The rising incidence of mangled extremity seen in modern trauma has lead to significant patient mortality. A lot of research is going on at microcellular level for a better understanding of tissue injury, repair and regeneration. PAX-7 is one such transcription factor, a marker of satellite stem cells in skeletal muscle. Though few studies have shown concrete evidence of increased expression of PAX-7 in the nearby injured zone in skeletal muscle post-injury, none has studied its expression in an event of mangled injury of limb in humans. We, hereby, attempted to identify whether PAX-7 expression of tissue near the zone of injury, after grievous trauma like mangled injury of extremities, actually increases, decreases or remains unaffected. A pilot study was conducted on 30 cases at a level 3 trauma centre; patients were segregated into two groups—group I with MESS score ≥ 7 and group II with score < 7. For group I patients, amputation was planned, and for group II, limb salvage surgery was planned. Skeletal muscle samples from three different zones (A, B and C) in group I, while pre- and post-debridement skeletal muscle samples in group II were sent for microscopic examination and IHC staining with PAX-7 antibody. A definite increase in PAX-7 expression, post-trauma near the zone of injury (Zone B and C in group I and post-debridement in group II), was noted. Increased expression of PAX-7 signifies increased recruitment of satellite stem cells near the injury zone, thereby reflecting the activation of skeletal muscle regeneration cascade. Hence, increased staining of PAX-7 in tissues could be a viable marker for identifying potential regeneration of skeletal muscle post-injury.
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This work has been funded by Indian Council of Medical Research (ICMR) (No.3/2/Sept.2016/PG-Thesis-HRD(8) Dated: 4.10.2016), Department of Health Research, New Delhi, and constituted part of a thesis submitted by the principal author.
Compliance with ethical standards
Conflict of interest
There are no conflicts of interest from any of the authors.
The study was approved by the Institute’s Ethical Committee and was performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments.
Informed consent was taken from the patients at the time of enrolment and the study procedure was explained in detail to all the enrolled patients and they were made to understand that they could withdraw from the study at any point of the study period. The study has not altered any of the management protocols of these patients. Identity of the participants was kept confidential.
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