Chitooligosaccharides alleviate hepatic fibrosis by regulating the polarization of M1 and M2 macrophages

High-performance lung-targeted bio-responsive platform for severe colistin-resistant bacterial pneumonia therapy

Polymyxins are the last line of defense against multidrug-resistant (MDR) Gram-negative bacterial infections. However, this last resort has been threatened by the emergence of superbugs carrying the mobile colistin resistance gene-1 (mcr-1). Given the high concentration of matrix metalloproteinase 3 (MMP-3) in bacterial pneumonia, limited plasma accumulation of colistin (CST) in the lung, and potential toxicity of ionic silver (Ag+), we designed a feasible clinical transformation platform, an MMP-3 high-performance lung-targeted bio-responsive delivery system, which we named "CST&Ag@CNMS". This system exhibited excellent lung-targeting ability (>80% in lungs), MMP-3 bio-responsive release property (95% release on demand), and synergistic bactericidal activity in vitro (2-4-fold minimum inhibitory concentration reduction). In the mcr-1+ CST-resistant murine pneumonia model, treatment with CST&Ag@CNMS improved survival rates (70% vs. 20%), reduced bacteria burden (2-3 log colony-forming unit [CFU]/g tissue), and considerably mitigated inflammatory response. In this study, CST&Ag@CNMS performed better than the combination of free CST and AgNO3. We also demonstrated the superior biosafety and biodegradability of CST&Ag@CNMS both in vitro and in vivo. These findings indicate the clinical translational potential of CST&Ag@CNMS for the treatment of lung infections caused by CST-resistant bacteria carrying mcr-1.

Alleviation of taurine on liver injury of type 2 diabetic rats by improving antioxidant and anti-inflammatory capacity

Type 2 diabetes mellitus (T2DM) is a serious metabolic disease characterized by insulin resistance and reduced insulin production, which causes abnormally elevated blood glucose. It has been reported that T2DM can enhance oxidative stress and inflammatory responses, and stimulate a variety of complications including liver injury. Studies have shown that taurine has antioxidant and anti-inflammatory effects that can not only ameliorate diabetes but also alleviate liver injury caused by various diseases. However, its effect on liver injury in T2DM is not clear. In our study, a high-fat diet and intraperitoneal injection of streptozotocin (STZ) was used to induce liver injury in T2DM rats, and taurine was given as a treatment. Through the use of HE staining on paraffin sections, ELISA, and qRT-PCR, the effects of taurine on liver pathological alterations, antioxidant capacity, and inflammatory response were investigated. We found that: hepatic transaminase levels of rats were reduced significantly following taurine administration; histopathological observations revealed that the morphology of rat hepatocytes was close to normal, and the number of inflammatory cells around liver vessels was significantly reduced; antioxidant-related indicators were significantly increased, including SOD, CAT, GSH-Px and T-AOC, while related factors of the Nrf2 signalling pathway and its downstream HO-1, NQO1 and γ-GCS were significantly increased; the expression of the JAK2-STAT1 signalling pathway, TLR4/NF-κB signalling pathway and NLRP3 inflammatory vesicle-related factors were significantly reduced. Our results suggest taurine can alleviate T2DM-induced liver injury by improving the antioxidant capacity of the liver and inhibiting macrophage M1-type polarization and the inflammatory response mediated thereby.

Jiawei Taohe Chengqi decoction inhibition of the notch signal pathway affects macrophage reprogramming to inhibit HSCs activation for the treatment of hepatic fibrosis

ETHNOPHARMACOLOGICAL RELEVANCE

Jiawei Taohe Chengqi Tang (JTCD) is a modified formulation of Traditional Chinese Medicine (TCM) known as Taohe Chengqi Decoction, which has been described in the ancient TCM literature "Treatise on Febrile Diseases". As a formula that can activate blood circulation and eliminate blood stasis and regulate Yin and Yang in traditional Chinese medicine applications, JTCD has been reported to be effective in the treatment of chronic liver disease and hepatic fibrosis (HF).

AIM OF STUDY

The current study aimed to evaluate the effectiveness of JTCD in modulating hepatic macrophages by regulating the Notch signal pathway, and to further investigate the mechanisms underlying macrophage reprogramming that leads to HF.

MATERIALS AND METHODS

Molecular assays were performed using in vitro cultures of human mononuclear THP-1 cells and human-derived hepatic stellate cells LX-2. CCl4-induced mice were utilized as an in vivo model to simulate HF.

