Formation Of Cell Research Articles

Actin Isovariant ACT2-Mediated Cellular Auxin Homeostasis Regulates Lateral Root Organogenesis inArabidopsis thaliana.

Lateral root (LR) organogenesis is regulated by cellular flux of auxin within pericycle cells, which depends on the membrane distribution and polar localization of auxin carrier proteins. The correct distribution of auxin carrier proteins relies on the intracellular trafficking of these proteins aided by filamentous actin as a track. However, the precise role of actin in lateral root development is still elusive. Here, using vegetative class actin isovariant mutants, we revealed that loss of actin isovariant ACT8 led to increased lateral root formation. The distribution of auxin within pericycle cells was altered in act8 mutant, primarily due to the altered distribution of AUX1 and PIN7. Interestingly, incorporation of act2 mutant in act8 background (act2act8) effectively nullified the LR phenotype observed in act8 mutant, indicating that ACT2 plays an important role in LR development. To explore further, we investigated the possibility that the act8 mutant's LR phenotype and cellular auxin distribution resulted from ACT2 overexpression. Consistent with the idea, enhanced lateral root formation, altered AUX1, PIN7 expression, and auxin distribution in pericycle cells were observed in ACT2 overexpression lines. Collectively, these results suggest that actin isovariant ACT2 but not ACT8 plays a pivotal role in regulating source-to-sink auxin distribution during lateral root organogenesis.

Targeting PDGF-CC as a promising therapeutic strategy to inhibit cholangiocarcinoma progression.

Cholangiocarcinoma (CCA) is an aggressive malignancy with limited treatment options and poor prognosis. Platelet-Derived Growth Factor CC (PDGF-CC) has been implicated in the progression of various tumors, but its specific role in CCA is not well understood. This study aims to investigate the expression and function of PDGF-CC in CCA and evaluate its potential as a therapeutic target. We conducted gene expression analysis using the GEPIA database to compare PDGF-CC mRNA levels in CCA tissues and normal tissues. Serum samples from CCA patients were analyzed for PDGF-CC protein levels, and immunohistochemistry was used to assess PDGF-CC expression in tissue samples. The impact of PDGF-CC on CCA cell behavior was examined by knocking out PDGF-CC in HuCCT1 and QBC939 cell lines, followed by assessments of cell proliferation, migration, invasion, and colony formation in vitro. Additionally, the effects of PDGF-CC knockout were evaluated in xenograft models. The therapeutic potential of PDGF-CC inhibition was further explored using pharmacological inhibitors and antibodies. PDGF-CC mRNA and protein levels were significantly elevated in CCA tissues and patient sera compared to normal controls. Immunohistochemical analysis confirmed increased PDGF-CC expression in CCA tissues. High PDGF-CC expression correlated with poor overall survival in CCA patients, as shown by Kaplan-Meier analysis. Functional assays revealed that PDGF-CC knockout significantly reduced proliferation, migration, invasion, and colony formation in HuCCT1 and QBC939 cells, the lines with the highest PDGF-CC levels. In vivo, PDGF-CC knockout markedly decreased tumor growth in xenograft models. Pharmacological inhibition of PDGF-CC mirrored the effects of genetic knockout, suggesting it as a viable therapeutic strategy. This study underscores the critical role of PDGF-CC in CCA progression and supports the potential of PDGF-CC inhibitors as a therapeutic approach. Given the association between high PDGF-CC expression and poor prognosis, targeting PDGF-CC may improve outcomes for CCA patients. Further clinical investigations are warranted to develop PDGF-CC-targeted therapies for CCA.

Anchorage of bacterial effector at plasma membrane via selective phosphatidic acid binding to modulate host cell signaling.

Binding phospholipid is a simple, yet flexible, strategy for anchorage of bacterial effectors at cell membrane to manipulate host signaling responses. Phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-biphosphate are the only two phospholipid species known to direct bacterial effectors to establish inner leaflet localization at the plasma membrane. Here, selectivity of phosphatidic acid (PA) by bacterial effectors for the plasma membrane anchorage and its molecular entity was identified. C-terminal BID domain of Bartonella T4SS effectors (Beps) directed the plasma membrane localization of Beps in host cells through binding with PA. A hydrophobic segment of the 'HOOK' subdomain from BID is inserted into the bilayer to enhance the interaction of positively charged residues with the lipid headgroups. Mutations of a conserved arginine facilitating the electrostatic interaction, a conserved glycine maintaining the stability of the PA binding groove, and hydrophobic residues determining membrane insertion, prevented the anchorage of Beps at the plasma membrane. Disassociation from plasma membrane to cytosol attenuated the BepC capacity to induce stress fiber formation and cell fragmentation in host cells. The substitution of alanine with aspartic acid at the -1 position preceding the conserved arginine residue hindered BepD anchoring at the plasma membrane, a vital prerequisite for its ability to elicit IL-10 secretion in host macrophages. In conclusion, our findings reveal the PA-binding properties of bacterial effectors to establish plasma membrane localization and will shed light on the intricate mechanisms employed by bacterial effectors within host cells.

