Orchestrated metal-coordinated carrier-free celastrol hydrogel intensifies T cell activation and regulates response to immune checkpoint blockade for synergistic chemo-immunotherapy.

The challenges generated by insufficient T cell activation and infiltration have constrained the application of immunotherapy. Making matters worse, the complex tumor microenvironment (TME), resistance to apoptosis collectively poses obstacles for cancer treatment. The carrier-free small molecular self-assembly strategy is a current research hotspot to overcome these challenges. This strategy can transform multiple functional agents into sustain-released hydrogel without the addition of any excipients. Herein, a coordination and hydrogen bond mediated tricomponent hydrogel (Cel hydrogel) composed of glycyrrhizic acid (GA), copper ions (Cu2+) and celastrol (Cel) was initially constructed. The hydrogel can regulate TME by chemo-dynamic therapy (CDT), which increases reactive oxygen species (ROS) in conjunction with GA and Cel, synergistically expediting cellular apoptosis. What's more, copper induced cuproptosis also contributes to the anti-tumor effect. In terms of regulating immunity, ROS generated by Cel hydrogel can polarize tumor-associated macrophages (TAMs) into M1-TAMs, Cel can induce T cell proliferation as well as activate DC mediated antigen presentation, which subsequently induce T cell proliferation, elevate T cell infiltration and enhance the specific killing of tumor cells, along with the upregulation of PD-L1 expression. Upon co-administration with aPD-L1, this synergy mitigated both primary and metastasis tumors, showing promising clinical translational value.

Neuroprotection of celastrol against postoperative cognitive dysfunction through dampening cGAS-STING signaling.

Neuroinflammation is a central player in postoperative cognitive dysfunction (POCD), an intractable and highly confounding neurological complication with finite therapeutic options. Celastrol, a quinone methide triterpenoid, is a bioactive ingredient extracted from Tripterygium wilfordii with talented anti-inflammatory capacity. However, it is unclear whether celastrol can prevent anesthesia/surgery-evoked cognitive deficits in an inflammation-specific manner. The STING agonist 5,6-dimethylxanthenone-4-acetic acid (DMXAA) was used to determine whether celastrol possesses neuroprotection dependent on the STING pathway in vivo and in vitro. Isoflurane and laparotomy triggered cGAS-STING activation, caspase-3/GSDME-dependent pyroptosis, and enhanced Iba-1 immunoreactivity. Celastrol improved cognitive performance and decreased the levels of cGAS, 2'3'-cGAMP, STING, NF-κB phosphorylation, Iba-1, TNF-α, IL-6, and IFN-ß. Downregulation of cleaved caspase-3 and N-GSDME was observed in the hippocampus of POCD mice and HT22 cells after celastrol administration, accompanied by limited secretion of pyroptosis-pertinent pro-inflammatory cytokines IL-1ß and IL-18. DMXAA neutralized the favorable influences of celastrol on cognitive function, as confirmed by the activation of the STING/caspase-3/GSDME axis. These findings implicate celastrol as a therapeutic agent for POCD through anti-inflammation and anti-pyroptosis.

Promising and challenging phytochemicals targeting LC3 mediated autophagy signaling in cancer therapy.

