Culture Supernatants Research Articles

SP1-mediated transcriptional repression of SFRP5 is correlated with cardiac fibroblast activation and atrial myocyte apoptosis in the development of atrial fibrillation

Secreted frizzled related protein 5 (SFRP5) is a recognized cardioprotective protein with diminished expression in atrial fibrillation (AF). This study investigates SFRP5's function in AF-related cardiac fibrosis and cardiomyocyte apoptosis, exploring the underlying dysregulation causes. Utilizing C57BL/6 mice, mouse cardiac fibroblasts (CFs), and HC-1 mouse atrial myocyte cell line, AF models were induced by angiotensin Ⅱ (Ang Ⅱ). SFRP5 levels were consistently decreased in plasma samples from clinical patients, modeled mice, and CF culture supernatants. Treatment with recombinant SFRP5 restored its levels, mitigating Ang Ⅱ-induced AF in mice and ameliorating atrial tissue fibrosis and oxidative stress. In vitro, SFRP5 recombinant protein suppressed CF activation and fibrosis-related markers. The study identified Sp1 transcription factor (SP1) binding to the SFRP5 promoter, causing transcriptional repression. SP1 knockdown reinstated SFRP5 levels in mice and CFs, thus suppressing fibrosis. Additionally, SP1 knockdown attenuated Ang Ⅱ-induced apoptosis in HC-1 cells, but this effect was counteracted by concurrent SFRP5 knockdown. In conclusion, this investigation underscores that SP1 mediates SFRP5 loss during AF by transcriptional repression, contributing to fibrosis and myocyte apoptosis. These findings illuminate potential therapeutic interventions targeting the SFRP5-SP1 axis in AF-related cardiac complications.

Abstract A036: DDR2 in ovarian tumor CAFs controls ferroptosis and response to Olaparib

Abstract In ovarian cancer, resistance to conventional cancer treatments has stimulated finding alternative targets that induce tumor cell death. Ferroptosis, a lipid peroxide-triggered form of iron-dependent cell death, is one such pathway. Current research has focused primarily on tumor cell-intrinsic mechanisms or how tumor associated immune cells might impact tumor cell ferroptosis. Cancer-associated fibroblasts (CAFs) are other key stromal cells in the tumor microenvironment and play critical roles in cancer progression, metastasis, and chemotherapeutic response. In ovarian cancer, the collagen receptor tyrosine kinase DDR2 is predominantly expressed by tumor stromal CAFs, not immune cell, and high tumor stromal cell expression of DDR2 in ovarian tumors is associated with poor survival and resistance to therapy. Thus, we asked whether DDR2 could impact ferroptosis regulation in CAFs, and if so, how this effect of DDR2 could impact ovarian tumor cell responses to cytocidal therapies. Through various genetic means, we generated multiple DDR2-expressing and DDR2-deficient human ovarian tumor and mouse breast tumor CAFs. We evaluated the response of the various CAFs to ferroptosis inducers (Erastin and RSL3) and inhibitors (Ferrostatin-1 and Deferoxamine). We find that the presence of DDR2 in CAFs protects these cells from induced ferroptosis through regulation of the xCT- GSH-GPX4 antioxidant pathway and cellular iron metabolism. DDR2-dependent regulation of xCT-GSH-GPX4 occurs through non-canonical activation of NRF2 via the Sequestosome-1 (SQSTM1/p62) protein. In iron metabolism, DDR2 affects the labile iron pool (LIP) by regulating ferritinophagy. The actions of DDR2 in CAFs protects these cells against Olaparib therapy, by inhibiting Olaparib-induced ferroptosis. Ovarian tumor CAF culture supernatant was found to protect ovarian tumor cell response to Erastin-induced ferroptosis, in a DDR2- dependent manner. Overall, this study uncovered a novel function of the action of DDR2 in tumor stromal CAFs in controlling iron and the xCT-GSH-GPX4 ferroptosis regulatory axis through non-canonical p62-KEAP1-NRF2 activation. These findings suggest that CAFs, through DDR2-mediated regulation of ferroptosis, could play a role in therapeutic sensitivity/resistance in ovarian cancer. Citation Format: Julien Lesage, Alessandra DiMauro, Katherine C. Fuh, Gregory D. Longmore. DDR2 in ovarian tumor CAFs controls ferroptosis and response to Olaparib [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr A036.

Probiotic bacteria-released extracellular vesicles enhance macrophage phagocytosis in polymicrobial sepsis by activating the FPR1/2 pathway.