TMIC-23. INVESTIGATING THE FUNCTIONAL ROLE OF SECRETED FERRITIN FROM GLIOBLASTOMA CELL TYPES

Abstract Glioblastoma (GBM) is the most common primary malignant brain tumor in adults with a survival rate ~5%. Our laboratory previously showed the inhibitory effect of iron and ferritin-bound iron on migration and spheroid formation in GBM cells. Furthermore, studies have shown the release of extracellular vesicles (EVs) and their iron-related cargoes are regulated by cellular iron concentrations. Building on these findings, this study aims to investigate the impact of EV-associated ferritin on migration in GBM. To achieve this, we examined the influence of iron on EV release from four GBM cell lines, comprising two cancer stem cells (CSCs) and two non-CSCs: T387, T3691, LN229, and T98G. Using Nanoparticle tracking analysis (NTA), we demonstrated that 100 μM of ferric ammonium citrate (FAC) significantly increases EV release in the CSC line after 24 hours (p-value <0.01). Conversely, there was no significant impact on the non-CSC line under the same conditions. Based on these results, the ability of iron to regulate EV release is dependent on CSC versus non-CSC status. Given the functional role of ferritin on migration potential in GBM, we used immunoblotting to examine ferritin release from cells following iron treatment. We observed a reduction in ferritin release from CSCs following FAC treatment compared to the control, while non-CSCs, in contrast, released more ferritin after treatment. Interestingly, ferritin released from CSCs was predominantly within EVs, whereas ferritin released from non-CSCs was not associated with EVs. To assess the functional impact of ferritin release on migration, we utilized a Transwell migration system, and observed that EVs from iron-treated cells reduced migration in the recipients. Together, these findings expand our understanding of differential responses of ferritin in CSC and non-CSC EVs to iron treatment and will allow us to identify new targets and strategies for managing GBM progression.

DDDR-08. PIM1 INHIBITION: A NOVEL THERAPEUTIC APPROACH FOR IDH-MUTANT GLIOMAS

Abstract BACKGROUND PIM1, a constitutively active serine/threonine kinase has emerged as a relevant target in cancer treatment. Previously, we discovered that IDH-mutant glioma exhibited high kinase activity of PIM1, suggesting an increased sensitivity to PIM1 inhibition. Here we sought to investigate PIM1 inhibition as a therapeutic approach for IDH-mutant gliomas. METHODS Patient-derived IDH-mutant and wildtype glioma cell lines were used to evaluate the impact of PIM1inhibition on cell viability, proliferation, and colony formation. mRNA and protein expression of PIM1 were determined by qRT-PCR, Western-blot, and immunohistochemistry. m6A dot-blot assay was conducted to detect m6A RNA levels in glioma cells. m6A modification status and its location in PIM1 transcript were evaluated by m6A RNA immunoprecipitation array. RNA-binding protein immunoprecipitation was performed using anti-YTHDF1 antibody to identify PIM1 RNA-YTHDF1 protein interactions. RESULTS An upregulation of PIM1 protein is demonstrated in IDH-mutant patient tumor tissues and cells. A pan-PIM inhibitor, AZD1208 significantly suppressed cell viability, cell proliferation, and colony formation in IDH-mutant cells but had a lesser effect in IDH-wildtype cells. Interestingly, a lower mRNA expression of PIM1 is observed, while the protein level is significantly elevated in IDH-mutant cells compared to wildtype cells, suggesting post-transcriptional and translational regulation of PIM1 associated with IDH mutation. Mechanistically, 2-hydroxyglutarate, unique to IDH-mutant gliomas, competitively inhibits α-KG-dependent RNA demethylase FTO. We demonstrated suppressed FTO activity and an increased m6A RNA level in IDH-mutant glioma cells. An enrichment of m6A modification at motif “GG (m6A) CU” located in the 3’UTR is found in the PIM1 transcript. Furthermore, we demonstrated that the m6A modification site is recognized by the m6A reader YTHDF1 to promote protein translation, leading to an elevated PIM1 protein expression. CONCLUSION m6A RNA modification contributes to an enhanced PIM1 activity and thereby a selective sensitivity to PIM1 inhibition in IDH-mutant gliomas.