BACKGROUND: Phytochemicals possess a wide range of anti-tumor properties, including the modulation of autophagy and regulation of programmed cell death. Autophagy is a critical process in cellular homeostasis and its dysregulation is associated with several pathological conditions, such as cancer, neurodegenerative diseases, and diabetes. In cancer, autophagy plays a dual role by either promoting tumor growth or suppressing it, depending on the cellular context. During autophagy, autophagosomes engulf cytoplasmic components such as proteins and organelles. LC3-II (microtubule-associated protein 1 light chain 3-II) is an established marker of autophagosome formation, making it central to autophagy monitoring in mammals. OBJECTIVE: To explore the regulatory role of phytochemicals in LC3-mediated autophagy and their potential therapeutic impact on cancer. The review emphasizes the involvement of autophagy in tumor promotion and suppression, particularly focusing on autophagy-related signaling pathways like oxidative stress through the NRF2 pathway, and its implications for genomic stability in cancer development. METHODS: The review focuses on a comprehensive analysis of bioactive compounds including Curcumin, Celastrol, Resveratrol, Kaempferol, Naringenin, Carvacrol, Farnesol, and Piperine. Literature on these compounds was examined to assess their influence on autophagy, LC3 expression, and tumor-related signaling pathways. A systematic literature search was conducted across databases including PubMed, Scopus, and Web of Science from inception to 2023. Studies were selected from prominent databases, focusing on their roles in cancer diagnosis and therapeutic interventions, particularly in relation to LC3-mediated mechanisms. RESULTS: Phytochemicals have been shown to modulate autophagy through the regulation of LC3-II levels and autophagic flux in cancer cells. The interaction between autophagy and other cellular pathways such as oxidative stress, inflammation, and epigenetic modulation highlights the complex role of autophagy in tumor biology. For instance, Curcumin and Resveratrol have been reported to either induce or inhibit autophagy depending on cancer type, influencing tumor progression and therapeutic responses. CONCLUSION: Targeting autophagy through LC3 modulation presents a promising strategy for cancer therapy. The dual role of autophagy in tumor suppression and promotion, however, necessitates careful consideration of the context in which autophagy is induced or inhibited. Future research should aim to delineate these context-specific roles and explore how phytochemicals can be optimized for therapeutic efficacy. Novel therapeutic strategies should focus on the use of bioactive compounds to fine-tune autophagy, thereby maximizing tumor suppression and inducing programmed cell death in cancer cells.

Celastrol attenuates the invasion and migration and augments the anticancer effects of olaparib in prostate cancer.

BACKGROUND: Prostate cancer (PCa) is a leading malignancy among men globally, with rising incidence rates emphasizing the critical need for better detection and therapeutic approaches. The roles of HSP90AB1 and PARP1 in prostate cancer cells suggest potential targets for enhancing treatment efficacy. METHODS: This study investigated the overexpression of HSP90AB1 and PARP1 in prostate cancer cells and the impact of HSP90AB1 knockdown on the sensitivity of these cells to the PARP inhibitor olaparib. We also explored the combined effect of olaparib and celastrol, an HSP90 inhibitor, on the clonogenic survival, migration, proliferation, and overall viability of prostate cancer cells, alongside the modulation of the PI3K/AKT pathway. An in vivo PC3 xenograft mouse model was used to assess the antitumor effects of the combined treatment. RESULTS: Our findings revealed significant overexpression of HSP90AB1 and PARP1 in prostate cancer cells. Knockdown of HSP90AB1 increased cell sensitivity to olaparib. The combination of olaparib and celastrol significantly reduced prostate cancer cell survival, migration, proliferation, and enhanced cumulative DNA damage. Celastrol also downregulated the PI3K/AKT pathway, increasing cell susceptibility to olaparib. In vivo experiments demonstrated that celastrol and olaparib together exerted strong antitumor effects. CONCLUSIONS: The study indicates that targeting both HSP90AB1 and PARP1 presents a promising therapeutic strategy for prostate cancer. The synergistic combination of celastrol and olaparib enhances the efficacy of treatment against prostate cancer, offering a potent approach to combat this disease.

Hyaluronic acid-zein shell-core biopolymer nanoparticles enhance hepatocellular carcinoma therapy of celastrol via CD44-mediated cellular uptake.

Low concentrations or limited residence times in tumor tissues, making celastrol (Cel) difficult to exert significant therapeutic effects. Thus, we developed Zein/hyaluronic acid core-shell nanoparticles (Cel/Zein@HA NPs) for active targeted delivery of Cel via CD44 receptor over-expression on cancer cells, which may strengthen the therapeutic efficacy of Cel and improve delivery targeting. Cel-loaded Zein nanoparticles (core), are elegantly enveloped by a hydrophilic HA coating that forms the shell, resulting in significantly improved encapsulation efficiency and ensured good stability. The cellular uptake of Cel/Zein@HA NPs in HepG2 cells was 1.57-fold higher than nontargeting Cel/Zein NPs. Near-infrared fluorescence imaging confirmed the accumulation of Cel/Zein@HA NPs in H22 liver cancer tumors in mice, resulting in effective antitumor effects and good biosafety. Besides, in vitro and in vivo experiments showed that compared with Cel/Zein NPs, Cel/Zein@HA NPs had more efficient inhibitory effect on tumor proliferation and lower systemic toxicity. Further studies revealed that Cel/Zein@HA NPs induced apoptosis in hepatocellular carcinoma cells by modulating Bax and Bcl-2 expression, while also inhibiting tumor angiogenesis by decreasing CD31 and VEGF levels. Overall, this study presents a promising strategy for enhancing targeted liver cancer therapy through the utilization of biopolymer nanoparticle-based nano-pharmaceuticals that facilitate CD44-mediated cellular uptake.

