Curcumin increases heat shock protein 70 expression via different signaling pathways in intestinal epithelial cells

Biomedical Promise of Sustainable Microwave-Engineered Symmetric Curcumin Derivatives

Curcumin is a polyphenol of the Curcuma longa plant, which can be used for various medicinal purposes, such as inflammation and cancer treatment. In this context, two symmetric curcumin derivatives (D1-(1E,6E)-1,7-bis(4-acetamidophenyl)hepta-1,6-diene-3,5-dione and D2-p,p-dihydroxy di-cinnamoyl methane) were obtained by the microwave-based method and evaluated for their antitumoral effect on human cervix cancer in comparison with toxicity on non-tumoral cells, taking into account that they were predicted to act as apoptosis agonists or anti-inflammatory agents. The HeLa cell line was incubated for 24 and 72 h with a concentration of 50 μg/mL of derivatives that killed almost half of the cells compared to the control. In contrast, these compounds did not alter the viability of MRC-5 non-tumoral lung fibroblasts until 72 h of incubation. The nitric oxide level released by HeLa cells was higher compared to MRC-5 fibroblasts after the incubation with 100 μg/mL. Both derivatives induced the decrease of catalase activity and glutathione levels in cancer cells without targeting the same effect in non-tumoral cells. Furthermore, the Western blot showed an increased protein expression of HSP70 and a decreased expression of HSP60 and MCM2 in cells incubated with D2 compared to control cells. We noticed differences regarding the intensity of cell death between the tested derivatives, suggesting that the modified structure after synthesis can modulate their function, the most prominent effect being observed for sample D2. In conclusion, the outcomes of our in vitro study revealed that these microwave-engineered curcumin derivatives targeted tumor cells, much more specifically, inducing their death.

Partially hydrolyzed guar gum upregulates heat shock protein 27 in intestinal Caco-2 cells and mouse intestine via mTOR and ERK signaling

BACKGROUND

The intestinal epithelium acts as a barrier against harmful luminal materials, thus preventing intestinal diseases and maintaining intestinal health. Heat shock protein 27 (HSP27) promotes intestinal epithelial integrity under both physiological and stressed conditions. The effects of partially hydrolyzed guar gum (PHGG) on HSP27 expression in intestinal Caco-2 cells and mouse intestines were investigated.

RESULTS

The present study showed that PHGG upregulated HSP27 expression in Caco-2 cells without upregulating Hspb1, the gene encoding HSP27. Feeding PHGG increased HSP25 expression in epithelial cells of the small intestine of mice. Inhibition of protein translation using cycloheximide suppressed PHGG-mediated HSP27 expression, indicating that PHGG upregulated HSP27 via translational modulation. Signaling inhibition of the mechanistic target of rapamycin (mTOR) and phosphatidyl 3-inositol kinase reduced PHGG-mediated HSP27 expression, whereas mitogen-activated protein kinase kinase inhibition by U0126 increased HSP27 expression, irrespective of PHGG administration. PHGG increases mTOR phosphorylation and reduces extracellular signal-regulated protein kinase (ERK) phosphorylation.

CONCLUSION

PHGG-mediated translation of HSP27 in intestinal Caco-2 cells and mouse intestine via the mTOR and ERK signaling pathways may promote intestinal epithelial integrity. These findings help us better understand how dietary fibers regulate the physiological function of the intestines. © 2023 Society of Chemical Industry.

Role of heat shock protein 70 in regulation of anti-inflammatory response to curcumin in 3T3-L1 adipocytes

BACKGROUND/OBJECTIVES

Curcumin is a well-known phytochemical with anti-inflammatory effects. Heat shock protein (HSP) 70, an intracellular chaperone, inhibits proinflammatory signaling activation. Although curcumin has been shown to induce HSP70 expression in various cell types, whether HSP70 mediates the anti-inflammatory effects of curcumin in mature adipocytes remains unclear.

MATERIALS/METHODS

To assess the role of HSP70 in regulating the anti-inflammatory response to curcumin in adipocytes, fully differentiated 3T3-L1 adipocytes were treated with curcumin, lipopolysaccharide (LPS), and/or the HSP70 inhibitor pifithrin-μ (PFT-μ). The expression levels of HSP70 and proinflammatory cytokines were then measured.