LncRNA GClnc1 promotes osteosarcoma progression by stabilizing NONO and blocking FBXW7-mediated ubiquitination

BackgroundLong non-coding RNA (lncRNA) plays a vital role in the occurrence and development of varieties of tumors. Previous studies have shown that lncRNA GClnc1 is highly expressed in osteosarcoma (OS). However, the mechanism of lncRNA GClnc1 in osteosarcoma has not been fully elucidated. In this study, we investigated the biological roles of lncRNA GClnc1 in osteosarcoma and unveiled its underlying mechanisms.MethodsThe expression of lncRNA GClnc1 in OS cells was detected by real-time quantitative PCR (qRT-PCR). The functional roles of lncRNA GClnc1 were examined by CCK8, trans-well, scratch wound healing assay, colony formation, and apoptosis assays in osteosarcoma cells upon silencing or overexpressing GClnc1. Western blot analysis, qRT-PCR, and RNA co-immunoprecipitation (RIP) assays were used to detect the interaction between lncRNA GClnc1 and NONO.ResultsThe expression of lncRNA GClnc1 was up-regulated in osteosarcoma cell lines. Knockdown of lncRNA GClnc1 suppressed the cell growth, migration, and invasion of OS cells, whereas the over-expression of GClnc1 improved the proliferation, migration, and invasion of OS cells. Mechanistically, we identified that lncRNA GClnc1 regulates the stability of NONO by blocking FBXW7-mediated ubiquitination degradation. Additionally, overexpression of NONO can reverse GClnc1 silencing exerted suppression of the cell proliferation, migration, and invasion, and vice versa.ConclusionsOur study elucidated that lncRNA GClnc1 participates in the progression of OS by regulating the NONO signal pathway. Targeting GClnc1 provides a potential target for future clinical treatment of OS.

DNAR-11. INHIBITION OF RAD52 ACTIVITY INDUCES DNA DAMAGE BY ACCUMULATING R-LOOPS IN DIFFUSE MIDLINE GLIOMA

Abstract Diffuse midline glioma (DMG) is one of the most devastating childhood cancers with a median survival of < 1year from diagnosis. There is a critical need for new therapeutics for improving treatment outcomes for DMG patients. We performed genome-wide CRISPR/Cas9 screening and identified RAD52 as a potential therapeutic target in DMG cells. RAD52 inhibition, using shRNA-mediated RAD52 depletion and treatment with RAD52 inhibitor, D-I03, suppressed DMG cell proliferation. Western blotting revealed that RAD52 inhibition increased DNA double-starand breaks (DSBs) marker γH2AX while it decreased repair markers BRCA1 and RAD51. Also, RAD52 inhibition causes a sustained level of phosphorylated RAD50 and γH2AX in irradiated DMG cells over 24 hours. Immunocytochemistry (ICC) of γH2AX and repair marker 53BP1 showed that RAD52 inhibition sustained DNA damage with high levels of γH2AX at 24 hours following radiation while the level of 53BPI was decreased, thereby inhibiting DNA DSB repair. DNA repair assay showed that RAD52 inhibition suppressed DNA DSB repair through a homologous recombination pathway. RNA sequencing showed that RAD52 inhibition downregulated genes associated with the DNA repair pathway. Importantly, RAD52 inhibition increased the radiosensitivity of DMG cells. To understand the mechanism of RAD52 inhibition on DNA damage, we performed dot plot assay and ICC of S9.6 which recognizes DNA-RNA hybrids (also known as R-loops) and found accumulation of R-loop formation in DMG cells treated with RAD52 inhibitor. In addition, RAD52 inhibition decreased the expression of RNA polymerase II. Finally, the combination therapy of RAD52 inhibitor and radiation inhibited tumor growth and increased survival of mice bearing DMG patient-derived xenografts, outperforming either monotherapy. Together, our results highlight that RAD52 inhibition induces DNA damage by accumulating R-loops, results in reducing DMG cell proliferation, while also increase DMG radiosensitivty, and providing a rationale for developing combination therapy with radiation for the treatment of DMG.

Inhibiting SIRT2 Attenuates Sepsis-Induced Acute Kidney Injury via FOXO1 Acetylation-Mediated Autophagy Activation.

Sepsis-associated acute kidney injury (SAKI), a common complication in intensive care units (ICUs), is linked to high morbidity and mortality. Sirtuin 2 (SIRT2), an NAD+-dependent deacetylase, has been shown to have distinct effects on autophagy regulation compared to other sirtuins, but its role in SAKI remains unclear. This study explored the potential of SIRT2 as a therapeutic target for SAKI. We found that inhibition of SIRT2 with the antagonist AGK2 improved the survival of septic mice. SIRT2 inhibition reduced kidney injury, as indicated by lower levels of KIM-1, NGAL, serum creatinine (Scr), blood urea nitrogen (BUN), and proinflammatory cytokines following cecal ligation and puncture (CLP). Pretreatment with AGK2 in septic mice increased autophagosome and autolysosome formation in renal tubular epithelial cells (RTECs) and upregulated LC3 II expression in the renal cortex. Consistent with in vivo findings, SIRT2 gene silencing promoted autophagy in LPS-treated HK-2 cells, whereas SIRT2 overexpression inhibited it. Mechanistically, SIRT2 inhibition increased FOXO1 acetylation, inducing its nuclear-to-cytoplasmic translocation, which promoted kidney autophagy and alleviated SAKI. Our study suggests SIRT2 as a potential target for SAKI therapy.

