Paeoniflorin, a novel heat shock protein-inducing compound

Hsp70: A Multifunctional Chaperone in Maintaining Proteostasis and Its Implications in Human Disease

Hsp70, a 70 kDa molecular chaperone, plays a crucial role in maintaining protein homeostasis. It interacts with the DnaJ family of co-chaperones to modulate the functions of client proteins involved in various cellular processes, including transmembrane transport, extracellular vesicle trafficking, complex formation, and proteasomal degradation. Its presence in multiple cellular organelles enables it to mediate stress responses, apoptosis, and inflammation, highlighting its significance in disease progression. Initially recognized for its essential roles in protein folding, disaggregation, and degradation, later studies have demonstrated its involvement in several human diseases. Notably, Hsp70 is upregulated in multiple cancers, where it promotes tumor proliferation and serves as a tumor immunogen. Additionally, epichaperome networks stabilize protein-protein interactions in large and long-lived assemblies, contributing to both cancer progression and neurodegeneration. However, extracellular Hsp70 (eHsp70) in the tumor microenvironment can activate immune cells, such as natural killer (NK) cells, suggesting its potential in immunotherapeutic interventions, including CAR T-cell therapy. Given its multifaceted roles in cellular physiology and pathology, Hsp70 holds immense potential as both a biomarker and a therapeutic target across multiple human diseases. This review highlights the structural and functional importance of Hsp70, explores its role in disease pathogenesis, and discusses its potential in diagnostic and therapeutic applications.

Paeoniflorin Attenuates Oxidative Stress and Inflammation in Parkinson's Disease by Activating the HSF1-NRF1 Axis

This study is to explore the effects of paeoniflorin (PF) on oxidative stress (OS) and inflammation in Parkinson's disease (PD) via the HSF1-NRF1 axis. SH-SY5Y cells were pretreated with PF and induced with α-synuclein preformed fibrils (PFF), followed by gain- and loss-of-function assays. Afterward, detection was conducted on cell viability, mitochondrial membrane potential ([Formula: see text]m), and reactive oxygen species (ROS), cyclooxygenase (COX)-2, and inducible nitric oxide synthase (iNOS) levels. The binding of HSF1 to NRF1 promoter was evaluated. HSF1 and NRF1 expression was examined. Lastly, PD mouse models were established, followed by observation of the behavioral features of mice. Apoptosis; cleaved-Caspase 3, cleaved-Caspase 8, repulsive guidance molecule A (RGMa), GAP-43, and brain-derived neurotrophic factor (BDNF) expression; and superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH-Px), catalase (CAT), tumor necrosis factor (TNF)-α, interleukin (IL)-2, IL-6, and IL-10 levels were determined in mice and cells. HSF1 and NRF1 were downregulated, and HSF1 promoted NRF1 transcription and PF dose-dependently augmented HSF1 and NRF1 expression. PF dose-dependently reduced RGMa expression, ROS, MDA, TNF-α, IL-2, and IL-6 levels; mitigated apoptosis; and lowered cleaved-Caspase 3, cleaved-Caspase 8, COX-2, and iNOS expression while improving cell viability; increasing [Formula: see text]m, GAP-43, and BDNF expression; and raising SOD, GSH-Px, CAT, and IL-10 levels in PFF-induced SH-SY5Y cells. These effects were neutralized by HSF1 knockdown. In conclusion, PF dose-dependently activated the HSF1-NRF1 axis and alleviated OS and inflammation in PFF-treated mice, thereby impeding PD progression in mice.

Terpenoids as potential phytoconstituent in the treatment of diabetes: From preclinical to clinical advancement

BACKGROUND

Diabetes mellitus, a hyperglycemic condition associated with multitudinous organ dysfunction, is a hallmark of the metabolic disorder. This life-threatening condition affects millions of individuals globally, harming them financially, physically and psychologically in the course of therapy.

PURPOSES

The course therapy for illnesses has undergone ground-breaking transformations due to recent technical advances and insights. Alternatively, the administration of hyperglycemia-reducing agents results in several complications, including severe cardiovascular disease, kidney failure, hepatic problems, and several dermatological conditions. Consideration of alternate diabetic therapy having minimal side effects or no adverse reactions has been driven by such problems.

STUDY DESIGN

An extensive literature study was conducted in authoritative scientific databases such as PubMed, Scopus, and Web of Science to identify the studies elucidating the bioactivities of terpenoids in diabetic conditions.

METHODS

Keywords including 'terpenoids', 'monoterpenes', 'diterpenes', 'sesquiterpenes', 'diabetes', 'diabetes mellitus', 'clinical trials', 'preclinical studies', and 'increased blood glucose' were used to identify the relevant research articles. The exclusion criteria, such as English language, duplication, open access, abstract only, and studies not involving preclinical and clinical research, were set. Based on these criteria, 937 relevant articles were selected for further evaluation.

RESULTS

Triterpenes can serve as therapeutic agents for diabetic retinopathy, peripheral neuropathy, and kidney dysfunction by inhibiting several pathways linked to hyperglycemia and its complications. Therefore, it is essential to draw special attention to these compounds' therapeutic effectiveness and provide scientific professionals with novel data.

CONCLUSION

This study addressed recent progress in research focussing on mechanisms of terpenoid, its by-products, physiological actions, and therapeutic applications, particularly in diabetic and associated disorders.

Neurodegenerative Proteinopathies Induced by Environmental Pollutants: Heat Shock Proteins and Proteasome as Promising Therapeutic Tools

Environmental pollutants' (EPs) amount and diversity have increased in recent years due to anthropogenic activity. Several neurodegenerative diseases (NDs) are theorized to be related to EPs, as their incidence has increased in a similar way to human EPs exposure and they reproduce the main ND hallmarks. EPs induce several neurotoxic effects, including accumulation and gradual deposition of misfolded toxic proteins, producing neuronal malfunction and cell death. Cells possess different mechanisms to eliminate these toxic proteins, including heat shock proteins (HSPs) and the proteasome system. The accumulation and deleterious effects of toxic proteins are induced through HSPs and disruption of proteasome proteins' homeostatic function by exposure to EPs. A therapeutic approach has been proposed to reduce accumulation of toxic proteins through treatment with recombinant HSPs/proteasome or the use of compounds that increase their expression or activity. Our aim is to review the current literature on NDs related to EP exposure and their relationship with the disruption of the proteasome system and HSPs, as well as to discuss the toxic effects of dysfunction of HSPs and proteasome and the contradictory effects described in the literature. Lastly, we cover the therapeutic use of developed drugs and recombinant proteasome/HSPs to eliminate toxic proteins and prevent/treat EP-induced neurodegeneration.

