Heteryunine A, an amidated tryptophan-catechin-spiroketal hybrid with antifibrotic activity from Heterosmilax yunnanensis.

An unprecedented spiro-C-glycoside adduct, heteryunine A (1), along with two uncommon alkaloids featuring a 2,3-diketopiperazine skeleton, heterpyrazines A (2) and B (3), were discovered in the roots of Heterosmilax yunnanensis. The detailed spectroscopic analysis helped to clarify the planar structures of these compounds. Compound 1, containing 7 chiral centers, features a catechin fused with a spiroketal and connects with a tryptophan derivative by a CC bond. Its complex absolute configuration was elucidated by rotating frame overhauser enhancement spectroscopy (ROESY), specific rotation, and the 13C nuclear magnetic resonance (NMR) and electronic circular dichroism (ECD) calculation. The possible biosynthetic routes for 1 were deduced. Compounds 1 and 2 showed significant antifibrotic effects and further research revealed that they inhibited the activation, migration and proliferation of hepatic stellate cells (HSCs) through suppressing the activity of Ras homolog family member A (RhoA).

Fourteen new 2-benzylbenzofuran glycosides with cardioprotective activity from Heterosmilax yunnanensis.

Fourteen new 2-benzylbenzofuran O-glycosides (1-13, 15) and one new key precursor, diarylacetone (14) were isolated from the roots of Heterosmilax yunnanensis Gagnep, which all have characteristic 2,3,4-O-trisubstituted benzyl. Their structures were elucidated by 1D and 2D NMR, HRESIMS, UV and IR. The isolated compounds were assessed for their cardioprotective activities and compounds 1, 3 and 6 could significantly improve cardiomyocytes viability. Moreover, the mechanistic study revealed that these three compounds could significantly decrease intracellular ROS levels and maintain mitochondrial homeostasis upon hypoxia inducement. Consequently, 1, 3 and 6 might serve as potential lead compounds to prevent myocardial ischemia.

ID1 expressing macrophages support cancer cell stemness and limit CD8+ T cell infiltration in colorectal cancer.

Elimination of cancer stem cells (CSCs) and reinvigoration of antitumor immunity remain unmet challenges for cancer therapy. Tumor-associated macrophages (TAMs) constitute the prominant population of immune cells in tumor tissues, contributing to the formation of CSC niches and a suppressive immune microenvironment. Here, we report that high expression of inhibitor of differentiation 1 (ID1) in TAMs correlates with poor outcome in patients with colorectal cancer (CRC). ID1 expressing macrophages maintain cancer stemness and impede CD8+ T cell infiltration. Mechanistically, ID1 interacts with STAT1 to induce its cytoplasmic distribution and inhibits STAT1-mediated SerpinB2 and CCL4 transcription, two secretory factors responsible for cancer stemness inhibition and CD8+ T cell recruitment. Reducing ID1 expression ameliorates CRC progression and enhances tumor sensitivity to immunotherapy and chemotherapy. Collectively, our study highlights the pivotal role of ID1 in controlling the protumor phenotype of TAMs and paves the way for therapeutic targeting of ID1 in CRC.

Mesaconine alleviates doxorubicin-triggered cardiotoxicity and heart failure by activating PINK1-dependent cardiac mitophagy.

Aberrant mitophagy has been identified as a driver for energy metabolism disorder in most cardiac pathological processes. However, finding effective targeted agents and uncovering their precise modulatory mechanisms remain unconquered. Fuzi, the lateral roots of Aconitum carmichaelii, shows unique efficacy in reviving Yang for resuscitation, which has been widely used in clinics. As a main cardiotonic component of Fuzi, mesaconine has been proven effective in various cardiomyopathy models. Here, we aimed to define a previously unrevealed cardioprotective mechanism of mesaconine-mediated restoration of obstructive mitophagy. The functional implications of mesaconine were evaluated in doxorubicin (DOX)-induced heart failure models. DOX-treated mice showed characteristic cardiac dysfunction, ectopic myocardial energy disorder, and impaired mitophagy in cardiomyocytes, which could be remarkably reversed by mesaconine. The cardioprotective effect of mesaconine was primarily attributed to its ability to promote the restoration of mitophagy in cardiomyocytes, as evidenced by elevated expression of PINK1, a key mediator of mitophagy induction. Silencing PINK1 or deactivating mitophagy could completely abolish the protective effects of mesaconine. Together, our findings suggest that the cardioprotective effects of mesaconine appear to be dependent on the activation of PINK1-induced mitophagy and that mesaconine may constitute a promising therapeutic agent for the treatment of heart failure.

