General physiology and biophysics最新文献

In this study, we investigated the therapeutic potential of calycosin (from Astragalus) in Alzheimer's disease (AD), focusing on ferroptosis modulation. APP/PS1 mice received 40 mg/kg calycosin for 3 months. Cognitive function was assessed via Morris water maze test. Tau hyperphosphorylation and amyloid-β (Aβ) aggregation were analyzed using immunofluorescence and Western blotting. In vitro, Aβ1-42-treated HT22 neuronal cells were exposed to calycosin. Ferroptosis-related phenotypes were assessed in vivo and in vitro using Prussian blue staining, commercial kits, and Western blotting. The nuclear factor-erythroid factor 2-related factor 2 (Nrf2) signaling was examined by Western blotting. Calycosin treatment significantly improved cognitive deficits in APP/PS1 mice and inhibited Tau hyperphosphorylation and Aβ aggregation. Calycosin attenuated neurotoxicity and Tau hyperphosphorylation in Aβ1-42-treated HT22 cells. Moreover, calycosin inhibited ferroptosis in vivo and in vitro by decreasing iron aggregation and lipid peroxidation, downregulating transferrin receptor expression, and upregulating ferroportin, cystine/glutamate antiporter, and glutathione peroxidase 4 expression. Mechanistically, the anti-ferroptosis effects of calycosin were linked to the activation of the Nrf2-mediated pathway. These findings suggest that calycosin may exhibit neuroprotective effects against neuronal ferroptosis in AD, indicating its potential as a therapeutic candidate for further investigation in AD.

Circular RNA (circRNA) has been confirmed to be a regulator for septic acute kidney injury (AKI). It is reported that circ_0049271 has abnormal expression in AKI patients, but its role and mechanism in septic AKI remain unclear. Lipopolysaccharide (LPS)-stimulated HK-2 cells were served as the cellular model of sepsis-associated AKI (SAKI). qRT-PCR was conducted for examining the expression of circ_0049271, KEAP1 and miR-331-3p. Cell proliferation and apoptosis were detected by EdU assay and flow cytometry. The protein levels of apoptosis-related markers, RUNX family transcription factor 1 (RUNX1), and PI3K/AKT/mTOR pathway-related markers were tested using Western blot. RNA interaction was confirmed by dual-luciferase reporter assay, RIP assay, and RNA pull-down assay. Our data showed that circ_0049271 was enhanced in LPS-induced HK-2 cells. Silencing of circ_0049271 attenuated LPS-induced HK-2 cell oxidative stress, apoptosis, and inflammation. In terms of mechanism, circ_0049271 targeted miR-331-3p to promote LPS-induced HK-2 cell injury. RUNX1 was a target of miR-331-3p, and RUNX1 overexpression reversed miR-331-3p-mediated inhibitory effects on LPS-induced HK-2 cell injury. Moreover, circ_0049271 sponged miR-331-3p to positively regulate RUNX1 expression, thus activating the PI3K/AKT/mTOR pathway. In conclusion, our data indicated that circ_0049271 contributed to LPS-induced HK-2 cell injury by regulating miR-331-3p/RUNX1 pathway, providing potential molecular targets for the treatment of SAKI.

Diabetic nephropathy (DN) is a major complication of diabetes, imposing substantial socioeconomic and public health challenges. N6-methyladenosine (m6A) modification, a prevalent epigenetic mechanism, influences cellular processes and disease progression. Wilms' tumor 1-associating protein (WTAP), an m6A methyltransferase subunit, was investigated for its role in DN. Bioinformatics identified differentially expressed genes in DN, and a high glucose (HG)-induced podocyte model was established to mimic DN in vitro. Techniques like Western blot, CCK-8, ELISA, flow cytometry, and TUNEL evaluated protein expression, cell viability, inflammation, oxidative stress, and apoptosis. SRAMP predicted m6A sites in DDX3Y mRNA, validated by MeRIP, while xenograft models confirmed in vivo effects. DDX3Y expression was elevated in DN and HG-induced podocytes, and sh-DDX3Y attenuated HG-induced injury. WTAP promoted DDX3Y mRNA stability via m6A methylation, exacerbating podocyte dysfunction. In diabetic mice, WTAP modulated DDX3Y to induce renal insufficiency and histopathological damage. Collectively, WTAP regulates DDX3Y via m6A methylation to promote HG-induced podocyte injury and DN progression.