ROS-responsive nanomicelles encapsulating celastrol ameliorate pressure overload-induced cardiac hypertrophy by regulating the NF-κB signaling pathway.

Celastrol (CEL) belongs to the group of non-steroidal immunosuppressants with the potential to improve cardiac hypertrophy (CH). However, the poor biocompatibility and low bioavailability of CEL limit its in vivo application. This study was aimed to develop a targeted drug delivery system that can efficiently and safely deliver CEL to target tissues, providing a research basis for the application of CEL in CH therapy. A novel ROS-sensitive drug-loaded nanomicelle, dodecanoic acid (DA)-phenylboronic acid pinacol ester-dextran polymer encapsulating CEL (DBD@CEL), was synthesized using chemical synthesis. Then, the morphology, particle size, drug-loaded content, and ROS-responsive release behavior of DBD@CEL were studied. Pharmacokinetics and biocompatibility were evaluated using healthy mice. Finally, the ability and mechanism of DBD@CEL in improving CH in vivo were investigated using a mouse CH model. DBD@CEL was successfully prepared with a drug loading of 18.9%. It exhibited excellent stability with an average particle size of 110.0 ± 1.7 nm. Within 48 h, DBD@CEL released only 19.4% in the absence of H2O2, while in the presence of 1 mM H2O2, the release rate increased to 71.5%. Biocompatibility studies indicated that DBD@CEL did not cause blood cell hemolysis, had no impact on normal organs, and did not result in abnormal blood biochemical indicators, demonstrating excellent biocompatibility. In vivo studies revealed that DBD@CEL regulated the activation of NF-κB signaling, inhibits pyroptosis and oxidative stress, and thereby ameliorates CH. The ROS-responsive DBD@CEL nanodrug delivery system enhances the therapeutic activity of CEL for CH, providing a promising drug delivery system for the clinical treatment of CH.

Genotoxic and Anti-Migratory Effects of Camptothecin Combined with Celastrol or Resveratrol in Metastatic and Stem-like Cells of Colon Cancer.

Background: Colorectal cancer is one of the leading and most lethal neoplasms. Standard chemotherapy is ineffective, especially in metastatic cancer, and does not target cancer stem cells. A promising approach to improve cancer treatment is the combination therapy of standard cytostatic drugs with natural compounds. Several plant-derived compounds have been proven to possess anticancer properties, including the induction of apoptosis and inhibition of cancer invasion. This study was focused on investigating in vitro the combination of camptothecin (CPT) with celastrol (CEL) or resveratrol (RSV) as a potential strategy to target metastatic (LOVO) and stem-like (LOVO/DX) colon cancer cells. Methods: The genotoxic effects that drive cancer cells into death-inducing pathways and the ability to inhibit the migratory properties of cancer cells were evaluated. The γH2AX+ assay and Fast-Halo Assay (FHA) were used to evaluate genotoxic effects, the annexin-V apoptosis assay to rate the level of apoptosis, and the scratch test to assess antimigratory capacity. Results: The results showed that both combinations CPT-CEL and CPT-RSV improve general genotoxicity of CPT alone on metastatic cells and CSCs. However, the assessment of specific double-stranded breaks (DSBs) indicated a better efficacy of the CPT-CEL combination on LOVO cells and CPT-RSV in LOVO/DX cells. Interestingly, the combinations CPT-CEL and CPT-RSV did not improve the pro-apoptotic effect of CPT alone, with both LOVO and LOVO/DX cells suggesting activation of different cell death mechanisms. Furthermore, it was found that the combinations of CPT-CEL and CPT-RSV improve the inhibitory effect of camptothecin on cell migration. Conclusions: These findings suggest the potential utility of combining camptothecin with celastrol or resveratrol in the treatment of colon cancer, including more aggressive forms of the disease. So far, no studies evaluating the effects of combinations of these compounds have been published in the available medical databases.

Exploring the Potential of Terpenoids as a Possible Treatment for Cancer: Structure-Activity Relationship and Mechanistic Studies.

