Proteomic profiling of endothelin-1-stimulated hypertrophic cardiomyocytes reveals the increase of four different desmin species and α-B-crystallin

Abstract

We performed a proteomic investigation on primary cultures of neonatal rat cardiomyocytes after treatment with 10 nM endothelin-1 (ET1) for 48 h, an in vitro model for cardiac hypertrophy. Two-dimensional gel electrophoresis profiles of cell lysates were compared after colloidal Coomassie Blue staining. 12 protein spots that significantly changed in density due to ET1 stimulation were selected for in-gel digestion and identified through mass spectrometry. Of these, 8 spots were increased and 4 were decreased. Four of the increased proteins were identified as desmin, the cardiac component of intermediate filaments and one as alpha-B-crystallin, a molecular chaperone that binds desmin. All the desmins increased 2- to 5-fold, and alpha-B-crystallin increased 2-fold after ET1 treatment. Desmin cytoskeleton has been implicated in the regulation of mitochondrial activity and distribution, as well as in the formation of amyloid bodies. Mitochondria-specific fluorescent probe MitoTracker indicated mitochondrial redistribution in hypertrophic cells. An increase of amyloid aggregates containing desmin upon treatment with ET1 was detected by filter assay. Of the four proteins that showed decreased abundance after ET1 treatment, the chaperones hsp60 and grp75 were decreased 13- and 9-fold, respectively. In conclusion, proteomic profiling of ET1-stimulated rat neonatal cardiomyocytes reveals specific changes in cardiac molecular phenotype mainly involving intermediate filament and molecular chaperone proteins.

Divide and Conquer

“…Our group has recently reported that the levels of PTM-forms of desmin are altered in the mitochondrial fraction of a canine model of HF compared both to shams and animals rescued by CRT 58 . This observation opens an interesting line of investigation, as desmin is known to regulate mitochondrial positioning and behavior through, albeit, an unknown mechanism 5, 155 . One potential explanation is that desmin, maintaining the spatial organization between sarcomeres and mitochondria, ensures that energy production and consumption are properly coupled (Figure 4).…”

Left ventricular hypertrophy induced by abdominal aortic banding and its prevention by angiotensin receptor blocker telmisartan—a proteomic analysis

“…For example, it was reported that lower mass range (22-23 kDa) of HSP27 were less abundant whereas high mass range (27-28 kDa) were up-regulated in right ventricular hypertrophy [7]. In endothelin 1-induced LVH, HSP60 and grp75 were decreased 13-fold and ninefold, respectively [1]. In the present study, antioxidative-related HSP2 (MW/pI, 27.3 kD/7.2) was expressed in telmisartan group only.…”

Effects of Hypertension and Exercise on Cardiac Proteome Remodelling

“…From those, α B-crystalline, associated with cardioprotection and ANP, a biomarker for pathologic cardiac hypertrophy, presented the highest upregulations [43]. A more recent study found similar data, indicating that cardiomyocyte hypertrophy induced by ET-1 led to proteome modulation with the increase in expression of desmin protein species and α B-crystalline  [79]. Other cardiac hypertrophic stimuli, such as isoproterenol (ISO), were also observed to promote an alteration in healthy cardiac tissue and in the cardiac proteome, shown by 2-DE MS/MS analysis [80].…”