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Streptococcus pyogenes is a bacterium that causes systemic diseases such as pharyngitis and toxic shock syndrome. S. pyogenes produces molecules that inhibit the function of the human immune system, thus allowing growth and spread of the pathogen in tissues. It is known that S. pyogenes CAMP factor induces vacuolation in macrophages; however, the mechanism remains unclear. In the current study, the mechanism by which CAMP factor induces vacuolation in macrophages was investigated. CAMP factor was found to induce calcium ion uptake in murine macrophage RAW264.7 cells. In addition, EDTA inhibited calcium ion uptake and vacuolation in the cells. The L-type voltage-dependent calcium ion channel blockers nifedipine and verapamil reduced vacuolation. Furthermore, the phosphoinositide 3-kinase inhibitors LY294002 and wortmannin also inhibited the vacuolation induced by CAMP factor. Fluorescent microscopy revealed that clathrin localized to the vacuoles. These results suggest that the vacuolation is related to calcium ion uptake by RAW264.7 cells via L-type voltage-dependent calcium ion channels. Therefore, it was concluded that the vacuoles induced by S. pyogenes CAMP factor in macrophages are clathrin-dependent endosomes induced by activation of the phosphoinositide 3-kinase signaling pathway through calcium ion uptake.
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http://dx.doi.org/10.1111/1348-0421.12647 | DOI Listing |
Langmuir
September 2025
CIPR, KFUPM, Dhahran 31261, Saudi Arabia.
Emulsion formation presents a significant operational challenge in oil production, necessitating the continuous development of novel and effective demulsification methods. However, the lack of a fundamental understanding of the mechanisms that regulate the formation of these emulsions significantly complicates this process. In this study, we systematically investigated the influence of Ca ions on crude oil emulsions.
View Article and Find Full Text PDFGen Physiol Biophys
September 2025
Faculty of Exact and Natural Sciences, I. Javakhishvili Tbilisi State University, Tbilisi, Georgia.
In this study, both pure and calcium-containing complex liposomes made from DPPC phospholipids were investigated using calorimetric and spectrophotometric methods. Liposomes were prepared using a new technology in both water and a 20% glycerol aqueous solution. Glycerol allows drug-containing DPPC liposomes to penetrate the dermis of the skin through the epidermis.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2025
Department of Stomatology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 611731, China.
Radiation-induced skin injury (RSI) remains a significant clinical challenge due to persistent oxidative stress, chronic inflammation, and impaired tissue regeneration. It is demonstrated that RSI is accompanied by dysregulation of the immune microenvironment, wherein macrophages act as key regulators of all pathological cascades. Here, we developed a dual network hydrogel (Gel/SA@MXene) through dual cross-linking via UV irradiation and calcium ions to accelerate radiation-combined wound healing.
View Article and Find Full Text PDFElife
September 2025
Department of Chemistry, University of Massachusetts, Amherst, United States.
Voltage-dependence gating of ion channels underlies numerous physiological and pathophysiological processes, and disruption of normal voltage gating is the cause of many channelopathies. Here, long timescale atomistic simulations were performed to directly probe voltage-induced gating transitions of the big potassium (BK) channels, where the voltage sensor domain (VSD) movement has been suggested to be distinct from that of canonical Kv channels but remains poorly understood. Using a Core-MT construct without the gating ring, multiple voltage activation transitions were observed at 750 mV, allowing detailed analysis of the activated state of BK VSD and key mechanistic features.
View Article and Find Full Text PDFMedComm (2020)
September 2025
The activation of nucleotide oligomerization domain-like receptor (NLR) family, pyrin domain-containing protein 3 (NLRP3) inflammasome is implicated in the pathogenesis of various inflammatory diseases. The natural product oridonin possesses a novel mechanism for NLRP3 inhibition and a unique binding mode with NLRP3, but its poor anti-inflammatory activity limits further application. After virtual screening of diverse natural product libraries, dehydrocostus lactone (DCL) was considered as a potential NLRP3 inhibitor.
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