Session Type: Abstract Submissions (ACR)
Background/Purpose: ANKRD1 codes for ankyrin repeat domain containing protein 1, which belongs to the muscle ankyrin repeat protein family involved in a mechano-signaling pathway that links myofibrillar stress response to muscle gene expression. In addition, ANKRD1 has an important role in transcriptional regulation, myofibrillar assembly, cardiogenesis and myogenesis. Recently, at first time, our group had demonstrated that ANKRD1 was overexpressed in dermatomyositis muscle specimens. Herein, we analyzed ANKRD1 expression in muscle biopsies of patients with polymyositis (PM).
Methods: RNA was extracted from frozen muscle biopsies samples of 33 untreated adult with PM (Bohan and Peter’s criteria, 1975). As a control group, we analyzed 20 muscle biopsies with no histological change from untreated adult patients with non-inflammatory myopathy diseases. Additional to ANKRD1, the gene coding for hypoxia-inducible factor 1, alpha subunit (HIF1A) was also analyzed to estimate hypoxia degree. The ANKRD1 and HIF1A transcript expression levels were determined by quantitative real time PCR using Sybr Green method. Muscle biopsies were analyzed histologically by semi-quantitative method of HE stained biopsies. Expression and localization of ANKRD1 and HIF1a in muscle biopsies was accessed by immunohistochemistry.
Results: Higher ANKRD1 and HIF1A expressions levels were observed in PM samples relative to control group (p<0.001 and p<0.001). In addition, the expression levels of both genes were correlated (r=0.380, P=0.029). We also observed a positive correlation of both genes to degree of muscle impairment and inflammatory infiltration. However, ANKRD1 and HIF1A expression levels did not correlate to demographic, clinical and laboratory features (p>0.05). Immunohistochemistry showed that ANKRD1 and HIF1a were expressed mainly by affected muscle fibers.
Conclusion: Our results demonstrated ANKRD1 is overexpressed and correlated to HIF1A and to infiltrate inflammation found in PM muscle specimens. ANKRD1 involvement in myogenesis and angiogenesis mechanism will be further investigated.
S. K. Shinjo,
S. M. Oba-Shinjo,
S. K. N. Marie,
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/overexpression-of-ankyrin-repeat-domain-containing-protein-1-gene-ankrd1-in-polymyositis-muscle-biopsies-is-correlated-to-hypoxia/