Decreased Levels of Chaperones in Mucopolysaccharidoses and Their Elevation as a Putative Auxiliary Therapeutic Approach

Mucopolysaccharidoses (MPS) are rare genetic disorders belonging to the lysosomal storage diseases. They are caused by mutations in genes encoding lysosomal enzymes responsible for degrading glycosaminoglycans (GAGs). As a result, GAGs accumulate in lysosomes, leading to impairment of cells, organs and, consequently, the entire body. Many of the therapies proposed thus far require the participation of chaperone proteins, regardless of whether they are therapies in common use (enzyme replacement therapy) or remain in the experimental phase (gene therapy, STOP-codon-readthrough therapy). Chaperones, which include heat shock proteins, are responsible for the correct folding of other proteins to the most energetically favorable conformation. Without their appropriate levels and activities, the correct folding of the lysosomal enzyme, whether supplied from outside or synthesized in the cell, would be impossible. However, the baseline level of nonspecific chaperone proteins in MPS has never been studied. Therefore, the purpose of this work was to determine the basal levels of nonspecific chaperone proteins of the Hsp family in MPS cells and to study the effect of normalizing GAG concentrations on these levels. Results of experiments with fibroblasts taken from patients with MPS types I, II, IIIA, IIIB, IIIC, IID, IVA, IVB, VI, VII, and IX, as well as from the brains of MPS I mice (Idua^-/-), indicated significantly reduced levels of the two chaperones, Hsp70 and Hsp40. Interestingly, the reduction in GAG levels in the aforementioned cells did not lead to normalization of the levels of these chaperones but caused only a slight increase in the levels of Hsp40. An additional transcriptomic analysis of MPS cells indicated that the expression of other genes involved in protein folding processes and the cell response to endoplasmic reticulum stress, resulting from the appearance of abnormally folded proteins, was also modulated. To summarize, reduced levels of chaperones may be an additional cause of the low activity or inactivity of lysosomal enzymes in MPS. Moreover, this may point to causes of treatment failure where the correct structure of the enzyme supplied or synthesized in the cell is crucial to lower GAG levels.

Natural Products Targeting Hsp90 for a Concurrent Strategy in Glioblastoma and Neurodegeneration

Glioblastoma multiforme (GBM) is one of the most common aggressive, resistant, and invasive primary brain tumors that share neurodegenerative actions, resembling many neurodegenerative diseases. Although multiple conventional approaches, including chemoradiation, are more frequent in GBM therapy, these approaches are ineffective in extending the mean survival rate and are associated with various side effects, including neurodegeneration. This review proposes an alternative strategy for managing GBM and neurodegeneration by targeting heat shock protein 90 (Hsp90). Hsp90 is a well-known molecular chaperone that plays essential roles in maintaining and stabilizing protein folding to degradation in protein homeostasis and modulates signaling in cancer and neurodegeneration by regulating many client protein substrates. The therapeutic benefits of Hsp90 inhibition are well-known for several malignancies, and recent evidence highlights that Hsp90 inhibitors potentially inhibit the aggressiveness of GBM, increasing the sensitivity of conventional treatment and providing neuroprotection in various neurodegenerative diseases. Herein, the overview of Hsp90 modulation in GBM and neurodegeneration progress has been discussed with a summary of recent outcomes on Hsp90 inhibition in various GBM models and neurodegeneration. Particular emphasis is also given to natural Hsp90 inhibitors that have been evidenced to show dual protection in both GBM and neurodegeneration.

The Protective Effects of Nutraceutical Components in Methotrexate-Induced Toxicity Models—An Overview

There are multiple concerns associated with methotrexate (MTX), widely recognized for anti-neoplastic and anti-inflammatory effects in life-threatening disease conditions, i.e., acute lymphoblastic leukemia, non-Hodgkin’s lymphoma, psoriasis, and rheumatoid arthritis, due to long-term side effects and associated toxicity, which limits its valuable potential. MTX acts as an inhibitor of dihydrofolate reductase, leading to suppression of purine and pyrimidine synthesis in high metabolic and turnover cells, targeting cancer and dysregulated immune cells. Due to low discrimination between neoplastic cells and naturally high turnover cells, MTX is prone to inhibiting the division of all fast-dividing cells, causing toxicity in multiple organs. Nutraceutical compounds are plant-based or food-derived compounds, used for their preventive and therapeutic role, ascertained in multiple organ dysfunctions, including cardiovascular disease, ischemic stroke, cancer, and neurodegenerative diseases. Gut microbiota and microbiota-derived metabolites take part in multiple physiological processes, their dysregulation being involved in disease pathogenesis. Modulation of gut microbiota by using nutraceutical compounds represents a promising therapeutic direction to restore intestinal dysfunction associated with MTX treatment. In this review, we address the main organ dysfunctions induced by MTX treatment, and modulations of them by using nutraceutical compounds. Moreover, we revealed the protective mechanisms of nutraceuticals in MTX-induced intestinal dysfunctions by modulation of gut microbiota.

Botanical Interventions to Improve Glucose Control and Options for Diabetes Therapy

Diabetes mellitus is a major public health problem worldwide. This endocrine disease is clustered into distinct subtypes based on the route of development, with the most common forms associated with either autoimmunity (T1DM) or obesity (T2DM). A shared hallmark of both major forms of diabetes is a reduction in function (insulin secretion) or mass (cell number) of the pancreatic islet beta-cell. Diminutions in both mass and function are often present. A wide assortment of plants have been used historically to reduce the pathological features associated with diabetes. In this review, we provide an organized viewpoint focused around the phytochemicals and herbal extracts investigated using various preclinical and clinical study designs. In some cases, crude extracts were examined directly, and in others, purified compounds were explored for their possible therapeutic efficacy. A subset of these studies compared the botanical product with standard of care prescribed drugs. Finally, we note that botanical formulations are likely suspects for future drug discovery and refinement into class(es) of compounds that have either direct or adjuvant therapeutic benefit.

A standardized extract of Asparagus officinalis stem improves HSP70-mediated redox balance and cell functions in bovine cumulus-granulosa cells

Heat shock (HS) protein 70 (HSP70), a well-known HS-induced protein, acts as an intracellular chaperone to protect cells against stress conditions. Although HS induces HSP70 expression to confer stress resistance to cells, HS causes cell toxicity by increasing reactive oxygen species (ROS) levels. Recently, a standardized extract of Asparagus officinalis stem (EAS), produced from the byproduct of asparagus, has been shown to induce HSP70 expression without HS and regulate cellular redox balance in pheochromocytoma cells. However, the effects of EAS on reproductive cell function remain unknown. Here, we investigated the effect of EAS on HSP70 induction and oxidative redox balance in cultured bovine cumulus-granulosa (CG) cells. EAS significantly increased HSP70 expression; however, no effect was observed on HSP27 and HSP90 under non-HS conditions. EAS decreased ROS generation and DNA damage and increased glutathione (GSH) synthesis under both non-HS and HS conditions. Moreover, EAS synergistically increased HSP70 and HSF1 expression and increased progesterone levels in CG cells. Treatment with an HSP70 inhibitor significantly decreased GSH level, increased ROS level, and decreased HSF1, Nrf2, and Keap1 expression in the presence of EAS. Furthermore, EAS significantly increased progesterone synthesis. Thus, EAS improves HSP70-mediated redox balance and cell function in bovine CG cells.

