Bortezomib protects against dextran sulfate sodium‑induced ulcerative colitis in mice

Bortezomib in cancer therapy: Mechanisms, side effects, and future proteasome inhibitors

The ubiquitin-proteasome pathway (UPP) regulates protein stability and normal cellular functions with the help of autocatalytic proteasome complex. Studies have linked aberrant proteasome activity to malignant cells and found that proteasome inhibitors play a significant role as therapeutic drugs for various types of cancer, specifically multiple myeloma and mantle cell lymphoma. Bortezomib, the first FDA-approved proteasome inhibitor for treating different stages of multiple myeloma, acts on cancer cells by inhibiting the 26S proteasome, modulating NF-κB, phosphorylating Bcl-2, upregulating of NOXA, blocking p53 degradation, activating caspase, generating reactive oxygen species (ROS), and inhibiting angiogenesis. However, its efficacy is limited due to side effects such as peripheral neuropathy (PN), thrombotic microangiopathy (TMA), and acute interstitial nephritis (AIN). Therefore, a better understanding of its precise mechanism of action may help mitigate these side effects. In this review, we have discussed the proposed mechanisms of action and off target effects of Bortezomib, along with the prospects of next generation potential proteasome inhibitor drugs in the treatment of cancer.

Anti-inflammatory Effect of a Novel Pectin Polysaccharide From Rubus chingii Hu on Colitis Mice

Rubus chingii Hu has been used as a functional food for a long time. A novel pectin polysaccharide named RCHP-S from R. chingii Hu was structurally identified and explored its anti-inflammatory effect on colitis mice. RCHP-S was composed of mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, and arabinose. NMR spectroscopy and methylation analysis showed that RCHP-S was mainly composed of HG-type pectin domains but also contains a small amount of RG-I. The anti-inflammatory tests indicated that the mouse macrophage RAW 264.7 cells pretreated with RCHP-S could show a significant inhibitory effect on the mRNA level of iNOS, IL-1β, IL-6, and TNF-α in vitro. Polysaccharide RCHP-S reduced the enteritis symptoms in dextran sulfate sodium (DSS)-induced colitis mice by inhibiting released inflammatory factors. These results indicated that the R. chingii Hu polysaccharide can be used as food additives for the treatment of intestinal inflammation.

Aqueous Extract of Cimicifuga dahurica Reprogramming Macrophage Polarization by Activating TLR4-NF-κB Signaling Pathway

Purpose

Cimicifuga dahurica (C. dahurica), which has been used in traditional oriental medicine for a long period, was reported to exert extensive antitumor activity, but the effect and molecular biological mechanism of C. dahurica on multiple myeloma (MM) has not been elaborated. Tumor-associated macrophages (TAMs) exhibit a sustained polarization between tumor killing M1 subtype and tumor supporting M2 subtype. And a lower ratio of M1/M2 is associated with tumor angiogenesis, proliferation and invasion. We explored the inhibitory effect of the aqueous extract of the root of C. dahurica (CRAE) on tumor growth by reprogramming macrophage polarization in the tumor microenvironment.

Methods

Mice bearing SP2/0 multiple myeloma were treated with CRAE. Western blotting (WB), immunohistochemistry (IHC) and immunofluorescence staining were utilized to assess tumor growth and TAM populations. Macrophages were depleted by injection of clodronate liposomes to determine and measure the role of CRAE as an anti-tumor agent by targeting macrophages. To simulate tumor microenvironment, MM cells H929 and TAMs were co-cultured using the transwell co-culture system. By using CRAE as an immunoregulator in M2-like macrophages, we analyzed CRAE-treated macrophage-associated surface markers and cytokines by flow cytometry and WB.

Results

The results indicated that CRAE treatment could reduce tumor burden of MM mice and a high degree of M1-like macrophages infiltration was detected in tumor tissues. In vitro co-culture system, CRAE significantly promoted the polarization of M2 to M1 phenotype, which led to the increase in apoptosis of myeloma cells. It was found that the M1 polarization induced by CRAE depended on the TLR4-MyD88-TAK1-NF-κB signal transduction.

Conclusion

This study elucidated the anticancer mechanism of the aqueous extract of C. dahurica (CRAE) through reprogramming macrophage polarization and highlighted that CRAE could act as a potential novel option for cancer immunotherapy.