NSDHL contributes to breast cancer stem-like cell maintenance and tumor-initiating capacity through TGF-β/Smad signaling pathway in MCF-7 tumor spheroid

BackgroundNAD(P)-dependent steroid dehydrogenase-like protein (NSDHL), which is involved in breast tumor growth and metastasis, has been implicated in the maintenance of cancer stem cells. However, its role in regulating breast cancer stem-like cells (BCSCs) remains unclear. We have previously reported the clinical significance of NSDHL in patients with estrogen receptor-positive (ER +) breast cancer. This study aimed to elucidate the molecular mechanisms by which NSDHL regulates the capacity of BCSCs in the ER + human breast cancer cell line, MCF-7.MethodsNSDHL knockdown suppressed tumor spheroid formation in MCF-7 human breast cancer cells grown on ultralow-attachment plates. RNA sequencing revealed that NSDHL knockdown induced widespread transcriptional changes in the MCF-7 spheroids. TGF-β signaling pathway was the most significantly enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway (fold change ≥ 2, P ≤ 0.05) identified in NSDHL-knockdown MCF-7 spheroids compared with the control. In orthotopic tumor models injected with NSDHL-knockdown MCF-7 spheroids, tumor initiation and growth were strongly suppressed compared with those in the control.ResultsBCSC populations with CD44+/CD24- and CD49f+/EpCAM + phenotypes and high ALDH activity were decreased in NSDHL-knockdown MCF-7 spheroids and xenograft tumors relative to controls, along with decreased secretion of TGF-β1 and 3, phosphorylation of Smad2/3, and expression of SOX2. In RNA-sequencing data from The (TCGA) database, a positive correlation between the expression of NSDHL and SOX2 was found in luminal-type breast cancer specimens (n = 998). Our findings revealed that NSDHL plays an important role in maintaining the BCSC population and tumor-initiating capacity of ER-positive MCF-7 spheroids, suggesting that NSDHL is an attractive therapeutic target for eliminating BCSCs, thus preventing breast cancer initiation and progression.ConclusionsOur findings suggest that NSDHL regulates the BCSC/tumor-initiating cell population in MCF-7 spheroids and xenograft tumors.

Sterile Alpha Motif Domain-Containing 5 Suppresses Malignant Phenotypes and Tumor Growth in Breast Cancer: Regulation of Polo-Like Kinase 1 and c-Myc Signaling in a Xenograft Model.

Background Breast cancer, particularly the triple-negative breast cancer (TNBC) subtype, remains a significant clinical challenge due to its resistance to standard chemotherapy and high recurrence rate. In this study, we explored the role of Sterile Alpha Motif Domain-Containing 5 (SAMD5) as a potential regulatory partner with the c-Myc oncogenic signaling pathway in breast cancer. Materials and methods Functional assays were conducted to investigate the effects of SAMD5 overexpression on cell viability, colony formation, and invasive behavior in TNBC cell lines. This study further assessed the expression levels of proliferation and invasion markers, including Ki67 (a marker for cell proliferation), Matrix Metalloproteinase-2 (MMP2), and Matrix Metalloproteinase-9 (MMP9). Mechanistic analyses identified a negative correlation between SAMD5 and Polo-like Kinase 1 (PLK1), a gene frequently overexpressed in breast cancer, particularly in TNBC. The effects of PLK1 knockdown on cell viability, colony formation, and invasion were observed, along with the impact of PLK1 overexpression on SAMD5's inhibitory activity. In vivo studies were performed using a xenograft tumor model in nude mice to evaluate the impact of SAMD5 overexpression on tumor weight and volume. Results SAMD5 overexpression significantly reduced cell viability, colony formation, and invasion in TNBC cells, and downregulated key proteins in the c-Myc signaling pathway, including c-Myc itself, β-catenin, Cyclin-Dependent Kinase 4 (CDK4), Cyclin-Dependent Kinase 6 (CDK6), and Cyclin D1. PLK1 overexpression was found to counteract SAMD5's inhibitory effects. In vivo experiments demonstrated that SAMD5 overexpression led to a marked reduction in tumor weight and volume, effects that were partially reversed by PLK1 overexpression. Conclusions SAMD5 acts as a tumor suppressor in breast cancer, particularly in TNBC, by inhibiting critical cellular processes and downregulating the c-Myc signaling pathway. This effect appears to be mediated, in part, through its negative association with PLK1. Targeting the SAMD5/PLK1 axis offers a promising therapeutic strategy for addressing aggressive breast cancers.

