Tumor-resident Lactobacillus iners confer chemoradiation resistance through lactate-induced metabolic rewiring

<div>AbstractPurpose:<p>Overweight/obese (OW/OB) patients with metastatic melanoma unexpectedly have improved outcomes with immune checkpoint inhibitors (ICI) and BRAF-targeted therapies. The mechanism(s) underlying this association remain unclear, thus we assessed the integrated molecular, metabolic, and immune profile of tumors, as well as gut microbiome features, for associations with patient body mass index (BMI).</p>Experimental Design:<p>Associations between BMI [normal (NL < 25) or OW/OB (BMI ≥ 25)] and tumor or microbiome characteristics were examined in specimens from 782 patients with metastatic melanoma across 7 cohorts. DNA associations were evaluated in The Cancer Genome Atlas cohort. RNA sequencing from 4 cohorts (<i>n</i> = 357) was batch corrected and gene set enrichment analysis (GSEA) by BMI category was performed. Metabolic profiling was conducted in a subset of patients (<i>x</i> = 36) by LC/MS, and in flow-sorted melanoma tumor cells (<i>x</i> = 37) and patient-derived melanoma cell lines (<i>x</i> = 17) using the Seahorse XF assay. Gut microbiome features were examined in an independent cohort (<i>n</i> = 371).</p>Results:<p>DNA mutations and copy number variations were not associated with BMI. GSEA demonstrated that tumors from OW/OB patients were metabolically quiescent, with downregulation of oxidative phosphorylation and multiple other metabolic pathways. Direct metabolite analysis and functional metabolic profiling confirmed decreased central carbon metabolism in OW/OB metastatic melanoma tumors and patient-derived cell lines. The overall structure, diversity, and taxonomy of the fecal microbiome did not differ by BMI.</p>Conclusions:<p>These findings suggest that the host metabolic phenotype influences melanoma metabolism and provide insight into the improved outcomes observed in OW/OB patients with metastatic melanoma treated with ICIs and targeted therapies.</p><p><i><a href="https://aacrjournals.org/clincancerres/article/doi/10.1158/1078-0432.CCR-22-3028" target="_blank">See related commentary by Smalley, p. 5</a></i></p></div>

Overweight/obese (OW/OB) patients with metastatic melanoma unexpectedly have improved outcomes with immune checkpoint inhibitors (ICI) and BRAF-targeted therapies. The mechanism(s) underlying this association remain unclear, thus we assessed the integrated molecular, metabolic, and immune profile of tumors, as well as gut microbiome features, for associations with patient body mass index (BMI). Associations between BMI [normal (NL < 25) or OW/OB (BMI ≥ 25)] and tumor or microbiome characteristics were examined in specimens from 782 patients with metastatic melanoma across 7 cohorts. DNA associations were evaluated in The Cancer Genome Atlas cohort. RNA sequencing from 4 cohorts (n = 357) was batch corrected and gene set enrichment analysis (GSEA) by BMI category was performed. Metabolic profiling was conducted in a subset of patients (x = 36) by LC/MS, and in flow-sorted melanoma tumor cells (x = 37) and patient-derived melanoma cell lines (x = 17) using the Seahorse XF assay. Gut microbiome features were examined in an independent cohort (n = 371). DNA mutations and copy number variations were not associated with BMI. GSEA demonstrated that tumors from OW/OB patients were metabolically quiescent, with downregulation of oxidative phosphorylation and multiple other metabolic pathways. Direct metabolite analysis and functional metabolic profiling confirmed decreased central carbon metabolism in OW/OB metastatic melanoma tumors and patient-derived cell lines. The overall structure, diversity, and taxonomy of the fecal microbiome did not differ by BMI. These findings suggest that the host metabolic phenotype influences melanoma metabolism and provide insight into the improved outcomes observed in OW/OB patients with metastatic melanoma treated with ICIs and targeted therapies. See related commentary by Smalley, p. 5.

