MITOCHONDRIAL DYSFUNCTION AND ELECTROPHYSIOLOGICAL ABNORMALITIES IN SMA PATIENT-DERIVED IPSCS

Bitirim C. V.

ISSCR 2024, Hamburg, Almanya, 10 - 13 Temmuz 2024, ss.626

  • Yayın Türü: Bildiri / Özet Bildiri
  • Basıldığı Şehir: Hamburg
  • Basıldığı Ülke: Almanya
  • Sayfa Sayıları: ss.626
  • Ankara Üniversitesi Adresli: Evet

Özet

Spinal Muscular Atrophy (SMA) is a neurodegenerative disorder characterized

by the progressive loss of motor neurons in the spinal cord,

leading to muscle weakness and atrophy. While the genetic basis of

SMA is well-established, recent research has unveiled the involvement

of mitochondrial dysfunction in the pathophysiology of the disease.

Some experimental data imply that the determination of the mitochondria

dysfunctions at the developmental and progression stages in

SMA pathogenesis may contribute to the cardiomyopathy. Therefore,

here, we aimed to determine the impacts of SMN gene mutation on

mitochondrial functions and electrophysiological properties of human

induced pluripotent stem cells (hiPSCs) and hiPSC-derived ventricular

cardiomyocytes (iPSC-vCM) from SMA patients. The hiPSCs were

isolated from blood samples of SMA patients (0-2 years-of-age) and

healthy-control donors. The function of mitochondria was examined

by monitoring the reactive oxygen species (ROS) production ([ROS]i),

mitochondrial membrane potential (MMP) and ATP in both control and

SMA-iPSCs groups by using DCFDA, JC-1 dyes, and Luminescent Cell

Viability Assay Kit respectively. Our data showed that cellular [ROS]

i production was increased and MMP was significantly depolarized in

SMA-iPSCs compared to control-iPSCs. Additionally, an increase in

ATP levels has been observed in SMA groups compared to the control

groups. iPSCs were differentiated into ventricular cardiomyocytes

(iPSC-vCM) and characterized by qRT-PCR and immunofluorescence

assays. Following characterization steps, patch-clamp analysis was

performed to measure action potential parameters and voltage-dependent

Na+, K+ and Ca2+ channel-currents. Our electrophysiological data

demonstrated the SMN gene mutation induces changes in ionic mechanisms

and electrical activities of iPSC-vCM through marked changes

in channel currents. These results suggest that SMA patient-derived

iPSCs shown the mitochondrial dysfunction leading to the electrophysiological

abnormalities in iPSC-derived ventricular cardiomyocytes.

Overall data may demonstate that membrane ion channels and

mitochondria may be a potential therapeutic target for management of

SMA-related heart failure.