Decoding transcriptional identity in developing human sensory neurons and organoid modeling.

Dorsal root ganglia (DRGs) play a crucial role in processing sensory information, making it essential to understand their development. Here, we construct a single-cell spatiotemporal transcriptomic atlas of human embryonic DRG. This atlas reveals the diversity of cell types and highlights the extrinsic signaling cascades and intrinsic regulatory hierarchies that guide cell fate decisions, including neuronal/glial lineage restriction, sensory neuron differentiation and specification, and the formation of neuron-satellite glial cell (SGC) units. Additionally, we identify a human-enriched NTRK3+/DCC+ nociceptor subtype, which is involved in multimodal nociceptive processing. Mimicking the programmed activation of signaling pathways invivo, we successfully establish functional human DRG organoids and underscore the critical roles of transcriptional regulators in the fate commitment of unspecialized sensory neurons (uSNs). Overall, our research elucidates the multilevel signaling pathways and transcription factor (TF) regulatory hierarchies that underpin the diversity of somatosensory neurons, emphasizing the phenotypic distinctions in human nociceptor subtypes.

Inhibition of lysophosphatidic acid receptor 2 attenuates neonatal chronic lung disease in mice by preserving vascular and alveolar development

AimBronchopulmonary dysplasia (BPD) is a common morbidity in extremely premature infants. Previous studies demonstrated the important role of lysophosphatidic acid (LPA) in inflammation in BPD. However, the role of LPA and its receptors in hyperoxia-induced vascular malformations in BPD remains to be elucidated. Methods and ResultsElevated plasma LPA levels were observed in mice with BPD compared to controls (792 vs. 607 ng/mL, p < 0.05). Inhibition of LPA signaling protected against hyperoxia-induced lung injury in neonatal mice, demonstrated by a 2.8-fold increase in pulmonary vascular density and a 14% reduction in alveolar enlargement. In vitro studies showed that LPA suppressed tube formation in human umbilical vein endothelial cells (HUVECs) by approximately 50%. LPA receptor 2 (LPA2) was identified as a functional LPA receptor in primary endothelial cells from the lungs of hyperoxic mice and in HUVECs under hyperoxic conditions. The LPA2 antagonist H2L5186303 enhanced the tube formation ability of HUVECs exposed to LPA, both under normoxia (4-fold) and hyperoxia (5-fold). Moreover, H2L5186303 significantly protected against hyperoxia-induced vascular malformation (2-fold) and improved alveolarization in neonatal mice (12% decrease in mean linear intercept, MLI). Early growth response 1 (EGR1) was characterized as a downstream target of LPA2, silencing EGR1 restored tube formation in HUVECs exposed to LPA and hyperoxia. ConclusionsOur in vitro and in vivo findings demonstrate that the inhibition of LPA/LPA2 signaling mitigates hyperoxia-induced pulmonary vascular malformations, suggesting the LPA/LPA2-dependent signaling pathway has therapeutic potential for extremely premature infants with BPD.

Broussoflavonol F exhibited anti-proliferative and anti-angiogenesis effects in colon cancer via modulation of the HER2-RAS-MEK-ERK pathway

BackgroundA prenylated flavonoid, broussoflavonol F (BFF), was isolated from Macaranga genus with cytotoxicities against various cancer cells, though its underlying mechanisms have not been fully elucidated. HypothesisThis study aimed to investigate the anti-tumor and anti-angiogenesis activities of BFF and its underlying mechanisms in colon cancer. MethodIn the in vitro study, the cytotoxic effects of BFF in human colon cancer HCT-116 and LoVo cells were examined using MTT assay, BrdU assay and colony formation assay. The anti-proliferative effects of BFF in these cells were assessed via cell apoptosis and cell cycle analysis using flow cytometry. The anti-angiogenesis effects of BFF in human endothelial HEMC-1 cells were also detected using scratch wound healing assay and tube formation assay. While the in vivo effects of BFF in colon cancer were further examined in zebrafish embryos and HCT116 tumor-bearing mice. The underlying mechanisms of BFF were predicted using network pharmacology analysis, and Western blotting was performed to validate both in vitro and in vivo results. ResultsBFF exhibited cytotoxicities on 5 colon cancer cell lines, as well as anti-proliferative activities via inducing apoptosis and cell cycle arrest at the G0/G1 phase in HCT116 and LoVo cells. BFF at 1.25-5 µM also suppressed cell proliferation in these two colon cancer cell lines by downregulating HER2, RAS, p-BRAF, p-MEK and p-Erk protein expressions. In addition, BFF at 2.5-5 µM could significantly decrease the length of subintestinal vessels of zebrafish embryos through decreasing mRNA expressions of NRP1a, PDGFba, PDGFRb, KDR, FLT1 and VEGRaa. Besides, BFF exhibited anti-angiogenesis activity via inhibiting cell proliferation, motility and tube formation in HMEC-1 cells. Furthermore, intraperitoneal administration of BFF (10 mg/kg) suppressed tumor growth and decreased the expression of tumor proliferation marker Ki-67 and angiogenesis marker CD31 in the tumor tissues in HCT116 tumor-bearing mice. BFF treatment could also significantly decrease expressions of RAS, p-BRAF, p-MEK and p-Erk in the tumor section, which are consistent with the in vitro results. ConclusionsThis study revealed the anti-tumor and anti-angiogenesis effects of BFF in colon cancer. This is the first report of the in vitro and in vivo anti-proliferative activity of BFF in colon cancer through regulating the HER2-RAS-MEK-ERK pathway. These findings further support the research development of BFF as an anti-cancer agent in colon cancer.

