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

Paeoniflorin is a promising natural monomer for neurodegenerative diseases via modulation of Ca2+ and ROS homeostasis

Neurodegenerative diseases (NDDs) are a range of neurological disorders featured by neuronal degeneration and apoptosis. Cellular Calcium (Ca²⁺) and reactive oxygen species (ROS) dyshomeostasis are the earliest and important events in the development of NDDs and may yield promising therapeutic targets for NDDs. Paeoniflorin, a water-soluble monoterpene glucoside, is the major bioactive monomer extracted from the root of Paeonia lactiflora pall. Increasing evidence has suggested that this natural compound might be used to treat various NDDs, and its potential molecular mechanisms are related to the modulation of Ca²⁺/ROS homeostasis in cells. In addition, paeoniflorin accounts for more than 40% of the total glucosides of herbaceous peonies with abundant herbaceous sources. Furthermore, it has also been validated as a safe extraction in clinical pharmacological research with a wide therapeutic window. Hence, it is rational to anticipate paeoniflorin being a promising candidate for the treatment of NDDs via regulating Ca²⁺/ROS dyshomeostasis.

A review on the pharmacokinetics of paeoniflorin and its anti-inflammatory and immunomodulatory effects

Increasing pharmacological evidence supports that paeoniflorin, a water-soluble monoterpene glycoside isolated from Paeonia lactiflora Pall. (Shaoyao in Chinese), has a wide range of medicinal properties including anti-inflammatory, antioxidant, antithrombotic, anticonvulsive, analgesic, cardioprotective, neuroprotective, hepatoprotective, antidepressant-like, antitumoral, and immune-regulatory activities; as well as enhancing cognition and attenuating learning impairment. In addition to pharmacodynamic studies, information on pharmacokinetics is also significant for the further development and utilization of paeoniflorin. The present review focuses on the absorption, distribution, metabolism, and excretion of paeoniflorin, especially main pharmacological activities of paeoniflorin on inflammation and immune function. According to the findings obtained both in vitro and in vivo, a broad application prospect has been opened for paeoniflorin. However, further studies are needed to clarity the direct molecular mechanisms and key targets underlying the beneficial effects of paeoniflorin on inflammation and immunity.

Paeoniflorin: a monoterpene glycoside from plants of Paeoniaceae family with diverse anticancer activities

OBJECTIVES

Paeoniflorin, a representative pinane monoterpene glycoside in plants of Paeoniaceae family, possesses promising anticancer activities on diverse tumours. This paper summarized the advance of Paeoniflorin on cancers in vivo and in vitro, discussed the related molecular mechanisms, as well as suggested some perspectives of the future investigations.

KEY FINDINGS

Anticancer activities of paeoniflorin have been comprehensively investigated, including liver cancer, gastric cancer, breast cancer, lung cancer, pancreatic cancer, colorectal cancer, glioma, bladder cancer and leukaemia. Furthermore, the potential molecular mechanisms corresponding to the antitumour effects of Paeoniflorin might be related to the following aspects: inhibition of tumour cell proliferation and neovascularization, induction apoptosis, and inhibition of tumour invasion and metastasis.

SUMMARY

Paeoniflorin has wide spectrum antitumour activities; however, in vivo and clinical investigations on antitumour effect of Paeoniflorin are lacking which should be focused on further studies. Our present review on antitumour effects of Paeoniflorin would be beneficial for the further molecular mechanisms study, candidate antitumour drug development and clinical research of Paeoniflorin in the future.

DNA Microarray-Based Screening and Characterization of Traditional Chinese Medicine

The application of DNA microarray assay (DMA) has entered a new era owing to recent innovations in omics technologies. This review summarizes recent applications of DMA-based gene expression profiling by focusing on the screening and characterizationof traditional Chinese medicine. First, herbs, mushrooms, and dietary plants analyzed by DMA along with their effective components and their biological/physiological effects are summarized and discussed by examining their comprehensive list and a list of representative effective chemicals. Second, the mechanisms of action of traditional Chinese medicine are summarized by examining the genes and pathways responsible for the action, the cell functions involved in the action, and the activities found by DMA (silent estrogens). Third, applications of DMA for traditional Chinese medicine are discussed by examining reported examples and new protocols for its use in quality control. Further innovations in the signaling pathway based evaluation of beneficial effects and the assessment of potential risks of traditional Chinese medicine are expected, just as are observed in other closely related fields, such as the therapeutic, environmental, nutritional, and pharmacological fields.