Autophagic Flux Detection: Significance and Methods Involved.

Macroautophagy is an important biological process in eukaryotic cells by which longevity proteins, misfolded proteins, and damaged organelles are degraded. The autophagy process consists of three key steps: (1) the formation of autophagosomes; (2) the fusion of the autophagosomes with lysosomes; and (3) the degradation of the contents of autolysosomes. If any of the three steps is impaired, autophagy will not be able to complete its biological function. Dysfunctional or blocked autophagy is closely involved in the pathogenesis of a variety of diseases. The accurate determination of the autophagy activity in vivo and in vitro has become a challenge in the field of autophagy research. At present, the most widely used detection method to determine autophagy activity in mammalian cells is to quantify LC3B in the cells by Western blot, or to observe the formation and changes of autophagosomes and autolysosomes by immunofluorescence and electron microscopy. However, ignoring the dynamic characteristics of autophagy and only evaluating the number of autophagosomes or the presence of LC3B cannot completely reflect the activation or a blockage of the autophagy system, and objectively analyze its real role in the occurrence and development of a disease. For example, the accumulation of autophagosomes and autolysosomes can occur through an increase in substrate to be degraded after the activation of autophagy, or it may be caused by the partial obstruction or blockage of autophagy. In this chapter, new and familiar ways to detect the autophagic flux are methodically summarized to provide researchers with a multi-angled viewpoint.

Disrupting the TRIB3-SQSTM1 interaction reduces liver fibrosis by restoring autophagy and suppressing exosome-mediated HSC activation.

Impaired macroautophagy/autophagy is involved in the pathogenesis of hepatic fibrosis. However, how aberrant autophagy promotes fibrosis is far from understood. Here, we aimed to define a previously unrevealed pro-fibrotic mechanism for the stress protein TRIB3 (tribbles pseudokinase 3)-mediated autophagy dysfunction. Human fibrotic liver tissues were obtained from patients with cirrhosis who underwent an open surgical repair process. The functional implications of TRIB3 were evaluated in mouse models of hepatic fibrosis induced by bile duct ligation (BDL) or thioacetamide (TAA) injection. Human fibrotic liver tissues expressed higher levels of TRIB3 and selective autophagic receptor SQSTM1/p62 (sequestosome 1) than nonfibrotic tissues and the elevated expression of TRIB3 and SQSTM1 was positively correlated in the fibrotic tissues. Silencing Trib3 protected against experimentally induced hepatic fibrosis, accompanied by restored autophagy activity in fibrotic liver tissues. Furthermore, TRIB3 interacted with SQSTM1 and hindered its binding to MAP1LC3/LC3, which caused the accumulation of SQSTM1 aggregates and obstructed autophagic flux. The TRIB3-mediated autophagy impairment not only suppressed autophagic degradation of late endosomes but also promoted hepatocellular secretion of INHBA/Activin A-enriched exosomes which caused migration, proliferation and activation of hepatic stellate cells (HSCs), the effector cells of liver fibrosis. Disrupting the TRIB3-SQSTM1 interaction with a specific helical peptide exerted potent protective effects against hepatic fibrosis by restoring autophagic flux in hepatocytes and HSCs. Together, stress-elevated TRIB3 expression promotes hepatic fibrosis by interacting with SQSTM1 and interfering with its functions in liver-parenchymal cells and activating HSCs. Targeting this interaction is a promising strategy for treating fibroproliferative liver diseases.Abbreviations: 3-MA: 3-methyladenine; AAV: adeno-associated virus; ACTA2/α-SMA: actin, alpha 2, smooth muscle, aorta; BDL: bile duct ligation; BECN1/Beclin 1: beclin 1, autophagy related; CHX: cycloheximide; CQ: chloroquine; Edu: 5-ethynyl-2-deoxyuridine; ESCRT: endosomal sorting complexes required for transport; HSC: hepatic stellate cell; ILV: intralumenal vesicle; LAMP1: lysosomal-associated membrane protein 1; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MVB: multivesicular body; PIK3C3: phosphatidylinositol 3-kinase, catalytic subunit type 3; PPI: protein-protein interaction; SQSTM1/p62: sequestosome 1; TAA: thioacetamide; TEM: transmission electron microscopy; TGFB1/TGFß1: transforming growth factor, beta 1; TLR2: toll-like receptor 2; TRIB3: tribbles pseudokinase 3.

