Temporal characteristics of astrocytic activation in the TNC in a mice model of pain induced by recurrent dural infusion of inflammatory soup

Background Astrocytic activation might play a significant role in the central sensitization of chronic migraine (CM). However, the temporal characteristics of the astrocytic activation in the trigeminal nucleus caudalis (TNC) and the molecular mechanism under the process remain not fully understood. Therefore, this study aims to investigate the duration and levels change of astrocytic activation and to explore the correlation between astrocytic activation and the levels change of cytokines release. Methods We used a mice model induced by recurrent dural infusion of inflammatory soup (IS). The variation with time of IS-induced mechanical thresholds in the periorbital and hind paw plantar regions were evaluated using the von Frey filaments test. We detected the expression profile of glial fibrillary acidic protein (GFAP) in the TNC through immunofluorescence staining and western blot assay. We also investigated the variation with time of the transcriptional levels of GFAP and ionized calcium binding adapter molecule 1 (Iba1) through RNAscope in situ hybridization analysis. Then, we detected the variation with time of cytokines levels in the TNC tissue extraction and serum, including c-c motif chemokine ligand 2 (CCL2), c-c motif chemokine ligand 5 (CCL5), c-c motif chemokine ligand 7 (CCL7), c-c motif chemokine ligand 12 (CCL12), c-x-c motif chemokine ligand 1 (CXCL1), c-x-c motif chemokine ligand 13 (CXCL13), interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), macrophage colony-stimulating factor (M-CSF), interleukin 1beta (IL-1β), interleukin 6 (IL-6), interleukin 10 (IL-10), interleukin 17A (IL-17A). Results Recurrent IS infusion resulted in cutaneous allodynia in both the periorbital region and hind paw plantar, ranging from 5 d (after the second IS infusion) to 47 d (28 d after the last infusion) and 5 d to 26 d (7 d after the last infusion), respectively. The protein levels of GFAP and messenger ribonucleic acid (mRNA) levels of GFAP and Iba1 significantly increased and sustained from 20 d to 47 d (1 d to 28 d after the last infusion), which was associated with the temporal characteristics of astrocytic activation in the TNC. The CCL7 levels in the TNC decreased from 20 d to 47 d. But the CCL7 levels in serum only decreased on 20 d (1 d after the last infusion). The CCL12 levels in the TNC decreased on 22 d (3 d after the last infusion) and 33 d (14 d after the last infusion). In serum, the CCL12 levels only decreased on 22 d. The IL-10 levels in the TNC increased on 20 d. Conclusions Our results indicate that the astrocytic activation generated and sustained in the IS-induced mice model from 1 d to 28 d after the last infusion and may contribute to the pathology through modulating CCL7, CCL12, and IL-10 release.

Hsp90 Induces Acsl4-dependent Glioma Ferroptosis via Dephosphorylate Ser637 at Drp1

Background: Ferroptosis is a newly identified form of regulated cell death (RCD) characterized by the iron-dependent lipid reactive oxygen species (ROS) accumulation, but its exact mechanism in gliomas remains elusive. Acyl–coenzyme A (CoA) synthetase long-chain family member 4 (Acsl4), a pivotal enzyme in the regulation of lipid biosynthesis, has been found to benefit the initiation of ferroptosis, but its role in gliomas likewise needs clarification. Erastin, widely investigated as an inducer of ferroptosis, was recently found to regulate lipid peroxidation by regulating Acsl4 other than glutathione peroxidase 4 (GPX4) in ferroptosis. Methods: Relationship between Hsp90, Drp1 and Acsl4 was determined by Co-immunoprecipitation/ Mass spectrometry and western blot assay. The impact of Hsp90 and Drp1 on Acsl4-dependent ferroptosis was examined by lipid peroxidation indicators in patient-derived PL1 and PG7 cells. The morphological changes of mitochondria are observed by confocal-fluorescence microscopy and transmission electron microscope. Therapeutic efficacy of Erastin-induced ferroptosis in vivo was examined in xenograft mouse models.Results: In this study, we demonstrated that heat shock protein 90 (Hsp90) and dynamin-related protein 1 (Drp1) actively regulated Acsl4 expression in erastin-induced ferroptosis in gliomas. Hsp90 overexpression and calcineurin (CN)–mediated Drp1 dephosphorylation at serine 637 (Ser637) promoted ferroptosis by altering mitochondrial morphology and increasing Acsl4-mediated lipid peroxidation. Importantly, the Hsp90–Acsl4 pathway mediated Acsl4-dependent ferroptosis, amplifying the anticancer activity of erastin in vitro and in vivo. Conclusions: Our study not only uncovered an important role of Hsp90–Drp1–Acsl4 pathway in erastin-induced ferroptosis but also reveals an efficient mechanism of Acsl4 as a potential therapeutic target to ferroptosis-mediated glioma therapy.