Antimicrobial and Antibiofilm Activities and Mechanism of Action of Chelerythrine Against Carbapenem-Resistant Serratia marcescens In Vitro

Aim: To evaluate the antimicrobial and antibiofilm effects of chelerythrine (CHE) against carbapenem-resistant Serratia marcescens (CRSM). Materials and Methods: The minimum inhibitory concentration (MIC) of CHE against CRSM was determined using the agar dilution method. Changes in intracellular adenosine triphosphate (ATP) concentration, intracellular pH, cell membrane potential, and cell membrane integrity were investigated to assess the influence of CHE on the cell membrane. The effects of CHE on cell morphology were observed by field emission scanning electron microscopy (FESEM) and transmission electron microscopy. The antibiofilm formation of CHE was measured by crystal violet staining and visualized with confocal laser scanning microscopy (CLSM) and FESEM. The influence of CHE on biofilm components was further investigated using CLSM specific combined with double-dyeing methods. Results: Our results showed that CHE had an MIC at 125 μg/mL against CRSM was capable of inhibiting the growth of CRSM and destroying its cell membrane integrity, as well as obviously changing the cell morphology. Sub-MIC CHE displayed robust inhibitory effects against CRSM biofilm formation by mediating the production of biofilm components. In addition, CLSM- and FESEM-mediated evaluation of the damage of biofilm cells and biofilm persistence revealed that at high concentrations, CHE could compromise the cells within biofilms and remove preformed biofilms. Conclusion: CHE shows promise as a natural antimicrobial substance against biofilm-positive CRSM, with the potential to serve as an alternative therapeutic agent.

Therapeutic Potential of Heme Oxygenase-1 in Aneurysmal Diseases

Abdominal aortic aneurysm (AAA) and intracranial aneurysm (IA) are serious arterial diseases in the aorta and brain, respectively. AAA and IA are associated with old age in males and females, respectively, and if rupture occurs, they carry high morbidity and mortality. Aneurysmal subarachnoid hemorrhage (SAH) due to IA rupture has a high rate of complication and fatality. Despite these severe clinical outcomes, preventing or treating these devastating diseases remains an unmet medical need. Inflammation and oxidative stress are shared pathologies of these vascular diseases. Therefore, therapeutic strategies have focused on reducing inflammation and reactive oxygen species levels. Interestingly, in response to cellular stress, the inducible heme oxygenase-1 (HO-1) is highly upregulated and protects against tissue injury. HO-1 degrades the prooxidant heme and generates molecules with antioxidative and anti-inflammatory properties, resulting in decreased oxidative stress and inflammation. Therefore, increasing HO-1 activity is an attractive option for therapy. Several HO-1 inducers have been identified and tested in animal models for preventing or alleviating AAA, IA, and SAH. However, clinical trials have shown conflicting results. Further research and the development of highly selective HO-1 regulators may be needed to prevent the initiation and progression of AAA, IA, or SAH.

Paeoniflorin attenuates early brain injury through reducing oxidative stress and neuronal apoptosis after subarachnoid hemorrhage in rats

Paeoniflorin is a natural monoterpene glucoside from Paeoniae Radix with neuroprotective properties. However, it is still unclear whether paeoniflorin has neuroprotective effects on subarachnoid hemorrhage (SAH). This study explores the effect of paeoniflorin on early brain injury (EBI) using rat SAH model. We found that paeoniflorin significantly improves neurological deficits, attenuates brain water content and Evans blue extravasation at 72 h after SAH. Paeoniflorin attenuates the oxidative stress following SAH as evidenced by decrease of reactive oxygen species (ROS), malondialdehyde (MDA), 3-Nitrotyrosine, and 8-Hydroxy-2-deoxy guanosine (8-OHDG) level, increase of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase activity, and up-regulates the nuclear factor erythroid‑related factor 2 (Nrf2)/heme oxygenase‑1 (HO-1) pathway. Inhibition of microglia activation and neuro-inflammatory response both contributed to paeoniflorin's protective effects. Moreover, paeoniflorin treatment significantly reduces the ratio of Bax/Bcl-2, active caspase-3/ neuronal nuclei (NeuN) and TUNEL/DAPI positive cells at 72 h following SAH. Our results indicate that paeoniflorin may attenuate early brain injury after experimental SAH.

Anti-inflammatory and immunoregulatory effects of paeoniflorin and total glucosides of paeony

As a Traditional Chinese Medicine, Paeonia lactiflora Pallas has been used to treat pain, inflammation and immune disorders for more than 1000 years in China. Total glycoside of paeony (TGP) is extracted from the dried root of Paeonia lactiflora Pallas. Paeoniflorin (Pae) is the major active component of TGP. Our research group has done a lot of work in the pharmacological mechanisms of Pae and found that Pae possessed extensive anti-inflammatory and immune regulatory effects. Pae could inhibit inflammation in the animal models of autoimmune diseases, such as experimental arthritis, psoriatic mice and experimental autoimmune encephalomyelitis, and so on. Pae modulates the functions and activation of immune cells, decreases inflammatory medium production, and restores abnormal signal pathway. Pae could balance the subsets of immune cells through inhibiting abnormal activated cell subsets and restoring regulatory cell subsets. Pae could regulate signaling pathways (GPCR pathway, MAPKs /NF-κB patway, PI3K /Akt /mTOR pathway, JAK2 /STAT3 pathway, TGFβ /Smads, and etc.). TGP is composed of Pae, hydroxyl-paeoniflorin, paeonin, albiflorin and benzoylpaeoniflorin etc. Pae accounts for more than 40% of TGP. Like Pae, TGP has anti-inflammatory and immune regulatory effects. TGP has been widely used to treat autoimmune diseases, including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), psoriasis, allergic contact dermatitis, and etc. in China. Furthermore, TGP has some superior features with immune regulation, gentle effect, many indications and few adverse drug reactions. These findings suggest that TGP may be a promising anti-inflammatory and immune drug with soft regulation and has more superiority in the treatment of AIDs. Currently, TGP is used for the treatment of RA, SLE and other AIDs in more than 1000 hospitals in China, which obtained great social and economic benefits.

