its modulation by immunosuppressive therapy

Background and objectivesMyasthenia gravis associated with antibodies against muscle-specific kinase (MuSK-MG) is a well-characterized IgG4-autoimmune disease, however, the mechanisms driving IgG4 predominance remain poorly understood. This study investigated whether promoter DNA methylation of cytokine genes involved in IgG4 class switching is associated with this immune response. MethodsPeripheral blood mononuclear cells were isolated from MuSK-MG patients (n=36), acetylcholine receptor myasthenia gravis (AChR-MG) patients as disease controls (n=7), and sex-matched healthy controls (n=12). Promoter DNA methylation of IL4, IL10, and IL13 was assessed by methylation-sensitive high-resolution melting and relative cytokine mRNA expression by qPCR. Associations with clinical variables, and antibody levels were subsequently evaluated. ResultsMuSK-MG patients showed lower median IL13 promoter methylation compared with healthy controls (p = 0.004). Median IL4 promoter methylation was also reduced in MuSK-MG compared with healthy controls (p < 0.001) and AChR-MG disease controls (p < 0.001), whereas no differences were observed for IL10 promoter methylation. Relative mRNA expression of IL4 (p = 0.0005), IL10 (p = 0.0462), and IL13 (p = 0.0002) was increased in MuSK-MG compared with AChR-MG. Compared with healthy controls, only IL4 expression remained significantly increased (p < 0.0001). Promoter methylation was inversely correlated with relative mRNA expression for IL4 (p < 0.0001), while IL13 showed a similar but non-significant trend (p = 0.054), no association was observed for IL10. Multivariable analysis demonstrated that treatment at sampling was independently associated with lower IL10 and IL13 promoter methylation, whereas no associations were observed with age, sex, disease phase, or disease duration. Promoter methylation did not correlate with total serum IgG4 or anti-MuSK IgG4 levels. DiscussionMuSK-MG is associated with selective hypomethylation of IL4 and IL13 promoters accompanied by increased cytokine gene expression, while IL10 promoter methylation remains unchanged. The association between treatment and IL10 and IL13 promoter methylation suggests that immunosuppressive therapy may influence epigenetic regulation in MuSK-MG. Together, these findings support a role for epigenetic dysregulation of Th2-associated cytokines in the immunological environment associated with IgG4 subclass switch. To our knowledge, this is the first study investigating IL4, IL10, and IL13 promoter DNA methylation in MuSK-MG.

immunology↗

bioRxiv2026

Crosstalk Between Calcium Dynamics and ROS Levels in U87 Glioblastoma Cells Exposed to Extremely Low Frequency Pulsed Electromagnetic Fields

Extremely low-frequency pulsed electromagnetic fields (ELF-PEMFs) have been proposed to modulate intracellular signaling in cancer cells, however, the primary mediators and their temporal sequence remain incompletely understood. In this study, U87 glioblastoma cells were exposed to ELF-PEMF at varying frequencies and amplitudes, and intracellular calcium (Ca2+) dynamics, reactive oxygen species (ROS) levels, and mitochondrial membrane potential ({Delta}{Psi}m) were monitored. Exposure likely led to rapid ROS elevation and a decrease in {Delta}{Psi}m, indicating early mitochondrial involvement in ELF-PEMF responses. Fast Fourier transform (FFT) analysis of Ca2+ oscillations suggested that low-frequency exposures produced higher spectral power and amplitude compared with controls, consistent with enhanced Ca2+ signaling activity. Parallel pharmacological experiments demonstrated that ROS elevation may occur independently of IPL-dependent endoplasmic reticulum (ER) Ca2+ release, as 2-Aminoethoxydiphenyl borate (2-APB) inhibition did not prevent ROS increase. In contrast, treatment with the antioxidant N-acetylcysteine (NAC) effectively suppressed ROS without significantly altering basal cytosolic Ca2+ levels. These observations indicate that ROS likely acts as an early mediator of cellular responses to ELF-PEMF exposure, with downstream modulation of calcium signaling pathways. The magnitude of ROS elevation and Ca2+ modulation was strongly dependent on field frequency and amplitude, consistent with a frequency-dependent biological window. Overall, ROS likely acts as a primary mediator of ELF-PEMF bioeffects, highlighting its potential relevance for glioblastoma therapy, and future studies are warranted to assess other glioma lines to confirm generalizability.

cell biology↗

bioRxiv2025

Integrated Ultrasound Neuromodulation and Optical Neuroimaging in Awake Mice using a Transparent Ultrasound Transducer Cranial Window

Ultrasound neuromodulation is a rapidly advancing, non-invasive technique with significant therapeutic potential for treating various neurological disorders. Although extensive in vitro and in vivo studies have provided valuable insights into its modulatory effects, the underlying mechanisms remain poorly understood, limiting its clinical translation. Optical neuroimaging techniques can help investigate these mechanisms; however, the opacity and bulkiness of conventional ultrasound transducers pose significant challenges for their integration with in vivo ultrasound neuromodulation studies, particularly in awake rodents. To address these limitations, we propose a straightforward solution: a miniaturized lithium niobate-based transparent ultrasound transducer (TUT) integrated as a thinned-skull cranial window for ultrasound stimulation while facilitating multimodal optical neuroimaging in awake mice brain. Using laser speckle contrast imaging and intrinsic optical signal imaging, we studied changes in brain hemodynamics in response to various ultrasound stimulation sequences. Our experiments demonstrated that TUT cranial window can robustly induce neuromodulatory effects with observed increase in both cerebral blood flow and total hemoglobin, with peak and cumulative hemodynamic changes directionally correlated with ultrasound stimulation duration and intensity. Overall, these findings highlight that TUT cranial window can seamlessly integrate ultrasound stimulation and optical neuroimaging in awake mouse brain models, offering promising prospects for uncovering the underlying mechanisms of ultrasound neuromodulation.

neuroscience↗