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. Calorimetric and spectrophotometric experiments show that calcium ions are incorporated into the structure of DPPC liposomes. Consequently, these nanoparticles can be used to treat diseases that require a significant amount of calcium, ensuring that the calcium within the liposomes will not cause side effects when it enters the bloodstream. Through the conducted experiments, we examined the structure and thermal stability of calcium DPPC liposomes prepared in water and glycerol, which is essential for their effective practical use. We found that the structure of all complex liposomes is multilamellar, which enables them to incorporate a larger amount of calcium ions than unilamellar liposomes. Based on the calorimetric experiments conducted, we identified a new approach to determine the maximum amount of drug, including calcium, that can be incorporated into nanoparticles, which is a crucial factor.

Exosomes derived from various cells have been demonstrated to contribute to cardiac repair by regulating macrophage polarization in myocardial infarction. However, how exosomes secreted from cardiomyocytes under hypoxia-ischemia (Hypo-Exo) regulate macrophage polarization in the local tissues is elusive. This study aimed to determine the underlying mechanisms by which Hypo-Exo polarized M2 macrophages. Hypo-Exo was harvested from the supernatant of oxygen glucose deprivation (OGD)-conditioned H9c2, identified using transmission electron microscopy, nanoparticle tracking analysis, and western blot, and then applied to RAW264.7 and C57BL/6N mice. Echocardiography, TTC, H&E, Masson, and immunofluorescence staining were used to evaluate the therapeutic effects of Hypo-Exo in the MI mouse model. The effects of Hypo-Exo on RAW264.7 were examined by RT-qPCR. Hypo-Exo labeled with PKH26 could be engulfed by RAW264.7 cells and promote M2 macrophage polarization. Hypo-Exo inhibited atrial natriuretic peptide (ANP) mRNA expression in RAW264.7 cells, and three cargo miRNAs of Hypo-Exo were upregulated to degrade the ANP expression. Instead of downregulating ANP, OGD supernatant upregulated ANP expression to activate M1 macrophages. Our study demonstrated a novel mechanism that Hypo-Exo carried with miRNAs as a communicator to degrade the expression level of ANP mRNA in macrophages by which Hypo-Exo polarized M2 macrophages to improve recovery from MI in mice.

This study explores how human antigen R (HuR) stabilizes fibroblast growth factor 19 (FGF19) mRNA, inhibiting Kupffer cell (KC) activation to reduce inflammation and fibrosis in non-alcoholic fatty liver disease (NAFLD). An animal model of NAFLD was established in mice by administering a high-fat diet (HFD). In vitro study utilized a lipopolysaccharide-induced immortalized mouse KC model. HuR expression markedly decreased in HFD-induced NAFLD liver tissue. Overexpression of HuR via adeno-associated virus (AAV) vectors mitigated key pathological features of NAFLD, including hepatic inflammation and fibrosis. Moreover, HuR overexpression suppressed KC activation in both in vitro and in vivo models. Mechanistically, HuR bound AU-rich elements in FGF19 mRNA, enhancing its stability. FGF19 overexpression similarly mitigated HFD-induced liver pathology. Conversely, FGF19 silencing reversed HuR's inhibition of KC activation and abrogated HuR's protection against liver inflammation and fibrosis. This research elucidates a novel mechanism underlying the interaction between HuR and FGF19 in mitigating the pathological progression of NAFLD, providing potential therapeutic targets for this prevalent liver disease.