&lt;div&gt;AbstractPurpose:&lt;p&gt;Overweight/obese (OW/OB) patients with metastatic melanoma unexpectedly have improved outcomes with immune checkpoint inhibitors (ICI) and BRAF-targeted therapies. The mechanism(s) underlying this association remain unclear, thus we assessed the integrated molecular, metabolic, and immune profile of tumors, as well as gut microbiome features, for associations with patient body mass index (BMI).&lt;/p&gt;Experimental Design:&lt;p&gt;Associations between BMI [normal (NL &lt; 25) or OW/OB (BMI ≥ 25)] and tumor or microbiome characteristics were examined in specimens from 782 patients with metastatic melanoma across 7 cohorts. DNA associations were evaluated in The Cancer Genome Atlas cohort. RNA sequencing from 4 cohorts (&lt;i&gt;n&lt;/i&gt; = 357) was batch corrected and gene set enrichment analysis (GSEA) by BMI category was performed. Metabolic profiling was conducted in a subset of patients (&lt;i&gt;x&lt;/i&gt; = 36) by LC/MS, and in flow-sorted melanoma tumor cells (&lt;i&gt;x&lt;/i&gt; = 37) and patient-derived melanoma cell lines (&lt;i&gt;x&lt;/i&gt; = 17) using the Seahorse XF assay. Gut microbiome features were examined in an independent cohort (&lt;i&gt;n&lt;/i&gt; = 371).&lt;/p&gt;Results:&lt;p&gt;DNA mutations and copy number variations were not associated with BMI. GSEA demonstrated that tumors from OW/OB patients were metabolically quiescent, with downregulation of oxidative phosphorylation and multiple other metabolic pathways. Direct metabolite analysis and functional metabolic profiling confirmed decreased central carbon metabolism in OW/OB metastatic melanoma tumors and patient-derived cell lines. The overall structure, diversity, and taxonomy of the fecal microbiome did not differ by BMI.&lt;/p&gt;Conclusions:&lt;p&gt;These findings suggest that the host metabolic phenotype influences melanoma metabolism and provide insight into the improved outcomes observed in OW/OB patients with metastatic melanoma treated with ICIs and targeted therapies.&lt;/p&gt;&lt;p&gt;&lt;i&gt;&lt;a href="https://aacrjournals.org/clincancerres/article/doi/10.1158/1078-0432.CCR-22-3028" target="_blank"&gt;See related commentary by Smalley, p. 5&lt;/a&gt;&lt;/i&gt;&lt;/p&gt;&lt;/div&gt;

It is reported that long intergenic non-coding RNA 00662 (LINC00662) plays an oncogenic role in tumours. However, the mechanism of LINC00662 in regulating the progression and radiosensitivity of cervical cancer (CC) is not clear. In this study, quantitative real-time polymerase chain reaction (qRT-PCR) was adopted to detect LINC00662 and miR-497-5p expressions in CC tissues and cells. The expression of cell division cycle 25 A (CDC25A) in CC cells was examined by Western blot. CC cell proliferation was determined by cell counting kit-8 (CCK-8) and BrdU assays. The survival rate of CC cells was evaluated by colony formation assay under different doses of X-ray irradiation. CC cell migration and invasion were probed by Transwell assay. Besides, the interactions between miR-497-5p and LINC00662, and miR-497-5p and the 3'UTR of CDC25A were verified by dual-luciferase reporter assay, RIP assay, and RNA pull-down experiments. We demonstrated that, LINC00662 expression was remarkably raised in CC tissues and cell lines. LINC00662 overexpression promoted proliferation, migration, invasion and radioresistance of CC cells, and LINC00662 knockdown inhibited the above malignant phenotypes of CC cells. In terms of mechanism, LINC00662 facilitated CC progression and radioresistance by adsorbing miR-497-5p and indirectly up-regulating CDC25A expression. In a word, the LINC00662/miR-497-5p/CDC25A axis boosts proliferation and metastasis of CC cells and enhances the radioresistance of cancer cells. SIGNIFICANCE OF THE STUDY: CC poses a threat to the health of women all over the world. In this study, we demonstrated for the first time that LINC00662 expression was remarkably raised in CC tissues and cells. Cellular experiments confirmed that LINC00662 facilitated cell proliferation, migration, invasion and radiation resistance through the miR-497-5p/CDC25A axis, which might be a promising target for CC treatments.

