Cell Biochemistry and Biophysics最新文献

Mammary Gland Protein-40 (MGP-40), also known as chitinase-3-like protein 1 (CHI3L1), is involved in critical biological processes such as inflammation, tissue remodeling, and cell proliferation, especially during the involution phase of the mammary gland. This study aimed to explore the molecular mechanisms of MGP-40 by identifying its novel interacting partners in buffalo mammary epithelial cells (BuMECs). Stable overexpression of MGP-40 in BuMECs was achieved through transfection with the pCIneo-MGP-40 vector, followed by G418 selection and confirmation by Western blot analysis. To identify interacting proteins, Co-immunoprecipitation (Co-IP) of BuMEC lysate using an anti-YKL-40 antibody was performed, and the eluted proteins were analyzed using SDS-PAGE and mass spectrometry (MALDI-TOF/TOF). The analysis revealed several interacting proteins, including synaptotagmin-like 3, Ras-related Rab19, RIB34A-like protein with coiled coils, and ATP synthase subunit g. These interacting partners suggest that MGP-40 is involved in crucial cellular processes like vesicle trafficking, cytoskeletal organization, and energy metabolism, extending its known functions in inflammation and tissue remodeling. Notably, the interactions with synaptotagmin-like 3 and Rab proteins emphasize MGP-40's potential role in vesicular transport, essential for milk production in mammary epithelial cells, while the association with ATP synthase subunit g links MGP-40 to energy regulation during lactation. These findings provide preliminary insights into the potential roles of MGP-40 in mammary gland physiology, particularly in cellular processes such as vesicle trafficking and energy metabolism. Further studies, including in vivo validation, are essential to confirm these interactions and clarify their relevance to mammary gland function and pathology.

Danger-associated molecular patterns (DAMPs) are released on the onset of tissue injury or death, which tend to trigger innate immunity and regulate various immune pathways. Among the various DAMP molecules, S100A8 and S100A9 belonging to Ca²⁺ binding proteins with EF-hands and Zn²⁺ ion binding sites have been implicated in aggravating the pathogenesis of rheumatoid arthritis (RA), upon interaction with pattern recognition receptors (PRR) such as TLR4, RAGE and CD36 receptors. Thus, the present study aims to assess the effect of Ca²⁺ or Zn²⁺ ions on the interaction of S100A8 and S100A9 proteins towards the PRRs. Protein-protein interaction analysis showed that the TLR4-S100A8Ca²⁺Zn²⁺, TLR4-S100A8 Zn²⁺, RAGE-S100A8/A8Zn²⁺, RAGE-S100A8/A8Ca²⁺, CD36-S100A8Ca²⁺, and CD36-S100A9/A9Ca²⁺ showed higher affinity against each other. The 100 ns molecular dynamics simulation showed that the TLR4-S100A8Ca²⁺, RAGE-S100A8/A8Ca²⁺ and CD36-S100A8Ca²⁺ complexes showed minimal fluctuations in their trajectory indicating that Ca²⁺ bound complexes were more stable than the other complexes. Furthermore, SPR analysis showed that S100A9 exhibited higher binding affinity towards PRRs in the presence of Ca²⁺ and Zn²⁺ ions. Considering the fact that physiological levels of both Ca²⁺ and Zn²⁺ ions play a critical role in the binding of S100A8 and S100A9 proteins against the PRRs, it can be emphasized that the S100A9 and RAGE receptors could be the critical players in the RA pathogenesis due to its impeccable binding towards the PRRs in the presence of both Ca²⁺ and Zn²⁺ ions. Nonetheless, further in vivo, and in vitro studies are imperative to validate these findings and identify potential targets for RA treatment.