The abnormal proliferation and activation of fibroblasts have been implicated in idiopathic pulmonary fibrosis. Herein, the present research explored the impacts of the relationship between hydroxysafflor yellow A (HSYA) and a disintegrin and metalloproteinase 17 (ADAM17) on fibroblast activation, which can provide novel insight into the treatment and management of idiopathic pulmonary fibrosis. MRC-5 fibroblasts were firstly activated with TGF-β1, followed by measurement of ADAM17 expression through qRT-PCR and Western blot. Fibrosis-related gene and protein expression levels, cell viability, proliferation, migration, and fibroblast-to-myofibroblast transdifferentiation were determined by qRT-PCR and Western blot, MTS, EdU, Transwell, and immunofluorescence assays, respectively. Moreover, the regulatory relationships among HSYA, ADAM17, and the NF-κB/STAT3 pathway in MRC-5 cells were analyzed by bioinformatics analysis, qRT-PCR, and Western blot. The results show that HSYA treatment could diminish the fibrosis-related gene and protein expression patterns, proliferation, migration, and fibroblast-to-myofibroblast transdifferentiation in TGF-β1-stimulated MRC-5 cells. Moreover, HSYA could repress the TGF-β1-triggered ADAM17 up-regulation, thereby suppressing the NF-κB/STAT3 pathway. Furthermore, over-expression of ADAM17 negated the inhibitory effect of HSYA on fibroblast activation induced by TGF-β1. The findings revealed that HSYA blocked the NF-κB/STAT3 pathway activation by down-regulating ADAM17, thereby inhibiting TGF-β1-induced fibroblast activation.

We investigated how zinc finger protein 471 (ZNF471) affects nasopharyngeal carcinoma (NPC) cell growth, migration, invasion and stemness and offer possible treatment targets for NPC research. The GEO2R online dataset was used to query the expression of ZNF471 in NPC tissues. ZNF471 overexpression plasmid was transfected into NPC cell lines. Cell Counting Kit-8 (CCK8) was used to detect cell viability, 5-Ethynyl-2'-deoxyuridine (Edu) to detect cell proliferation, Wound Healing Assay to detect cell migration, Transwell Assay to detect cell invasion, and Spheroid Formation Assay to detect the stemness characteristics of NPC cells. Western blot assay was used to determine the downstream genes matrix metalloproteinase 7 (MMP-7) and Myelocytomatosis viral oncogene homolog (c-Myc), as well as the protein expression of β-catenin, a protein linked to the Wnt/β-catenin pathway. Overexpression of ZNF471 significantly inhibited NPC cell viability, reduced the number of Edu-positive cells, migration rate, cell invasion number, and tumor cell spheroid formation number. Besides, overexpression of ZNF471 reduced the protein expression of β-catenin and the downstream genes c-Myc and MMP-7. In conclusion, ZNF471 inhibits the growth, migration, invasion and stemness of NPC cells, which may be related to its inhibition of Wnt/β-catenin pathway activation.

The involvement of serotonin (5-HT) in mood and appetite regulation is well established. This neurotransmitter is released from the neurons located in brainstem raphe nuclei. The excitability of the raphe 5-HT neurons, determining 5-HT neurotransmission, is regulated by various biomolecules, among them gastroenteric hormones, such as gastrin-releasing peptide (GRP). We aimed to examine the effects of the GRP homolog bombesin, and antagonist of bombesin BB1 receptor PD 176252, on the excitability of 5-HT neurons in in vivo conditions. In order to achieve its permeability through the blood-brain barrier, bombesin was fused to the cell-membrane transduction domain of the human immunodeficiency virus-type-1 Tat protein. We found that Tat-bombesin complex increased the firing activity of 5-HT neurons; PD 176252 had an opposite effect. GRP might thus regulate 5-HT neurotransmission via a mechanism involving BB1 receptors. BB1 ligands may therefore be used for the treatment of mood and eating disorders.

Circular RNAs (circRNAs) are covalently closed RNA structures that play a pivotal role in the initiation and progression of cervical cancer (CC). However, it is unclear how these RNAs influence cancer stem cell (CSC)-like properties in CC. Here, we performed circRNA microarray analysis and identified an intergenic circRNA, hsa_circ_0007905, that was significantly upregulated in patients with CC. Moreover, hsa_circ_0007905 was found to be highly expressed in CSC-enriched subsets of cervical cancer cell lines. Functionally, knocking down hsa_circ_0007905 suppressed proliferative, migratory invasive and self-renewal abilities, as well as stimulated apoptosis of CSCs in CC. Mechanistically, hsa_circ_0007905 functions as a "sponge" to inversely control miR-330-5p expression, which directly targets VDAC1. Overexpressing VDAC1 or inhibiting miR-330-5p blocked the roles of silencing hsa_circ_0007905 on CSCs. Thus, we revealed the mechanism by which hsa_circ_0007905 competitively adsorbs miR-330-5p to mediate VDAC1 expression to promote stemness and inhibit apoptosis of CSCs in CC, offering an therapeutic target for treating CC.