Cancer stands as a significant global health challenge due to its mortality rates and the complexities involved in its treatment. Addressing issues, such as metastasis, recurrence, chemoresistance, and treatment-related toxicity, remains pivotal in cancer therapy advancement. Therefore, exploration of novel therapeutic agents has emerged as a priority. As the risk of cancer continues to rise, effective measures must be taken to combat it. One promising approach is to explore natural remedies, such as terpenoids, which have demonstrated anticancer activity. Utilizing terpenoids could aid in the development of potent compounds to fight cancer. By studying the structural makeup of various terpenoid derivatives from previous research, we can identify which structural groups are essential for their anticancer activity. This understanding of the structure-activity relationship is crucial for developing new, effective anticancer agents based on terpenoids. Terpenoids, a diverse class of plant-derived secondary metabolites composed of multiple isoprene units, have garnered attention for their potential anticancer and pharmacological qualities. Some terpenoids exhibit notable anticancer effects by concentrating on several stages of cancer development. They show promise in blocking the initiation of early carcinogenesis by the induction of cell cycle arrest, the inhibition of cancer cell differentiation, and the induction of apoptosis. This study delves into the investigation of specific terpenoids showcasing promising anticancer activity against prevalent malignancies, including breast, colon, ovarian, and lung cancers. The study also explores the relationship between the structure and activity of these compounds, which sheds light on how effective they are against a variety of cancer cell types. The comprehensive discussion centres on elucidating terpenoids with substantial potential for combating diverse cancer types, offering insights into their structural features and promising anticancer mechanisms.

The ß-glucan nanotube carrier achieves detoxification and efficacy enhancement of celastrol in intrahepatic cholangiocarcinoma therapy by increasing targeted controlled release and macrophage polarization.

Celastrol (Cel) is a monomer from a famous traditional Chinese medicine named Tripterygium wilfordii Hook. f. Cel has shown great potential in treating intrahepatic cholangiocarcinoma (ICC) but still faces problems, including poor water solubility, high toxicity, and lack of targeting ability. Thus, the present work constructed a drug-delivery system using black fungus polysaccharide self-assembled -nanotubes (BFP). Cel-loaded nanotubes (BFP-Cel) were confirmed to have a high loading content of Cel (38 %), liver targeting, and enzyme-controlled release abilities. Moreover, BFP carriers could significantly increase the uptake efficiency of Cel by tumor cells. In vivo experiments showed that BFP-Cel could effectively inhibit tumor growth and reduce the physiological toxicity of Cel. Furthermore, BFP, as a carrier, could regulate the immune microenvironment in the liver through the activation of macrophages and play an immunomodulatory role. In summary, the BFP nanotube carrier could achieve detoxification and efficacy enhancement of Cel in treating ICC by increasing the targetability, controlled release ability, cell-uptake effect, and regulation of the immune microenvironment.

Development of Dual-Targeted Mixed Micelles Loaded with Celastrol and Evaluation on Triple-Negative Breast Cancer Therapy.

Considering that the precise delivery of Celastrol (Cst) into mitochondria to induce mitochondrial dysfunction may be a potential approach to improve the therapeutic outcomes of Cst on TNBC, a novel tumor mitochondria dual-targeted mixed-micelle nano-system was fabricated via self-synthesized triphenylphosphonium-modified cholesterol (TPP-Chol) and hyaluronic acid (HA)-modified cholesterol (HA-Chol). The Cst-loaded mixed micelles (Cst@HA/TPP-M) exhibited the characteristics of a small particle size, negative surface potential, high drug loading of up to 22.8%, and sustained drug release behavior. Compared to Cst-loaded micelles assembled only by TPP-Chol (Cst@TPP-M), Cst@HA/TPP-M decreased the hemolysis rate and upgraded the in vivo stability and safety. In addition, a series of cell experiments using the triple-negative breast cancer cell line MDA-MB-231 as a cell model proved that Cst@HA/TPP-M effectively increased the cellular uptake of the drug through CD44-receptors-mediated endocytosis, and the uptake amount was three times that of the free Cst group. The confocal results demonstrated successful endo-lysosomal escape and effective mitochondrial transport triggered by the charge converse of Cst@HA/TPP-M after HA degradation in endo-lysosomes. Compared to the free Cst group, Cst@HA/TPP-M significantly elevated the ROS levels, reduced the mitochondrial membrane potential, and promoted tumor cell apoptosis, showing a better induction effect on mitochondrial dysfunction. In vivo imaging and antitumor experiments based on MDA-MB-231-tumor-bearing nude mice showed that Cst@HA/TPP-M facilitated drug enrichment at the tumor site, attenuated drug systemic distribution, and polished up the antitumor efficacy of Cst compared with free Cst. In general, as a target drug delivery system, mixed micelles co-constructed by TPP-Chol and HA-Chol might provide a promising strategy to ameliorate the therapeutic outcomes of Cst on TNBC.