من المتوقع أن يتجاوز عبء السرطان العالمي المتوقع 20 مليون حالة سرطان جديدة بحلول عام 2025. على الرغم من التقدم الأخير في علاج الأورام ، لا يزال علاج السرطان الناجح يمثل تحديًا. يوفر مجال تكنولوجيا النانو الناشئ فرصًا رائعة لتشخيص السرطان ، والتصوير ، وعلاج السرطان. يعتبر التخليق الحيوي لجسيمات الفضة النانوية عن طريق الفطريات طريقة نظيفة وغير سامة بيئيًا مقارنة بالطرق الفيزيائية والكيميائية الأخرىالغرض من هذه الدراسة هو تحديد التأثير التآزري للجسيمات النانوية المركبة من Fusarium oxysporum مع Weisella cibaria ضد خلايا سرطان عنق الرحمأجريت هذه الدراسة من عام 2022 إلى مارس 2023 في معمل ميكروبيولوجيا الغذاء في قسم الأحياء / كلية العلوم / الجامعة المستنصرية. تم عزل بكتيريا حمض اللاكتيك (LAB) من مصادر الغذاء (الشلغم ، اللهانه ، الشوندر والقرنابيط) ، بعد خطوات متسلسلة من كلوريد الصوديوم المعالج ، ثم تم تربيتها في مرق MRS (Man-Rogosa-Sharpe) ، وتم فحصها تحت المجهر. تم الكشف عن النشاط المضاد للبكتيريا في المواد الطافية الخالية من الخلايا (CFS) التي تنتجها هذه العزلات لاختيار الأفضل وتشخيصها عن طريق تسلسل تفاعل البوليميراز المتسلسل والحمض النووي. تم الحصول على الجسيمات النانوية (AgNo3) التي تم إنتاجها من Fusarium oxysporum بالتخليق الحيوي من مختبر الدراسات العليا للفطريات ، وتم إخضاع هذه الفطريات لاختبار السمية. تمت دراسة تأثير التآزر للجسيمات النانوية المختارة من LAB و Fusarium oxysporum ضد خلايا سرطان عنق الرحم. أظهرت هذه الدراسة أن جميع مصادر الغذاء كانت غنية بـ LAB وأن أفضل نشاط مضاد للجراثيم كان مصدر اللفت ووفقًا للتشخيص الجزيئي كان Weisella cibaria والذي سجل في NCBI كـ (MG7865551). أظهر التأثير التآزري لـ Weisella cibaria والجسيمات النانوية انخفاض معدل بقاء خط السرطان بعد 72 ساعة من التعرض لهذا التأثير.

Lactic acid bacteria (LAB) are widely used in the food and health industries due to their Generally Recognized as Safe (GRAS) status and Qualified Presumption of Safety (QPS) designation. However, recent research has revealed that some Lactobacillus species harbor antimicrobial-resistance genes, which may contribute to the rise of antimicrobial resistance (AMR). Genome analysis of LAB, available through resources like the National Centre for Biotechnology Information (NCBI) database, which lists over 13,711 genomes within the Lactobacillaceae family, provides valuable insights into strain selection and gene identification. This genomic data is instrumental in identifying LAB strains that not only offer health benefits, such as immunomodulation, pathogen antagonism, vitamin production (especially B vitamins), and potential anticancer properties, but also carry genes linked to antimicrobial resistance, including penicillin-binding proteins (PBPs). Such insights enable the categorization and safety screening of LAB strains, allowing for safer applications in both the healthcare and food sectors, while also guiding future research on LAB’s role in combatting conditions like obesity and hyperammonemia. In this study, Lactobacillus crispatus strain B4 (CP059140.1), Lactobacillus iners (CP049223.1), and Lactobacillus johnsonii (CP062068.1) were used as representative strains that harbor erm(B) and tet genes. 23S rRNA (adenine(2058)-N(6))-methyltransferase Erm(B) protein and tetracycline-resistant protein of L.crispatus were also predicted, and Ramachandran plot revealed that the structure has 96.86% and 84.43% in the favored regions, respectively.