Akkermansia muciniphila: a promising target for the therapy of metabolic syndrome and related diseases.

The probiotic Akkermansia muciniphila (A. muciniphila) is an intestinal bacterium that was first identified in human feces in 2004. Its specialization in mucin degradation makes it a key microorganism that maintains intestinal mucosal barrier function. As an unique representative strain of the phylum Verrucomicrobia that can be cultured in vitro, A. muciniphila is much easier to detect by metagenomic analysis of intestinal flora. In the past few years, A. muciniphila has been getting increasing attention for the positive correlation between its intestinal colonization and host homeostatic metabolism. In this review, we summarize the relationship between A. muciniphila and host health and diseases, especially focusing on metabolic diseases and related mechanisms, as well as the natural food and drug-derived substrates affecting its colonization in the host, expecting to provide evidence and clues for the development of drugs targeting A. muciniphila.

Targeting Extracellular Heat Shock Protein 70 Ameliorates Doxorubicin-Induced Heart Failure Through Resolution of Toll-Like Receptor 2-Mediated Myocardial Inflammation.

Background Heart failure (HF) is one of the most significant causes of morbidity and mortality for the cardiovascular risk population. We found previously that extracellular HSP70 (heat shock protein) is an important trigger in cardiac hypertrophy and fibrosis, which are associated with the development of heart dysfunction. However, the potential role of HSP70 in response to HF and whether it could be a target for the therapy of HF remain unknown. Methods and Results An HF mouse model was generated by a single IP injection of doxorubicin at a dose of 15 mg/kg. Ten days later, these mice were treated with an HSP70 neutralizing antibody for 5 times. We observed that doxorubicin treatment increased circulating HSP70 and expression of HSP70 in myocardium and promoted its extracellular release in the heart. Blocking extracellular HSP70 activity by its antibody significantly ameliorated doxorubicin-induced left ventricular dilation and dysfunction, which was accompanied by a significant inhibition of cardiac fibrosis. The cardioprotective effect of the anti-HSP70 antibody was largely attributed to its ability to promote the resolution of myocardial inflammation, as evidenced by its suppression of the toll-like receptor 2-associated signaling cascade and modulation of the intracellular distribution of the p50 and p65 subunits of nuclear factor-κB. Conclusions Extracellular HSP70 serves as a noninfectious inflammatory factor in the development of HF, and blocking extracellular HSP70 activity may provide potential therapeutic benefits for the treatment of HF.

Targeting HMGB1 ameliorates cardiac fibrosis through restoring TLR2-mediated autophagy suppression in myocardial fibroblasts.

BACKGROUND: Extracellular high-mobility group box 1 (HMGB1) has been identified as playing a critical role in the pathogenesis of tissue fibrosis. However, the underlying mechanism of its involvement in cardiac fibrosis is still not well-defined. Here, we aim to investigate whether toll-like receptor 2 (TLR2) contributes to the extracellular HMGB1-mediated development and progression of cardiac fibrosis. METHODS: A mouse model of cardiac fibrosis was induced by subcutaneous injection of isoproterenol (ISO). Glycyrrhizic acid (GA), an inhibitor of HMGB1 derived from natural products, was simultaneously administered by intraperitoneal injection. Echocardiography, H&E and Sirius red staining were used to evaluate cardiac function and fibrosis. The myocardial expression of autophagy-associated proteins was examined using immunoblotting. Cardiac fibroblasts were treated with different concentrations of HMGB1 to examine the expression levels of α-SMA, collagen I and autophagy markers. Interactions of HMGB1/TLR2 and α-SMA/p62 were examined by immunoprecipitation and immunofluorescence. RESULTS: ISO-treated mice showed characteristic cardiac fibrosis, increased expression and co-localization of HMGB1 and TLR2, as well as impaired autophagic signals in myocardial tissues, which could be prevented by silencing TLR2. Exogenous administration of HMGB1 blocked the autophagic flux in fibroblasts, which caused extensive accumulation of collagen I and α-SMA. In addition, cardiac fibrosis was alleviated by GA treatment through abrogating the interaction between HMGB1 and TLR2. CONCLUSIONS: Our study suggests that the interaction between TLR2 and HMGB1 contributes to the pathogenesis of cardiac fibrosis via suppressing fibroblast autophagy, and that inhibiting HMGB1 with GA provides therapeutic benefits for the treatment of fibroproliferative heart diseases.

