Literature Analysis: SEMA7A Mutation Uncovers a Novel Pathogenic Mechanism of PFIC, Empowered by ANT BIO's Multiplex Fluorescence IHC Kit

1. Literature Information

Journal: EMBO Molecular Medicine

Impact Factor: 12.137

Key Product Utilized: 6-Color Multiplex Fluorescence IHC Staining Kit (Anti-Rabbit Secondary Antibody, Catalog No.: abs50030) from the Absin product line of ANT BIO PTE. LTD.

2. Research Background

Progressive Familial Intrahepatic Cholestasis (PFIC) is a group of rare autosomal recessive liver disorders characterized by early-onset cholestasis, severe pruritus, and progressive liver damage, which often culminates in liver failure in childhood or adolescence without timely intervention. The pathogenesis of PFIC is closely associated with genetic mutations that impair bile acid transport or excretion, and several subtypes of PFIC have been identified based on different causal genes. However, a considerable number of PFIC cases remain unexplained by known genetic defects, highlighting the need for further exploration of novel pathogenic mechanisms.

Semaphorin 7A (SEMA7A) is a membrane-bound protein primarily involved in axon growth and various other biological processes. Previous studies have linked SEMA7A mutations to vertebral fractures and Kallmann syndrome, but its role in liver diseases, particularly PFIC, has not been reported before. This research aims to investigate the potential correlation between SEMA7A mutations and familial cholestasis, thereby filling the gap in current understanding of PFIC's genetic etiology.

3. Research way

The research team initiated the study with a female pediatric patient presenting with unexplained elevated serum levels of alanine transaminase (ALT), aspartate transaminase (AST), and total bile acid (TBA), which are typical indicators of liver dysfunction and cholestasis. To identify the underlying genetic cause, the team first performed genetic testing on the patient, focusing on known PFIC-related genes and other potential pathogenic genes.

After detecting a homozygous R148W mutation in the SEMA7A gene and a concurrent SLC10A1 S267F allele in the patient, the team conducted functional validation using a mouse model. They generated Sema7a homozygous mutant mice and compared their liver function parameters, liver histopathological changes, and bile acid (BA) levels with wild-type and heterozygous mice. To elucidate the underlying mechanism, the team further investigated the expression of canalicular membrane BA transporters using multiplex fluorescence immunohistochemistry and other techniques. Finally, the therapeutic effect of ursodeoxycholic acid (UDCA) and glutathione (GSH) on this novel type of PFIC was evaluated.

4. Research Results

Firstly, genetic testing confirmed that the female pediatric patient with elevated serum ALT, AST, and TBA carried a homozygous SEMA7A R148W mutation. Although the patient also had an SLC10A1 S267F allele, subsequent experiments showed that mice homozygous for SLC10A1 S267F had normal liver function, excluding this allele as the cause of the patient's symptoms.

Secondly, similar to the pediatric patient, Sema7a homozygous mutant mice exhibited significantly elevated serum ALT, AST, and TBA levels. Liver histology and LC-MS/MS analysis revealed hydropic degeneration of hepatocytes and increased hepatic BA levels in these mutant mice, confirming the presence of intrahepatic cholestasis.

Mechanistically, the SEMA7A R145W mutation was found to downregulate the expression of canalicular membrane BA transporters, specifically bile salt export pump (Bsep) and multidrug resistance-associated protein 2 (Mrp2). This reduction in transporter expression impaired bile acid excretion, leading to BA accumulation and subsequent cholestatic liver injury.

Finally, therapeutic intervention experiments demonstrated that treatment with UDCA and GSH significantly improved the abnormal liver function of patients with this novel type of PFIC, providing a potential therapeutic strategy for clinical management.

5. Product Empowerment

The 6-Color Multiplex Fluorescence IHC Staining Kit (Catalog No.: abs50030) from the Absin product line of ANT BIO PTE. LTD. played a crucial role in validating the key mechanism of this research. To accurately assess the expression of Bsep and Mrp2 in liver tissues and cultured primary hepatocytes, the research team performed multiplex immunofluorescence staining on liver sections and cell coverslips in strict accordance with the manufacturer's instructions.

This kit enabled simultaneous detection of Bsep and Mrp2 on a single section, facilitating the direct observation of their spatial distribution and relative expression levels in wild-type and Sema7a mutant mice. The high sensitivity and specificity of the kit ensured the reliability and accuracy of the staining results, which were critical for confirming the downregulation of Bsep and Mrp2 expression caused by the SEMA7A mutation. Without this advanced multiplex staining tool, the precise characterization of the pathogenic mechanism linking SEMA7A mutation to intrahepatic cholestasis would have been significantly hindered.

6. Brand Mission

ANT BIO PTE. LTD. is dedicated to empowering life science research through the provision of high-quality, reliable reagents and comprehensive solutions. Our specialized sub-brands (Absin, Starter, UA) are strategically positioned to cover a full spectrum of research needs: Absin focuses on general reagents and kits, Starter specializes in antibodies, and UA is dedicated to recombinant proteins. We strive to support researchers in unlocking scientific mysteries, advancing medical progress, and addressing unmet clinical needs through continuous innovation and customer-centric services.

7. Related Product List

8. Disclaimer

This article is AI-compiled and interpreted based on the original work in DOI: 10.1002/advs.202413562. All intellectual property (e.g., images, data) of the original publication shall belong to the journal and the research team. For any infringement, please contact us promptly and we will take immediate action.

9. Brand Promotion Copy

ANT BIO PTE. LTD. – Empowering Scientific Breakthroughs

At ANTBIO, we are committed to advancing life science research through high-quality, reliable reagents and comprehensive solutions. Our specialized sub-brands (Absin, Starter, UA) cover a full spectrum of research needs, from general reagents and kits to antibodies and recombinant proteins. With a focus on innovation, quality, and customer-centricity, we strive to be your trusted partner in unlocking scientific mysteries and driving medical progress. Explore our product portfolio today and elevate your research to new heights.