BCAR1 facilitates the survival of lung adenocarcinoma cells by augmenting the unfolded protein response, autophagy, and the formation of vasculogenic mimicry

BackgroundOur objective was to elucidate the pivotal roles of BCAR1 in unfolded protein response (UPR), autophagy and vasculogenic mimicry (VM) formation, processes that essential for the metastasis of lung adenocarcinoma (LUAD) cells. MethodsThe morphological assessment of endoplasmic reticulum (ER) status and autolysosomes in H1975 and H1299 LUAD cells following BCAR1 knockout (KO) was conducted using transmission electron microscope. The expression of markers and cellular functions related to the UPR, autophagy, and VM formation were examined in LUAD cells tissues. Additionally, proteomic analysis of LUAD cells was performed via mass spectrometry, and the pertinent signaling pathways were analyzed using bioinformatics tools. ResultsBCAR1-KO inhibited autophagy and UPR induced triggered starvation in LUAD cells. Cleaved-ATF6a-mediated UPR and subsequent autophagy, enhanced by BCAR1, were confirmed using the UPR stimulator and blocker. High BCAR1 expression, along with elevated UPR and autophagy, predicts poor prognosis in LUAD patients. BCAR1-KO reduced tube formation and VM markers expressions in LUAD cells. Additionally, BCAR1 expression positively correlated with VM formation in BALB/c-nu mice xenografts and LUAD patient tissues. ConclusionBCAR1 promotes LUAD metastasis by enhancing cancer cell survival in nutrient-poor environments through ATF6-mediated UPR activation and autophagy. As BCAR1 induces VM formation, metastatic lesions eventually colonize. Thus, BCAR1 is a promising anti-metastasis target.

Characterizing the interplay between Acinetobacter baumannii, A549 cells, and anti-Omp34 antibodies: implications for adherence, internalization, and cytotoxicity.

Acinetobacter baumannii thrives within eukaryotic cells, influencing persistence, treatment approaches, and progression of disease. We probed epithelial cell invasion by A. baumannii and the influence of antibodies raised to outer membrane protein 34 (Omp34) on epithelial interactions. We expressed and purified recombinant Omp34 and induced anti-Omp34 antibodies in Bagg albino or BALB/c mice. Omp34 was evaluated for acute toxicity in mice through histological analysis of six organs. The host cell line, A549, was exposed to both A. baumannii 19606 and a clinical isolate. The study also investigated serum resistance, adherence, internalization, and proliferation of A. baumannii in A549 cells, with and without anti-Omp34 sera, utilizing cell culture techniques and light microscopy. A549 cell viability was evaluated by A. baumannii challenge and exposure to anti-Omp34 sera. Actin disruption experiments using cytochalasin D probed microfilament and microtubule roles in A. baumannii invasion. Omp34 prompted antibody production without toxicity in mice. The serum showed bactericidal effects on both strains. Additionally, both A. baumannii strains were found to form biofilms. Omp34 serum was observed to decrease biofilm formation, bacterial adherence, internalization, and proliferation in A549 cells. Furthermore, the use of anti-Omp34 serum enhanced the post-infection survival of the host cell. Pre-exposure of A549 cells to cytochalasin D reduced bacterial internalization, highlighting the role of actin polymerization in the invasion process. Microscopic analysis revealed various interactions, such as adherence, membrane alterations, vacuolization, apoptosis, and cellular damage. Anti-Omp34 serum-exposed A549 cells were protected and showed reduced damage. The findings reveal that A. baumannii can significantly multiply intracellularly within host cells. This suggests the bacterium's ability to establish an environment conducive to its replication by preventing fusion with degradative lysosomes and inhibiting acidification. This finding contributes to the understanding of A. baumannii's intracellular persistence and highlights the role of Omp34 in influencing apoptosis, autophagy, and bacterial adherence, which may impact the development of effective treatments against A. baumannii infections.

