Impaired wound healing and ulcer complications are a leading cause of death in diabetic patients. In this study, we report the design and synthesis of a cyclometalated iridium(III) metal complex 1a ...as a stabilizer of hypoxia-inducible factor-1α (HIF-1α). In vitro biophysical and cellular analyses demonstrate that this compound binds to Von Hippel-Lindau (VHL) and inhibits the VHL-HIF-1α interaction. Furthermore, the compound accumulates HIF-1α levels in cellulo and activates HIF-1α mediated gene expression, including VEGF, GLUT1, and EPO. In in vivo mouse models, the compound significantly accelerates wound closure in both normal and diabetic mice, with a greater effect being observed in the diabetic group. We also demonstrate that HIF-1α driven genes related to wound healing (i.e. HSP-90, VEGFR-1, SDF-1, SCF, and Tie-2) are increased in the wound tissue of 1a-treated diabetic mice (including, db/db, HFD/STZ and STZ models). Our study demonstrates a small molecule stabilizer of HIF-1α as a promising therapeutic agent for wound healing, and, more importantly, validates the feasibility of treating diabetic wounds by blocking the VHL and HIF-1α interaction.
Lysine‐specific demethylase 5A (KDM5A) has recently become a promising target for epigenetic therapy. In this study, we designed and synthesized metal complexes bearing ligands with reported ...demethylase and p27 modulating activities. The Rh(III) complex 1 was identified as a direct, selective and potent inhibitor of KDM5A that directly abrogate KDM5A demethylase activity via antagonizing the KDM5A‐tri‐/di‐methylated histone 3 protein–protein interaction (PPI) in vitro and in cellulo. Complex 1 induced accumulation of H3K4me3 and H3K4me2 levels in cells, causing growth arrest at G1 phase in the triple‐negative breast cancer (TNBC) cell lines, MDA‐MB‐231 and 4T1. Finally, 1 exhibited potent anti‐tumor activity against TNBC xenografts in an in vivo mouse model, presumably via targeting of KDM5A and hence upregulating p27. Moreover, complex 1 was less toxic compared with two clinical drugs, cisplatin and doxorubicin. To our knowledge, complex 1 is the first metal‐based KDM5A inhibitor reported in the literature. We anticipate that complex 1 may be used as a novel scaffold for the further development of more potent epigenetic agents against cancers, including TNBC.
A rhodium(III)‐based complex has been discovered as an inhibitor of KDM5A, an epigenetic target for triple‐negative breast cancer. The complex inhibited the KDM5A–H3K4me3 interaction and suppressed proliferation of triple‐negative breast cancer (TNBC) tumors in mice and may be used as a novel scaffold for further development of more potent epigenetic agents against cancers, including TNBC.
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Non-small cell lung cancer (NSCLC) accounts for approximately 85% of all lung cancers. Our previous studies have proven that Trillium tschonoskii Maxim. (TTM), a traditional Chinese ...medicine, possesses potent anti-tumor effect. However, the detailed components and molecular mechanism of TTM in anti-NSCLC are still unknown. In the present experiment, polyphyllin VI (PPVI) was successfully isolated from TTM with guidance of the anti-proliferative effect in A549 cells, and the cell death of PPVI treated A549 and H1299 cells was closely linked with the increased intracellular ROS levels. In addition, PPVI induced apoptosis by promoting the protein expression of Bax/Bcl2, caspase-3 and caspase-9, and activated autophagy by improving LC3 II conversion and GFP-LC3 puncta formation in A549 and H1299 cells. The mechanism study found that the activity of mTOR which regulates cell growth, proliferation and autophagy was significantly suppressed by PPVI. Accordingly, the PI3K/AKT and MEK/ERK pathways positively regulating mTOR were inhibited, and AMPK negatively regulating mTOR was activated. In addition, the downstream of mTOR, ULK1 at Ser 757 which downregulates autophagy was inhibited by PPVI. The apoptotic cell death induced by PPVI was confirmed, and it was significantly suppressed by the overexpression of AKT, ERK and mTOR, and the induced autophagic cell death which was depended on the Atg7 was decreased by the inhibitors, such as LY294002 (LY), Bafilomycin A1 (Baf), Compound C (CC) and SBI-0206965 (SBI). Furthermore, the mTOR signaling pathway was regulated by the increased ROS as the initial signal in A549 and H1299 cells. Finally, the anti-tumor growth activity of PPVI in vivo was validated in A549 bearing athymic nude mice. Taken together, our data have firstly demonstrated that PPVI is the main component in TTM that exerts the anti-proliferative effect by inducing apoptotic and autophagic cell death in NSCLC via the ROS-triggered mTOR signaling pathway, and PPVI may be a promising candidate for the treatment of NSCLC in future.
