Journal of Cellular Physiology最新文献

Platelets, as anucleate blood cells, play a pivotal role in the pathogenesis of cardiovascular diseases (CVDs), making antiplatelet therapy essential for preventing thrombotic events such as myocardial infarction. Thromboxane A₂ (TXA₂) is a key pro-aggregatory mediator that drives platelet activation. Phosphorylation of vasodilator-stimulated phosphoprotein (VASP) at Ser157 and Ser239 serves as a marker of cyclic nucleotide-mediated inhibitory signaling. The crosstalk between TXA₂ signaling and site-specific VASP phosphorylation in arachidonic acid (AA)-stimulated human platelets remains unclear and requires further investigation. In this study, AA at 60 µM induced maximal platelet activation, as evidenced by ultrastructural changes and increased P-selectin expression. Picotamide, a thromboxane synthase (TXS) inhibitor, effectively reversed AA-induced alterations, including ultrastructural remodeling, P-selectin expression, TXA₂ production, adenosine triphosphate (ATP)-release, mobilization of [Ca²⁺]ᵢ, and integrin α_IIbβ₃ activation. Importantly, picotamide's inhibition of platelet aggregation was unaffected by adenylate or guanylate cyclase inhibitors, suggesting a mechanism independent of cyclic nucleotide signaling. AA selectively increased VASP phosphorylation at Ser239, but not Ser157. While picotamide alone had no effect, its sequential administration with AA significantly enhanced Ser157 phosphorylation without altering Ser239 levels. These findings suggest that AA differentially regulates VASP phosphorylation sites via distinct mechanisms: Ser239 via a TXA₂-independent pathway associated with inhibitory signaling, and Ser157 via a TXA₂-dependent pathway linked to platelet activation. Finally, picotamide demonstrated superior antithrombotic efficacy compared to aspirin at an equivalent dose, as evidenced by real-time intravital imaging of thrombotic platelet plug formation in vivo. These results highlight TXS inhibition as a promising strategy for modulating platelet activation and thrombosis.

Oscillations in intracellular Ca²⁺ [Ca²⁺]_i are essential for mouse oocyte activation following fertilization. These [Ca²⁺]_i oscillations also induce repetitive hyperpolarizations in the membrane potential (Em). The present study aimed to identify the channels underlying the Em hyperpolarizations. Sulfhydryl reagents such as thimerosal, that oxidize the IP3-R channel, mimic the physiological changes at fertilization by eliciting simultaneous Em changes and [Ca²⁺]_i oscillations. Thimerosal-induced Em and [Ca²⁺]_i changes were prevented by the non-specific Ca²⁺-activated Cl^- channel (CaCC) inhibitors DIDS and NFA, as well as the TMEM16A/Anoctamin 1 CaCC specific inhibitor, T16Ainh-01. The K⁺ channel blocker TEA, and voltage-gated Cl^- channel blocker 9AC failed to inhibit the Em or [Ca²⁺]_i changes. TMEM16A protein was expressed in all stages of mouse preimplantation development, being localized at the plasma membrane in oocytes. Culture of zygotes in the TMEM16A inhibitor prevented development to the blastocyst stage. In summary, we present the first evidence for CaCC channels, namely TMEM16A, being critical for the initiation of Em hyperpolarisations in mouse oocytes.

Branching morphogenesis is a key process for constructing the tree-like architecture of multiple organs. The mechanisms regulating pancreatic ductal morphogenesis are still poorly understood, especially in the context of the particular pH dynamics of this organ. Indeed, ductal cells periodically release an alkaline juice to balance stomach acidity during digestion. This leads to a drop in extracellular pH (pHe) in the extracellular matrix (ECM) to maintain intracellular pH (pHi) homeostasis. Among the transporters involved in pH regulation, NHE1 also regulates epithelial branching morphogenesis in various tissues/organs. However, neither the effect of the changing pHe nor the role of NHE1 in branching morphogenesis has been investigated in a physiomimetic model in the human pancreas. Here, using 3D organotypic cultures of human pancreatic ductal cells (HPDE), we found that cells seeded on a Matrigel rich-ECM resembling normal ECM formed branched duct-like structures, which did not form on a more fibrotic Collagen I-rich ECM. Further, these cells overexpressed NHE1 mainly at the basolateral membrane. Ductal morphogenesis was affected by acidic pHe (pHe 6.7), which determined a hyper-branched network, and this was further increased by the inhibition of NHE1. We conclude that ECM composition and extracellular acidosis modulate branching morphogenesis in pancreatic ductal HPDE cells via NHE1 activity.