Objective To detect the expression of miRNA-95 in cervical cancer tissues and cell lines with different radiosensitivity and study the effect of its regulation on radiosensitivity of cervical cancer cells. Methods Real-time PCR was used to detect the expression of miRNA-95 in cervical cancer tissues of 20 patients with radiosensitivity, 20 patients with radiation tolerance, radioresistant cervical cancer cell lines (HeLa, SiHa), and radiosensitive cervical cancer cell lines (Me180). MiRNA-95 mimics (miRNA-95 mimics group)and miRNA-95 inhibition (miRNA-95 inhibition group)were transfected into radioresistant HeLa and SiHa cells by liposome 2000, miRNA-NC was set as control group. CCk-8 assay was used to detect the proliferation of cervical cancer cells irradiated with 60Co γ-rays at 0, 2, 4, 6, 8, 10 Gy. After 4 Gy irradiation, cell clonal formation ability was detected by plate monoclonal assay, and cell apoptosis was detected by flow cytometry. Dual luciferase activity assay was used to detect the target gene of miRNA-95 in cervical cancer cells. Nude mice were used to detect the changes of tumor formation ability. Results The expression of miRNA-95 in cervical cancer tissues of patients with radiotherapy tolerance was significantly higher than that of patients with radiotherapy sensitivity (t=12.279, P<0.05). The expressions of miRNA-95 in HeLa and SiHa cells were significantly higher those that of Me180 cells (t=5.162, 7.114, P<0.05). When the cells were treated with miRNA-95 inhibition, the expression of miRNA-95 in HeLa and SiHa cell lines was significantly lower than that of microRNA-NC group (t=5.162, 7.114, P< 0.05), the cell proliferation rate decreased significantly (t=8.273, 11.354, 13.489, 15.396 and 6.197, 9.185, 10.994, 12.442, P<0.05), the cell monoclonal formation rate decreased significantly (t=8.378, 7.931, P<0.05), and the apoptosis rate increased significantly (t=10.265, 8.386, P<0.05). The tumorigenic weight of nude mice in the miRNA95 inhibition group was significantly decreased (t=8.881, 10.037, P<0.05). Conclusions The miRNA-95 had low levels in both radiosensitive cervical cancer tissues and cells. Inhibiting the expression of microRNA-95 can significantly improve the radiosensitivity of cervical cancer cells by targeting SGPP1 gene. Key words: miRNA-95; Cervical cancer; Radiotherapy sensitivity; Cell proliferation; Apoptosis

Immunometabolism, which is the metabolic reprogramming of anaerobic glycolysis, oxidative phosphorylation, and metabolite synthesis upon immune cell activation, has gained importance as a regulator of the homeostasis, activation, proliferation, and differentiation of innate and adaptive immune cell subsets that function as key factors in immunity. Metabolic changes in epithelial and other stromal cells in response to different stimulatory signals are also crucial in infection, inflammation, cancer, autoimmune diseases, and metabolic disorders. The crosstalk between the PI3K–AKT–mTOR and LKB1–AMPK signaling pathways is critical for modulating both immune and nonimmune cell metabolism. The bidirectional interaction between immune cells and metabolism is a topic of intense study. Toll-like receptors (TLRs), cytokine receptors, and T and B cell receptors have been shown to activate multiple downstream metabolic pathways. However, how intracellular innate immune sensors/receptors intersect with metabolic pathways is less well understood. The goal of this review is to examine the link between immunometabolism and the functions of several intracellular innate immune sensors or receptors, such as nucleotide-binding and leucine-rich repeat-containing receptors (NLRs, or NOD-like receptors), absent in melanoma 2 (AIM2)-like receptors (ALRs), and the cyclic dinucleotide receptor stimulator of interferon genes (STING). We will focus on recent advances and describe the impact of these intracellular innate immune receptors on multiple metabolic pathways. Whenever appropriate, this review will provide a brief contextual connection to pathogenic infections, autoimmune diseases, cancers, metabolic disorders, and/or inflammatory bowel diseases.