Abatacept (Cytotoxic T Lymphocyte Antigen 4-Fragment Crystallizable) Reduces Allergic Inflammation of Ovalbumin-Sensitized Mice.

Background Abatacept (Aba) is a cytotoxic T-lymphocyte antigen-4 and fragment crystallizable fusion protein. Aba blocks B7/Cluster of differentiation 28 - cytotoxic T-lymphocyte antigen-4 costimulatory pathway, inhibits cluster of differentiation 4+ T-cell activation, and is used as an anti-inflammatory drug. Objectives We conducted this study to assess the effectiveness of Aba in the treatment of allergic rhinitis (AR) in a mouse model. Methods We divided 40 four-week-old BALB/c mice into four groups: control group ( n = 10), positive control group (AR, n = 10), Aba group (AR + Aba, n = 10), and dexamethasone group (AR + Dex, n = 10). Mice in each group were challenged intranasally with daily ovalbumin (OVA) administration. Episodes of sneezing and nose rubbing were counted. Mice were sacrificed on day 42 and cytokines were measured in nasal lavage fluid. Nasal mucosae of five mice from each group were used for reverse transcriptase-polymerase chain reaction and western blot assay. Samples were collected from five mice from each group for histological analysis. Results Symptoms of AR significantly improved in the AR + Aba and AR + Dex groups compared with the AR group. Fewer eosinophils and goblet cells were seen in the AR + Aba and AR + Dex groups compared with the AR group. Both the AR + Aba and AR + Dex groups showed a significant decrease in nasal T helper 2 cytokine levels, including interleukin (IL)-4, IL-5, IL-13 and T cell activation related IL-17A, and interferon gamma (IFN- γ). Total immunoglobulin (Ig) E and OVA-specific IgG1 levels were also significantly lower in the AR + Aba and AR + Dex groups. OVA-specific IgE level was also significantly lower in the AR + Aba than AR group. Conclusions Aba suppresses allergic inflammation and appears to be a good treatment for AR.

The role of the Siglec-G ITIM domain during bacterial infection

Siglecs, membrane-bound lectins of the sialic acid-binding immunoglobulin superfamily, inhibit immune responses by recruiting tyrosine phosphatases (e.g., SHP-1 and SHP-2) through their cytoplasmic immunoreceptor tyrosine-based inhibition motif (ITIM) domain. The role of Siglecs in infection has been extensively studied, but downstream signaling through the ITIM domain remains unclear. Here, we used a GST pull-down assay to identify additional proteins associated with the ITIM domain during bacterial infection. Gdi2 bound to ITIM under normal homeostasis, but Rab1a was recruited to ITIM during bacterial infection. Western blot analysis confirmed the presence of SHP-1 and SHP-2 in eluted ITIM-associated proteins under normal homeostasis. We confirmed the association of ITIM with Gdi2 or Rab1a by transfection of corresponding expression vectors in 293T cells followed by immunoprecipitation-western blot assay. Thus, ITIM’s role in the inhibition of the immune response during bacterial infection may be regulated by interaction with Gdi2 and Rab1a in addition to SHP-1 and SHP-2.

LncRNA MBNL1-AS1 Represses Proliferation and Cancer Stem-Like Properties of Breast Cancer Through MBNL1-AS1/ZFP36/CENPA Axis