RESULTS

Our results demonstrated that JTCD exhibited dual effects by inhibiting hepatic stellate cell (HSCs) activation and modulating the polarisation of macrophages towards the M2 phenotype while decreasing the M1 phenotype. Network pharmacological analyses and molecular docking studies revealed that the Notch signal pathway was significantly enriched and played a crucial role in the therapeutic response of JTCD against HF. Moreover, through the establishment of a co-culture model, we validated that JTCD inhibited the Notch signal pathway in macrophages, leading to alterations in macrophage reprogramming, subsequent inhibition of HSC activation, and ultimately exerting anti-HF effects.

CONCLUSION

In conclusion, our findings provide solid evidence for JTCD in treating HF, as it suppresses the Notch signal pathway in macrophages, regulates macrophage reprogramming, and inhibits HSC activation.

Qijia rougan formula ameliorates ECM deposition in hepatic fibrosis by regulating the JAK1/STAT6-microRNA-23a feedback loop in macrophage M2 polarization

Hepatic fibrosis is the critical pathological stage in the progression of chronic liver disease to cirrhosis and hepatocellular carcinoma (HCC). However, no approved anti-hepatic fibrosis drugs are available currently. Qijia Rougan Formula (QRF) is a traditional Chinese medicine (TCM) with significant clinical efficacy on hepatic fibrosis. It was derived from Sanjiasan, a famous decoction documented in the Book of Treatise on the Pestilence in the Ming Dynasty of China. However, the underlying regulatory mechanisms remain elusive. This study further confirmed the therapeutic effects of QRF on hepatic fibrosis and dissected its underlying molecular mechanisms from the perspective of macrophage M2 polarization, one of the critical events in hepatic fibrosis. Experimentally, QRF significantly improved extracellular matrix (ECM) deposition and fibrosis in the liver of model rats. QRF diminished the proportion of M2 macrophages, decreased the levels of TGF-β, PDGFB and IL-10, and regulated the expression of p-JAK1, p-STAT6, JAK1 and microRNA-23a both in vitro and in vivo. Collectively, it was confirmed that QRF effectively improves liver function and hepatocyte damage, and reduces ECM deposition. QRF ameliorates hepatic fibrosis by regulating JAK1/STAT6-microRNA-23a negative feedback loop to inhibit macrophage M2 polarization and thus reduce ECM deposition. Our study illustrates the potential of QRF for hepatic fibrosis therapy, suggesting that QRF is a promising anti-hepatic fibrosis drug candidate.

Marine biomaterials in biomedical nano/micro-systems

Marine resources in unique marine environments provide abundant, cost-effective natural biomaterials with distinct structures, compositions, and biological activities compared to terrestrial species. These marine-derived raw materials, including polysaccharides, natural protein components, fatty acids, and marine minerals, etc., have shown great potential in preparing, stabilizing, or modifying multifunctional nano-/micro-systems and are widely applied in drug delivery, theragnostic, tissue engineering, etc. This review provides a comprehensive summary of the most current marine biomaterial-based nano-/micro-systems developed over the past three years, primarily focusing on therapeutic delivery studies and highlighting their potential to cure a variety of diseases. Specifically, we first provided a detailed introduction to the physicochemical characteristics and biological activities of natural marine biocomponents in their raw state. Furthermore, the assembly processes, potential functionalities of each building block, and a thorough evaluation of the pharmacokinetics and pharmacodynamics of advanced marine biomaterial-based systems and their effects on molecular pathophysiological processes were fully elucidated. Finally, a list of unresolved issues and pivotal challenges of marine-derived biomaterials applications, such as standardized distinction of raw materials, long-term biosafety in vivo, the feasibility of scale-up, etc., was presented. This review is expected to serve as a roadmap for fundamental research and facilitate the rational design of marine biomaterials for diverse emerging applications.

Aggravated hepatic fibrosis induced by phenylalanine and tyrosine was ameliorated by chitooligosaccharides supplementation

Hepatic fibrosis is a classic pathological manifestation of metabolic chronic hepatopathy. The pathological process might either gradually deteriorate into cirrhosis and ultimately liver cancer with inappropriate nutrition supply, or be slowed down by several multifunctional nutrients, alternatively. Herein, we found diet with excessive phenylalanine (Phe) and tyrosine (Tyr) exacerbated hepatic fibrosis symptoms of liver dysfunction and gut microflora dysbiosis in mice. Chitooligosaccharides (COS) could ameliorate hepatic fibrosis with the regulation of amino acid metabolism by downregulating the mTORC1 pathway, especially that of Phe and Tyr, and also with the alleviation of the dysbiosis of gut microbiota, simultaneously. Conclusively, this work presents new insight into the role of Phe and Tyr in the pathologic process of hepatic fibrosis, while revealing the effectiveness and molecular mechanism of COS in improving hepatic fibrosis from the perspective of metabolites.