Sepsis-induced organ failure and high mortality are largely ascribed to the failure of bacterial clearance from the infected tissues. Recently, probiotic bacteria-released extracellular vesicles (BEVs) have been implicated as critical mediators of intercellular communication which are widely involved in the regulation of the inflammatory response. However, their functional role in macrophage phagocytosis during sepsis has never been explored. BEVs were collected from three different strains of probiotics including Lactiplantibacillus plantarum WCFS1 (LP WCFS1), Lactobacillus rhamnosus Gorbach-Goldin (LGG), and Escherichia coli Nissle 1917 (EcN), or from LGG cultured under three pH conditions (pH5-acid, pH6.5-standard, pH8-akaline) through differential centrifugation, filtration, and ultracentrifugation of their culture supernatants. In vitro phagocytosis was measured in Raw264.7 cells and bone marrow-derived macrophages using pHrodo red E. coli BioParticles. The in vivo therapeutic effects of BEVs were tested using a feces-injection-in-peritoneum (FIP) model of polymicrobial sepsis. LGG-derived EVs (BEVLGG) were the best among these three probiotics BEVs in stimulating macrophages to take up bacteria. Furthermore, BEVLGG collected from pH8 culture condition (BEVpH8) exhibited the strongest capacity of phagocytosis, compared with BEVpH5and BEVpH6.5. Treatment of septic mice with BEVpH8significantly prolonged animal survival; increased bacterial clearance from the blood, peritoneal lavage fluid, and multiple organs; and decreased serum levels of pro-inflammatory cytokines/chemokines, as well as reduced multiple organ injuries, in comparison with control-treated septic mice. Mechanistically, RNA-seq and bioinformatic analysis identified that the FPR1/2 signaling was remarkably activated, along with its downstream pathways (PI3K-Akt-MARCO and NADPH-ROS) in BEVpH8-treated macrophages, compared with control cells. Accordingly, pre-addition of Boc2, a specific antagonist of FPR1/FPR2, to macrophages significantly attenuated BEVpH8-mediated phagocytosis, compared to controls. This study demonstrates that LGG-derived BEVs may have therapeutic effects against sepsis-induced organ injury and mortality through enhancing FPR1/2-mediated macrophage phagocytosis.

Neutrophils Respond Selectively to Physical Cues: Roughness Modulates Its Granule Release, and NETosis

Our study examined how different titanium alloy Ti6Al4V (Ti64) and zirconia (ZrO2) surfaces, ranging from rough to very smooth, affect the expression of elastase (NE), matrix metalloproteinase (MMP)-8, MMP-9, and extracellular traps (NETs) by neutrophils. Discs of Ti64 and ZrO2, 10 mm in diameter and 1.5 mm thick, were created using diamond-impregnated polishing burs and paste to produce rough (Ra > 3 µm), smooth (Ra ≥ 1 to 1.5 µm), and very smooth (Ra < 0.1 µm) surfaces. Neutrophils from Wistar rats were cultured on these surfaces, and the culture supernatants were then examined for NE, MMP-8, and MMP-9 using ELISA. At the same time, NET formation was demonstrated immunohistochemically by staining neutrophils with CD16b and DNA with DAPI. Overall, the expressions of NE and MMP-8 were significantly higher from neutrophil culture on Ti64 and ZrO2 rough surfaces compared to the very smooth surface (R > S > VS) after 2 h and 4 h of culture. The expression of MMP-9 also increased with culture time; however, no significant surface effects on expression were observed. Similarly, rough Ti64 and ZrO2 surfaces (R & S) also showed significantly larger NET formation compared to the very smooth surface (VS) after 4 h and 8 h cultures. Our findings suggest that increasing surface roughness on Ti64 and ZrO2 triggers higher NE, MMP-8, and NET formation secretion.

AI Promoted Virtual Screening, Structure-Based Hit Optimization, and Synthesis of Novel COVID-19 S-RBD Domain Inhibitors.

Coronavirus disease 2019 (COVID-19) is caused by a new, highly pathogenic severe-acute-respiratory syndrome coronavirus 2 (SARS-CoV-2) that infects human cells through its transmembrane spike (S) glycoprotein. The receptor-binding domain (RBD) of the S protein interacts with the angiotensin-converting enzyme II (ACE2) receptor of the host cells. Therefore, pharmacological targeting of this interaction might prevent infection or spread of the virus. Here, we performed a virtual screening to identify small molecules that block S-ACE2 interaction. Large compound libraries were filtered for drug-like properties, promiscuity and protein-protein interaction-targeting ability based on their ADME-Tox descriptors and also to exclude pan-assay interfering compounds. A properly designed AI-based virtual screening pipeline was applied to the remaining compounds, comprising approximately 10% of the starting data sets, searching for molecules that could bind to the RBD of the S protein. All molecules were sorted according to their screening score, grouped based on their structure and postfiltered for possible interaction patterns with the ACE2 receptor, yielding 31 hits. These hit molecules were further tested for their inhibitory effect on Spike RBD/ACE2 (19-615) interaction. Six compounds inhibited the S-ACE2 interaction in a dose-dependent manner while two of them also prevented infection of human cells from a pseudotyped virus whose entry is mediated by the S protein of SARS-CoV-2. Of the two compounds, the benzimidazole derivative CKP-22 protected Vero E6 cells from infection with SARS-CoV-2, as well. Subsequent, hit-to-lead optimization of CKP-22 was effected through the synthesis of 29 new derivatives of which compound CKP-25 suppressed the Spike RBD/ACE2 (19-615) interaction, reduced the cytopathic effect of SARS-CoV-2 in Vero E6 cells (IC50 = 3.5 μM) and reduced the viral load in cell culture supernatants. Early in vitro ADME-Tox studies showed that CKP-25 does not possess biodegradation or liver metabolism issues, while isozyme-specific CYP450 experiments revealed that CKP-25 was a weak inhibitor of the CYP450 system. Moreover, CKP-25 does not elicit mutagenic effect on Escherichia coli WP2 uvrA strain. Thus, CKP-25 is considered a lead compound against COVID-19 infection.