Reversal of Epithelial-Mesenchymal Transition by Natural Anti-Inflammatory and Pro-Resolving Lipids

Epithelial mesenchymal transition (EMT) is a key process in the progression of malignant cancer. Therefore, blocking the EMT can be a critical fast track for the development of anticancer drugs. In this paper, we update recent research output of EMT and we explore suppression of EMT by natural anti-inflammatory compounds and pro-resolving lipids.

Natural Products as Modulators of the Proteostasis Machinery: Implications in Neurodegenerative Diseases

Proteins play crucial and diverse roles within the cell. To exert their biological function they must fold to acquire an appropriate three-dimensional conformation. Once their function is fulfilled, they need to be properly degraded to hamper any possible damage. Protein homeostasis or proteostasis comprises a complex interconnected network that regulates different steps of the protein quality control, from synthesis and folding, to degradation. Due to the primary role of proteins in cellular function, the integrity of this network is critical to assure functionality and health across lifespan. Proteostasis failure has been reported in the context of aging and neurodegeneration, such as Alzheimer’s and Parkinson’s disease. Therefore, targeting the proteostasis elements emerges as a promising neuroprotective therapeutic approach to prevent or ameliorate the progression of these disorders. A variety of natural products are known to be neuroprotective by protein homeostasis interaction. In this review, we will focus on the current knowledge regarding the use of natural products as modulators of different components of the proteostasis machinery within the framework of age-associated neurodegenerative diseases.

Heat-Shock Proteins in Neuroinflammation

The heat-shock response, one of the main pro-survival mechanisms of a living organism, has evolved as the biochemical response of cells to cope with heat stress. The most well-characterized aspect of the heat-shock response is the accumulation of a conserved set of proteins termed heat-shock proteins (HSPs). HSPs are key players in protein homeostasis acting as chaperones by aiding the folding and assembly of nascent proteins and protecting against protein aggregation. HSPs have been associated with neurological diseases in the context of their chaperone activity, as they were found to suppress the aggregation of misfolded toxic proteins. In recent times, HSPs have proven to have functions apart from the classical molecular chaperoning in that they play a role in a wider scale of neurological disorders by modulating neuronal survival, inflammation, and disease-specific signaling processes. HSPs are gaining importance based on their ability to fine-tune inflammation and act as immune modulators in various bodily fluids. However, their effect on neuroinflammation processes is not yet fully understood. In this review, we summarize the role of neuroinflammation in acute and chronic pathological conditions affecting the brain. Moreover, we seek to explore the existing literature on HSP-mediated inflammatory function within the central nervous system and compare the function of these proteins when they are localized intracellularly compared to being present in the extracellular milieu.

Emerging small-molecule treatments for multiple sclerosis: focus on B cells

Multiple sclerosis (MS) is a major cause of disability in young adults. Following an unknown trigger (or triggers), the immune system attacks the myelin sheath surrounding axons, leading to progressive nerve cell death. Antibodies and small-molecule drugs directed against B cells have demonstrated good efficacy in slowing progression of the disease. This review focusses on small-molecule drugs that can affect B-cell biology and may have utility in disease management. The risk genes for MS are examined from the drug target perspective. Existing small-molecule therapies for MS with B-cell actions together with new drugs in development are described. The potential for experimental molecules with B-cell effects is also considered. Small molecules can have diverse actions on B cells and be cytotoxic, anti-inflammatory and anti-viral. The current B cell-directed therapies often kill B-cell subsets, which can be effective but lead to side effects and toxicity. A deeper understanding of B-cell biology and the effect on MS disease should lead to new drugs with better selectivity, efficacy, and an improved safety profile. Small-molecule drugs, once the patent term has expired, provide a uniquely sustainable form of healthcare.

Molecular insight into the therapeutic potential of phytoconstituents targeting protein conformation and their expression

BACKGROUND

Native protein conformation is essential for the functional activity of the proteins and enzymes. Defects in conformation or alterations in expression of the proteins have been reported in various diseases.

PURPOSE

The aim of this study is to review the molecular insight into the therapeutic potential of phytoconstituents targeting protein conformations or expressions.

METHODS

Published literatures were searched in PubMed, Scopus, Web of Science; Article published till Dec 2017 were extracted. The literature was assessed from the Central University of Rajasthan, India. Present study evaluate article based on the role of active plant constituents on the conformation and expression of the different proteins.

RESULTS

Plant components play their role either at the molecular level or cellular level and exhibit antibacterial, antiviral, anti-neurodegenerative and other activities. Plant active compounds isolated from different plants may either stabilize or destabilize the conformation of proteins or alter expression level of the protein involved in these diseases, therefore, can play a significant role in preventing diseases caused by the alteration in these proteins.

CONCLUSION

In the present article, we have reviewed the molecular mechanism of plant active compounds, their target proteins, methods of extraction and identification, and their biological significances. Therefore, a proper understanding of the effect of these herbal molecules on the concerned proteins may help to develop new herbal-based therapeutics for various diseases.

Induction of suppressor of cytokine signaling 3 via HSF-1-HSP70-TLR4 axis attenuates neuroinflammation and ameliorates postoperative pain

Postoperative pain is a common form of acute pain that, if not managed effectively, can become chronic pain. Evidence has shown that glia, especially microglia, mediate neuroinflammation, which plays a vital role in pain sensitization. Moreover, toll-like receptor 4 (TLR4), the tumor necrosis factor receptor (TNF-R), the interleukin-1 receptor (IL-1R), and the interleukin-6 receptor (IL-6R) have been considered key components in central pain sensitization and neuroinflammation. Therefore, we hypothesized that activation of the body's endogenous "immune brakes" will inhibit these receptors and achieve inflammation tolerance as well as relieve postoperative pain. After searching for potential candidates to serve as this immune brake, we identified and focused on the suppressor of cytokine signaling 3 (SOCS3) gene. To regulate SOCS3 expression, we used paeoniflorin to induce heat shock protein 70 (HSP70)/TLR4 signaling. We found that paeoniflorin significantly induced SOCS3 expression both in vitro and in vivo and promoted the efflux of HSP70 from the cytoplasm to the extracellular environment. Furthermore, paeoniflorin markedly attenuated incision-induced mechanical allodynia, and this effect was abolished by small interfering RNAs targeting SOCS3. These findings demonstrated an effective and safe strategy to alleviate postoperative pain.