Facile engineered macrophages-derived exosomes-functionalized PLGA nanocarrier for targeted delivery of dual drug formulation against neuroinflammation by modulation of microglial polarization in a post-stroke depression rat model.

Post-stroke depression (POSD) is a common difficulty and most predominant emotional syndrome after stroke often consequences in poor outcomes. In the present investigation, we have designed and studied the neurologically active celastrol/minocycline encapsulated with macrophages-derived exosomes functionalized PLGA nanoformulations (CMC-EXPL) to achieve enhanced anti-inflammatory behaviour and anti-depressant like activity in a Rat model of POSD. The animal model of POSD was established through stimulating process with chronic unpredictable mild stress (CUM) stimulations after procedure of middle cerebral artery occlusion (MCAO). Neuronal functions and Anti-inflammation behaviours were observed by histopathological (H&E) examination and Elisa analyses, respectively. The anti-depressive activity of the nanoformulations treated Rat models were evaluated by open-field and sucrose preference test methods. Microglial polarization was evaluated via flow-cytometry and qRT-PCR observations. The observed results exhibited that prepared nanoformulations reduced the POSD-stimulated depressive-like activities in rat models as well alleviated the neuronal damages and inflammatory responses in the cerebral hippocampus. Importantly, prepared CMC-EXPL nanoformulation effectively prevented the M1 pro-inflammatory polarization and indorsed M2 anti-inflammatory polarization, which indicates iNOS and CD86 levels significantly decreased and upsurged Arg-1 and CD206 levels. CMC-EXPL nanoformulation suggestively augmented anti-depressive activities and functional capability and also alleviated brain inflammation in POSD rats, demonstrating its therapeutic potential for POSD therapy.

Intratracheal delivery of macrophage targeted Celastrol-loaded PLGA nanoparticles for enhanced anti-inflammatory efficacy in acute lung injury mice.

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are common causes of respiratory failure in critically ill patients. There is still a lack of definitive and effective treatment options, and the mortality rate remains as high as 30% to 40%. Effective therapeutics for ALI/ARDS are greatly hindered by the side effects resulting from inefficient delivery to the disease lesions and off-targeting biodistribution of drugs. Macrophages play an integral role in maintaining the steady state of the immune system and are involved in inflammation processes. Thus, nanodrug to accurately target macrophages have the potential to transform disease treatment. Here, we developed an mannosylated drug delivery system to target and deliver celastrol (Cel) to the alveolar macrophages for enhanced alleviating the cytokines in LPS-induce ALI mice. In vitro data demonstrated that the as-synthesized Man@Cel-NPs significantly improved the targeting of Cel into the inflammatory macrophages via mannose receptor-mediated phagocytosis. In vivo experiments further showed that intratracheal delivery of Man@Cel-NPs can improve the dysregulation of inflammatory response in LPS-induced mice by inhibiting the release of inflammatory cytokines and increasing autophagy and decreasing apoptosis in lungs. This work provides a potential NP platform for the locally tracheal delivery of herbal ingredients and exhibits promising clinical potential in the treatment of numerous respiratory diseases, including ALI/ARDS.

Celastrol induces DNA damage and cell death in BCR-ABL T315I-mutant CML by targeting YY1 and HMCES.

