NT5E mutations and arterial calcifications.

Area of Science:

• Genetics
• Biochemistry
• Cardiovascular Medicine

Background:

• Arterial calcifications are linked to cardiovascular disease risk.
• The genetic underpinnings of arterial calcifications remain largely unknown.

Purpose of the Study:

• Investigate the genetic basis of symptomatic arterial and joint calcifications in three families.
• Identify the specific gene mutations responsible for the observed calcification phenotype.

Main Methods:

• Clinical, radiographic, and genetic analyses were conducted across three families.
• Techniques included SNP analysis, gene sequencing, PCR, Western blotting, enzyme assays, and in vitro calcification studies.
• Functional studies assessed NT5E gene expression, CD73 protein activity, and the impact of adenosine treatment.

Main Results:

• Nine individuals across three families presented with arterial and joint calcifications.
• Mutations in the NT5E gene, encoding CD73, were identified in all affected individuals.
• These mutations led to nonfunctional CD73, reduced NT5E expression, increased alkaline phosphatase, and calcium phosphate crystal accumulation.
• Genetic rescue and adenosine treatment normalized cellular function and reduced calcification.

Conclusions:

• Mutations in NT5E are causative of symptomatic arterial and joint calcifications.
• The CD73-adenosine pathway plays a crucial role in inhibiting ectopic tissue calcification.
• This study elucidates a novel metabolic pathway involved in vascular calcification.