Abstract 4134539: Hybrid Cardiomyocyte Targeting Peptide Down-regulates NF-κB Pathway in Human Cardiomyocytes

Introduction: Role of NF-κB driven inflammation leading to heart failure with preserved ejection fraction has received little attention. Our previous in vivo work with cardiac targeting peptide (CTP) in guinea pigs identified suppression of NF- κB pathway by CTP. In the current work we sought to further study the effects of a hybrid version of CTP (hCTP: amino acids at positions 3 and 11 substituted with D-amino acids) on TNF-α mediated NF-κB activation, as well as expression of its downstream inflammatory markers IL-1β and IL-8. Methods: Human cardiomyocytes (CMCs) were transfected using Lipofectamine 3000 with a reporter luciferase plasmid carrying an NF-κB promoter site upstream of the luciferase gene. Cells were treated with various concentrations of hCTP for 24 hours, followed by a TNF-α challenge (20ng/mL), addition of luciferin as substrate, and measurement of luminescence. Cell viability in response to above manipulations was assessed by FACS using live-dead stain. CMCs were treated as above, and cell culture supernatants analyzed for IL-8 levels using human ELISA kit. In another set of experiments, CMCs were transfected with NF-κB reporter plasmid, and after treatment for 24 hours with various concentrations of hCTP, incubated with 10nM angiotensin 2 (Ang2) and 100nM phenylephrine (PE) for 24hrs to assess levels of IL-1β in the cell culture media using an ELISA assay. Results: hCTP inhibited TNF-α mediated NF-κB activation with a dose-response curve, with maximum inhibition with hCTP seen at 10µM concentrations (p<0.001). Treatment with hCTP inhibited the TNF-α induced IL-8 secretion with significant decreases seen even at the 1µM dose. Similarly, secretion of IL-1β production by CMCs in response to Ang2/PE stimulation was suppressed by hCTP even at the lowest tested dose (1µM; p<0.5). Conclusions: Our data suggests that hCTP inhibited NF-κB pathway transcriptional activity in response to TNF-α stimulation in a dose-dependent fashion in human CMCs. Furthermore, treatment with hCTP inhibited TNF-α induced IL-8 and IL-1β secretion even at doses as low as 1µM. The ability of hCTP to efficiently targeting this inflammatory pathway suggests that it has therapeutic potential in the treatment of heart failure. Further in vivo studies are ongoing to test this hypothesis.

Effect of Culture Supernatant of Clostridium butyricum TO-A on Human DNA-Repair-Factor-Encoding Gene Promoters

In this study, Clostridium butyricum TO-A culture supernatant (CBCS) or butyric acid was added to a culture medium of human cervical carcinoma HeLa S3 cells, and changes in DNA-repair-related gene promoter activities were investigated. The HeLa S3 cells were transfected with a luciferase (Luc) expression vector containing approximately 500 bp of the 5′-upstream region of several human DNA-repair-related genes and cultured with a medium containing the CBCS (10%) or butyric acid (2.5 mM). The cells were harvested after 19 to 42 h of incubation. A Luc assay revealed that the human ATM, PARG, PARP1, and RB1 gene promoter activities were significantly increased. A Western blot analysis showed that the amounts of the proteins encoded by these genes markedly increased. Furthermore, 8, 24, and 48 h after the addition of the CBCS (10%), total RNA was extracted and subjected to RNAseq analysis. The results showed that the expression of several inflammation- and DNA-replication/repair-related genes, including NFKB and the MCM gene groups, decreased markedly after 8 h. However, the expression of the histone genes increased after 24 h. Elucidation of the mechanism by which the CBCS and butyrate affect the expression of genes that encode DNA-repair-associated proteins may contribute to the prevention of carcinogenesis, the risk of which rises in accordance with aging.