Autophagy as a target for development of anti-diabetes drugs derived from natural compounds.

Patients with diabetes have a high level of blood glucose because their body cannot produce enough insulin or properly respond to this hormone. In both situations, it has become evident that persistent high concentrations of glucose, insulin, insulin-like growth factor, and insulin resistance lead to dysfunction and destruction of autophagic activity in the cells of islet and other organs involved in complications of diabetes, including the liver, cardiovascular, and nervous systems. Accumulating evidences have revealed that autophagy is a novel therapeutic target with a wide range of beneficial effects on diabetes and that plenty of drugs and natural products are involved in autophagy modulation, either inducing or inhibiting autophagy, through multiple signaling pathways. In this review, we summarize the roles of several clinical drugs and compounds derived from natural products in diabetes and its complications through regulation of autophagy, expecting to inspire further investigation of the underlying mechanisms of these compounds and to facilitate their better clinical application.

Antagonism of Interleukin-17A ameliorates experimental hepatic fibrosis by restoring the IL-10/STAT3-suppressed autophagy in hepatocytes.

Interleukin-17A has been identified as a driver of hepatic stellate cell activation and plays a critical role in the pathogenesis of hepatic fibrosis. However, the underlining fibrosis-promoting mechanism of IL-17A is far from understood. Here we aimed to define whether hepatocytes directly respond to IL-17A stimulation and are associated with the development of hepatic fibrosis. The functional significance of IL-17A was evaluated in bile duct ligation (BDL) or thioacetamide (TAA) injection-induced mouse models of hepatic fibrosis. Human cirrhosis and control tissues were obtained from the patients with cirrhosis who received an open surgical repair process. Neutralizing IL-17A promoted the resolution of BDL or TAA-induced acute or chronic inflammation and fibrosis, resulted in a shift of the suppressive immune response in fibrotic liver toward a Th1-type immune response, and restored autophagy activity in both cholestatic and hepatotoxic liver injury induced fibrotic liver tissues, which was accompanied by a significant inhibition of STAT3 phosphorylation. Moreover, we found that IL-17A stimulated the concentration-and time-dependent phosphorylation of STAT3 in AML-12 liver cells. Blocking STAT3 with a specific inhibitor STATTIC or STAT3 siRNA protected from the IL-17A-induced autophagy suppression in AML-12 cells, indicating that STAT3 mediates IL-17A-suppressed autophagy. Administration of IL-10, which activated STAT3 and inhibited autophagy, reversed the therapeutic effect of IL-17A antagonism in vivo. Our study suggests that the IL-17A/STAT3 signaling pathway plays a crucial role in the pathogenesis of hepatic fibrosis through suppressing hepatocellular autophagy and that blocking this pathway may provide therapeutic benefits for the treatment of hepatic fibrosis.

Pigment dispersion glaucoma induced by the chafing effect of intraocular lens haptics in Asian eyes.

PURPOSE: To study the possible mechanism and treatment for pigment dispersion glaucoma (PDG) caused by single-piece acrylic (SPA) intraocular lens (IOL) ciliary sulcus fixation in Asian eyes. MATERIALS AND METHODS: Patients referred for PDG caused by SPA IOL ciliary sulcus fixation to our hospital from April 2005 to June 2011 were included. The patients' general information, IOL type, interval between initial surgery and PDG occurrence, examination findings, antiglaucoma medicine regimen and surgical interventions were recorded. RESULTS: In total, six eyes from five Chinese patients were included in this study. The intraocular pressure (IOP) increased 19-30 days after cataract surgery and was not satisfactorily controlled with antiglaucoma medication. Dense pigmentation was deposited on the IOLs and on the anterior chamber angle. IOL haptic chafing was noted on the rear iris surface. IOL repositioning in the capsular bag was performed in three eyes and was combined with trabeculectomy in two eyes with progressive glaucoma. An IOL exchange with three-piece IOL ciliary sulcus fixation was performed in the other three eyes. Scanning electron microscopy of the explanted IOLs demonstrated a rough edge on the IOL haptics. CONCLUSIONS: SPA IOLs were not suitable for ciliary sulcus fixation. The chafing effect of the IOL haptics on the posterior iris pigment epithelium could induce PDG in Asian eyes. IOLs should be positioned in the capsular bag or a three-piece IOL should be used instead.