A Network-Based Approach for Predicting Hsp27 Knock-Out Targets in Mouse Skeletal Muscles

Abstract

Thanks to genomics, we have previously identified markers of beef tenderness, and computed a bioinformatic analysis that enabled us to build an interactome in which we found Hsp27 at a crucial node. Here, we have used a network-based approach for understanding the contribution of Hsp27 to tenderness through the prediction of its interactors related to tenderness. We have revealed the direct interactors of Hsp27. The predicted partners of Hsp27 included proteins involved in different functions, e.g. members of Hsp families (Hsp20, Cryab, Hsp70a1a, and Hsp90aa1), regulators of apoptosis (Fas, Chuk, and caspase-3), translation factors (Eif4E, and Eif4G1), cytoskeletal proteins (Desmin) and antioxidants (Sod1). The abundances of 15 proteins were quantified by Western blotting in two muscles of HspB1-null mice and their controls. We observed changes in the amount of most of the Hsp27 predicted targets in mice devoid of Hsp27 mainly in the most oxidative muscle. Our study demonstrates the functional links between Hsp27 and its predicted targets. It suggests that Hsp status, apoptotic processes and protection against oxidative stress are crucial for post-mortem muscle metabolism, subsequent proteolysis, and therefore for beef tenderness.

Calcium Homeostasis and Muscle Energy Metabolism Are Modified in HspB1-Null Mice

“…The present data are complementary to those obtained in a previous analysis focused on the direct interactors of Hsp27 [6], in which we reported muscle-specific differences in the HspB1 -null mouse. In the present study, the proteins altered after HspB1 invalidation belonged mainly to calcium homeostasis, energy metabolism and apoptosis pathway.…”

“…This illustrates an opposite relationship between Hsp27 and proteins representative of fast glycolytic type in agreement with the present results showing higher abundance of some fast glycolytic proteins in the HspB1 -null mice. In the present study, we failed to find differences in the abundances of small Hsps, namely, Hsp20 and αB-crystallin, described in the m. Soleus of the HspB1 -null mouse [6]. This suggests a muscle-specific effect of the invalidation of HspB1 .…”

“…In particular, Hsp27 encoded by the HspB1 gene was a hub protein, suggesting its key role in tenderness. In order to depict the molecular mechanisms involved in tenderness through the Hsp27 protein, we engineered a knock-out mouse by targeted invalidation of the HspB1 gene [6]. In an initial study, we used a network-basis approach combined to biochemistry to reveal Hsp27 interactors that may be related to tenderness.…”

“…In an initial study, we used a network-basis approach combined to biochemistry to reveal Hsp27 interactors that may be related to tenderness. However this approach enabled predicting Hsp27 targets solely in the Soleus muscle [6]. In another study, we also provided evidence that the HspB1 -null mouse displays ultrastructural abnormalities in the myofibrillar structure of mutant mice [7].…”

Recent advances in omic technologies for meat quality management

“…The study of HSPB1 KO mice (Kammoun, Picard, & Cassar-Malek, 2011) allowed us to gain understanding on the biological pathways involving the Hsp27 protein in tenderness by computing protein networks (Kammoun, Picard, Henry-Berger, & Cassar-Malek, 2013). A role in ultrastructural organization of muscle was also revealed (Kammoun et al, 2014).…”