Long-term exposure to UVB (280–320 nm) can cause oxidative skin damage, inflammatory injury, and skin cancer. Research on nicotinamide mononucleotide (NMN) and lactic acid bacteria (LAB) with regard to antioxidation, anti-inflammation, and prevention of other age-related diseases has received increasing attention. In the present study, the in vitro antioxidant analysis showed that NMN combined with Lactobacillus fermentum TKSN041 (L. fermentum TKSN041) has a high scavenging ability on hydroxyl (OH), 2, 2′-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) diammonium salt (ABTS) and 1, 1-diphenyl-2-picrylhydrazyl (DPPH), and it also possess a good total antioxidant capacity. The animal experimental results show that NMN combined with LAB maintained normal liver morphology of mice and reduced pathological damage to murine skin. NMN combined with LAB significantly increased the serum levels of total superoxide dismutase (T-SOD), catalase (CAT), and interleukin (IL)-10, but reduced the levels of malondialdehyde, advanced glycation end products, tumor necrosis factor (TNF)-α, and IL-6. NMN combined with LAB increased T-SOD, CAT, IL-10, Na+-K+-ATPase, and NAD+ levels in the skin, but reduced TNF-α level in the skin. NMN combined with LAB increased the mRNA expression levels of SOD1, CAT, glutathione (GSH), inhibitor of NF-κB (IκB-α), IL-10, AMP-activated protein kinase (AMPK), adaptor protein, phosphotyros ineinteraction, PH domain and leucine zipper containing 1 (APPL1), peroxisome proliferator-activated receptor γ co-activator-1α (PGC-1α), and forkhead transcription factor O (FOXO) in the skin and liver, but decreased the mRNA expression levels of nuclear factor (NF)-κBp65, TNF-α, IL-6, and rapamycin target protein (mTOR). NMN combined with LAB increased the protein expression levels of AMPK, IκB-α, SOD1, and CAT in the skin tissues and reduced protein expression of NF-κBp65. NMN combined with L. fermentum TKSN041 improved murine skin damage caused by UVB irradiation, and the protective mechanism may be related to activation of the AMPK signaling pathway. The results of this study are expected to provide a reference for preventing and the treating skin photoaging.

The acquisition of cancer stem-like properties is believed to be responsible for cancer metastasis and therapeutic resistance in cervical cancer (CC). CC tissues display a high expression level of hexokinase 2 (HK2), which is critical for the proliferation and migration of CC cells. However, little is known about the functional role of HK2 in the maintenance of cancer stem cell-like ability and cisplatin resistance of CC cells. Here, we showed that the expression of HK2 is significantly elevated in CC tissues, and high HK2 expression correlates with poor prognosis. HK2 overexpression (or knockdown) can promote (or inhibit) the sphere-forming ability and cisplatin resistance in CC cells. In addition, HK2-overexpressing CC cells show enhanced expression of cancer stem cell-associated genes (including SOX2 and OCT4) and drug resistance-related gene MDR1. The expression of HK2 is mediated by miR-145, miR-148a, and miR-497 in CC cells. Overexpression of miR-148a is sufficient to reduce sphere formation and cisplatin resistance in CC cells. Our results elucidate a novel mechanism through which miR-148a regulates CC stem cell-like properties and chemoresistance by interfering with the oncogene HK2, providing the first evidence that dysregulation of the miR-148a/HK2 signaling plays a critical role in the maintenance of sphere formation and cisplatin resistance of CC cells. Our findings may guide future studies on therapeutic strategies that reverse cisplatin resistance by targeting this pathway.