Extracellular vesicles from mouse bone marrow macrophages-derived osteoclasts treated with zoledronic acid contain miR-146a-5p and miR-322-3p, which inhibit osteoclast function

Medication-related osteonecrosis of the jaw (MRONJ) is an intractable form of osteonecrosis of the jaw that rarely occurs in patients using bone resorption inhibitors such as bisphosphonates (BPs). Then, extracellular vesicles (EVs) carry various signaling molecules, such as mRNAs, microRNAs (miRNAs), and proteins, and have attracted attention as intercellular communication tools. Recently, the role of EVs in communication between osteoclasts and surrounding bone cells has been confirmed. This study aimed to elucidate the effects of EVs derived from osteoclasts treated with zoledronic acid (ZA), one of the BPs on osteoclast function. EVs were isolated by ultracentrifugation of the culture supernatant of osteoclasts treated with ZA, and miRNAs were extracted from these EVs. Tartrate-resistant acid phosphatase staining of the ZA treated osteoclasts showed reduced osteoclastogenesis. In addition, pit assay showed that ZA significantly decreased the bone resorption capacity of osteoclasts. miRNA-seq analysis identified 11 upregulated and 5 downregulated differentially expressed genes (DEGs) in the miRNA of EVs derived from ZA-treated osteoclasts compared to EVs derived from osteoclasts not treated with ZA. qRT-PCR analysis confirmed the amount of these specific miRNAs, with miR-146a-5p, and miR-322-3p being significantly upregulated by ZA. Overexpression of miR-146a-5p in osteoclasts inhibited osteoclastogenesis and decreased the mRNA expression of osteoclast markers. In addition, Traf6 was identified as a candidate target gene of miR-146a-5p in several miRNA databases. Indeed, the overexpression of miR-146a-5p decreased the expression level of Traf6 in osteoclasts. Additionally, overexpression of miR-322-3p in the pre-osteoblast, MC3T3-E1 cells, resulted in a significant increase in the mRNA expression levels of Sp7. Our data indicate that BPs attenuate osteoclastogenesis by simultaneously altering the characteristics of osteoclast-derived EVs. Overexpression of miR-146a-5p and miR-322-3p influences osteoclast differentiation, and Traf6 is a target gene of miR-146a-5p. On the other hand, Overexpression of miR-322-3p affects osteoblast differentiation. We suggest that ZA-treated osteoclast-derived EVs may play an important role in osteoclast function and bone resorption.

Comparison of three methods for generating the coccoid form of Helicobacter pylori and proteomic analysis

BackgroundHelicobacter pylori changes from spiral to coccoid depending on the host state, environmental factors, and surrounding microbial communities. The coccoid form of H. pylori still maintains its complete cellular structure, retains virulence genes, and thus plays a role in pathogenicity. To understand the coccoid form, it is crucial to establish the in vitro generation of the coccoid H. pylori. Although some conditions have been studied for the generation of the coccoid form, few studies have compared these conditions for coccoid generation. Here, we generated coccoid forms via three methods and compared the differences in morphology, viability, culturability, and protein expression.ResultsThe coccoid H. pylori was generated in vitro via three methods: a starvation method, a method using amoxicillin, and a method using the culture supernatant of Streptococcus mitis. The morphology and viability of the cells were examined by fluorescence microscopy after staining with SYTO9 and propidium iodide. The culturability of H. pylori was examined by counting colony-forming units on chocolate agar plates. In the starvation group, no colonies formed after 7 days, but viable coccoids were continuously observed. In the amoxicillin-treated group, the culturability decreased rapidly after 12 h, and showed a viable but non culturable (VBNC) state after the third day. Most cells treated with S. mitis supernatant changed to coccoid forms after 7 days, but colonies were continuously formed, probably due to living spiral forms. We performed proteomics to analyse the differences in protein profiles between the spiral and coccoid forms and protein profiles among the coccoid forms generated by the three methods.ConclusionAmoxicillin treatment changed H. pylori to VBNC cells faster than starvation. Treatment with the S. mitis supernatant prolonged the culturability of H. pylori, suggesting that the S. mitis supernatant may contain substances that support spiral form maintenance. Proteomic analysis revealed that the expression of proteins differed between the spiral form and coccoid form of H. pylori, and this variation was observed among the coccoid forms produced via three different methods. The proteins in the coccoid forms produced by the three methods differed from each other, but common proteins were also observed among them.