RESULTS

Curcumin upregulated HSP70 expression at both protein and mRNA levels and attenuated LPS-induced Il6, Ptx3, and Ccl2 mRNA upregulation. PFT-μ tended to exacerbate the LPS-induced upregulation of Il6, Ptx3, Ccl2, and Tnfa mRNA expression. However, on curcumin pretreatment, the tendency of PFT-μ to upregulate LPS-induced proinflammatory cytokine expression decreased or disappeared.

CONCLUSION

These results indicate that HSP70 is involved in the regulation of inflammatory responses but may not be crucial for the anti-inflammatory effects of curcumin in 3T3-L1 adipocytes.

N-butyrate increases heat shock protein 70 through heat shock factor 1 and AMP-activated protein kinase pathways in human intestinal Caco-2 cells

Impaired integrity of the intestinal epithelium is a cause of intestinal and extraintestinal diseases. Heat shock protein 70 (HSP70), a cytoprotective protein, plays an important role in maintaining intestinal homeostasis. The intestinal expression of HSP70 is linked with the local microbiota. The present study investigated the molecular mechanisms underlying the upregulation of HSP70 by n-butyrate, a major metabolite of the intestinal microbiota in human intestinal Caco-2 cells. Treatment of Caco-2 cells with n-butyrate upregulated HSP70 protein and mRNA levels in a dose-dependent manner. Using luciferase reporter assay, it was found that n-butyrate enhanced the transcriptional activity of HSP70. These effects were sensitive to the inhibition of heat shock factor 1 (HSF1), a transcription factor, and AMP-activated protein kinase (AMPK). N-butyrate increased the phosphorylation (activity) of HSF1 and AMPK. Taken together, this study shows that n-butyrate is partly involved in the microbiota-dependent intestinal expression of HSP70, and the effect is exerted through the HSF1 and AMPK pathways.

Targeting HSP47 and HSP70: promising therapeutic approaches in liver fibrosis management

Liver fibrosis is a liver disease in which there is an excessive buildup of extracellular matrix proteins, including collagen. By regulating cytokine production and the inflammatory response, heat shock proteins (HSPs) contribute significantly to a wider spectrum of fibrotic illnesses, such as lung, liver, and idiopathic pulmonary fibrosis by aiding in the folding and assembly of freshly synthesized proteins, HSPs serve as chaperones. HSP70 is one of the key HSPs in avoiding protein aggregation which induces its action by sending unfolded and/or misfolded proteins to the ubiquitin–proteasome degradation pathway and antagonizing influence on epithelial-mesenchymal transition. HSP47, on the other hand, is crucial for boosting collagen synthesis, and deposition, and fostering the emergence of fibrotic disorders. The current review aims to provide light on how HSP70 and HSP47 affect hepatic fibrogenesis. Additionally, our review looks into new therapeutic approaches that target HSP70 and HSP47 and could potentially be used as drug candidates to treat liver fibrosis, especially in cases of comorbidities.

Current Development and Future Application Prospects of Plants-Derived Polyphenol Bioactive Substance Curcumin as a Novel Feed Additive in Livestock and Poultry

Curcumin (CUR) is a kind of natural orange-yellow phenolic compound mainly extracted from the stems and roots of turmeric plants and other species in the genus Curcuma, furthermore, it is also the most important active ingredient exerting pharmacological functions in turmeric. In recent years, CUR has been frequently reported and has attracted widespread attention from scholars all over the world due to its numerous biological functions and good application prospects, such as anti-inflammatory, anticancer, antioxidant and providing lipid-lowering effects, etc. In addition, adding a certain dose of CUR to livestock and poultry feed is important for animal growth and development, which plays a key role in animal metabolism, reproduction, immunity and clinical health care. This review aims to summarize, based on the published papers and our own observations, the physical and chemical properties and the biological functions of the plant-derived bioactive ingredient CUR, especially regarding the latest research progress in regulating intestinal health as well as its current development and future application prospects in livestock and poultry as a novel feed additive, so as to provide theoretical and practical references for the further study of the application of CUR as a novel feed additive and a potential new antibiotic substitute, thereby improving the research field of plant-derived bioactive ingredients and promoting the healthy development of livestock and poultry.