Nonmelanoma skin cancer (NMSC) is the most common skin cancer burden on the U.S. population. Environmental exposure to chemical carcinogens is one of the major causes of NMSC initiation, promotion, and progression. Ursolic acid (UA) is a naturally abundant pentacyclic triterpenoid showing anticancer potentials against diverse cancers. In the current study, we developed a two-stage skin carcinogenesis model in SKH1 hairless mice by administering cancer-initiating agent benzo[a]pyrene (B[a]P) and promoting agent 12-O-tetra-decanoylphorbol-13-acetate to study the epigenetic, transcriptomic, and metabolic changes at different stages (5, 20, and 26 weeks) during the development of NMSC, and investigated how UA regulates B[a]P-mediated alterations for NMSC interception. We found that UA protects against B[a]P-induced tumorigenesis at different phases of NMSC. Epigenetic CpG methyl-seq showed UA abrogated B[a]P-mediated alterations in differentially methylated regions (DMRs) profiles. Transcriptomic RNA-seq data exhibited UA reversed the differentially expressed genes (DEGs) of several inflammatory genes, such as chemokine ligand 8 (Ccl8) and interleukin 17F (Il17f), and epigenetic genes, such as DNA-methyltransferase 3-like (Dnmt3l) and protein-l-isoaspartate O-methyltransferase domain-containing protein 1 (Pcmtd1) during different stages of NMSC. Association study between DEGs and DMRs showed that B[a]P promoted transcription of kallikrein-related peptidase 13 (Klk13) by promoter demethylation, while UA suppressed Klk13 expression through hypermethylation in the promoter during the initiation stage, indicating the early intervention of UA. Ingenuity pathway analysis further showed significant upregulation of macrophage-stimulating protein-recepteur d'origine nantais (MSP-RON) signaling pathway by B[a]P during the initiation stage while suppressed by UA treatment. The metabolomic study revealed UA modulated cancer-associated changes in metabolisms, including the TCA cycle and pyruvate metabolism/metabolites during the promotion phase, indicating UA plays a critical role in regulating B[a]P-regulated metabolic changes and intercepting NMSC progression. In summary, UA protects against the environmental carcinogen B[a]P-driven epigenetic, transcriptomic, and metabolic changes during the initiation, promotion, and progression of NMSC, potentially contributing to the anticancer effects of UA. (Supported by NIH R01 CA200129 to A.N.K) Citation Format: Md. Shahid Sarwar, Christina N. Ramirez, Hsiao-Chen Dina Kuo, Pochung Chou, Renyi Wu, Davit Sargsyan, Ahmad Shannar, Rebecca Mary Peter, Ran Yin, Yujue Wang, Xiaoyang Su, Ah-Ng Kong. Metabolic rewiring and epigenetic reprogramming by the environmental carcinogen benzo[a]pyrene in a two-stage skin carcinogenesis mouse model and cancer interception by triterpenoid ursolic acid. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5266.

Metabolic reprogramming in cancer cells not only sustains proliferative signaling but also modulates the anti-tumor immune response via secretion of immunomodulatory metabolites. Polyamines are small, positively charged metabolites synthesized from the urea cycle intermediate ornithine. While inhibition of polyamine synthesis has emerged as a target in cancer therapy, whether rewiring of polyamine metabolism in tumor cells impacts the tumor immune microenvironment remains unclear. Here, we find that polyamine acetylation is elevated in human and murine glioblastoma (GBM) tumors and demonstrate that tumor cell-derived N1-acetylspermidine can be taken up by myeloid cells to promote intracellular polyamine flux, cellular respiration and migration. Using a genetic model of GBM, deletion of the polyamine acetylation enzyme SAT1 (spermidine/spermine-N1-acetyltranferase1) reduced the metabolic activity of tumor cells, impeded myeloid infiltration and sensitized tumors to chemoradiation. Collectively, our findings highlight a previously unidentified role for spermidine acetylation, secretion and uptake in bridging the metabolic activity of tumor cells and myeloid cells, together, promoting mesenchymal/plurimetabolic states and therapeutic resistance in GBM.