VE-cadherin shedding in vitro and in patients with aortic aneurysm and dissection

VE-cadherin (VEC) is a major endothelial adhesion protein, which controls vascular homeostasis. During vascular diseases, VEC can be shed from the endothelial surface by proteases like ADAM10/17, which cleave the extracellular domain of VEC in response to inflammatory cytokines like TNF-α. The resulting, soluble fragments (sVEC) are discussed as a potential marker for endothelial barrier breakdown. However, its pathologic role or its potential as a specific biomarker for aortic diseases is yet unknown. Here we investigated the specificity and linkage of sVEC production with ADAM10/17 and TNF-α, both in vitro and in patients with aortic aneurysms and dissections, comparing the findings with those from patients with carotid stenosis and varicosis. Thereby, the baseline levels of sVEC, TNF-α, ADAM10 and Albumin was measured in clinical plasma samples and cell culture supernatants of human aortic endothelial cells (HAOEC) treated with TNF-α or ADAM10/17 inhibitors. The integrity of HAOEC monolayers was tested by permeability assays using Alexa488-conjugated dextran (10 kDa). Peripheral EDTA plasma samples taken preoperatively from patients ≥ 18 years of age that were diagnosed for aortic dissection (n = 29), aortic aneurysm (n = 76), carotid stenosis (n = 29) and varicose veins (n = 24) were included. In vitro shedding of VEC was induced by TNF-α and depends on ADAM10/17, which led to altered endothelial permeability. Absolute plasma sVEC levels in patients with aortic dissection (3016 ± 1008 ng/mL) and aneurysm (3288 ± 1376 ng/mL) were not statistically significantly different from patients with carotid stenosis (3013 ± 687.6 ng/mL) and varicose veins (3313 ± 1337 ng/mL). Plasma sVEC levels correlated positively with plasma TNF-α (r = 0.5586, p < 0.0001) and ADAM10 (r = 0.7003, p < 0.0001) levels with the highest degree of correlation between ADAM10 and sVEC for chronic aortic dissection (r = 0.7890, p = 0.0013), reflecting TNF-α and ADAM10 dependency of VEC shedding. In summary, VEC shedding and (plasma) sVEC levels are influenced by TNF-α and ADAM10/17 and could play a relevant role in the specific pathophysiological context of aortic diseases.

IFN-γ derived from activated human CD4+ T cells inhibits the replication of SARS-CoV-2 depending on cell-type and viral strain

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and vaccination elicit both T cell and B cell immune responses in immunocompetent individuals. However, the mechanisms underlying the antiviral effects mediated by CD4+ T cells are not fully understood. In this study, we analyzed the culture supernatant (SN) from polyclonally stimulated human CD4+ T cells as a model for soluble mediators derived from SARS-CoV-2-stimulated CD4+ T cells. Interestingly, this SN inhibited SARS-CoV-2 propagation in a viral strain- and host cell type-dependent manner. The original wild-type showed the highest susceptibility, whereas the Delta variant exhibited resistance in the human monocyte cell line. In addition, antibody-dependent enhancement (ADE) of infection with the original strain was also abolished in the presence of the SN. The findings showed that the inhibitory effect on viral propagation by the SN was mostly attributed to interferon-γ (IFN-γ) that was present in the SN. These results highlight the potential role of IFN-γ as an anti-SARS-CoV-2 mediator derived from CD4+ T cells, and suggest that we need to understand the SARS-CoV-2 strain-dependent sensitivity to IFN-γ in controlling clinical outcomes. In addition, characterization of new SARS-CoV-2 variants in terms of IFN-γ-sensitivity will have important implications for selecting therapeutic strategies.

A novel multiplexed immunoassay for surface-exposed proteins in plasma extracellular vesicles.

Small membranous extracellular vesicles (EV) incorporate proteins and nucleic acids from the parent cell. Proteins exposed on EV surface are dictated by cellular origin and biogenesis pathway. To better understand the EV origin and function, it is important to develop methods that reveal surface protein composition of heterogeneous EV populations in culture supernatants and in biofluids. Tetraspanins CD9, CD63, and CD81 are common and abundant EV markers. However, their relative enrichment (profile) on EVs of specific cellular origins is not fully elucidated. We introduce LuminEV, a novel version of the Luminex assay for the multiplexed analysis of EV surface proteins. Optimized LuminEV reagents enable direct, specific, and sensitive measurements of EV markers in biofluids and in culture supernatants, bypassing EV isolation step. LuminEV assay for CD9, CD63, and CD81 was validated by comparing simplex and multiplex measurements, establishing linearity, spike-in recovery, inter- and intra-assay precision, and reproducibility between operators. LuminEV measurements of CD9, CD63, and CD81 in conditioned media from 15 cell lines revealed strong variations between cell types and showed high sensitivity, which enabled EV detection without prior concentration. Using tetraspanin levels as a readout, we noted suppression and induction of EV release from the cultured cells by GW6869 and monensin. Measurement of EV CD9, CD63, and CD81 in blood plasma from 70 disease-free donors showed respective abundance of 72, 16, and 12%. CD63 displayed weak, albeit significant, negative correlation with age and was slightly lower in female samples. The assay was then used to detect cell type-specific EV surface markers, including CD235a (erythrocytes), GAP43 (neurons), and CD68 (macrophages), and to detect differences in tetraspanin profiles between healthy and diseased donors. In summary, LuminEV offers robust and sensitive approach for multiplexed assessment of EV surface proteins, to facilitate the research into EV biology, biomarker, and therapeutic applications.