Resource-efficient electrodes with metallized woven-glass-grid current collectors for lithium-ion batteries.

A novel class of resource-efficient, woven-glass-grid current collectors (CCs) for Li-ion batteries is introduced. These CCs are based on ultra-light multifilament glass threads, woven to a grid and surrounded with a thin metal layer (equivalent to a 1 µm-thick metal foil) in a roll-to-roll physical vapor deposition process. This saves > 90% of the required Cu and Al metals and reduces the mass of the CCs by > 80%. At the same time, the gravimetric capacity of anodes with graphite and cathodes with LiCoO2 active material increases by 48% and 14%, respectively, while full cells are characterized by an increase of 26%. Thus, the specific energy can be improved by 25%. A complete anode and cathode fabrication process from preparing the CCs and electrodes to cells is described and demonstrated in coin cell format. Coin cells with woven-glass-grid CCs achieved 300 cycles with a capacity retention of 93%, a Coulombic efficiency of > 99.9%, and a higher rate capability until a C-rate of 3C. This technology opens up new possibilities for designing ultralight CCs with dedicated surface properties for Li and beyond Li batteries.

Global coupling of R-loopdynamics with RNA polymerase II modulates gene expression and early development of Drosophila.

R-loops are involved in many biological processes in cells, yet the regulatory principles for R-loops in vivo and their impact on development remain to be explored. Here, we modified the CUT&Tag strategy to profile R-loops in Drosophila at multiple developmental stages. While high GC content promotes R-loop formation in mammalian cells, it is not required in Drosophila. In contrast, RNAPII abundance appears to be a universal inducing factor for R-loop formation, including active promoters and enhancers, and H3K27me3 decorated repressive regions and intergenic repeat sequences. Importantly, such a regulatory relationship is dynamically maintained throughout development, and development-related transcription factors may regulate RNAPII activation and R-loop dynamics. By ablating Spt6, we further showed the global R-loop induction coupled with RNAPII pausing. Importantly, depending on the gene length, genes underwent up- or down-regulation, both of which were largely reversed by rnh1 overexpression, suggesting that R-loops play a significant role in the divergent regulation of transcription by Spt6 ablation. DNA damage, defects in survival, and cuticle development were similarly alleviated by rnh1 overexpression. Altogether, our findings indicate that dynamic R-loop regulation is dictated by RNAPII pausing and transcription activity, and plays a feedback role in gene regulation, genome stability maintenance, and Drosophila development.

Activation, regulation, and effects of the mitochondrial unfolded protein response in endothelial cells

Abstract Introduction Endoplasmic reticulum stress and the resulting unfolded protein response (UPRER) play significant roles in endothelial dysfunction and atherosclerosis. However, the understanding of the mitochondrial unfolded protein response (UPRMito) in endothelial dysfunction is limited. This study aims to characterize the activation, regulation, and effects of the UPRMito to provide a comprehensive understanding of endothelial UPRMito. Methods and Results RNA sequencing and quantitative proteomic analysis were employed to investigate the impact of stressors on mitochondrial (MitoBlock-6, CDDO) and endoplasmic (Tunicamycin) protein homeostasis on the transcriptome and proteome of Human Coronary Artery Endothelial cells (HCAEC, Fig.1). The analysis identified 12,745 unique transcripts and 7,891 unique proteins. Mitocarta annotation highlighted the regulatory effect induced by these stressors, particularly on mitochondrial proteins and transcripts (Fig. 2). Geneset enrichment analyses revealed upregulation of pathways regulated by activating transcription factors 4/5 (ATF4/5) and the integrated stress response marker CHOP. Analysis of protein expression changes unveiled that 21 proteins were upregulated by both CDDO and MitoBlock-6, including essential mitochondrial chaperones (HSP10 and HSP60). In contrast, the UPRER stressor Tunicamycin did not induce canonical UPRMito activation. Additionally, 142 proteins were commonly downregulated, affecting crucial biological processes such as mitochondrial translation, mitochondrial gene expression, and ribosome biogenesis. Importantly, NAD+ADP-ribosyltransferase activity was highly downregulated, involving PARP proteins with roles in DNA damage repair. On a functional level, mitochondrial stressors led to dose-dependent alterations in HCAEC viability, apoptosis, and reactive oxygen species formation (ROS) measured by resazurin-based assays, caspase 3/7 activity, and MitoSox staining, respectively. Low doses and short incubations with mitochondrial stressors promoted endothelial cell health through cytoprotective UPRMito pathways, while prolonged incubation led to unresolvable mitochondrial stress (exemplarily shown in Fig. 3). SiRNA-mediated gene silencing of the UPRMito regulators ATF4 and ATF5 promoted mitochondrial ROS formation in cells treated with mitochondrial stressors. These effects were particularly more pronounced after ATF5-Knockdown, suggesting that ATF5 is the main regulator of the UPRMito in HCAEC (Fig. 4). Moreover, high-dose UPRMito stressors led to an impairment in mitochondrial membrane integrity with cytosolic release of pro-inflammatory mtDNA. Conclusion UPRMito and UPRER lead to a different stress response. Depending on the underlying conditions, both stress responses can exert both cytoprotective and cytotoxic effects. Further studies are required to analyze the in vivo relevance and possible therapeutic exploitation of the UPRMito in endothelial dysfunction and atherosclerosis.Figures