Background: Emerging studies suggested the notion that long noncoding RNAs (lncRNAs) were key regulators of cancer progression. In this research, the expression and roles of MBNL1-AS1 were explored in breast cancer (BC).Methods: In the present research, the MBNL1-AS1 expression in breast cancer tissue, as well as in cell line was studied by qRT-PCR assays. The effects of MBNL1-AS1 on proliferation and stemness were evaluated by MTT assays, colony formation assays, orthotopic breast tumor mice models, and sphere formation assays. Flexmap 3D assays were performed to show that MBNL1-AS1 downregulated the Centromere protein A (CENPA) secretion in BC cells. Western blot, RNA pull-down assays, RNA immunoprecipitation (RIP) assays, and Fluorescence in situ hybridization (FISH) were conducted to detect the mechanism.Results: The results revealed that the expression levels of MBNL1-AS1 were downregulated in breast cancer tissues and cell lines. In vitro and in vivo studies demonstrated that overexpression of MBNL1-AS1 markedly inhibited BC cells proliferation and stemness. RNA pull-down assay, RIP assay, western blot assay, and qRT-PCR assay showed that MBNL1-AS1 downregulated CENPA mRNA via directly interacting with Zinc Finger Protein 36 (ZFP36) and subsequently decreased the stability of CENPA mRNA. Restoration assays also confirmed that MBNL1-AS1 suppressed the CENPA-mediated proliferation and stemness in breast cancer cells. Conclusions: We elucidated a new mechanism for how MBNL1-AS1 regulated the phenotype of BC and targeting the MBNL1-AS1/ZFP36/CENPA axis might serve as therapeutic targets for BC patients.

Inhibition of Salmonella enterica serovar Typhimurium Type Ⅲ Secretion System and Infection Using Small Molecule Quercitrin

AimsThis study was conducted to screen the type Ⅲ secretion system (T3SS) inhibitors of Salmonella enterica serovar Typhimurium (S. Typhimurium) from natural compounds. Through systemic analysis the pharmacological activity and action mechanism of candidate compounds in vivo and in vitro. Methods and resultsUsing an effector-β-lactamase fusion reporter system in S. Typhimurium, we discovered that quercitrin could block effector SipA translocation into eukaryotic host cell without affecting bacterial growth, and inhibit invasion or epithelial cells damage. Using β-galactosidase activity and Western blot assay, it was found that quercitrin significantly inhibits the expression of SPI-1 genes (hilA and sopA) and effectors (SipA and SipC). The animal experiment results indicated that quercitrin reduces mortality, pathological damages and colony colonization of infected mice. ConclusionsSmall-molecule inhibitor quercitrin directly inhibits the founction of T3SS in S. Typhimurium, and provids a potential alternative antimicrobial against Salmonella infection.Significance and impact of the studyNatural compounds have become valuable resources for antibacterials discovery due to their widely structures and biological activities. However, the potential targets and molecular action mechanisms of candidate compounds responsible for anti-infections remain elusive. The T3SS plays a crucial role in bacterial invasion and pathogenesis process in S. Typhimurium. Compared with traditional antibiotics, small molecular compounds can inhibit the T3SS of Salmonella and achieve the effect of anti-infection. They have less pressure on bacterial survival and are not easy to produce drug resistance. This provides strong evidence for development novel anti-virulence drugs against Salmonella infection.

Exosomes Derived from Cancer-Associated Fibroblasts Regulate Cell Progression in Clear-Cell Renal-Cell Carcinoma

<b><i>Backgrounds:</i></b> Exosomes from multiple sources function as regulatory factors in progression of various tumors. However, studies on the impact of exosomes from cancer-associated fibroblasts (CAFs) on tumor-cell proliferation, migration, invasion, and cycle regulation in clear-cell renal-cell carcinoma (ccRCC) are still lacking. <b><i>Methods:</i></b> A Western blot assay was performed to test the exosome-related marker protein level in exosomes derived from CAFs and normal fibroblasts (NFs). A confocal microscope was utilized to observe the internalization of CAF- and NF-derived exosomes after coculturing with cancer cells. MTT, EdU, colony formation, and transwell assays were conducted to detect progression of cancer cells incubated with CAF-derived exosomes. A Western blot assay was also conducted to test expression levels of metastasis-associated proteins. Changes in cell apoptosis and cell cycle were measured by flow cytometry. <b><i>Results:</i></b> Expression of CAF-derived exosome-related marker proteins was higher than that from NFs. Exosomes derived from CAFs and NFs could enter into cancer cells smoothly and be internalized by cancer cells. After cancer cells were cocultured with CAF-derived exosomes, cell proliferation, migration, and invasion were notably enhanced, and cell apoptosis was reduced. Moreover, expression of fibronectin, N-cadherin, vimentin, MMP9, and MMP2 in cancer cells increased, while E-cadherin was decreased. Besides, the proportion of cancer cells in the S phase increased. <b><i>Conclusion:</i></b> CAF-derived exosomes are internalized into ccRCC cells and promote the progression of ccRCC.