Astragaloside IV Protects Against IL-1β-Induced Chondrocyte Damage via Activating Autophagy.

Osteoarthritis (OA) is a chronic inflammatory condition that affects the articular cartilage. Astragaloside IV (AS-IV) constitutes the primary active component of the Chinese herbal medicine Huangqi (Radix Astragali Mongolici). AS-IV demonstrates anti-inflammatory and anti-apoptotic attributes, exhibiting therapeutic potential across various inflammatory and apoptosis-related disorders. Nevertheless, its pharmaceutical effects in OA are yet to be fully defined. This study aimed to investigate the protective impact of AS-IV on rat chondrocytes treated with IL-1β and ascertain whether autophagy plays a role in this effect. Chondrocytes were isolated and cultivated from the knee joints of neonatal SD mice. The study included the blank control group, the model group, and the AS-IV concentration gradient group (50, 100, 200 μmol/L) to intervene with chondrocytes. The MTT assay was employed to assess cell viability at varying culture periods, enabling the determination of suitable concentration and duration. Subsequently, chondrocytes were treated with the optimal AS-IV concentration and divided into three groups: the model group replicated IL-1β-induced inflammatory chondrocyte injury, the AS-IV group received a co-culture of AS-IV and IL-1β, and a blank control group was established. Changes in cell morphology and structure were observed using ghost pen cyclic peptide staining. ELISA was used to measure TNF-α and GAG levels in cell supernatants. RT-qPCR assessed p62 and LC3 mRNA expression, while Western Blot evaluated p62 and LC3Ⅱ/Ⅰ protein expression. AS-IV promoted chondrocyte proliferation and concurrently inhibited cell apoptosis. An optimal AS-IV dose of 200 μmol/L and a suitable reaction time of 48 h were identified. Ghost pen cyclic peptide staining indicated that the model group's cytoskeleton exhibited fusiform changes with reduced immunofluorescence intensity, as opposed to the blank control group. The AS-IV group displayed more polygonal cytoskeletal morphology with increased immunofluorescence intensity. AS-IV reduced TNF-α levels and elevated GAG levels in the culture supernatant. Additionally, AS-IV lowered p62 mRNA and protein expression while increasing LC3 mRNA expression in cultured chondrocytes. Our findings suggest that AS-IV mitigates inflammatory chondrocyte injury, safeguarding chondrocytes through a potential autophagy suppression mechanism. These results imply that AS-IV could offer preventive advantages for OA.

The impact of Charcot-Leyden Crystal protein on mesothelioma chemotherapy: targeting eosinophils for enhanced chemosensitivity

In mesothelioma (MPM), clinical evidence indicates that the absolute eosinophil count negatively correlates with overall survival and response to standard chemotherapy. Since eosinophils poorly infiltrate MPM tumours, we hypothesised that endocrine rather than paracrine pathways mediate the therapeutic response. We thus studied the effect of eosinophil-associated factors on response to chemotherapy in mesothelioma. The culture supernatant conditioned by primary human eosinophils was added to mesothelioma cells in presence of the standard chemotherapeutic regimen. The effectiveness of an anti-eosinophil treatment was evaluated in a preclinical model of C57BL/6 mice transplanted with mesothelioma tumour cells. Supernatant of eosinophils differentiated from EOL1 cells or directly isolated from peripheral blood inhibited apoptosis induced by cisplatin and pemetrexed in 2D cultures and in spheroids. Transcriptomic analysis indicated that the anti-apoptotic effect mediated by eosinophils involved molecular interactions with the Charcot-Leyden Crystal protein or Galectin-10 (CLC-P/Gal10). The functional relevance of CLC-P/Gal10 was demonstrated by antibody-mediated depletion. Recombinant human CLC-P/Gal10 mimicked the anti-apoptotic activity of eosinophil-derived supernatants. In the mouse model, eosinophilia did not significantly affect tumour growth but altered the response to chemotherapy. Finally, pretreatment of eosinophilia with the anti-Siglec-F antibody before chemotherapy restored the effectiveness of the treatment. This study provides a mechanistic rationale to clinical evidence correlating the poor outcome of patients with mesothelioma and with eosinophil-derived CLC-P/Gal10, opening new prospects for intervention in this fatal solid tumour. Belgian Foundation against Cancer, Fonds National de la Recherche Scientifique (FNRS), Télévie, Foundation Léon Fredericq, ULiège.

Immune checkpoint molecules performance in ANCA vasculitis

ObjectiveThe PD-1 axis promotes protection against autoimmunity. Immune checkpoint (IC) molecules performance in anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) remains unknown. This study aims to assess the IC pathway’s role in...