PIEZO1 are mechanically-activated ion channels expressed in many cell types. Their pharmacological activation by the selective agonist Yoda1 has been reported to favor skeletal muscle regeneration by controlling the fate of myogenic precursors cells, but the underlying mechanisms remain largely unknown. Hereby, we investigated the possibility that PIEZO1 could control the release of small extracellular vesicles in myogenic C2C12 cells. Myoblasts and differentiated myotubes were treated with the PIEZO1 agonist Yoda1 (5 μM) for 24 hours. Released small extracellular vesicles were isolated by ultracentrifugation methods, and characterized by Western blotting, Nano Tracking and proteomic analysis. Pharmacological activation of PIEZO1 showed cell-type-specific effects: In myoblasts, Yoda1 treatment did not significantly affect the size or release of the small extracellular vesicles and resulted in only minor alterations to their proteomic profile. In myotubes Yoda1 treatment significantly increased small extracellular vesicles release and caused subtsantial alterations to the proteomic cargo. Notably, small extracellular vesicles released from both myoblasts and myotubes under PIEZO1 activation promoted myotube formation, though they did so through different capacities. Interestingly, in myotubes, Yoda1 also increased the expression of PIEZO1 protein of the vesicles suggesting a different biogenesis in undifferentiated and differentiated myogenic cells. Here, we propose PIEZO1 as a key element in controlling the release of small extracellular vesicles in myogenic precursors. Given the critical role of small extracellular vesicles in intercellular communication during muscle regeneration, our findings contribute to a better understanding of the role of PIEZO1 in the physiopathology of skeletal muscle tissue.

Palmitic acid (PA), the most abundant saturated fatty acid (SFA) in humans, plays a key role in energy metabolism, membrane synthesis, and signaling. Oligodendrocyte precursor cells (OPCs), which generate mature oligodendrocytes (OLs) forming the myelin sheath, are responsive to metabolic and redox signals. Despite increasing interest in lipid metabolism and mitochondrial dynamics as regulators of OPC fate, the effects of PA remain unclear. This study investigates the biphasic, dose-dependent effects of PA on OPCs using the oligodendrocyte precursor MO3.13 cell line and employs rat organotypic slice cultures to evaluate the effects of non-toxic PA doses under pathological conditions and on axonal (re)-myelination. In MO3.13 cells, high-dose PA (100 µM) induces mitochondrial fragmentation and caspase-7 activation, accompanied by reduced mitofusin-2 (MFN2) and phosphorylated dynamin-related protein 1 at Ser616 (p-DRP1), indicating altered fusion-fission balance and impaired reactive oxygen species (ROS) generation. In contrast, low-dose PA (25 µM) triggers a protective response involving nuclear factor erythroid 2–related factor 2 (Nrf2) activation and upregulation of antioxidant and lipid-regulatory genes (glutamate–cysteine ligase modifier subunit [GCLM], NAD(P)H dehydrogenase [quinone] 1 [NQO1], peroxisome proliferator-activated receptor gamma [PPARγ], and cluster of differentiation 36 [CD36]) resulting in reduced intracellular ROS and enhanced lipid mobilization. PA 25 µM promotes OPC differentiation by inhibiting migration and cell cycle progression and increasing myelin basic protein (MBP) and proteolipid protein (PLP) expression. Notably, early exposure (1 day) favors mitochondrial fusion, whereas prolonged exposure (4 days) shows a physiological shift to fission. PA 25 µM prevents neurodegeneration in hippocampal organotypic slice cultures exposed to a neuroinflammatory insult. In cerebellar organotypic slice cultures, PA 25 µM enhances axonal myelination and accelerates remyelination following lysolecithin-induced demyelination. These findings highlight the physiological relevance of low-dose PA in modulating OLs.

RETRACTION: H. Li, J. Yang, X. Wei, C. Song, D. Dong, Y. Huang, X. Lan, M. Plath, C. Lei, Y. Ma, X. Qi, Y. Bai, and H. Chen, “CircFUT10 Reduces Proliferation and Facilitates Differentiation of Myoblasts by Sponging miR-133a,” Journal of Cellular Physiology 233, no. 6 (2018): 4643-4651, https://doi.org/10.1002/jcp.26230.

The above article, published online on 18 October 2017 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal Editor-in-Chief, Robert Heath; and Wiley Periodicals LLC. The retraction has been agreed upon following concerns raised by a third party regarding data presented in the article. An investigation identified duplication between the two MyoD bands shown in Figure 3B and two MyhC bands in Figure 3H. All MyhC bands in Figure 3H were also found to be identical to western blot bands published in another article by the same authors, where they were presented as representing a different protein. Furthermore, overlaps were identified between images in Figure 6 A and images published in another article by the same authors, which were also used to represent different material. Finally, the miR-133a flow cytometry data shown in Figure 6B was also found to be identical to a dot plot found in another article published by the same authors, again representing different material. The authors cooperated with the investigation and provided some supporting data; however, this was not sufficient to restore the editors’ confidence in the results. The editors consider the results and conclusions unreliable. The authors did not respond when asked to agree to the final wording of the retraction.