Gallnut Tannic Acid Exerts Anti-stress Effects on Stress-Induced Inflammatory Response, Dysbiotic Gut Microbiota, and Alterations of Serum Metabolic Profile in Beagle Dogs

Stress exposure is a potential threat to humans who live or work in extreme environments, often leading to oxidative stress, inflammatory response, intestinal dysbiosis, and metabolic disorders. Gallnut tannic acid (TA), a naturally occurring polyphenolic compound, has become a compelling source due to its favorable anti-diarrheal, anti-oxidative, anti-inflammatory, and anti-microbial activities. Thus, this study aimed to evaluate the anti-stress effects of gallnut TA on the stress-induced inflammatory response, dysbiotic gut microbiota, and alterations of serum metabolic profile using beagle models. A total of 13 beagle dogs were randomly divided into the stress (ST) and ST + TA groups. Dietary supplementation with TA at 2.5 g/kg was individually fed to each dog in the ST + TA group for 14 consecutive days. On day 7, all dogs were transported for 3 h from a stressful environment (days 1–7) to a livable site (days 8–14). In our results, TA relieved environmental stress-induced diarrheal symptoms in dogs and were shown to protect from myocardial injury and help improve immunity by serum biochemistry and hematology analysis. Also, TA inhibited the secretion of serum hormones [cortisol (COR), glucocorticoid (GC), and adrenocorticotropic hormone (ACTH)] and the expression of heat shock protein (HSP) 70 to protect dogs from stress-induced injury, thereby relieving oxidative stress and inflammatory response. Fecal 16S rRNA gene sequencing revealed that TA stimulated the growth of beneficial bacteria (Allobaculum, Dubosiella, Coriobacteriaceae_UCG-002, and Faecalibaculum) and suppressed the growth of pathogenic bacteria (Escherichia-Shigella and Streptococcus), thereby increasing fecal butyrate levels. Serum metabolomics further showed that phytosphingosine, indoleacetic acid, arachidonic acid, and biotin, related to the metabolism of sphingolipid, tryptophan, arachidonic acid, and biotin, respectively, could serve as potential biomarkers of stress exposure. Furthermore, Spearman’s correlation analysis showed strong relationships between the four potential serum biomarkers and differential bacteria. Overall, gallnut TA may be a potential prebiotic for the prevention and treatment of stress-induced metabolic disorders by targeting intestinal microbiota.

Heat Shock Protein 70 Mediates the Protective Effect of Naringenin on High-Glucose-Induced Alterations of Endothelial Function

Endothelial dysfunction plays a pivotal role in the development and progression of diabetic vascular complications. Naringenin (Nar) is a flavanone bioactive isolated from citrus fruits known to have in vitro and in vivo antidiabetic properties. However, whether Nar affects endothelial function remains unclear in diabetes or under high-glucose (HG) condition. Using an in vitro model of hyperglycemia in human umbilical vein endothelial cells (HUVECs), we found that Nar administration markedly attenuated HG-induced alterations of endothelial function, evidenced by the mitigation of oxidative stress and inflammation, the reduction of cell adhesion molecular expressions, and the improvement of insulin resistance. We also found that HG exposure significantly reduced the levels of intracellular heat shock protein 70 (iHSP70 or iHSPA1A) and the release of HSP70 from HUVECs. HSP70 depletion mimicked and clearly diminished the protective effects of Nar on HG-induced alterations of endothelial function. In addition, Nar treatment significantly enhanced iHSP70 protein levels through a transcription-dependent manner. These results demonstrated that Nar could protect HUVECs against HG-induced alterations of endothelial function through upregulating iHSP70 protein levels. These findings are also helpful in providing new therapeutic strategies that are promising in the clinical use of Nar for the treatment of diabetes and diabetic complications.

Propionate and Dietary Fermentable Fibers Upregulate Intestinal Heat Shock protein70 in Intestinal Caco-2 Cells and Mouse Colon

Short-chain fatty acids (SCFAs), including propionate, are major metabolites of intestinal microorganisms and play an essential role in regulating intestinal epithelial integrity. Heat shock proteins (HSPs) promote cellular homeostasis under physiological and stressed conditions. This study aimed to investigate the regulation of intestinal HSP70 by propionate in human intestinal Caco-2 cells and the colon of fermentable dietary fiber (DF)-fed mice and germ-free mice. The results showed that propionate increased Hspa1a (HSP70 mRNA) level in Caco-2 cells, upregulated HSP70 protein, and phosphorylation of heat shock factor 1; however, the latter two were reduced by mitogen-activated protein kinases and the mechanistic target of rapamycin inhibitors. Feeding fermentable DFs, such as guar gum (GG) and partially hydrolyzed GG, increased both cecal SCFAs and colonic HSP70 expression, both of which were reduced in germ-free mice than in specific-pathogen-free mice. Collectively, the propionate-induced HSP70 expression was shown to be possibly involved in intestinal homeostasis.