CSRP1 (Cysteine and Glycine-Rich Protein 1) is a protein often overactivated in various cancers, promoting cell proliferation and survival, making it a key factor in cancer development. However, it is worth noting that the effect of this protein on the glycolysis process in Acute Myeloid Leukemia (AML) has not yet been studied. This study aims to investigate the role of the METTL3/YTHDF1 axis in regulating Glycolysis and its impact on AML progression by stabilizing CSRP1 mRNA. We analyzed CSRP1 expression in AML tissues and cell lines using quantitative real-time PCR (qRT-PCR) and Western blotting. Functional assays, including cell viability, colony formation, glycolysis related indicators, were performed to assess the impact of CSRP1 knockdown or overexpression on AML cells. RNA immunoprecipitation (RIP) and RNA stability assays were conducted to elucidate the mechanism of METTL3/YTHDF1-mediated regulation of CSRP1 mRNA. CSRP1 was significantly upregulated in AML tissues and cell lines. Knockdown of CSRP1 inhibited AML cell proliferation and glycolysis. Overexpression of CSRP1 promoted AML cell survival. Mechanistically, METTL3 enhanced CSRP1 mRNA stability via m6A modification, recognized and bound by YTHDF1, preventing mRNA degradation. The METTL3/YTHDF1/ CSRP1 axis plays a critical role in AML progression by regulating glycolysis. Targeting this pathway may provide a novel therapeutic strategy for AML treatment.

Psoriasis is a chronic cutaneous disease, affecting a significant portion of the global population. Topoisomerase II alpha (TOP2A) is upregulated in psoriasis samples, but the precise molecular mechanism remains unclear. We aimed to clarify the biological contribution of TOP2A in psoriasis progression. An in vitro psoriasis model was established on M5-induced keratinocytes (HaCaT cells) to simulate the psoriasis-like alterations. Following TOP2A knockdown without or with c terminal binding protein 1 (CTBP1) overexpression, CCK-8 and EDU staining were employed to analyze the viability and proliferation of HaCaT cells under M5 conditions. The capacities of HaCaT cell migration and invasion were examined with wound healing- and transwell assays. RT-qPCR and immunoblotting were adopted for evaluation of the inflammation and differentiation of M5-stimualted HaCaT cells. Additionally, the binding between TOP2A and CTBP1 was predicated using bioinformatics tools and detected by Co-IP. Finally, the expression of proteins in Wnt/β-catenin signaling was analyzed with the application of immunoblotting. Results suggested that TOP2A was upregulated in psoriasis skin lesions and M5-induced HaCaT cells. Interference with TOP2A attenuated the proliferation, migration, invasion, and inflammatory response in M5-treated HaCaT cells. In particular, TOP2A bound to CTBP1 and upregulated CTBP1 expression in HaCaT cells. Remarkably, CTBP1 upregulation blocked the impacts of TOP2A depletion on the biological behaviors of M5-treated HaCaT cells. Besides, TOP2A deficiency upregulated DKK1 expression as well as downregulated Wnt1, β-catenin, and c-Myc expression in HaCaT cells exposed to M5, which was restored by further CTBP1 overexpression. In summary, TOP2A binds CTBP1 to activate Wnt/β-catenin signaling, thereby promoting the progression of psoriasis.

Exosomes are extracellular vesicles with a diameter ranging from 40 to 160 nm. They are produced by hepatocytes, cholangiocytes, hepatic stellate cells (HSCs), liver sinusoidal endothelial cells (LSECs) and Kupffer cells in liver tissue. The secretion of exosomes might vary in quantity and composition in reaction to multiple triggers and various stages of disease. They transport various payloads, such as proteins, DNAs, and RNAs, and enable cell interaction to regulate myriad physiological and pathological processes in liver tissue. Long non-coding RNAs (lncRNAs) are a crucial component of exosomes with an excellent capability to regulate multiple cellular activities such as differentiation, development, metabolism, proliferation, apoptosis, and activation. With the advancements in transcriptomic and genomic study methods and database management technology, the functions and mechanisms of exosomal lncRNAs in liver diseases have been well-studied. This article delves into the detailed role of exosomal lncRNAs in liver disease onset and progression, ranging from hepatocellular carcinoma (HCC) to liver fibrosis drug-induced liver damage (DILI) and steatotic liver diseases.