BACKGROUND: Chronic myeloid leukemia (CML) is driven primarily by the constitutively active BCR-ABL fusion oncoprotein. Although the development of tyrosine kinase inhibitors has markedly improved the prognosis of CML patients, it remains a significant challenge to overcome drug-resistant mutations, such as the T315I mutation of BCR-ABL, and achieve treatment-free remission in the clinic. PURPOSE: The identification of new intervention targets beyond BCR-ABL could provide new perspectives for future research and therapeutic intervention. A network pharmacology analysis was conducted to identify the most promising natural product with anti-CML activity. Celastrol was selected for further analysis to gain insights into its mechanism of action (MoA), with the aim of identifying potential new intervention targets for BCR-ABL T315I-mutant CML. METHODS: Transcriptomic and proteomic analyses were conducted to systematically investigate the molecular MoA of celastrol in K562T315I cells. To identify the target proteins of celastrol, mass spectrometry-coupled cellular thermal shift assay (MS-CETSA) was carried out, followed by validations with genetic knockdown and overexpression, cell proliferation assay, comet assay, Western blotting, celastrol probe-based in situ labeling and pull-down assay, molecular docking, and biolayer interferometry. RESULTS: Our multi-omics analyses revealed that celastrol primarily induces DNA damage accumulation and the unfolded protein response in K562T315I cells. Among the twelve most potential celastrol targets, experimental evidence demonstrated that the direct interaction of celastrol with YY1 and HMCES increases the levels of DNA damage, leading to cell death. CONCLUSION: This study represents the first investigation utilizing a proteome-wide label-free target deconvolution approach, MS-CETSA, to identify the protein targets of celastrol. This study also develops a new systems pharmacology strategy. The findings provide new insights into the multifaceted mechanisms of celastrol and, more importantly, highlight the potential of targeting proteins in DNA damage and repair pathways, particularly YY1 and HMCES, to combat drug-resistant CML.

The neuroprotective role of celastrol on hippocampus in diabetic rats by inflammation restraint, insulin signaling adjustment, Aß reduction and synaptic plasticity alternation.

Celastrol, the primary constituent of Tripterygium wilfordii, has demonstrated neuroprotective properties in rats with dementia by reducing inflammation. A high-fat diet and streptozotocin injection were utilized to establish a diabetic rat model, which was then employed to investigate the possible protective effect of celastrol against the development of diabetes-induced learning and memory deficits. Afterwards, the experimental animals received a dose of celastrol by gavage (4 mg/kg/d). An animal study showed that celastrol enhanced insulin sensitivity and glucose tolerance in diabetic rats. In the Morris water maze test, rats with diabetes performed poorly in terms of spatial learning and memory; treatment with celastrol improved these outcomes. Additionally, administration of celastrol downregulated the expression of inflammatory-related proteins (NF-κB, IKKα, TNF-α, IL-1ß, and IL-6) and greatly reduced the generation of Aß in the diabetic hippocampus tissue. Moreover, the insulin signaling pathway-related proteins PI3K, AKT, and GSK-3ß were significantly upregulated in diabetic rats after celastrol was administered. Also, celastrol prevented damage to the brain structures and increased the synthesis of synaptic proteins like PSD-95 and SYT1. In conclusion, celastrol exerts a neuroprotective effect by modulating the insulin signaling system and reducing inflammatory responses, which helps to ameliorate the cognitive impairment associated with diabetes.

Hepatoma-Targeting and ROS-Responsive Polymeric Micelle-Based Chemotherapy Combined with Photodynamic Therapy for Hepatoma Treatment.

Background: The combination of nanoplatform-based chemotherapy and photodynamic therapy (PDT) is a promising way to treat cancer. Celastrol (Cela) exhibits highly effective anti-hepatoma activity with low water solubility, poor bioavailability, non-tumor targeting, and toxic side effects. The combination of Cela-based chemotherapy and PDT via hepatoma-targeting and reactive oxygen species (ROS)-responsive polymeric micelles (PMs) could solve the application problem of Cela and further enhance antitumor efficacy. Methods: In this study, Cela and photosensitizer chlorin e6 (Ce6) co-loaded glycyrrhetinic acid-modified carboxymethyl chitosan-thioketal-rhein (GCTR) PMs (Cela/Ce6/GCTR PMs) were prepared and characterized. The safety, ROS-sensitive drug release, and intracellular ROS production were evaluated. Furthermore, the in vitro anti-hepatoma effect and cellular uptaken in HepG2 and BEL-7402 cells, and in vivo pharmacokinetic, tissue distribution, and antitumor efficacy of Cela/Ce6/GCTR PMs in H22 tumor-bearing mice were then investigated. Results: Cela/Ce6/GCTR PMs were successfully prepared with nanometer-scale particle size, favorable drug loading capacity, and encapsulation efficiency. Cela/Ce6/GCTR PMs exhibited a strong safety profile and better hemocompatibility, exhibiting less damage to normal tissues. Compared with Cela-loaded GCTR PMs, the ROS-responsiveness of Cela/Ce6/GCTR PMs was increased, and the release of Cela was accelerated after combination with PDT. Cela/Ce6/GCTR PMs can efficiently target liver tumor cells by uptake and have a high cell-killing effect in response to ROS. The combination of GCTR PM-based chemotherapy and PDT resulted in increased bioavailability of Cela and Ce6, improved liver tumor targeting, and better anti-hepatoma effects in vivo. Conclusion: Hepatoma-targeting and ROS-responsive GCTR PMs co-loaded with Cela and Ce6 combined with PDT exhibited improved primary hepatic carcinoma therapeutic effects with lower toxicity to normal tissues, overcoming the limitations of monotherapy and providing new strategies for tumor treatment.