Chemical synthesis of oligosaccharides and their application in new drug research

Oligosaccharides are the ubiquitous molecules of life. In order to translate human bioglycosylation into clinical applications, homogeneous samples of oligosaccharides and glycoconjugates can be obtained by chemical, enzymatic or other biological methods for systematic studies. However, the structural complexity and diversity of glycans and their conjugates present a major challenge for the synthesis of such molecules. This review summarizes the chemical synthesis methods of oligosaccharides, the application of oligosaccharides in the field of medicinal chemistry according to their related biological activities, and shows the great prospect of oligosaccharides in the field of pharmaceutical chemistry.

Protective effects of blocking PD-1 pathway on retinal ganglion cells in a mouse model of chronic ocular hypertension

Purpose

In this study, we aimed to investigate whether Programmed cell death 1 ligand 1/programmed cell death 1 ligand 2 (PD-L1/PD-L2) double knockout (dKO) has a protective effect on RGCs in a mouse model of chronic ocular hypertension (COHT).

Methods

We used superparamagnetic iron oxide to induce COHT in mice. Apoptosis of retinal ganglion cells (RGCs) and activation of microglia were evaluated using western blotting (WB) and immunofluorescence staining of the mouse retina. In addition, we also conducted transcriptome sequencing and further gene expression analyses using the gene ontology (GO) and Kyoto Encyclopedia of Genes (KEGG) database.

Results

In the mouse model of COHT, PD-L1/PD-L2 prevented the apoptosis of RGCs to some extent. Blocking the programmed cell death 1 (PD-1) pathway also increased the number of anti-inflammatory M2-activated microglia and enhanced the phosphorylation of its related pathway signal transducer and activator of transcription (STAT)6. Sequencing results showed that this protective effect may have been achieved by regulating the NF-B, tumour necrosis factor (TNF), PI3K/Akt and toll-like receptor signaling pathway etc.

Conclusion

Blocking the PD-1 pathway has a protective effect on RGCs in the mouse model of COHT induced by superparamagnetic iron oxide.

Ongoing involvers and promising therapeutic targets of hepatic fibrosis: The hepatic immune microenvironment

Hepatic fibrosis is often secondary to chronic inflammatory liver injury. During the development of hepatic fibrosis, the damaged hepatocytes and activated hepatic stellate cells (HSCs) caused by the pathogenic injury could secrete a variety of cytokines and chemokines, which will chemotactic innate and adaptive immune cells of liver tissue and peripheral circulation infiltrating into the injury site, mediating the immune response against injury and promoting tissue reparation. However, the continuous release of persistent injurious stimulus-induced inflammatory cytokines will promote HSCs-mediated fibrous tissue hyperproliferation and excessive repair, which will cause hepatic fibrosis development and progression to cirrhosis even liver cancer. And the activated HSCs can secrete various cytokines and chemokines, which directly interact with immune cells and actively participate in liver disease progression. Therefore, analyzing the changes in local immune homeostasis caused by immune response under different pathological states will greatly enrich our understanding of liver diseases' reversal, chronicity, progression, and even deterioration of liver cancer. In this review, we summarized the critical components of the hepatic immune microenvironment (HIME), different sub-type immune cells, and their released cytokines, according to their effect on the development of progression of hepatic fibrosis. And we also reviewed and analyzed the specific changes and the related mechanisms of the immune microenvironment in different chronic liver diseases.Moreover, we retrospectively analyzed whether the progression of hepatic fibrosis could be alleviated by modulating the HIME.We aimed to elucidate the pathogenesis of hepatic fibrosis and provide the possibility for exploring the therapeutic targets for hepatic fibrosis.

Biodegradation and Prospect of Polysaccharide from Crustaceans

Marine crustacean waste has not been fully utilized and is a rich source of chitin. Enzymatic degradation has attracted the wide attention of researchers due to its unique biocatalytic ability to protect the environment. Chitosan (CTS) and its derivative chitosan oligosaccharides (COSs) with various biological activities can be obtained by the enzymatic degradation of chitin. Many studies have shown that chitosan and its derivatives, chitosan oligosaccharides (COSs), have beneficial properties, including lipid-lowering, anti-inflammatory and antitumor activities, and have important application value in the medical treatment field, the food industry and agriculture. In this review, we describe the classification, biochemical characteristics and catalytic mechanisms of the major degrading enzymes: chitinases, chitin deacetylases (CDAs) and chitosanases. We also introduced the technology for enzymatic design and modification and proposed the current problems and development trends of enzymatic degradation of chitin polysaccharides. The discussion on the characteristics and catalytic mechanism of chitosan-degrading enzymes will help to develop new types of hydrolases by various biotechnology methods and promote their application in chitosan.