Abstract
Resistance of cancer cells to chemotherapy is a significant clinical concern and mechanisms regulating cell death in cancer therapy, including apoptosis, autophagy or necrosis, have been ...extensively investigated over the last decade. Accordingly, the identification of medicinal compounds against chemoresistant cancer cells
via
new mechanism of action is highly desired. Autophagy is important in inducing cell death or survival in cancer therapy. Recently, novel autophagy activators isolated from natural products were shown to induce autophagic cell death in apoptosis-resistant cancer cells in a calcium-dependent manner. Therefore, enhancement of autophagy may serve as additional therapeutic strategy against these resistant cancers. By computational docking analysis, biochemical assays, and advanced live-cell imaging, we identified that neferine, a natural alkaloid from
Nelumbo nucifera
, induces autophagy by activating the ryanodine receptor and calcium release. With well-known apoptotic agents, such as staurosporine, taxol, doxorubicin, cisplatin and etoposide, utilized as controls, neferine was shown to induce autophagic cell death in a panel of cancer cells, including apoptosis-defective and -resistant cancer cells or isogenic cancer cells,
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calcium mobilization through the activation of ryanodine receptor and Ulk-1-PERK and AMPK-mTOR signaling cascades. Taken together, this study provides insights into the cytotoxic mechanism of neferine-induced autophagy through ryanodine receptor activation in resistant cancers.
Emerging evidence indicates important protective roles being played by autophagy in neurodegenerative disorders through clearance of aggregate-prone or mutant proteins. In the current study, we aimed ...to identify autophagy inducers from Chinese medicinal herbs as a potential neuroprotective agent that enhances the clearance of mutant huntingtin and α-synuclein in PC-12 cells. Through intensive screening using the green fluorescent protein-light chain 3 (GFP-LC3) autophagy detection platform, we found that the ethanol extracts of Radix Polygalae (Yuan Zhi) were capable of inducing autophagy. Further investigation showed that among three single components derived from Radix Polygalae--i.e., polygalacic acid, senegenin and onjisaponin B--onjisaponin B was able to induce autophagy and accelerate both the removal of mutant huntingtin and A53T α-synuclein, which are highly associated with Huntington disease and Parkinson disease, respectively. Our study further demonstrated that onjisaponin B induces autophagy via the AMPK-mTOR signaling pathway. Therefore, findings in the current study provide detailed insights into the protective mechanism of a novel autophagy inducer, which is valuable for further investigation as a new candidate agent for modulating neurodegenerative disorders through the reduction of toxicity and clearance of mutant proteins in the cellular level.
Chronic inflammation of the central nervous system (CNS) is critical to the pathogenesis of neuropsychiatric disorders (NPDs) that affect the global population. Current therapeutics for NPDs are ...limited to relieving symptoms and induce many adverse effects. Therefore, the discovery of novel therapeutic agents from natural sources is urgently needed. Intriguingly, the immune responses of peripheral organs are closely linked through the molecular communication between resident and blood-borne cellular components, which shape the neuroinflammatory phenotypes of NPDs. Since the gut and spleen are the two largest immunological organs of the body, the brain–gut–microbiome and brain–spleen axes have been implicated in the connection between the CNS and the peripheral immune system. Accordingly, it has been proposed that the local CNS inflammation observed in NPDs is regulated via the manipulation of the systemic immune system by targeting the gut and spleen. Additionally, the complexity of the signalling network underlying the communication between the CNS and the systemic immune system suggests a strong potential for treating NPDs through a polypharmacological approach. The close association between systemic immunity and the homeostasis of the CNS points to the concept of repurposing interventions for systemic immune disorders to treat NPDs. Notably, natural products represent a promising source of such effective compounds due to both their pharmacological potency and safety. This review discusses the complex implications of dysregulated systemic immunity mediated by the brain–spleen and brain–gut–microbiome axes in NPDs, such as Alzheimer’s disease, Parkinson’s disease, schizophrenia and major depressive disorder. In addition, the potential of repurposing natural product-based bioactive compounds for treating NPDs via modulating systemic immune disorders is intensively discussed.
Complex 1 possesses selectivity and imaging capabilities for CCNT1 and is able to inhibit TNBC by targeting AFF4–CCNT1 interaction in cellulo and in vivo.