Background: Phospholipid phosphatase 4 (PLPP4) has been identified as a potential regulator of cancer cell dynamics, however, the role of PLPP4 in breast cancer (BC) progression and the sensitivity of BC cells to doxorubicin (DOX) remain elusive.

Methods: The study analyzed the expression of PLPP4 and cell cycle-associated protein 1 (CAPRIN1) expression in BC tissues and cells using quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) and western blotting assays. Functional assays including colony formation, EdU, Transwell, and flow cytometry were employed to assess cellular behaviors. The sensitivity of BC cells to DOX was analyzed by CCK-8 assay and an in vivo xenograft model assay. The association between PLPP4 and CAPRIN1 was investigated using RNA immunoprecipitation assay and dual-luciferase reporter assay.

Results: Upregulation of PLPP4 expression was observed in BC tissues and cells. Downregulation of PLPP4 expression in BC cells resulted in a suppression of their proliferative capacity, as well as a reduction in migratory and invasive capabilities. Additionally, this manipulation enhanced cell susceptibility to apoptosis and improved the sensitivity of these cells to DOX. When PLPP4 was knocked down in vivo in transplantable tumors, there was a marked enhancement in the responsiveness to DOX treatment. The transcription factor CAPRIN1 was found to regulate the expression of PLPP4 in the HCC1937 and MDA-MB-231 cell lines. Upregulation of CAPRIN1 was observed in both BC tissues and cells, and overexpression of PLPP4 reversed the effects of CAPRIN1 silencing on BC cell proliferation, migration, invasion, apoptosis, and DOX sensitivity.

Conclusion: This study demonstrates that CAPRIN1 transcriptionally activates PLPP4 to inhibit DOX sensitivity and promote BC progression. Targeting PLPP4 may represent a novel therapeutic strategy to enhance the efficacy of DOX in BC patients.

Adipose tissue represents an organ that is highly dynamic and contributes toward vital survival events such as immune responses, lactation, metabolism fuel, and thermogenesis. Data emerging from recent studies support the notion of adipose tissue being organized into a complex system characterized by a discrete anatomy, elevated physiological plasticity, and specific vascular and nerve supplies. Vasoactive intestinal peptide (VIP), along with its receptors, type 1 (VPAC1) and type 2 (VPAC2), has been implicated in various physiological and pathophysiological processes. However, studies on VIP and its receptors in adipose tissue are limited. To explore VIP's presence and activity, as well as its adipose tissue-based receptors, we conducted a study on isolated adipocytes and adipose tissue from inguinal white adipose tissue (WAT) and interscapular brown adipose tissue (BAT) in normal and cold-stressed rats. Our findings indicate the presence of the gene expression VIP and VPAC1 in both WAT and BAT under normal conditions, while VPAC2 was absent. In both WAT and BAT, cold exposure upregulated VIP gene expression. However, the response of VIP receptors to cold exposure is controversial. VPAC2 gene expression was induced in both WAT and BAT, while VPAC1 gene expression presented no change of significance in BAT and a slight reduction in WAT. Additionally, VIP, VPAC1, and VPAC2 proteins were identified from Western blot studies on white and brown adipocytes. After exposure to cold there was an increase of significance in the VIP, VPAC1, and VPAC2 protein levels. This study provides novel insights into how VIP and its receptors alter gene expression and protein levels in adipose tissue and adipocytes during cold stress, indicating their potential involvement in adipose tissue regulation. The findings propose VIP's potentially crucial role in adipose tissue's adaptation to cold stress by affecting the metabolic and biochemical functions of subcutaneous and interscapular adipocytes, with potentially significant implications in the context of developing therapies targeting metabolic disorders.