Illumina-based analysis of endophytic bacterial diversity of tree peony (Paeonia Sect. Moutan) roots and leaves

Diverse communities of bacteria inhabit plant tissues and those bacteria play a crucial role for plant health and growth. Tree peony (Paeonia Sect. Moutan) is known for its excellent ornamental and medicinal values as Chinese traditional plant, but little is known about its associated bacterial community under natural conditions. To examine how endophytic bacteria in tree peony vary across tissues and cultivars, PCR-based Illumina was applied to reveal the diversity of endophytic bacteria in tree peony. A total of 149,842 sequences and 21,463 operational taxonomic units (OTUs) were obtained. The OTU abundance of roots was higher than leaves across other three cultivars except for ‘Kinkaku’ and ‘Luoyanghong’. The community was composed of five dominant groups (Proteobacteria, Firmicutes, Bacteroidetes, Acidobacteria and Actinobacteria) in all samples. Endophytic bacteria community structures had changed in leaves and roots. Sequences of Pseudomonas and Enterobacteriaceae were prevalent in root samples, whereas Succinivibrio and Acinetobacter were the dominant genus in leaf samples. Otherwise, the distribution of each dominant genus among the 5 cultivars was either varied. These findings suggested that both plant genotype and tissues contribute to the shaping of the bacterial communities associated with tree peony.

Enhanced resistance against Vibrio harveyi infection by carvacrol and its association with the induction of heat shock protein 72 in gnotobiotic Artemia franciscana

Induction of HSP72 is a natural response of stressed organisms that protects against many insults including bacterial diseases in farm (aquatic) animals. It would therefore be of great health benefit to search for natural compounds that are clinically safe yet able to induce HSP72 in animals. The phenolic compound carvacrol, an approved food component, had been shown in in vitro study to act as a co-inducer of HSP72, enhancing HSP72 production only in combination with a bona fide stress compared to the compound alone. However, in vitro model systems do not completely represent an in vivo physiology. Here, using the well-established gnotobiotic Artemia model system, we determined whether carvacrol could induce HSP72 in vivo, whether this putative effect could generate resistance in Artemia against biotic/abiotic stress and also unraveled the mechanism behind the possible HSP72-inducing effect of carvacrol. The gnotobiotic system is crucial for such studies because it avoids the interference of any extraneous factors on host-compound interaction. Here, carvacrol was shown to be a potent HSP72 inducer. Induction of HSP72 was associated with the generation of resistance in Artemia larvae against subsequent lethal heat stress or pathogenic Vibrio harveyi. Our results also provided new insight on the mode of HSP72 inducing action of carvacrol, in which the initial generation of reactive molecule H2O2 by the compound plays a key role. Overall results add new information about the bioactivity of carvacrol and advance our knowledge of this compound as potential prophylactic agent for controlling Vibrio infection in aquaculture animals.

Paeoniflorin, a novel heat-shock protein inducing compound, and human myometrial contractility in vitro

AIM

Heat shock proteins (HSPs) are synthesized in virtually all organisms in response to increases in temperature. They are associated with a relaxant effect on the human myometrium and are present in decreased concentration in the myometrium at the time of labor. Paeoniflorin is derived from Paeonia lactiflora and has been shown to induce the synthesis of HSPs in cultured mammalian cells. The purpose of the study was to evaluate the effect of paeoniflorin on human uterine contractility.

MATERIAL AND METHODS

Samples of human myometrium were taken at lower segment cesarean section. Dissected muscle strips were suspended under isometric conditions and exposed to cumulative additions of paeoniflorin in concentrations ranging from 1 nmol/L to 10 mol/L. Control experiments were simultaneously performed.

RESULTS

Paeoniflorin was found to exert an inhibitory effect on spontaneous and agonist-induced contractions compared to control strips. The mean maximal inhibition values were: 42.21% ± 9.26 for spontaneous contractions (n = 6; P < 0.0001) and 47.84% ± 9.05 for oxytocin-induced contractions (n = 6; P < 0.0001).

CONCLUSION

The HSP inducing compound, paeoniflorin, had a relaxant effect on human uterine contractility in vitro. These results reinforce the fact that HSPs may play a physiological role in the onset of labor and may also provide future targets for novel tocolytic treatments.

A role of Heat Shock Protein 70 in Photoreceptor Cell Death: Potential as a Novel Therapeutic Target in Retinal Degeneration

Retinal degenerative diseases (RDs) such as retinitis pigmentosa (RP) are a genetically heterogeneous group of disorders characterized by night blindness and peripheral vision loss, which caused by the dysfunction and death of photoreceptor cells. Although many causative gene mutations have been reported, the final common end stage is photoreceptor cell death. Unfortunately, no effective treatments or therapeutic agents have been discovered. Heat shock protein 70 (HSP70) is highly conserved and has antiapoptotic activities. A few reports have shown that HSP70 plays a role in RDs. Thus, we focused on the role of HSP70 in photoreceptor cell death. Using the N-methyl-N-nitrosourea (MNU)-induced photoreceptor cell death model in mice, we could examine two stages of the novel cell death mechanism; the early stage, including HSP70 cleavage through protein carbonylation by production of reactive oxygen species, lipid peroxidation and Ca(2+) influx/calpain activation, and the late stage of cathepsin and/or caspase activation. The upregulation of intact HSP70 expression by its inducer is likely to protect photoreceptor cells. In this review, we focus on the role of HSP70 and the novel cell death signaling process in RDs. We also describe candidate therapeutic agents for RDs.

Nonlethal dose of silver nanoparticles attenuates TNF-α-induced hepatic epithelial cell death through HSP70 overexpression

Silver nanoparticles (Ag-nps) have been widely used in various biomedical products. Compared with its hazardous effects extensively being studied, rare attention has been paid to the potential protective effect of Ag-nps to human health. The present study was designed to evaluate the protective effects of Ag-nps and heat shock treatment on tumor necrosis factor-α (TNF-α)-induced cell damage in Clone 9 cells. Clone 9 cells were pretreated with nonlethal concentration of Ag-nps (1 μg/ml) or heat shock, and then cell damages were induced by TNF-α (1 ng/ml). Protective effects of Ag-nps administration or heat shock treatment were determined by examining the TNF-α-induced changes in cell viabilities. The results showed that the intensity of cytotoxicity produced by TNF-α was alleviated upon treatment with nonlethal concentration of Ag-nps (1 μg/ml). Similar protective effects were also found upon heat shock treatment. These data demonstrate that Ag-nps and heat shock treatment were equally capable of inducing heat shock protein 70 (HSP70) protein expression in Clone 9 cells. The results suggest that clinically Ag-nps administration is a viable strategy to induce endogenous HSP70 expression instead of applying heat shock. In conclusion, our study for the first time provides evidence that Ag-nps may act as a viable alternative for HSP70 induction clinically.

