Store-operated calcium entry dysfunction in CRAC channelopathy: Insights from a novel STIM1 mutation

Area of Science:

• Molecular Biology
• Immunology
• Genetics

Background:

• Store-operated calcium entry (SOCE) is vital for cellular calcium homeostasis.
• STIM1 and ORAI1 proteins are key components of the SOCE mechanism.
• Mutations in STIM1 can cause CRAC channelopathies, leading to immune deficiencies.

Purpose of the Study:

• To investigate a novel STIM1 mutation in a patient with CRAC channelopathy.
• To analyze the functional consequences of the mutation on STIM1 splicing and SOCE.
• To explore antisense oligonucleotide therapy for STIM1-related disorders.

Main Methods:

• Genetic sequencing to identify STIM1 mutation (NM_003156 c.792-3C > G).
• Analysis of STIM1 splicing variants in patient cells.
• Functional assessment of calcium influx and SOCE.
• Development and testing of antisense oligonucleotide treatment.

Main Results:

• Identified a novel homozygous STIM1 mutation in a patient with CRAC channelopathy, immune deficiency, and muscle weakness.
• Observed three STIM1 spliced forms (wild-type, exon 7 skipping, intronic retention) in patient cells.
• Demonstrated impaired SOCE and loss of STIM1 function in patient cells.
• Showed that antisense oligonucleotide treatment restored STIM1 splicing and improved SOCE.

Conclusions:

• The novel STIM1 mutation leads to CRAC channelopathy through aberrant splicing and impaired SOCE.
• Antisense oligonucleotide therapy represents a promising therapeutic strategy for STIM1-related channelopathies.
• This study enhances understanding of STIM1 mutation complexity and clinical variability.