Myocardial infarction (MI) is an acute cardiovascular diseases, distinguished primarily by cardiomyocyte damage due to ischemia and hypoxia. Nerve growth factor (NGF) is paramount in ischemic heart disease, it contributes to maintaining heart function and protecting the heart. Nonetheless, the effects of NGF on cardiomyocyte damage induced by hypoxia and the precise mechanisms involved are still to be elucidated. Utilizing western blot and immunofluorescence methods to quantify the NGF levels in cardiomyocytes (H9C2) of rats after hypoxia. Cell Counting Kit-8 (CCK-8) assay was employed to monitor the dynamic changes in cells vitality. The lactate dehydrogenase (LDH), Fe²⁺, malondialdehyde (MDA), superoxide dismutase (SOD) and reactive oxygen species (ROS) levels were evaluated by different kits. Moreover, the PI3K/Akt/Nrf2 pathway and ferroptosis-linked protein levels were analyzed using western blotting. In H9C2 cells, exposure to hypoxia for 24 h led to weakened NGF level, as well as lowered cell vitality and SOD activity, but elevated levels of LDH, Fe²⁺, MDA, and ROS, triggering ferroptosis. Overexpression NGF alleviated the ferroptosis in H9C2 cells caused by hypoxia, while NGF knockdown intensified this process. Additionally, overexpression NGF reinforced heme oxygenase-1 (HO-1) and Nrf2 levels, and Akt and PI3K phosphorylation, whereas NGF silencing produced contrary outcomes. Furthermore, the PI3K/Akt pathway inhibitor negated the elevation in HO-1 and Nrf2 levels mediated by NGF amplification. In contrast, the pathway activator reversed the lowering in Nrf2 and HO-1 levels caused by silencing NGF. This suggested that NGF mediates the activation of Nrf2 through the PI3K/Akt axis. Overall, by mediating the activation of Nrf2 through the PI3K/Akt axis, NGF reduced the damage to H9C2 cells caused by hypoxia and thus hindered ferroptosis.

Extensive research has demonstrated that astrocytes actively participate in the regulation of synaptic communication. To examine the dynamic behavior of the model, a neuron-astrocyte model has been solved, and a bifurcation analysis has been performed. This paper uses the equilibrium point, stability theory, and the center manifold theorem to theoretically investigate the dynamical analysis of Ca²⁺ oscillations in the cytosol. The connections at tripartite synapses between the cells have been modeled using IP₃ and 2-AG. A mathematical model is used to depict the overall framework of bifurcation and induced Ca²⁺ dynamics. The differences in the presence and disappearance of Ca²⁺ oscillations are partially explained by two subcritical Hopf bifurcation points, according to the results. Communication between the cells occurs through the oscillations of Ca²⁺ concentration. Furthermore, numerical simulations are conducted to confirm the efficacy of the suggested approach. Thus, our findings imply that neuron-astrocyte crosstalk plays a fundamental role in generating a variety of neuronal activities, thereby improving the brain's capacity for information processing.

Ferroptosis, a newly discovered mode of cell death, is a type of iron-dependent regulated cell death characterized by intracellular excessive lipid peroxidation and imbalanced redox. As the liver is susceptible to oxidative damage and the abnormal iron accumulation is a major feature of most liver diseases, studies on ferroptosis in the field of liver diseases are of great interest. Studies show that targeting the key regulators of ferroptosis can effectively alleviate or even reverse the deterioration process of liver diseases. System Xc^- and glutathione peroxidase 4 are the main defense regulators of ferroptosis, while acyl-CoA synthetase long chain family member 4 is a key enzyme causing peroxidation in ferroptosis. Generally speaking, ferroptosis should be suppressed in alcoholic liver disease, non-alcoholic fatty liver disease, and drug-induced liver injury, while it should be induced in liver fibrosis and hepatocellular carcinoma. In this review, we summarize the main regulators involved in ferroptosis and then the mechanisms of ferroptosis in different liver diseases. Treatment options of drugs targeting ferroptosis are further concluded. Determining different triggers of ferroptosis can clarify the mechanism of ferroptosis occurs at both physiological and pathological levels.