Legumes are an attractive choice for developing new products since their health benefits. Fermentation can effectively improve the quality of soymilk. This study evaluated the impact of Lactobacillus plantarum fermentation on the physicochemical parameters, vitamins, organic acids, aroma substances, and metabolites of chickpea milk. The lactic acid bacteria (LAB) fermentation improved the color, antioxidant properties, total phenolic content, total flavonoid content, lactic acid content, and vitamin B6 content of raw juice. In total, 77 aroma substances were identified in chickpea milk by headspace solid-phase microextraction with gas chromatography/mass spectrometry (HS-SPME-GC-MS); 43 of the 77 aroma substances increased after the LAB fermentation with a significant decrease in beany flavor content (p < 0.05), improving the flavor of the soymilk product. Also, a total of 218 metabolites were determined in chickpea milk using non-targeted metabolomics techniques, including 51 differentially metabolites (28 up-regulated and 23 down-regulated; p < 0.05). These metabolites participated in multiple metabolic pathways during the LAB fermentation, ultimately improving the functional and antioxidant properties of fermented soymilk. Overall, LAB fermentation can improve the flavor, nutritional, and functional value of chickpea milk accelerating its consumer acceptance and development as an animal milk alternative.

Rationale: Ischemic stroke poses a significant health burden with limited treatment options. Lymphocyte Cytosolic Protein 1 (LCP1) facilitates cell migration and immune responses by aiding in actin polymerization, cytoskeletal rearrangements, and phagocytosis. We have demonstrated that the long non-coding RNA (lncRNA) Maclpil silencing in monocyte-derived macrophages (MoDMs) led to LCP1 inhibition, reducing ischemic brain damage. However, the role of LCP1 of MoDMs in ischemic stroke remains unknown. Methods and Results: We investigated the impact of LCP1 on ischemic brain injury and immune cell signaling and metabolism. We found that knockdown of LCP1 in MoDMs demonstrated robust protection against ischemic infarction and improved neurological behaviors in mice. Utilizing the high-dimensional CyTOF technique, we demonstrated that knocking down LCP1 in MoDMs led to a reduction in neuroinflammation and attenuation of lymphopenia, which is linked to immunodepression. It also showed altered immune cell signaling by modulating the phosphorylation levels of key kinases and transcription factors, including p-PLCg2, p-ERK1/2, p-EGFR, p-AKT, and p4E-BP1 as well as transcription factors like p-STAT1, p-STAT3, and p-STAT4. Further bioinformatic analysis indicated that Akt and EGFR are particularly involved in fatty acid metabolism and glycolysis. Indeed, single-cell sequencing analysis confirmed that enrichment of fatty acid and glycolysis metabolism in Lcp1high monocytes/macrophages. Furthermore, Lcp1high cells exhibited enhanced oxidative phosphorylation, chemotaxis, migration, and ATP biosynthesis pathways. In vitro experiments confirmed the role of LCP1 in regulating mitochondrial function and fatty acid uptake. Conclusions: These findings contribute to a deeper understanding of LCP1 in the context of ischemic stroke and provide valuable insights into potential therapeutic strategies targeting LCP1 and metabolic pathways, aiming to attenuating neuroinflammation and lymphopenia.

SummarySeveral studies have recently pointed towards an increased occurrence and prevalence of several taxa of the lactic acid bacteria (LAB) in the microbiota of the upper respiratory tract (URT) under healthy conditions versus disease. These include several species of the Lactobacillales such as Lacticaseibacillus casei, Lactococcus lactis and Dolosigranulum pigrum. In addition to physiological studies on their potential beneficial functions and their long history of safe use as probiotics in other human body sites, LAB are thus increasingly to be explored as alternative or complementary treatment for URT diseases. This review highlights the importance of lactic acid bacteria in the respiratory tract and their potential as topical probiotics for this body site. We focus on the potential probiotic properties and adaptation factors that are needed for a bacterial strain to optimally exert its beneficial activity in the respiratory tract. Furthermore, we discuss a range of in silico, in vitro and in vivo models needed to obtain better insights into the efficacy and adaptation factors specifically for URT probiotics. Such knowledge will facilitate optimal strain selection in order to conduct rigorous clinical studies with the most suitable probiotic strains. Despite convincing evidence from microbiome association and in vitro studies, the clinical evidence for oral or topical probiotics for common URT diseases such as chronic rhinosinusitis (CRS) needs further substantiation.