Paeoniflorin eliminates a mutant AR via NF-YA-dependent proteolysis in spinal and bulbar muscular atrophy

The accumulation of abnormal proteins is a common characteristic of neurodegenerative diseases. This accumulation reflects a severe disturbance of cellular homeostasis in pathogenic protein clearance. Here, we demonstrated that the activation of the two major proteolytic machineries, the molecular chaperone-ubiquitin proteasome system (UPS) and the autophagy system, were simultaneously enhanced by paeoniflorin (PF), a major component of Paeonia plants, and exerted therapeutic effects in models of spinal and bulbar muscular atrophy (SBMA). PF significantly increased the expression of nuclear factor-YA (NF-YA), which strongly upregulated the molecules involved in the proteolytic machinery [molecular chaperones, carboxyl terminus of Hsc70-interacting protein and transcription factor EB], which thus mitigated the behavioral and pathological impairments in an SBMA mouse model through the upregulation of pathogenic androgen receptor protein clearance in motor neurons and muscles. These findings demonstrated that PF is able to enhance both the UPS and autophagy systems by upregulating the expression of NF-YA, which promotes therapeutic effects in an SBMA model.

Enzyme-treated asparagus extract promotes expression of heat shock protein and exerts antistress effects

A novel enzyme-treated asparagus extract (ETAS) has been developed as a functional material produced from asparagus stem. Studies were conducted to determine the effect of ETAS on heat shock protein 70 (HSP70) expression and alleviation of stress. HeLa cells were treated with ETAS, and HSP70 mRNA and protein levels were measured using a reverse transcription-polymerase chain reaction (RT-PCR) assay and an enzyme-linked immunosorbent assay (ELISA), respectively. ETAS showed significant increases in HSP70 mRNA at more than 0.125 mg/mL and the protein at more than 1.0 mg/mL. The antistress effect was evaluated in a murine sleep-deprivation model. A sleep-deprivation stress load resulted in elevation of blood corticosterone and lipid peroxide concentrations, while supplementation with ETAS at 200 and 1000 mg/kg body weight was associated with significantly reduced levels of both stress markers, which were in the normal range. The HSP70 protein expression level in mice subjected to sleep-deprivation stress and supplemented with ETAS was significantly enhanced in stomach, liver, and kidney, compared to ETAS-untreated mice. A preliminary and small-sized human study was conducted among healthy volunteers consuming up to 150 mg/d of ETAS daily for 7 d. The mRNA expression of HSP70 in peripheral leukocytes was significantly elevated at intakes of 100 or 150 mg/d, compared to their baseline levels. Since HSP70 is known to be a stress-related protein and its induction leads to cytoprotection, the present results suggest that ETAS might exert antistress effects under stressful conditions, resulting from enhancement of HSP70 expression.

Aqueous Extract of Paeonia lactiflora and Paeoniflorin as Aggregation Reducers Targeting Chaperones in Cell Models of Spinocerebellar Ataxia 3

Spinocerebellar ataxia (SCA) types 1, 2, 3, 6, 7, and 17 as well as Huntington's disease are a group of neurodegenerative disorders caused by expanded CAG repeats encoding a long polyglutamine (polyQ) tract in the respective proteins. Evidence has shown that the accumulation of intranuclear and cytoplasmic misfolded polyQ proteins leads to apoptosis and cell death. Thus suppression of aggregate formation is expected to inhibit a wide range of downstream pathogenic events in polyQ diseases. In this study, we established a high-throughput aggregation screening system using 293 ATXN3/Q75-GFP cells and applied this system to test the aqueous extract of Paeonia lactiflora (P. lactiflora) and its constituents. We found that the aggregation can be significantly prohibited by P. lactiflora and its active compound paeoniflorin. Meanwhile, P. lactiflora and paeoniflorin upregulated HSF1 and HSP70 chaperones in the same cell models. Both of them further reduced the aggregation in neuronal differentiated SH-SY5Y ATXN3/Q75-GFP cells. Our results demonstrate how P. lactiflora and paeoniflorin are likely to work on polyQ-aggregation reduction and provide insight into the possible working mechanism of P. lactiflora in SCA3. We anticipate our paper to be a starting point for screening more potential herbs for the treatment of SCA3 and other polyQ diseases.

Water extract from the leaves of Withania somnifera protect RA differentiated C6 and IMR-32 cells against glutamate-induced excitotoxicity

Glutamate neurotoxicity has been implicated in stroke, head trauma, multiple sclerosis and neurodegenerative disorders. Search for herbal remedies that may possibly act as therapeutic agents is an active area of research to combat these diseases. The present study was designed to investigate the neuroprotective role of Withania somnifera (Ashwagandha), also known as Indian ginseng, against glutamate induced toxicity in the retinoic acid differentiated rat glioma (C6) and human neuroblastoma (IMR-32) cells. The neuroprotective activity of the Ashwagandha leaves derived water extract (ASH-WEX) was evaluated. Cell viability and the expression of glial and neuronal cell differentiation markers was examined in glutamate challenged differentiated cells with and without the presence of ASH-WEX. We demonstrate that RA-differentiated C6 and IMR-32 cells, when exposed to glutamate, undergo loss of neural network and cell death that was accompanied by increase in the stress protein HSP70. ASH-WEX pre-treatment inhibited glutamate-induced cell death and was able to revert glutamate-induced changes in HSP70 to a large extent. Furthermore, the analysis on the neuronal plasticity marker NCAM (Neural cell adhesion molecule) and its polysialylated form, PSA-NCAM revealed that ASH-WEX has therapeutic potential for prevention of neurodegeneration associated with glutamate-induced excitotoxicty.

Chemical inducers of heat shock proteins derived from medicinal plants and cytoprotective genes response

Environmental stress induces damage that activates an adaptive response in any organism. The cellular stress response is based on the induction of cytoprotective proteins, the so-called stress or heat shock proteins (HSPs). HSPs are known to function as molecular chaperones which are involved in the therapeutic approach of many diseases. Therefore in the current study we searched nontoxic chaperone inducers in chemical compounds isolated from medicinal plants. Screening of 80 compounds for their Hsp70-inducing activity in human lymphoma U937 cells was performed by western blotting. Five compounds showed significant Hsp70 up-regulation among them shikonin was most potent. Shikonin was able to induce Hsp70 at 0.1 µM after 3 h without activation of heat shock transcription factor 1 (HSF-1). It also induces significant reactive oxygen species generation. The expression level of genes responsive to shikonin was studied using global-scale microarrays and computational gene expression analysis tools. Significant increase in the nuclear factor erythroid 2-related factor 2 (Nrf2, NFEL2L2) -mediated oxidative stress response was observed that leads to the activation of HSP. The results of gene chip analysis were further confirmed by real-time qPCR assay. In short, the detailed mechanisms of Hsp70 induction by shikonin is not fully understood, Nrf2 and its target genes might be involved in the Hsp70 up-regulation in U937 cells.

