The cell cycle inhibitor P21 promotes the development of pulmonary fibrosis by suppressing lung alveolar regeneration

The cell cycle inhibitor P21 has been implicated in cell senescence and plays an important role in the injury-repair process following lung injury. Pulmonary fibrosis (PF) is a fibrotic lung disorder characterized by cell senescence in lung alveolar epithelial cells. In this study, we report that P21 expression was increased in alveolar epithelial type 2 cells (AEC2s) in a time-dependent manner following multiple bleomycin-induced PF. Repeated injury of AEC2s resulted in telomere shortening and triggered P21-dependent cell senescence. AEC2s with elevated expression of P21 lost their self-renewal and differentiation abilities. In particular, elevated P21 not only induced cell cycle arrest in AEC2s but also bound to P300 and β-catenin and inhibited AEC2 differentiation by disturbing the P300-β-catenin interaction. Meanwhile, senescent AEC2s triggered myofibroblast activation by releasing profibrotic cytokines. Knockdown of P21 restored AEC2-mediated lung alveolar regeneration in mice with chronic PF. The results of our study reveal a mechanism of P21-mediated lung regeneration failure during PF development, which suggests a potential strategy for the treatment of fibrotic lung diseases.

TRIB3‒GSK-3

Pulmonary fibrosis (PF) is a chronic, progressive, fatal interstitial lung disease with limited available therapeutic strategies. We recently reported that the protein kinase glycogen synthase kinase-3

Improvement in affinity and thermostability of a fully human antibody against interleukin-17A by yeast-display technology and CDR grafting

Monoclonal antibodies (mAbs) are widely used in many fields due to their high specificity and ability to recognize a broad range of antigens. IL-17A can induce a rapid inflammatory response both alone and synergistically with other proinflammatory cytokines. Accumulating evidence suggests that therapeutic intervention of IL-17A signaling offers an attractive treatment option for autoimmune diseases and cancer. Here, we present a combinatorial approach for optimizing the affinity and thermostability of a novel anti-hIL-17A antibody. From a large naïve phage-displayed library, we isolated the anti-IL-17A mAb 7H9 that can neutralize the effects of recombinant human IL-17A. However, the modest neutralization potency and poor thermostability limit its therapeutic applications. affinity optimization was then used to generate 8D3 by using yeast-displayed random mutagenesis libraries. This resulted in four key amino acid changes and provided an approximately 15-fold potency increase in a cell-based neutralization assay. Complementarity-determining regions (CDRs) of 8D3 were further grafted onto the stable framework of the huFv 4D5 to improve thermostability. The resulting hybrid antibody 9NT/S has superior stabilization and affinities beyond its original antibody. Human fibrosarcoma cell-based assays and analyses in mice indicated that the anti-IL-17A antibody 9NT/S efficiently inhibited the secretion of IL-17A-induced proinflammatory cytokines. Therefore, this lead anti-IL-17A mAb might be used as a potential best-in-class candidate for treating IL-17A related diseases.

1,25-Dihydroxyvitamin D3 protects obese rats from metabolic syndrome promoting regulatory T cell-mediated resolution of inflammation

Vitamin D has been found to produce therapeutic effects on obesity-associated insulin resistance and dyslipidemia through its potent anti-inflammatory activity, but the precise immunomodulatory mechanism remains poorly understood. In the present study we found that 1,25-dihydroxyvitamin D [1,25(OH)D], the biologically active form of vitamin D, significantly attenuated monosodium glutamate (MSG)-induced obesity and insulin resistance as indicated by body weight reduction, oral glucose tolerance improvement, and a glucose infusion rate increase as detected with hyperinsulinemic-euglycemic clamp. Moreover, 1,25(OH)D not only restored pancreatic islet functions but also improved lipid metabolism in insulin-targeted tissues. The protective effects of 1,25(OH)D on glycolipid metabolism were attributed to its ability to inhibit an obesity-activated inflammatory response in insulin secretory and targeted tissues, as indicated by reduced infiltration of macrophages in pancreas islets and adipose tissue while enhancing the expression of in liver tissue, which was accompanied by increased infiltration of Treg cells in immune organs such as spleen and lymph node as well as in insulin-targeted tissues such as liver, adipose, and muscle. Together, our findings suggest that 1,25(OH)D serves as a beneficial immunomodulator for the prevention and treatment of obesity or metabolic syndrome through its anti-inflammatory effects.

Progress of autophagy screening systems / 药学学报

Autophagy is an active research area in the biomedical field as its role has been identified in many physiological and pathological processes. Accordingly, there is a growing demand to identify, quantify and manipulate the process accurately. Meanwhile, there is great interest in identifying compounds that modulate autophagy because they may have applications in the treatment of a variety of autophagy-related diseases. In this review, we summarize the current status of autophagy screening systems to facilitate identification of autophagy modulators.

