Electrospun Poly-l-Lactic Acid Membranes Promote M2 Macrophage Polarization by Regulating the PCK2/AMPK/mTOR Signaling Pathway.

Electrospun membranes are widely used in tissue engineering. Regretfully, there is limited research on how its morphological characteristics precisely regulate macrophage activation and immune response. Therefore, electrospun poly-l-lactic acid (PLLA) membranes with different alignments (align and random) and diameters (nanoscale and microscale) are prepared to investigate the effects of different surface morphologies on M2 macrophage polarization. Additionally, transcriptome, proteome, and phosphoproteome sequencings are combined to examine the underlying regulatory mechanisms. The results show that the electrospun PLLA membranes with different surface morphologies have good biocompatibility and can regulate the phenotype and function of macrophages by changing the micromorphology of the matrix surface. Especially, macrophages cultured on the electrospun membranes of the A600 group exhibit higher M2 macrophage polarization than the other three groups. Furthermore, the findings demonstrate that electrospun PLLA membranes enhance AMP-activated protein kinase (AMPK)/ mammalian target of rapamycin (mTOR) signaling activation by upregulating the expression of integrin phosphoenolpyruvate carboxykinase 2 (PCK2), which is critical for M2 macrophage polarization. Taken together, electrospun PLLA membranes promote M2 macrophage polarization by regulating the PCK2/AMPK/mTOR signaling pathway. This research can provide further theoretical bases for scaffold design, immunoregulatory mechanisms, and clinical application based on electrospinning technology in the future.

Integrated multi-omics reveal gut microbiota-mediated bile acid metabolism alteration regulating immunotherapy responses to anti-α4ß7-integrin in Crohn's disease.

Gut microbiota and related metabolites are both crucial factors that significantly influence how individuals with Crohn's disease respond to immunotherapy. However, little is known about the interplay among gut microbiota, metabolites, Crohn's disease, and the response to anti-α4ß7-integrin in current studies. Our research utilized 2,4,6-trinitrobenzene sulfonic acid to induce colitis based on the humanized immune system mouse model and employed a combination of whole-genome shotgun metagenomics and non-targeted metabolomics to investigate immunotherapy responses. Additionally, clinical cases with Crohn's disease initiating anti-α4ß7-integrin therapy were evaluated comprehensively. Particularly, 16S-rDNA gene high-throughput sequencing and targeted bile acid metabolomics were conducted at weeks 0, 14, and 54. We found that anti-α4ß7-integrin therapy has shown significant potential for mitigating disease phenotypes in remission-achieving colitis mice. Microbial profiles demonstrated that not only microbial composition but also microbially encoded metabolic pathways could predict immunotherapy responses. Metabonomic signatures revealed that bile acid metabolism alteration, especially elevated secondary bile acids, was a determinant of immunotherapy responses. Especially, the remission mice significantly enriched the proportion of the beneficial Lactobacillus and Clostridium genera, which were correlated with increased gastrointestinal levels of BAs involving lithocholic acid and deoxycholic acid. Moreover, most of the omics features observed in colitis mice were replicated in clinical cases. Notably, anti-α4ß7 integrin provided sustained therapeutic benefits in clinical remitters during follow-up, and long-lasting remission was linked to persistent changes in the microbial-related bile acids. In conclusion, gut microbiota-mediated bile acid metabolism alteration could play a crucial role in regulating immunotherapy responses to anti-α4ß7-integrin in Crohn's disease. Therefore, the identification of prognostic microbial signals facilitates the advancement of targeted probiotics that activate anti-inflammatory bile acid metabolic pathways, thereby improving immunotherapy responses. The integrated multi-omics established in our research provide valuable insights into potential mechanisms that impact treatment responses in complex diseases.

Comparative efficacy and safety of combination therapy with infliximab for Crohn's disease: a systematic review and network meta-analysis.

PURPOSE: There is not enough information to position medications for the treatment of Crohn's disease (CD). Therefore, using a network meta-analysis and systematic review, we evaluated the efficacy and safety of combination therapy and infliximab (IFX) monotherapy in CD patients. METHODS: We identified randomized controlled trials (RCTs) in CD patients who were given IFX-containing combination therapy versus IFX monotherapy. Induction and maintenance of clinical remission were the efficacy outcomes, while adverse events were the safety outcomes. The surface under cumulative ranking (SUCRA) probabilities was used to assess ranking in the network meta-analysis. RESULTS: In total, 15 RCTs with 1586 CD patients were included in this study. There was no statistical difference between different combination therapies in induction and maintenance of remission. In terms of inducing clinical remission, IFX + EN (SUCRA: 0.91) ranked highest; in terms of maintaining clinical remission, IFX + AZA (SUCRA: 0.85) ranked highest. There was no treatment that was significantly safer than the others. In terms of any adverse events, serious adverse events, serious infections, and infusion/injection-site reactions, IFX + AZA (SUCRA: 0.36, 0.12, 0.19, and 0.24) was ranked lowest for all risks; while IFX + MTX (SUCRA: 0.34, 0.06, 0.13, 0.08, 0.34, and 0.08) was rated lowest for risk of abdominal pain, arthralgia, headache, nausea, pyrexia, and upper respiratory tract infection. CONCLUSION: Indirect comparisons suggested that efficacy and safety of different combination treatments are comparable in CD patients. For maintenance therapies, IFX + AZA was ranked highest for clinical remission and lowest for adverse events. Further head-to-head trials are required.

Novel Biocompatible Au Nanostars@PEG Nanoparticles for In Vivo CT Imaging and Renal Clearance Properties.

Nanoprobes are rapidly becoming potentially transformative tools on disease diagnostics for a wide range of in vivo computed tomography (CT) imaging. Compared with conventional molecular-scale contrast agents, nanoparticles (NPs) promise improved abilities for in vivo detection. In this study, novel polyethylene glycol (PEG)-functionalized Au nanoparticles with star shape (AuNS@PEG) with strong X-ray mass absorption coefficient were synthesized as CT imaging contrast agents. Experimental results revealed that AuNS@PEG nanoparticles are well constructed with ultrasmall sizes, effective metabolisability, high computed tomography value, and outstanding biocompatibility. In vivo imaging also showed that the obtained AuNS@PEG nanoparticles can be efficiently used in CT-enhanced imaging. Therefore, the synthesized contrast agent AuNS@PEG nanoparticles as a great potential candidate can be widely used for CT imaging.