A Potential Probiotic for Diarrhea: Clostridium tyrobutyricum Protects Against LPS-Induced Epithelial Dysfunction via IL-22 Produced By Th17 Cells in the Ileum

Probiotics are clinically used for diarrhea and inflammatory bowel diseases in both humans and animals. Previous studies have shown that Clostridium tyrobutyricum (Ct) protects against intestinal dysfunction, while its regulatory function in the gut needs further investigation and the related mechanisms are still not fully elucidated. This study aims to further verify the protective function of Ct and reveal its underlying mechanisms in alleviating diarrhea and intestinal inflammation. Ct inhibited LPS-induced diarrhea and intestinal inflammation in the ileum. IL-22 was identified and the protective role of Ct in the ileum presented an IL-22-dependent manner according to the transcriptomic analysis and in vivo interference mice experiments. The flow cytometric analysis of immune cells in the ileum showed that Ct enhanced the proportions of Th17 cells in response to LPS. The results of in situ hybridization further verified that Ct triggered Th17 cells to produce IL-22, which combined with IL-22RA1 expressed in the epithelial cells. Moreover, Ct was unable to enhance the levels of short-chain fatty acids (SCFAs) in the ileum, suggesting that the protective role of Ct in the ileum was independent of SCFAs. This study uncovered the role of Ct in alleviating diarrhea and inflammation with the mechanism of stimulating Th17 cells in the lamina propria to produce IL-22, highlighting its potential application as a probiotic for diarrhea and inflammation in the ileum.

Eriodictyol attenuates TNBS-induced ulcerative colitis through repressing TLR4/NF-kB signaling pathway in rats

Ulcerative colitis (UC) is a chronic disease characterized by mucosal and submucosal inflammation, which has a low cure rate and is prone to relapse, due to the immune imbalance of the body. Inhibition of inflammation-related pathways can delay the progression of UC. Toll-like receptor 4 (TLR4) pathway is considered to be one of the important signaling pathways involved in colon inflammation. Eriodictyol (EDT) is a natural flavonoid widely distributed in foodborne plants. EDT plays an important role in the regulation of inflammation and related signaling pathways. However, whether EDT plays a role in UC remains unknown. Herein, we established a TNBS induced animal model of enteritis in Wistar rats. Our data confirmed the establishment of TNBS induced animal model of enteritis and the administration Eriodictyol in Wistar rats. EDT treatment alleviated TNBS-induced intestinal tissue injury in rats. We further found that EDT reduced MPO expression and regulated the cytokine parameters in TNBS-induced intestinal tissues of rats. The levels of TNF-α, IL-1β, IL-6, IL-10, IL-2, and IL-12 were also affected by the treatment of EDT. EDT also affected SOD, CAT, GSH-Px, and MDA level in rats with colitis. Moreover, EDT regulated TNBS-induced TLR4/NF-κB pathway activation, therefore inhibiting the progression of UC. Our results suggest that EDT could be a potential therapeutic agent for UC.

The TiO2-μ implant residual is more toxic than the Al2O3-n implant residual via blocking LAP and inducing macrophage polarization

Medical device residuals cause harmful effects and diseases in the human body, such as Particle Disease (PD), but the biological interaction of different types of particles is unclear. In this study, after a biological interaction screen between different particles, we aimed to explore the mechanism of the biological interaction between different types of particles, and the effect of a proteasome inhibitor on PD. Our studies showed that the titanium oxide microscale particle (Ti-μ) was more toxic than the aluminum oxide nanoscale particle (Al-n). Al-n activated LAP, attenuated the macrophage M1 polarization, inhibited the activator of the NF-κB pathway, and blocked the secretion of inflammatory factors and apoptosis in vitro, and also prevented the inflammation tissue disorder and aseptic loosening in vivo induced by Ti-μ. What is more, Bortezomib blocked apoptosis, secretion of inflammatory factors and the activation of the NF-κB pathway induced by TiO2 micro particles. Al-n-induced autophagy could play the function in the efficient clearance of dying cells by phagocytosis, and serves in dampening M1 polarization-related pro-inflammatory responses. While the Ti alloy medical implant and devices are applied worldwide, the toxicity of Ti-μ and its interaction with Al-n could be considered in the implant design, and Bortezomib was a potential therapeutic for PD.