Protective effect of paeoniflorin against oxidative stress in human retinal pigment epithelium in vitro

PURPOSE

This study was conducted to determine whether paeoniflorin (PF) could prevent H₂O₂-induced oxidative stress in ARPE-19 cells and to elucidate the molecular pathways involved in this protection.

METHODS

Cultured ARPE-19 cells were subjected to oxidative stress with H₂O₂ in the presence and absence of PF. The preventive effective of PF on reactive oxygen species (ROS) production and retinal pigment epithelium (RPE) cell death induced by H₂O₂ was determined by 2',7'- dichlorodihydrofluorescein diacetate (H₂DCFDA) fluorescence and 3-(4, 5-dimethylthiazol-2-yl)-2, 5 diphenyl tetrazolium bromide (MTT) assay. The ability of PF to protect RPE cells against ROS-mediated apoptosis was assessed by caspase-3 activity and 4', 6-diamidino-2-phenylindole (DAPI) staining. Furthermore, the protective effect of PF via the mitogen-activated protein kinase (MAPK) pathway was determined by western blot analysis.

RESULTS

PF protected ARPE-19 cells from H₂O₂-induced cell death with low toxicity. H₂O₂-induced oxidative stress increased ROS production and caspase-3 activity, which was significantly inhibited by PF in a dose-dependent manner. Pretreatment with PF attenuated H₂O₂-induced p38MAPK and extracellular signal regulated kinase (ERK) phosphorylation in human RPE cells, which contributed to cell viability in ARPE-19 cells.

CONCLUSIONS

This is the first report to show that PF can protect ARPE-19 cells from the cellular apoptosis induced by oxidative stress. The results of this study open new avenues for the use of PF in treatment of ocular diseases, such as age-related macular degeneration (AMD), where oxidative stress plays a major role in disease pathogenesis.

Culturable bacterial community analysis in the root domains of two varieties of tree peony (Paeonia ostii)

A total of 985 bacterial strains with different colony characteristics were isolated from the root of tree peony plants (variety 'Fengdan' and 'Lan Furong'); 69 operational taxonomic units were identified by amplified ribosomal DNA restriction analysis. Representatives of each group were selected for partial 16S rRNA gene sequencing and phylogenetic analysis. The major groups in the bulk soil, rhizosphere, and rhizoplane of Fengdan were Firmicutes (63.2%), Actinobacteria (36.3%), and Betaproteobacteria (53.0%), respectively. The major bacteria groups in the bulk soil, rhizosphere, and rhizoplane of Lan Furong were Actinobacteria (34.8%), Gammaproteobacteria (45.2%), and Betaproteobacteria (49.1%), respectively. In total, the bacterial isolates comprised 26 genera--14 in the bulk soil, 14 in the rhizosphere, and 11 in the rhizoplane. The most common genus in the bulk soil of Fengdan and Lan Furong was Bacillus (49.6% and 32.6%, respectively), in the rhizosphere Microbacterium (21.1%) and Pseudomonas (42.0%), and in the rhizoplane Variovorax (53.0% and 49.1%, respectively). The results show that there are obvious differences in the bacterial communities in the three root domains of the two varieties, and the plants exerted selective pressures on their associated bacterial populations. The host genotypes also influenced the distribution pattern of the bacterial community.

Suppression of Alzheimer's disease-related phenotypes by expression of heat shock protein 70 in mice

Amyloid-β peptide (Aβ) plays an important role in the pathogenesis of Alzheimer's disease (AD). Aβ is generated by proteolysis of β-amyloid precursor protein (APP) and is cleared by enzyme-mediated degradation and phagocytosis by microglia and astrocytes. Some cytokines, such as TGF-β1, stimulate this phagocytosis. In contrast, cellular upregulation of HSP70 expression provides cytoprotection against Aβ. HSP70 activity in relation to inhibition of Aβ oligomerization and stimulation of Aβ phagocytosis has also been reported. Although these in vitro results suggest that stimulating the expression of HSP70 could prove effective in the treatment of AD, there is a lack of in vivo evidence supporting this notion. In this study, we address this issue, using transgenic mice expressing HSP70 and/or a mutant form of APP (APPsw). Transgenic mice expressing APPsw showed less of an apparent cognitive deficit when they were crossed with transgenic mice expressing HSP70. Transgenic mice expressing HSP70 also displayed lower levels of Aβ, Aβ plaque deposition, and neuronal and synaptic loss than control mice. Immunoblotting experiments and direct measurement of β- and γ-secretase activity suggested that overexpression of HSP70 does not affect the production Aβ. In contrast, HSP70 overexpression did lead to upregulation of the expression of Aβ-degrading enzyme and TGF-β1 both in vivo and in vitro. These results suggest that overexpression of HSP70 in mice suppresses not only the pathological but also the functional phenotypes of AD. This study provides the first in vivo evidence confirming the potential therapeutic benefit of HSP70 for the prevention or treatment of AD.

Hsp70 expression and induction as a readout for detection of immune modulatory components in food

Stress proteins such as heat shock proteins (Hsps) are up-regulated in cells in response to various forms of stress, like thermal and oxidative stress and inflammation. Hsps prevent cellular damage and increase immunoregulation by the activation of anti-inflammatory T-cells. Decreased capacity for stress-induced Hsp expression is associated with immune disorders. Thus, therapeutic boosting Hsp expression might restore or enhance cellular stress resistance and immunoregulation. Especially food- or herb-derived phytonutrients may be attractive compounds to restore optimal Hsp expression in response to stress. In the present study, we explored three readout systems to monitor Hsp70 expression in a manner relevant for the immune system and evaluated novel Hsp co-inducers. First, intracellular staining and analysis by flow cytometry was used to detect stress and/or dietary compound induced Hsp70 expression in multiple rodent cell types efficiently. This system was used to screen a panel of food-derived extracts with potent anti-oxidant capacity. This strategy yielded the identity of several new enhancers of stress-induced Hsp70 expression, among them carvacrol, found in thyme and oregano. Second, CD4(+) T-cell hybridomas were generated that specifically recognized an immunodominant Hsp70 peptide. These hybridomas were used to show that carvacrol enhanced Hsp70 levels increased T-cell activation. Third, we generated a DNAJB1-luc-O23 reporter cell line to show that carvacrol increased the transcriptional activation of a heat shock promoter in the presence of arsenite. These assay systems are generally applicable to identify compounds that affect the Hsp level in cells of the immune system.