Scutellarein inhibits lung cancer growth by inducing cell apoptosis and inhibiting glutamine metabolic pathway

Ethnopharmacological relevanceScutellaria baicalensis Georgi, a widely used Chinese medicinal herb, has shown effectiveness against lung cancer. Scutellarein, a key component of Scutellaria baicalensis, also demonstrates anticancer properties in lung cancer. However, the underlying mechanisms have not yet been clarified. Aim of the studyThis study aimed to investigate the effects of scutellarein in the treatment of NSCLC and its underlying mechanisms. MethodsThis study explored the effects of scutellarein on non–small cell lung cancer (NSCLC) and its mechanisms. A Lewis lung cancer mouse model was established to assess scutellarein's anticancer activity in vivo. Additionally, the compound's effects on cell proliferation, colony formation, migration, and apoptosis were evaluated in vitro using A549 and H1299 lung cancer cells. Metabolomics analysis was conducted to identify changes in cellular metabolism due to scutellarein, while molecular docking and western blotting techniques were employed to elucidate the molecular mechanisms of its anti-lung cancer effects. ResultsScutellarein significantly inhibited lung cancer xenograft tumor growth. In vitro studies showed that scutellarein suppressed migration and colony formation in A549 and H1299 cells, induced cell cycle arrest, and triggered cell apoptosis. Notably, scutellarein profoundly altered amino acid metabolism, particularly affecting glutamine metabolites. It affected key glutamine transporters ASCT2 and LAT1, as well as glutaminase GLS1, leading to their reduced expression. ConclusionScutellarein effectively inhibits lung cancer growth both in vivo and in vitro by inducing cell apoptosis and downregulating the glutamine metabolic pathway.

CD90's role in vascularization and healing of rib fractures: insights from Dll4/notch regulation.

Vascularization after rib fracture is a crucial physiological process that is essential for the repair and healing of the rib. Studies have shown that CD90 plays a critical role in regulating rib fracture healing, but the underlying mechanism of its role has not been fully elucidated. CD90 adenovirus knockout mice were used to construct a rib injury model. The bone healing was observed by micro-CT. CD31/EMCN immunofluorescence staining was performed on bone tissue to observe the density of H-shaped and L-shaped blood vessels at the site of bone injury. CD31 and EMCN dual-stained single cells from the rib fracture sites were detected by flow cytometry. The periosteal stem cells transfected with CD90 or Notch1 overexpression and silencing vector were co-cultured with osteoblast MC3T3-E1 in osteogenic induction medium. Moreover, bone microvascular endothelial cells were extracted from the rib injury and co-cultured with the periosteal stem cells transfected with CD90. CCK-8 was used to detect cell viability, RT-qPCR and Western blot were used to detect Notch1, Notch2, Notch3, Notch4, CD31, HIF-1α, CD90, RUNX2, OCN and OPN expression. Alkaline phosphatase (ALP) staining and alizarin red staining were used to observe mineralized nodules. Immunofluorescence staining was used to detect the expression of Dll4, Notch, and CD90 in each group of cells. The angiogenesis experiment was conducted to observe cellular vascular formation. Compared with the Adsh-NC group, the bone healing in the Adsh-CD90 group was significantly impaired, with a marked reduction in the number and volume of blood vessels at the rib fracture site, as evidenced by CD31/EMCN immunofluorescence staining, which showed a reduction in the number of H type vessels at the site of bone injury. It was found that CD90 depletion can inhibit the signaling of Dll4/Notch in the rib fracture site. Furthermore, we found that overexpression of Notch1 reverses the impairment of tubule formation in bone microvascular endothelial cells caused by CD90 suppression.r.Dll4 protein reverses the inhibitory effect of CD90 deletion on periosteal stem cells and MC3T3-E1 cell viability and osteogenesis. In the end, we found that overexpression of Notch1 and CD90 can promote angiogenesis of bone microvascular endothelial cells and Notch pathway activation. CD90 can affect vascular formation in mouse rib fractures, and CD90 may be regulated by Dll4/Notch.