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•A virtual screening ...campaign is conducted to identify inhibitors of the AFF4–CCNT1 PPI from natural product analogues.•The inhibitors are used to develop the conjugate metal complex 1 as a probe for treating TNBC.•Complex 1 is the first probe that possesses high selectivity and imaging ability for CCNT1.•Complex 1 is able to inhibit TNBC by targeting AFF4–CCNT1 interaction in cellulo and in vivo.
The interaction between AFF4 and the P-TEFb cyclin T1 (CCNT1) subunit is linked with various human cancers, including triple-negative breast cancer (TNBC). However, the development of chemical probes targeting the AFF4–CCNT1 protein–protein interaction (PPI) has been hindered by the lack of available inhibitors for this interaction. In this study, we conducted a virtual screening campaign to identify inhibitors of the AFF4–CCNT1 PPI from natural product analogues, and the hits were used to develop the conjugate metal complex 1 as a probe for TNBC. Complex 1 bound to CCNT1 and reduced oncogene MYC transcription and the proliferation, metastasis, and stem-like ability of TNBC cells. It also exhibited desirable photophysical properties for imaging CCNT1 and could distinguish cancer cells from normal cells. In a murine model of breast cancer, complex 1 displayed strong anti-proliferation activity. To our knowledge, complex 1 is the first probe that possesses high selectivity and imaging ability for CCNT1, with the ability to suppress TNBC cell stem-like abilities and tumor growth through targeting the AFF4–CCNT1 interaction in vitro and in vivo.
Resistance of cancer cells to chemotherapy is a significant problem in oncology, and the development of sensitising agents or small-molecules with new mechanisms of action to kill these cells is ...needed. Autophagy is a cellular process responsible for the turnover of misfolded proteins or damaged organelles, and it also recycles nutrients to maintain energy levels for cell survival. In some apoptosis-resistant cancer cells, autophagy can also enhance the efficacy of anti-cancer drugs through autophagy-mediated mechanisms of cell death. Because the modulation of autophagic processes can be therapeutically useful to circumvent chemoresistance and enhance the effects of cancer treatment, the identification of novel autophagic enhancers for use in oncology is highly desirable. Many novel anti-cancer compounds have been isolated from natural products; therefore, we worked to discover natural, anti-cancer small-molecule enhancers of autophagy. Here, we have identified a group of natural alkaloid small-molecules that function as novel autophagic enhancers. These alkaloids, including liensinine, isoliensinine, dauricine and cepharanthine, stimulated AMPK-mTOR dependent induction of autophagy and autophagic cell death in a panel of apoptosis-resistant cells. Taken together, our work provides novel insights into the biological functions, mechanisms and potential therapeutic values of alkaloids for the induction of autophagy.
•Polyphenols in blueberry leaf were abundant making it advantaged in NAFLD phytotherapy.•Mitochondrial dNTP perturbation could contribute to mtDNA deletion and mitochondrial dysfunction.•Polyphenols ...improved mitochondrial dysfunction and oxidative defense to alleviate NAFLD.•Therapeutic mechanism could involve in the activation of AMPK/PGC1/SIRT3 pathway.
Since non-alcoholic fatty liver disease (NAFLD) pathogenesis is multi-factorial, pharmacotherapy with a specific target commonly exhibits limited efficacy. Phytotherapy, whose therapeutic efficacy is based on the combined action of several active compounds, offers new treatment opportunity for NAFLD. As a representative, many natural polyphenols could be utilized in phytotherapy for NAFLD.
In present work, we aimed to investigate the therapeutic effects and underlying mechanism of polyphenols in blueberry leaves (PBL) on NAFLD from a mitochondria-centric perspective since mitochondrial dysfunction could play a dominant role in NAFLD.
Identification and quantification of PBL were performed using liquid chromatography coupled with tandem mass spectrometry. The beneficial effects, especially improving mitochondrial function, and potential mechanism of PBL on NAFLD were studied by in vitro and in vivo study.
Polyphenols were abundant in blueberry leaves making it advantaged in NAFLD phytotherapy. PBL effectively alleviated hepatic steatosis, oxidative stress and inflammation as indicated by both in vitro and in vivo study. Furthermore, PBL mediated improvement of mitochondrial dysfunction and antioxidant capability through activation of AMPK/PGC-1α/SIRT3 signaling axis.
Considering that mitochondrial dysfunction takes precedence over hepatic steatosis and induces NAFLD development, we conclude that PBL improve mitochondrial dysfunction and oxidative defense, subsequently alleviate hepatic steatosis, oxidative stress and inflammation, and eventually alleviate NAFLD.
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