New methods to detect autophagic flux / 药学学报

Autophagy is a crucial biological process of eukaryotes, which is involved in cell growth, survival and energy metabolism, while the premise of the autophagy function is activated autophagic flux. It has been confirmed that impaired autophagic flux promotes pathogenesis of many chronic inflammatory diseases, especially cancer, neurodegenerative disease and tissue fibrosis, therefore the analysis of autophagic flux state is important for revealing autophagy function and the mechanism of autophagy related diseases. Given that autophagy is a dynamic process with multiple steps, it is very hard to observe the real state of autophagic flux. Summarized here is the novel concept and current approach to detect autophagic flux. This knowledge is crucial for the researching of the biological function of autophagy, and may provide some strategies for developing autophagy-related drug.

Morphological analysis of autophagy / 药学学报

Autophagy is an important homeostatic cellular recycling mechanism responsible for degrading injured or dysfunctional subcellular organelles and proteins in all living cells. The process of autophagy can be divided into three relatively independent steps: the initiation of phagophore, the formation of autophagosome and the maturation/degradation stage. Different morphological characteristics and molecular marker changes can be observed at these stages. Morphological approaches are useful to produce novel knowledge that would not be achieved through other experimental methods. Here we summarize the morphological methods in monitoring autophagy, the principles in data interpretation and the cautions that should be considered in the study of autophagy.

Antagonism of toll-like receptor 2 attenuates the formation and progression of abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is an inflammatory vascular disorder with high mortality. Accumulating evidence shows that toll-like receptor 2 (TLR2) plays a critical role in the regulation of wound-repairing process after tissue injury. We wondered if TLR2 signaling contributed to the pathogenesis of AAA and that targeting TLR2 would attenuate AAA development and progression. In this study, enhanced expression of TLR2 and its ligands were observed in human AAA tissue. Neutralization of TLR2 protected against AAA development and caused established AAA to regress in mouse models of AAA. In addition, TLR2-deficient mice also failed to develop AAA. The prophylactic and therapeutic effects of blocking TLR2 were accompanied by a significant resolution of inflammation and vascular remodeling, as indicated by the decreased expression or activity of MMP-2/9, α-SMA, inflammatory cytokines, and transcription factors NF-κB, AP-1 and STAT1/3 in AAA tissue. Mechanistically, blocking TLR2 decreased the expression and interaction of TLR2 and several endogenous ligands, which diminished chronic inflammation and vascular remodeling in the vascular tissue of AAA. Our studies indicate that the interactions between TLR2 and its endogenous ligands contribute to the pathogenesis of AAA and that targeting TLR2 offers great potential toward the development of therapeutic agents against AAA.

Autophagy in ageing and ageing-related diseases / 药学学报

Autophagy is an important homeostatic cellular recycling mechanism responsible for degrading injured or dysfunctional cellular organelles and proteins in all living cells. Aging is a universal phenomenon characterized by progressive deterioration of cells and organs due to accumulation of macromolecular and organelle damage. Growing evidences indicate that the rate of autophagosome formation and maturation and the efficiency of autophagosome/lysosome fusion decline with age. Dysfunctional autophagy has also been observed in age-related diseases. Autophagy disruption resulted accumulation of mutated or misfolded proteins is the essential feature of neurodegenerative disorders. However, in cancers, fibroproliferative diseases or cardiovascular diseases, autophagy can play either a protective or destructive role in different types of disease, and even in different stages of the same disease. The review will discuss the cellular and molecular mechanisms of autophagy and its important role in the pathogenesis of aging and age-related diseases, and the ongoing drug discovery strategies for therapeutic intervention.

Mycelium of Hirsutella hepiali Chen et Shen activates autophagy and protects against metabolic syndrome in mice fed with high fat diet / 药学学报

To investigate the protective effects and possible mechanism of Mycelium of Hirsutella hepiali Chen et Shen (MHCS) on metabolic syndromes, free fatty acid and MHCS-treated hepatocytes were used for detecting autophagy-related LC3, p62 and lipid accumulation. Moreover, high fat diet fed mice were used to establish metabolic syndromes model. 50-weeks age mice were randomly divided into: control group, model group and MHCS group. At 80-weeks age, 15 mice were randomly chosen from each group separately for examining oral glucose tolerance, serum insulin, insulin-like growth factor 1 (IGF-1), hepatic LC3, p62, p-NF-kappaB p65, NF-kappaB p65, IL-6 and CXCL-8. Moreover, insulin resistance index (IRI) was calculated. Hepatic pathological changes, including vacuoles, lipids accumulation and fibrosis were observed. Remaining mice were fed with diet separately to 110 weeks-age for statistics of mortality. MHCS promoted autophagy of free fatty acid treated hepatocytes. Mice fed with high fat plus MHCS diet exhibited improved oral glucose tolerance, insulin resistance, hepatic pathology, inflammation, mortality and activated autophagy. The protective effects of MHCS against metabolic syndroms might be through the activation of hepatic autophagy.