Cefiderocol has immunoregulative effects in LPS-induced vitro experimental model via inhibiting inflammation and ferroptosis

BackgroundCefiderocol is a new catecholamine-containing siderophore cephalosporin. It, however, remains unclear how cefiderocol modulates the immune response of the host. ObjectivesThis study elucidated whether cefiderocol exerts immunoprotective effects in an in vitro experimental model induced with lipopolysaccharide (LPS). MethodsMouse macrophage RAW 264.7 cells were exposed to LPS (100 ng/mL) or LPS + cefiderocol (40 mg/L) to assess the immunomodulatory effect of cefiderocol in vitro. ELISA was performed on cell culture supernatants to estimate cytokine levels. Ferroptosis level was also quantified by detecting intracellular reactive oxygen species (ROS) and iron levels through flow cytometry analysis. Malondialdehyde (MDA) and glutathione (GSH) levels were estimated by ELISA. We conducted western blotting assay for evaluating key ferroptosis pathway proteins. ResultsCefiderocol alleviated LPS-induced inflammation by reducing IL-6, TNF-α, and IL-1β production levels and enhancing the IL-10 production level. Further analysis to determine the underlying mechanism revealed that cefiderocol inhibited ferroptosis; this was confirmed by reduced ROS, MDA, and Fe2+ ion levels; increased GSH levels; upregulated expression of solute carrier family 7 member 11, glutathione peroxidase 4, nuclear factor erythroid 2-related factor 2, and ferroptosis suppressor protein 1; and downregulated expression of acyl-CoA synthetase long-chain family member 4. ConclusionsCefiderocol may play a key role in reducing inflammation by decreasing inflammatory cytokine release and suppressing ferroptosis.

Effectiveness of co-cultured Myristica fragrans Houtt. seed extracts with commensal Staphylococcus epidermidis and its metabolites in antimicrobial activity and biofilm formation of skin pathogenic bacteria

BackgroundSkin commensal bacteria (Staphylococcus epidermidis) can help defend against skin infections, and they are increasingly being recognized for their role in benefiting skin health. This study aims to demonstrate the activities that Myristica fragrans Houtt. seed extracts, crude extract (CE) and essential oil (EO), have in terms of promoting the growth of the skin commensal bacterium S. epidermidis and providing metabolites under culture conditions to disrupt the biofilm formation of the common pathogen Staphylococcus aureus.MethodsThe culture supernatant obtained from a co-culture of S. epidermidis with M. fragrans Houtt. seed extracts in either CE or EO forms were analyzed using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography tandem mass spectrometry (LC-MS/MS), in silico investigations, and applied to assess the survival and biofilm formation of S. aureus.ResultsThe combination of commensal bacteria with M. fragrans Houtt. seed extract either CE or EO produced metabolic compounds such as short-chain fatty acids and antimicrobial peptides, contributing to the antimicrobial activity. This antimicrobial activity was related to downregulating key genes involved in bacterial adherence and biofilm development in S. aureus, including cna, agr, and fnbA.ConclusionThese findings suggest that using the culture supernatant of the commensal bacteria in combination with CE or EO may provide a potential approach to combat biofilm formation and control the bacterial proliferation of S. aureus. This may be a putative non-invasive therapeutic strategy for maintaining a healthy skin microbiota and preventing skin infections.

Evaluating peripheral blood lymphocyte subset composition and lipopolysaccharide-induced cytokine secretory activity in mononuclear leukocyte cultures from patients with febrile and meningeal forms of tick-borne encephalitis

Introduction.Multiple studies on immune response in patients with various clinical forms of tick-borne encephalitis (TBE) have shown conflicting results. The study aim was to estimate the changes in peripheral blood lymphocyte subset counts and activity of spontaneous and lipopolysaccharide (LPS)-stimulated cytokine production in the mononuclear leukocyte cultures in patients with febrile and meningeal acute TBE.Materials and methods.Groups 1 and 2 included 16 and 12 patients with febrile and meningeal acute TBE, respectively. The control group included 13 healthy donors. Hemogram and T-lymphocyte, T-helper cell, T-cytotoxic and NK cell counts were analyzed by flow cytometry at week 1 of the disease as well as the spontaneous and LPS-stimulated secretion levels of TNFα, IL-1β, IL-6, IL-10, IL-8, and MCP-1 were assessed by ELISA in the supernatants of mononuclear cell cultures twice: during hospitalization and two weeks later. Statistical analysis was performed by the Mann–Whitney U-test, and Wilcoxon test.Results.Group 2 demonstrated significant decrease in spontaneous and/or LPS-stimulated levels of proinflammatory cytokines IL-1β, IL-6, MCP-1, and TNFα, but showed higher IL-8 level as compared with Group 1. In addition, spontaneous and/or LPS-induced levels of IL-6 and TNFαin Group 2 did not significantly differ from the controls, which presumably also indicated the suppression of their production. In contrast, spontaneous and/or LPS-induced levels of IL-1β, IL-6, MCP-1, and TNFαin Group 1 were higher than in the controls. The spontaneous IL-10 level in the patients from both groups were higher than in the controls. Peripheral blood lymphocyte and T-cytotoxic T-lymphocyte counts in both groups of TBE patients were lower than in the controls. There was significant increase in neutrophil counts, decrease in NK cell count in Group 2 as compared to the patients with a milder febrile form.Conclusion.Meningeal acute TBE patients was presumably associated with inadequate immune response with NK cell deficiency, T-cell dysfunction, increased neutrophil count in the peripheral blood and impaired pro-inflammatory cytokine production related to innate immune response.

