Phosphatidic Acid Stimulates Myoblast Proliferation through Interaction with LPA1 and LPA2 Receptors

Abstract

Phosphatidic acid (PA) is a bioactive phospholipid capable of regulating key biological functions, including neutrophil respiratory burst, chemotaxis, or cell growth and differentiation. However, the mechanisms whereby PA exerts these actions are not completely understood. In this work, we show that PA stimulates myoblast proliferation, as determined by measuring the incorporation of [3H]thymidine into DNA and by staining the cells with crystal violet. PA induced the rapid phosphorylation of Akt and ERK1/2, and pretreatment of the cells with specific small interferin RNA (siRNA) to silence the genes encoding these kinases, or with selective pharmacologic inhibitors, blocked PA-stimulated myoblast proliferation. The mitogenic effects of PA were abolished by the preincubation of the myoblasts with pertussis toxin, a Gi protein inhibitor, suggesting the implication of Gi protein-coupled receptors in this action. Although some of the effects of PA have been associated with its possible conversion to lysoPA (LPA), treatment of the myoblasts with PA for up to 60 min did not produce any significant amount of LPA in these cells. Of interest, pharmacological blockade of the LPA receptors 1 and 2, or specific siRNA to silence the genes encoding these receptors, abolished PA-stimulated myoblast proliferation. Moreover, PA was able to compete with LPA for binding to LPA receptors, suggesting that PA can act as a ligand of LPA receptors. It can be concluded that PA stimulates myoblast proliferation through interaction with LPA1 and LPA2 receptors and the subsequent activation of the PI3K/Akt and MEK/ERK1-2 pathways, independently of LPA formation.

Evaluation of the Timing of Use of Phosphatidic Acid in the Diet on Growth Performance and Breast Meat Yield in Broilers

“…The current study saw an overall improvement in body weight at d42 in PAA fed birds and specifically increased breast weight over birds not supplemented with PA or birds with PA supplementation that started after the first 14 days of growth. This may indicate that PA played a critical part in muscle cell growth during satellite cell proliferation seen by others [ 12 ]. In broilers, the maximum satellite cell activity occurs in the first week after hatch [ 13 ], although the overall growth in broilers increases until about 30 days of age [ 14 ].…”

“…As broilers have a sigmoid growth curve [ 9 ], the addition of PA to the feed appears to be more important to start from the beginning of production. This is the period where maximal satellite cell activity occurs [ 13 ] and PA has been demonstrated to stimulate the proliferation of these cells [ 12 ]. It is not clear from this current research whether just the initial starter diet phase is needed, as the feeding of PA either for the entire 6-week growout or for the last two or four weeks were only investigated.…”

“…The satellite cells hypertrophy by fusing with and donating their nuclei to existing muscle fibers resulting in muscle growth [ 10 , 11 ]. Phosphatidic acid has been shown to simulate myoblast proliferation through interaction with LPA1 and LPA2 receptors [ 12 ]. The first week posthatch in broilers, especially those selected for rapid growth, has been shown to be the period of maximal satellite cell activity and the most important for muscle production [ 13 ].…”

Implication of Ceramide Kinase/C1P in Cancer Development and Progression

“…Exogenous bacterial phospholipase D (PLD) (from Staphylococcus aureus ), an enzyme that produces PA at the plasma membrane of cells, recapitulated the inhibitory effects of exogenous PA on leukemia cell migration [ 35 ]. Since PA has mitogenic properties [ 55 , 56 , 57 ] and has been associated with progression of some cancer cell types [ 58 , 59 , 60 , 61 , 62 ], it might be possible that synthetic PA analogs lacking cell growth promoting properties could be useful for counteracting leukemia cell migration.…”

Single-Cell Transcriptome Dynamics of the Autotaxin-Lysophosphatidic Acid Axis During Muscle Regeneration Reveal Proliferative Effects in Mesenchymal Fibro-Adipogenic Progenitors

“…Other supporting studies have shown that LPA increases intracellular Ca 2+ concentration and induces DNA synthesis (Xu et al, 2008), reinforcing that LPA modulates myogenic cell growth and proliferation (Bernacchioni et al, 2018). Recently, Gomez-Larrauri and colleagues reported that PA induces DNA synthesis in C2C12 myoblast via LPAR1/LPAR2 and downstream ERK1/2-AKT signalling at similar concentrations to LPA (Gomez-Larrauri et al, 2021). Pharmacological inhibition of ENPP2 or Enpp2 knockdown reduces myogenic differentiation, via a mechanism whereby Enpp2 is a direct target gene of WNT/RSPO2-mediated TCF/LEF/β-CATENIN signalling (Sah et al, 2020).…”