Establishment and application of TLR2 receptor-based cell screening model / 药学学报

TLR2 activity plays an important role in the pathogenesis of autoimmune diseases, tumor carcinogenesis and cardio-cerebrovascular diseases. To establish a TLR2 receptor-based cell screening model, NF-kappaB promoter-driven luciferase reporter plasmids were transfected into human embryonic kidney cells (HEK293) stably expressing human TLR2 and co-receptors CD14, TLR1 and TLR6. Single clones were then isolated and characterized. Using this screening system, a human TLR2-binding peptide C8 was obtained from the Ph.D.-7 Phage Display Peptide Library through biopanning and rapid analysis of selective interactive ligands (BRASIL). The binding characteristic of C8 with human TLR2 was evaluated by ELISA, flow cytometry and immunofluorescence. The NF-kappaB luciferase activity assay showed that C8 could activate the TLR2/TLR1 signaling pathway and induce the production of cytokines TNF-alpha and IL-6. In conclusion, the TLR2 receptor-based cell screening system is successfully established and a new TLR2-binding peptide is identified by using this system.

DEDD decreases Smad3 activity, promotes tumor cell apoptosis and inhibits proliferation / 药学学报

DEDD is a member of the death-effector domain protein family. DEDD inhibits the Smad3 mediated transcriptional activity and participates in the regulation of apoptosis. In this study, how the death-effector domain of DEDD participates in the regulation of Smad3 activity and apoptosis has been further investigated. Immunoblotting, immunofluorescence and immunoprecipitation had been used to detect the effects of the full length DEDD and its two truncated mutants, N-DEDD and C-DEDD on Smad3 subcellular distribution, phosphorylation, and interaction between Smad4. The effects of the full length DEDD and its two truncated mutants on cell apoptosis and proliferation had also been explored by flow cytometry and MTT assay. It showed that DEDD and N-DEDD inhibit TGF-beta1 induced Smad3 nuclear translocation and the formation of Smad3-Samd4 complex. DEDD and its two mutants can induce cell apoptosis and inhibit cell proliferation. These results suggested that DEDD inhibits the activity of Smad3 through its death-effector domain. Both the two truncated mutants of DEDD participate in the regulation of apoptosis and cell proliferation.

Optimizing the host bacteria to make a large naive phage antibody library in the recombination system / 药学学报

To prepare large naive phage antibody library, the host bacteria with high transformation efficiency is used in the Cre-LoxP recombination system. The variable regions of immunoglobulin light and heavy genes were amplified from lymphocytes collected from adult peripheral blood and newborn cord blood. The genes were spliced to form the single-chain variable fragments (scFv) by overlap PCR, cloned into pDAN5a vector and then transformed into XL2-blue MRF' with the Hte gene. Compared with XL1-blue strain, the size of the primary library was increased by 3.9 times. The primary library infected Cre recombinase-expressing bacteria, and the genes between phagemids created many new VH/VL combinations. The library was calculated to have a diversity of 1.7 x 10(11) and validated by the selection of antibodies against six different protein antigens. This library provides the basis for further selection of antibody-based drugs. It is the first time to report that XL2-blue MRF' can be used to improve the diversity of the library in the recombination system.

Blocking extracellular HMGB1 activity protects against doxorubicin induced cardiac injury in mice / 药学学报

This study aims to investigate the preventive role and potential mechanisms of blocking extracellular HMGB1 function on doxorubicin induced cardiac injury. Mice were treated with HMGB1 blocker glycyrrhizin 1 h before and one time every day (intraperitoneal, 10 mg per mouse) after doxorubicin injection, and sacrificed on the day 14 after doxorubicin challenge. Cardiac function was evaluated by echocardiography and hemodynamic measurement. Myocardial inflammation and collagen deposition were analyzed by immunohistochemistry and picrosirius red staining. The interaction of HMGB1 and TLR2 was assessed by co-immunoprecipitation and confocal microscopy. The protein contents of HMGB1, MyD88, p65NF-kappaB and phospho-p65NF-kappaB were measured by Immunoblot. Compared with mice treated with saline, doxorubicin treatment led to an upregulation in HMGB1 expression. Blocking HMGB1 activity with glycyrrhizin protected mice against cardiac dysfunction, inflammatory response, and cardiac fibrosis induced by doxorubicin challenge. Glycyrrhizin inhibited the interaction of HMGB1 and TLR2, and blocked the downstream signaling of TLR2. In conclusion, blocking HMGB1 protected against doxorubicin induced cardiac injury by inhibiting TLR2 signaling pathway.