Resveratrol Reduces COMPopathy in Mice Through Activation of Autophagy

Misfolding mutations in cartilage oligomeric matrix protein (COMP) cause it to be retained within the endoplasmic reticulum (ER) of chondrocytes, stimulating a multitude of damaging cellular responses including ER stress, inflammation, and oxidative stress, which ultimately culminates in the death of growth plate chondrocytes and pseudoachondroplasia (PSACH). Previously, we demonstrated that an antioxidant, resveratrol, substantially reduces the intracellular accumulation of mutant-COMP, dampens cellular stress, and lowers the level of growth plate chondrocyte death. In addition, we showed that resveratrol reduces mammalian target of rapamycin complex 1 (mTORC1) signaling, suggesting a potential mechanism. In this work, we investigate the role of autophagy in treatment of COMPopathies. In cultured chondrocytes expressing wild-type COMP or mutant-COMP, resveratrol significantly increased the number of Microtubule-associated protein 1A/1B-light chain 3 (LC3) vesicles, directly demonstrating that resveratrol-stimulated autophagy is an important component of the resveratrol-driven mechanism responsible for the degradation of mutant-COMP. Moreover, pharmacological inhibitors of autophagy suppressed degradation of mutant-COMP in our established mouse model of PSACH. In contrast, blockage of the proteasome did not substantially alter resveratrol clearance of mutant-COMP from growth plate chondrocytes. Mechanistically, resveratrol increased SIRT1 and PP2A expression and reduced MID1 expression and activation of phosphorylated protein kinase B (pAKT) and mTORC1 signaling in growth plate chondrocytes, allowing clearance of mutant-COMP by autophagy. Importantly, we show that optimal reduction in growth plate pathology, including decreased mutant-COMP retention, decreased mTORC1 signaling, and restoration of chondrocyte proliferation was attained when treatment was initiated between birth to 1 week of age in MT-COMP mice, translating to birth to approximately 2 years of age in children with PSACH. These results clearly demonstrate that resveratrol stimulates clearance of mutant-COMP by an autophagy-centric mechanism. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Design, synthesis and evaluation of a baicalin and berberine hybrid compound as therapeutic agent for ulcerative colitis

Structural modification of active natural compoundswhichwereoriginated fromTraditional Chinese Medicine (TCM) have showedgreat advantagesin thedevelopmentof new drugs. In TCM, "Huangqin-Huanglian" is a classic "medicine couple"thathas been used to treat intestinal diseases for thousands ofyears, while baicalinand berberine are the major active compoundsof Huangqin and Huanglianrespectively. Based onthis"medicine couple",wedesignedand synthesizeda newbaicalin and berberine hybrid compound (BBH).Its molecular structure wasconfirmedby spectroscopy.The antibacterial activity of BBH was detected in vitro.Results indicatedthat the new hybrid compound exhibited the best antibacterial activity forproteobacteria as compared with its original synthetic materials (baicalin andberberine). In vivo, the effect of BBHon ulcerative colitiswas alsoinvestigated.BBH treatment significantly ameliorated the disease symptoms andpreventedthe colon damage of ulcerative colitis. Furthermore, BBH showed asignificant anti-inflammatory effect through regulating activities of SOD, MPOandexpressions of pro-inflammatory cytokines (TNF-α, IL-1β and IL-6) in colontissue. Data also suggested that BBH was more superior than baicalin and berberine inameliorating colonic damage. This indicated that the new hybrid compound BBHshowed enhanced efficacy in treating ulcerative colitis.

Quercetin Alleviates Intestinal Oxidative Damage Induced by H2O2 via Modulation of GSH: In Vitro Screening and In Vivo Evaluation in a Colitis Model of Mice