Th17 and T Regulatory Cytokines in Serum, Lesional Skin, and Stimulated Peripheral Blood Mononuclear Cell Culture Supernatants from Type 1 Leprosy Reaction Patients

There are conflicting reports regarding the roles of T helper-17 (Th17) and T regulatory (Treg) cells in type 1 leprosy reactions (T1Rs). Also, literature on the correlation of immunological parameters with a validated scoring system and the effect of treatment on cytokines is lacking. Adult patients with untreated T1R and nonreactional spectrum–matched controls were included in the study for comparison of levels of Th17 and Treg pathway cytokines in serum, skin lesions (reactional), and peripheral blood mononuclear cells (PBMCs) culture supernatants. Venous blood samples were collected at baseline and after resolution of reaction (post treatment with nonsteroidal anti-inflammatory drugs [NSAIDs] or steroids) for serum cytokine estimation and PBMC stimulation assays, and lesional (reactional) skin biopsy for cytokine messenger RNA (mRNA) estimation. Thirty-two cases of T1R were recruited (23 patients completed follow-up). Serum levels of cytokines were not significantly different between cases and controls or between pre- and post-treatment samples. Tissue mRNA and Mycobacterium leprae (M. leprae) antigen–stimulated PBMC culture supernatant levels of Interleukin (IL)-17A, IL-17F, IL-6, and IL-23 were significantly higher in T1R than in controls. Levels of IL-10 and Transforming Growth Factor-beta (TGF-β) were comparable among the two groups. The levels of all cytokines were significantly reduced after treatment. There was no significant difference in magnitude of the fall between those treated with steroids versus NSAIDs. This study suggests heightened Th17 response in T1R, with a prominent inability of the regulatory cytokines IL-10 and TGF-β to control the associated inflammation. The dynamics of change after resolution of T1R were comparable between NSAID and oral steroid treatment groups.

Targeted isolation of extracellular vesicles from cell culture supernatant using immuno-affinity chromatography

Extracellular vesicles (EVs) have emerged as promising therapeutics with broad clinical applications as diagnostic biomarkers and therapeutic drug delivery systems. Yet, these biopharmaceuticals pose a challenge in terms of manufacturing due to their complexity and heterogeneity. Despite advancements in the field, current purification technologies lack scalability and/or selectivity. Affinity chromatography (AC) − coupling unmatched specificity and scalability − could be used to simplify purification processing and generate clinical-grade EVs with higher titers and purity.In the present work, we report the implementation of an immuno-AC resin to capture and purify EVs directly from clarified cellular feedstocks. Firstly, to guide and support marker selection, vesicle phenotype characterization was conducted using single particle interferometric reflectance image sensing (SP-IRIS) coupled with immunofluorescence. CD81 was the marker which shown to be more present and more likely to have the other markers (CD63 and CD9). Thus, anti-CD81 VHH ligand was generated and evaluated towards recombinant CD81 protein and CD81 bearing EV particles using surface plasmon resonance (SPR). Different chromatographic studies with Anti-CD81 ligand immobilized onto agarose beads resin were conducted to optimize the process parameters (residence time, dynamic binding capacity and impurity clearance). At residence time of 2 min, on average 40 % of pure triple tetraspanin-positive EV fraction was recovered. The enrichment in EV particles herein obtained, based on scale-up calculations, it would be possible to produce 1 × 1013 EVs from a 1L cell culture, while meeting impurity requirements in a single-step purification process (impurity removal over 2 log reduction value). A single-step purification process is possible, enabling the successful isolation of homogeneous EVs population, counting with a final HCP titer of 60 ng/mL and 9 ng/mL of dsDNA impurities. EV’s morphological integrity and internalization ability were also demonstrated, showcasing elution’s efficiency under mild conditions.Overall, this work contributes to the development of a novel, highly specific, AC technology using a camelid-derived affinity ligand which, bridging the scalability requirements demanded of large-scale production, could potentiate the advent of EV-based therapies.