Therapeutic antibody: new opportunity for immunity and inflammatory diseases / 药学学报

With the development of therapeutic antibodies over the past decade, they have become the treatment options for immunity and inflammation diseases. Major limitations of mouse antibodies as therapeutic agents - immunogenicity, lack of effectors' functions and short serum half-life -- were subsequently identified and largely overcome by the advent of humanized and fully human antibody technologies. The therapeutic antibodies for immunity and inflammatory diseases are primarily utilized in the treatment of allograft rejection, autoimmune disease, autoinflammatory syndromes, allergies and other chronic inflammation. The action mechanisms of therapeutic antibody include blocking ligands or receptors, regulating receptor activity, clearing the target cells or activating receptor. Strategies for generating the antibody drugs with high efficacy and low side effects can be realized by modulation of Fc-mediated activities and optimization of antigen-binding domains.

Blocking IL-17A protects against lung injury-induced pulmonary fibrosis through promoting the activation of p50NF-kappaB / 药学学报

This study is to determine the preventive effect and mechanism of targeting IL-17A on pulmonary inflammation and fibrosis after acute lung injury. Mice were treated with anti-IL-17A antibody on the day 7 and sacrificed on the day 14 after bleomycin lung injury. The pulmonary inflammatory status and the deposition of collagen were measured by HE and Sirius stains staining. The contents of hydroxyproline and collagen were measured by using commercial kits. The survival rate of mice was calculated by Kaplan-Meier methods. The inflammatory cytokines in bronchoalveolar lavage fluid were measured by ELISA and the expressions of inflammation-related molecules were detected by Western blotting assay. Targeting of IL-17A could prevent the development of lung inflammation, decrease collagen deposition and the contents of hydroxyproline, and protect against the development of pulmonary fibrosis, which together led to an increase in the animal survival. Moreover, blocking IL-17A decreased the expression ofpro-fibrotic cytokines such as IL-17A, TGF-beta1 and IL-13; increased the expression of anti-fibrotic or anti-inflammatory factors such as IFN-gamma, COX-2, 5-LOX, 15-LOX. Indeed, IL-17A antagonism suppressed the activation of pro-inflammatory p65NF-kappaB but enhanced the activation of pro-resolving p50NF-kappaB. In conclusion, that blockade of IL-17A prevents the development of pulmonary fibrosis from acute lung injury, is because blocking IL-17A may prevent acute inflammation converting to chronic inflammation.

Toll like receptor 2 mediates bleomycin-induced acute lung injury, inflammation and fibrosis in mice / 药学学报

Anti-cancer drug bleomycin (BLM) can cause acute lung injury (ALI) which often results in pulmonary fibrosis due to a failure of resolving acute inflammatory response. The aim of this study is to investigate whether toll-like receptor (TLR) 2 mediates BLM-induced ALI, inflammation and fibrosis. BLM-induced dendritic cells (DCs) maturation was analyzed by flow cytometry and cytokine secretion was detected by the ELISA method. The expression and activity of p38 and ERK MAPK were determined with Western blotting. The roles of TLR2 in ALI, inflammation and fibrosis were investigated in C57BL/6 mice administered intratracheally with BLM. The results demonstrated that BLM-administered mice had higher expression of TLR2 (P<0.001) and its signaling molecules. Blocking TLR2 significantly inhibited the maturation of DCs and reversed BLM-stimulated secretion of cytokines in DCs, such as IL-6 (P<0.001), IL-17 (P<0.05) and IL-23 (P<0.05). TLR2 inhibition attenuated BLM-induced increase of inflammatory cells in bronchoalveolar lavage fluid (BALF), and reversed the immunosuppressive microenvironment by enhancing TH1 response (P<0.05) and inhibiting TH2 (P<0.001), Treg (P<0.01) and TH17 (P<0.01) responses. Importantly, blocking TLR2 in vivo significantly protected BLM-administered mice from pulmonary injury, inflammation and fibrosis and subsequently increased BLM-induced animal survival (from 50% to 92%). Therefore, TLR2 is a novel potential target for ALI and pulmonary fibrosis.

Immunomodulatory Function of Antibiotics and Their Effects on Pulmonary Fibrosis / 航天医学与医学工程

Objective To study the immuno-regulatory roles of antibiotics and their implication for pulmonary fibrosis.Methods The regulatory roles of antibiotics on the phenotypes of dendrite cells(DCs) and maturation of B lymphocytes in vitro were detected with flow cytometry.The roles of nystatin on pulmonary fibrosis in vivo were determined with bleomycin-induced acute injury model of mouse.Results Multiple antibiotics including nystatin apparently promoted the maturation of DCs and B cells,as well as subsequently promoted the polarization of Th2 cells through DCs.In addition,nystatin intensified bleomycin-induced pulmonary fibrosis.Conclusion Multiple antibiotics including nystatin induce suppressive immune responses and might aggravate pulmonary fibrosis like nystatin.