The gastrointestinal tract is exposed to pro-oxidants from food, host immune factors, and microbial pathogens, which may induce oxidative damage. Oxidative stress has been shown to play an important role in the onset of inflammatory bowel disease. This study aimed to use a novel model to evaluate the effects of a screened natural component and explore its possible mechanism. An in vitro oxidative stress Caco2 cell model induced by H₂O₂ was established using a real-time cellular analysis system and verified by addition of glutathione (GSH). A variety of plant components were chosen for the screening. Quercetin was the most effective phytochemical to alleviate the decreased cell index caused by H₂O₂ among the tested plant components. Furthermore, quercetin ameliorated dextran sulfate sodium salt (DSS)-induced colitis and further increased the serum GSH. The mechanism of quercetin protection was explored in Caco2. Reversed H₂O₂-induced cell damage and decreased reactive oxygen species and apoptosis ratio were observed in quercetin-treated cells. Also, quercetin increased expression of the glutamate-cysteine ligase catalytic subunit (GCLC), the first rate-limiting enzyme of glutathione synthesis, and increased intracellular GSH concentration under H₂O₂ treatment. This effect was abolished by the GCLC inhibitor buthionine sulfoximine. These results indicated that quercetin can improve cell proliferation and increase intracellular GSH concentrations by upregulating transcription of GCLC to eliminate excessive reactive oxygen species (ROS). Increased extracellular H₂O₂ concentration induced by quercetin under oxidative stress was related to the inhibition of AQP3 and upregulation of NOX1/2, which may contribute to the observed protective effects of quercetin. Moreover, the novel H₂O₂-induced oxidative stress cell model based on the real-time cellular analysis system was an effective model to screen natural products to deal with intestinal oxidative damage and help accelerate the discovery of new drugs for inflammatory bowel disease (IBD).

Nanosized Alumina Particle and Proteasome Inhibitor Bortezomib Prevented inflammation and Osteolysis Induced by Titanium Particle via Autophagy and NF-κB Signaling

Autophagy and NF-κB signaling are involving in the process of Particle Disease, which was caused by the particles released from friction interface of artificial joint, implant materials of particle reinforced composite, scaffolds for tissue engineering, or material for drug delivery. However, the biological interaction of different material particles and the mechanism of proteasome inhibitor, Bortezomib (BTZ), against Titanium (Ti) particle-induced Particle Disease remain unclear. In this study, we evaluated effect of nanosized Alumina (Al) particles and BTZ on reducing and treating the Ti particle-induced inflammatory reaction in MG-63 cells and mouse calvarial osteolysis model. We found that Al particles and BTZ could block apoptosis and NF- κB activation in osteoblasts in vitro and in a mouse model of calvarial resorption induced by Ti particles. We found that Al particles and BTZ attenuated the expression of inflammatory cytokines (IL-1β, IL-6, TNF-α). And Al prevented the IL-1β expression induced by Ti via attenuating the NF- κB activation β-TRCP and reducing the expression of Casepase-3. Expressions of autophagy marker LC3 was activated in Ti group, and reduced by Al and/not BTZ. Furthermore, the expressions of OPG were also higher in these groups than the Ti treated group. Collectively, nanosized Al could prevent autophagy and reduce the apoptosis, inflammatory and osteolysis induced by Ti particles. Our data offered a basic data for implant design when it was inevitable to use Ti as biomaterials, considering the outstanding mechanical propertie of Ti. What's more, proteasome inhibitor BTZ could be a potential therapy for wear particle-induced inflammation and osteogenic activity via regulating the activity of NF- κB signaling pathway.

Ameliorating effects of bortezomib, a proteasome inhibitor, on development of dextran sulfate sodium-induced murine colitis

We examined the effect of bortezomib, a proteasome inhibitor, on the development of dextran sulfate sodium (DSS)-induced colitis in mice. DSS-colitis was induced by the administration of 3% DSS in water in C57BL/6J mice. Bortezomib was intraperitoneally administered daily for 9 days from the start of DSS. Ubiquitination of IκBα was evaluated by immunoblot. Bortezomib significantly ameliorated DSS-induced body weight loss and reduced the disease activity. The translocation of NF-κBp65 into the nucleus was markedly suppressed in the DSS + bortezomib group compared to the DSS group, but this difference was not detected in submucosal tissue. Ubiquitinated IκBα in the cytoplasm of colon epithelial cells was increased in the DSS + bortezomib group compared to the DSS group. In HT-29 cells, bortezomib blocked tumor necrosis factor-α (TNF-α)-induced nuclear translocation of NF-κB and this was accompanied by an increase in ubiquitinated IκBα in the cytoplasm. The mRNA expression of inflammatory mediators in colonic epithelial cells was significantly reduced by the treatment of bortezomib. Bortezomib inhibited the nuclear translocation of NF-κB in colonic epithelial cells by suppressing the degradation of IκBα and contributed to an improvement in DSS colitis. Our study suggests that bortezomib may be a new treatment option for IBD.