Dissection of Targeting Molecular Mechanisms of Celastrol-induced Nephrotoxicity via A Combined Deconvolution Strategy of Chemoproteomics and Metabolomics.

Celastrol (Cel), derived from the traditional herb Tripterygium wilfordii Hook. f., has anti-inflammatory, anti-tumor, and immunoregulatory activities. Renal dysfunction, including acute renal failure, has been reported in patients following the administration of Cel-relative medications. However, the functional mechanism of nephrotoxicity caused by Cel is unknown. This study featured combined use of activity-based protein profiling and metabolomics analysis to distinguish the targets of the nephrotoxic effects of Cel. Results suggest that Cel may bind directly to several critical enzymes participating in metabolism and mitochondrial functions. These enzymes include voltage-dependent anion-selective channel protein 1 (essential for maintaining mitochondrial configurational and functional stability), pyruvate carboxylase (involved in sugar isomerization and the tricarboxylic acid cycle), fatty acid synthase (related to ß-oxidation of fatty acids), and pyruvate kinase M2 (associated with aerobic respiration). Proteomics and metabolomics analysis confirmed that Cel-targeted proteins disrupt some metabolic biosynthetic processes and promote mitochondrial dysfunction. Ultimately, Cel aggravated kidney cell apoptosis. These cumulative results deliver an insight into the potential mechanisms of Cel-caused nephrotoxicity. They may also facilitate development of antagonistic drugs to mitigate the harmful effects of Cel on the kidneys and improve its clinical applications.

Celastrol alleviates secondary brain injury following intracerebral haemorrhage by inhibiting neuronal ferroptosis and blocking blood-brain barrier disruption.

Background: Following recent research advancements, an increasing level of evidence had been published to indicate that celastrol exerted a therapeutic effect on a range of nervous system diseases. This study therefore aimed to investigate the potential involvement of celastrol on ferroptosis and the blood-brain barrier disruption in intracerebral haemorrhage. Methods: We established a rat intracerebral haemorrhage and adrenal pheochromocytoma cell (PC12) OxyHb models using an ACSL4 overexpression vector. Ferroptosis-related indices were assessed using corresponding assay kits, and immunofluorescence and flow cytometry were used to measure reactive oxygen species (ROS) levels. Additionally, quantitative PCR (qPCR) and western blot analyses were conducted to evaluate the expression of key proteins and elucidate the role of celastrol in intracerebral haemorrhage (ICH). Results: Celastrol significantly improved neurological function scores, blood-brain barrier integrity, and brain water content in rats with ICH. Moreover, subsequent analysis of ferroptosis-related markers, such as Fe2+, ROS, MDA, and SOD, suggested that celastrol exerted a protective effect against the oxidative damage induced by ferroptosis in ICH rats and cells. Furthermore, Western blotting indicated that celastrol attenuated ferroptosis by modulating the expression levels of key proteins, including acyl-CoA synthetase long-chain family member 4 (ACSL4), glutathione peroxidase 4 (GPX4), ferritin heavy chain 1 (FTH1), and anti-transferrin receptor 1 (TFR1) both in vitro and in vivo. ACSL4 overexpression attenuated the neuroprotective effects of celastrol on ICH in vitro. Molecular docking analysis revealed that celastrol interacted with ACSL4 via the GLU107, GLN109, ASN111, and LYS357 binding sites. Conclusions: Celastrol exerted antioxidant properties and aids in neurological recovery after stroke by suppressing ACSL4 expression during ferroptosis. As such, this drug represented a promising pharmaceutical candidate for the treatment of ICH.