The progress of early growth response factor 1 and leukemia

Early growth response gene-1 (EGR1) widely exists in the cell nucleus of such as, zebrafish, mice, chimpanzees and humans, an it also can be observed in the cytoplasm of some tumors. EGR1 was named just after its brief and rapid expression of different stimuli. Accumulating studies have extensively demonstrated that the widespread dysregulation of EGR1 is involved in hematological malignancies such as human acute myeloid leukemia (AML), chronic myelogenous leukemia, chronic lymphocytic leukemia, multiple myeloma, and B cell lymphoma. With the deep research on EGR1, its expression, function and regulatory mechanism has been gradually elucidated, and provides more possibilities for treatment strategies of patients with leukemia. Herein, we summarize the roles of EGR1 in its biological function and relationship with leukemia.

Protective effects of paeoniflorin against FasL-induced apoptosis of intervertebral disc annulus fibrosus cells via Fas-FasL signalling pathway

In the present study, we demonstrate that the degeneration of intervertebral discs is caused by ageing and apoptosis of matrix cells. Apoptosis is as essential as the function of proteoglycan synthesis in assessing the possible degeneration of intervertebral discs; paeoniflorin (PF) induces cytoprotective effects on various types of cells. In this study, the function of PF in inhibiting Fas ligand (FasL)-induced apoptosis in annulus fibrosus cells was assessed, and the correlation between apoptosis and the Fas-FasL pathway was determined. Annulus fibrosus cells were derived from the intervertebral discs of 1-month-old Sprague Dawley rats; the cells were characterised by toluidine blue staining and subjected to apoptosis with FasL. PF was diluted to various concentrations and added to annulus fibrosus cells at various times. The impact of PF and FasL on cell apoptosis of annulus fibrosus cells was determined by flow cytometry. Western blot analysis was performed to determine the protein expression levels of Fas and caspase-3. The percentages of apoptotic annulus fibrosus cells as well as the expression levels of caspase-3 and Fas were significantly reduced following treatment with 208, 20.8 or 2.08 µM PF. PF inhibits the activation of the Fas-FasL signal pathway and decreases FasL-induced apoptosis of annulus fibrosus cells.

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.

Inhibition of checkpoint kinase 1 abrogates G2/M checkpoint activation and promotes apoptosis under heat stress

Hyperthermia induced by heat stress (HS) inhibits the proliferation of cancer cells and induces their apoptosis. However, the mechanism underlying HS-induced apoptosis remains elusive. Here, we demonstrated a novel evidence that checkpoint kinase 1 (Chk1) plays crucial roles in the apoptosis and regulation of cell cycle progression in cells under HS. In human leukemia Jurkat cells, interestingly, the ataxia telangiectasia and Rad-3 related (ATR)-Chk1 pathway was preferentially activated rather than the ataxia telangiectasia mutated (ATM)-checkpoint kinase 2 (Chk2) pathway under HS. The selective inhibitors of ATR or Chk1 abrogated HS-induced apoptosis in human leukemia Jurkat cells whereas the inhibition of ATM or Chk2 caused only marginal effects. Inhibition of ATR and Chk1 also abrogated G2/M checkpoint activation by HS in Jurkat cells. The effects of small interfering RNA targeting Chk1 were similar to those of the selective inhibitor of Chk1. In addition, the efficiencies of Chk1 inhibition on G2/M checkpoint abrogation and apoptosis induction were confirmed in the adherent cancer cell lines HeLa, HSC3, and PC3, suggesting that the targeting of Chk1 can be effective in solid tumors cells. In conclusion, these findings indicate a novel molecular basis of G2/M checkpoint activation and apoptosis in cells exposed to HS.