The Antioxidant Phytochemical Schisandrin A Promotes Neural Cell Proliferation and Differentiation after Ischemic Brain Injury

Schisandrin A (SCH) is a natural bioactive phytonutrient that belongs to the lignan derivatives found in Schisandra chinensis fruit. This study aims to investigate the impact of SCH on promoting neural progenitor cell (NPC) regeneration for avoiding stroke ischemic injury. The promoting effect of SCH on NPCs was evaluated by photothrombotic model, immunofluorescence, cell line culture of NPCs, and Western blot assay. The results showed that neuron-specific class III beta-tubulin (Tuj1) was positive with Map2 positive nerve fibers in the ischemic area after using SCH. In addition, Nestin and SOX2 positive NPCs were significantly (p < 0.05) increased in the penumbra and core. Further analysis identified that SCH can regulate the expression level of cell division control protein 42 (Cdc42). In conclusion, our findings suggest that SCH enhanced NPCs proliferation and differentiation possible by Cdc42 to regulated cytoskeletal rearrangement and polarization of cells, which provides new hope for the late recovery of stroke.

Monosialoganglioside GM1 Deficiency Inhibits the Neurotrophic Effects of GDNF by Disrupting Lipid Raft Assembly

Recent studies have shown that monosialoganglioside GM1 deficiency can inhibit the signal transduction process of glial cell line-derived neurotrophic factor (GDNF), which plays an important role in the pathogenesis of Parkinson's disease (PD). However, its specific mechanism still needs to be explored. We inhibited the expression of GM1 by treating cells with D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP). CCK-8 assay, EdU cell proliferation assay and Western blot assay were used to evaluate the effect of GM1 deficiency on the proliferation and differentiation of SH-SY5Y cells induced by GDNF and on the GDNF-RET signaling pathway. Lipid rafts were isolated by Triton X-100 solubilization and OptiPrepTM density gradient centrifugation. The alterations of lipid raft assembly and the translocation of RET into lipid rafts were evaluated after PDMP treatment. We found that PDMP treatment inhibited the proliferation and differentiation of SH-SY5Y cells induced by GDNF and reduced the phosphorylation of RET and its downstream signaling molecules Erk and Akt. In addition, after PDMP treatment, caveolin-1 and flotillin-1, the prototypical markers of lipid rafts, diffused from lipid rafts to non-lipid raft microdomains, and GDNF-induced RET translocation into lipid rafts was also reduced. These alterations could be partially reversed by adding exogenous GM1. Our results suggest that ganglioside GM1 deficiency could compromise the neurotrophic effects and signals downstream of GDNF by altering the assembly of lipid raft membrane microdomains.

EZH2 Regulates Lipopolysaccharide-Induced Periodontal Ligament Stem Cell Proliferation and Osteogenesis through TLR4/MyD88/NF-κB Pathway

Background. Periodontitis induced by bacteria especially Gram-negative bacteria is the most prevalent chronic inflammatory disease worldwide. Emerging evidence supported that EZH2 plays a significant role in the inflammatory response of periodontal tissues. However, little information is available regarding the underlying mechanism of EZH2 in periodontitis. This study is aimed at determining the potential role and underlying mechanism of EZH2 in periodontitis. Methods. The protein levels of EZH2, H3K27ME, p-p65, p-IKB, TLR4, MyD88, Runx2, and OCN were examined by western blot assay. Proliferation was evaluated by CCK8 assay. The levels of TNFα, IL1β, and IL6 were detected by ELISA assay. Migration was detected by wound healing assay. The distribution of p65 was detected by immunofluorescence. The formation of mineralized nodules was analyzed using alizarin red staining. Results. LPS stimulation significantly promoted EZH2 and H3K27me3 expression in primary human periodontal ligament stem cells (PDLSCs). Targeting EZH2 prevented LPS-induced upregulation of the inflammatory cytokines and inhibition of cell proliferation and migration. Furthermore, EZH2 knockdown attenuated the TLR4/MyD88/NF-κB signaling to facilitate PDLSC osteogenesis. Conclusions. Modulation of the NF-κB pathway through the inhibition of EZH2 may offer a new perspective on the treatment of chronic apical periodontitis.