Celastrol-Ligustrazine compound proven to be a novel drug candidate for idiopathic pulmonary fibrosis by intervening in the TGF-ß1 mediated pathways-an experimental in vitro and vivo study.

Idiopathic Pulmonary Fibrosis (IPF) is a disease characterized by pulmonary interstitial fibrosis and collagen proliferation, currently lacking effective therapeutic options. The combined use of Celastrol and Ligustrazine has been proved to synergistically improve the pathological processes of inflammation and fibrosis. In earlier studies, we designed and synthesized a Celastrol-Ligustrazine compound CL-001, though its role in IPF remains unclear. Here, the effects and mechanisms of CL-001 in bleomycin (BLM)-induced IPF were investigated. In vivo, CL-001 significantly improved lung function, reduced pulmonary inflammation, and decreased collagen deposition, thereby preventing the progression of IPF. In vitro, CL-001 concurrently inhibited both Smad-dependent and Smad-independent pathways, thereby suppressing TGF-ß1-induced epithelial-mesenchymal transition (EMT) and epithelial cell migration. This inhibitory effect was superior to that of Celastrol or Ligustrazine administered alone. Additionally, CL-001 significantly increased the level of apoptosis and promoted the expression of apoptosis-related proteins (Caspase-8 and PARP), ultimately leading to widespread apoptosis in activated lung epithelial cells. In summary, CL-001 exhibits excellent anti-IPF effects both in vitro and in vivo, suggesting its potential as a novel candidate drug for IPF, warranting further development.

Engineered Carrier-Free Nanosystem-Induced In Situ Therapeutic Vaccines for Potent Cancer Immunotherapy.

In situ vaccines that can stimulate tumor immune response have emerged as a breakthrough in antitumor therapy. However, the immunosuppressed tumor microenvironment and insufficient infiltration of immune cells lead to ineffective antitumor immunity. Hence, a biomimetic carrier-free nanosystem (BCC) to induce synergistic phototherapy/chemotherapy-driven in situ vaccines was designed. A carrier-free nanosystem was developed using phototherapeutic reagents CyI and celastrol as raw materials. In vitro and in vivo studies have shown that under NIR light irradiation, BCC-mediated photo/chemotherapy not only accelerates the release of drugs to deeper parts of tumors, achieving timing and light-controlled drug delivery to result in cell apoptosis, but also effectively stimulates the antitumor response to induce in situ vaccine, which could invoke long-lasting antitumor immunity to inhibit tumor metastasis and eliminate distant tumor. This therapeutic strategy holds promise for priming robust innate and adaptive immune responses, arresting cancer progression, and inducing tumor dormancy.

The anti-cancer mechanism of Celastrol by targeting JAK2/STAT3 signaling pathway in gastric and ovarian cancer.

BACKGROUND: Celastrol is a natural triterpene exhibiting significant and extensive antitumor activity in a wide range of cancer. Due to unfavorable toxicity profile and undefined mechanism, Celastrol's application in clinical cancer therapy remains limited. Herein, we elucidate the pharmacological mechanism of Celastrol's anticancer effects, with a focus on STAT3 signaling pathway in cancers with high incidence of metastasis. METHODS: The safety profile of Celastrol were assessed in mice. In vitro analysis was performed in gastric cancer and ovarian cancer to assess the cytotoxicity, induction of reactive oxygen species (ROS) of Celastrol using STAT3 knockout cancer cells. Effects of Celastrol on STAT3 activation and transcription activity, JAK2/STAT3 signaling protein expression were assessed. Additionally, proteomic contrastive analysis was performed to explore the molecular association of Celastrol with STAT3 deletion in cancer cells. RESULTS: Celastrol has no obvious toxic effect at 1.5 mg/kg/day in a 15 days' administration. Celastrol inhibits tumor growth and increases ROS in a STAT3 dependent manner in gastric and ovarian cancer celllines. On molecular level, it downregulates IL-6 level and inhibits the JAK2/STAT3 signaling pathway by suppressing STAT3' activation and transcription activity. Proteomic contrastive analysis suggests a similar cellular mechanism of action between Celastrol and STAT3 deletion on regulating cancer progression pathways related to migration and invasion. CONCLUSION: Our research elucidates the anti-cancer mechanism of Celastrol through targeting the JAK2/STAT3 signaling pathway in cancer with high incidence of metastasis. This study provides a solid theoretical basis for the application of Celastrol in cancer therapy.