Sage tea drinking improves lipid profile and antioxidant defences in humans

Salvia officinalis (common sage) is a plant with antidiabetic properties. A pilot trial (non-randomized crossover trial) with six healthy female volunteers (aged 40–50) was designed to evaluate the beneficial properties of sage tea consumption on blood glucose regulation, lipid profile and transaminase activity in humans. Effects of sage consumption on erythrocytes’ SOD and CAT activities and on Hsp70 expression in lymphocytes were also evaluated. Four weeks sage tea treatment had no effects on plasma glucose. An improvement in lipid profile was observed with lower plasma LDL cholesterol and total cholesterol levels as well as higher plasma HDL cholesterol levels during and two weeks after treatment. Sage tea also increased lymphocyte Hsp70 expression and erythrocyte SOD and CAT activities. No hepatotoxic effects or other adverse effects were observed.

Reinvestigation of the effect of carbenoxolone on the induction of heat shock proteins

Carbenoxolone (CBX) is a semisynthetic derivative of the licorice root substance glycyrrhizinic acid and has been previously reported to induce only heat shock protein 70 [Hsp70, HSPA1A (the systematic name of heat shock protein is given in the parenthesis after each HSP, according to the recent nomenclature guidelines, Kampinga et al., Cell Stress Chaperones, 14:105-111, 2008) but not other heat shock proteins (HSPs) (Nagayama et al., Life Sci. 69:2867-2873, 2001). In this study, we reinvestigated the effect of CBX on the induction of HSPs in HeLa and human neuroblastoma (A-172) cells. CBX clearly induced not only Hsp70 but also Hsp90 (HSPC1), Hsp40 (DNAJB1), and Hsp27 (HSPB1) at concentrations of 10 to 800 microM for 16 h incubation. At higher concentrations (more than 400 microM), however, CBX appeared to be toxic. Treatment of cells with CBX resulted in enhanced phosphorylation and acquisition of DNA-binding ability of heat shock transcription factor 1 (HSF1). Furthermore, characteristic HSF1 granules were formed in the nucleus, suggesting that the induction of HSPs by CBX is mediated by the activation of HSF1. Furthermore, thermotolerance was induced by CBX treatment, as determined by clonogenic survival. Although the precise target of CBX is not known at present, these results indicate that CBX is one of the molecular chaperone inducers and suggest that some pharmacological activities of CBX might be ascribable in part to its molecular chaperone-inducing property.

Paeoniflorin protects RAW 264.7 macrophages from LPS-induced cytotoxicity and genotoxicity

LPS is one of the major constituents of the outer membrane of Gram-negative bacteria. LPS-induced activation of macrophage results in the nitrite (NO) production and the secretion of a pro-inflammatory mediator such as PGE(2). Excessive NO reacts with the superoxide anion to generate a selective oxidant and nitrating agent, peroxynitrite, which interacts with biological molecules and damages the cell membranes of them, being able to result in the cell death. We evaluated the protective effects of paeoniflorin (PF) against LPS-induced toxicity by measuring its dose-dependent effects on cell viability in MTT assay, NO production in NO assay, PGE(2) production in prostaglandin E(2) (PGE(2)) assay, and DNA damage in comet assay in LPS-treated RAW 264.7 macrophages. In the comet assay, we also analyzed tail length, tail DNA, and tail moment as the markers of DNA strand breaks. PF-treatment significantly protected RAW 264.7 macrophages against LPS-induced toxicity with the increase of viable cells, the decrease of NO and PGE(2), and the repair of DNA damage.

Heat stress and hormetin-induced hormesis in human cells: effects on aging, wound healing, angiogenesis, and differentiation

Accumulation of molecular damage and increased molecular heterogeneity are hallmarks of cellular aging. Mild stress-induced hormesis can be an effective way for reducing the accumulation of molecular damage, and thus slowing down aging from within. We have shown that repeated mild heat stress (RMHS) has anti-aging effects on growth and various other cellular and biochemical characteristics of normal human skin fibroblasts and keratinocytes undergoing aging in vitro. RMHS given to human cells increased the basal levels of various chaperones, reduced the accumulation of damaged proteins, stimulated proteasomal activities, increased the cellular resistance to other stresses, enhanced the levels of various antioxidant enzymes, enhanced the activity and amounts of sodium-potassium pump, and increased the phosphorylation-mediated activities of various stress kinases. We have now observed novel hormetic effects of mild heat stress on improving the wound healing capacity of skin fibroblasts and on enhancing the angiogenic ability of endothelial cells. We have also tested potential hormetins, such as curcumin and rosmarinic acid in bringing about their beneficial effects in human cells by inducing stress response pathways involving heat shock proteins and hemeoxygenase HO-1. These data further support the view that mild stress-induced hormesis can be applied for the modulation, intervention and prevention of aging and age-related impairments.

Principles and practice of hormetic treatment of aging and age-related diseases

Aging is characterized by stochastic accumulation of molecular damage, progressive failure of maintenance and repair, and consequent onset of age-related diseases. Applying hormesis in aging research and therapy is based on the principle of stimulation of maintenance and repair pathways by repeated exposure to mild stress. Studies on the beneficial biological effects of repeated mild heat shock on human cells in culture, and other studies on the anti-aging and life-prolonging effects of proxidants, hypergravity, irradiation and ethanol on cells and organisms suggest that hormesis as an antiaging and gerontomodulatory approach has a promising future. Its clinical applications include prevention and treatment of diabetes, cataract, osteoporosis, dementia and some cancers.

Identification of genes responsive to paeoniflorin, a heat shock protein-inducing compound, in human leukemia U937 cells

PURPOSE AND BACKGROUND

Paeoniflorin (PF) isolated from peony root (Paeoniae radix) has been used as a herbal medicine in East Asia for its anti-allergic, anti-inflammatory, and immunoregulatory effects. PF is known to cause apoptosis and to be a chemical heat shock protein (HSP) inducer. With this information, the effects on the gene expression in human leukemia U937 cells treated with PF were investigated.

METHODS

U937 cells, a human myelomonocytic cell line, were treated with PF at different concentrations (0-640 microg/ml). Expression level of Hsp70 was monitored by Western blotting. Gene expression was evaluated using high-density oligonucleotide microarrays and computational gene expression analysis tools and the results were verified by real-time quantitative PCR.

RESULTS

Although cell viability was not affected after PF treatment at a high concentration of 640 microg/ml, PF treatment (80-640 microg/ml) significantly elevated Hsp70 expression in a concentration-dependent manner. When the cells were treated with PF (160 microg/ml; 30 min), 35 up-regulated and 29 down-regulated genes were identified. Among the differentially expressed genes, a significant genetic network containing CDC2, FOSL1 and EGR1 was associated with biological functions such as cell death, gene expression or cellular growth and proliferation.

CONCLUSION

The present results indicate that PF affects the expression of many genes including Hsp70 and will provide a better understanding on the molecular mechanism of action of this compound in inducing HSPs in cells.