Cordycepin inhibits renal interstitial myofibroblast activation probably by inducing hepatocyte growth factor expression

Causal association between cardiovascular proteins and membranous nephropathy: a bidirectional Mendelian randomization

PURPOSE

Multiple circulating proteins have been reported to participate in human diseases. However, the association between cardiovascular proteins and membranous nephropathy (MN) remained profoundly elusive.

METHODS

A bidirectional Mendelian randomization (MR) analysis was conducted to explore the causal correlation between ninety cardiovascular proteins and MN. Genome-wide association study (GWAS) data of cardiovascular proteins and MN were all from European research. Inverse variance weighted (IVW) was used as the main approach. Moreover, MR-Egger, weighted median, weighted mode, and simple mode were also performed. Cochrane's Q test, MR-Egger, and MR-PRESSO were conducted for sensitivity analysis.

RESULTS

According to IVW method, fatty acid-binding protein and thrombomodulin (TM) were identified as risk factors for MN, while a protective role was detected in tissue-type plasminogen activator. Additionally, MN was associated with an elevated level of macrophage colony-stimulating factor 1, stem cell factor, TM, and tissue factor. Reversely, MN was also correlated with a downregulated level of beta-nerve growth factor, Cathepsin D, hepatocyte growth factor, interleukin-6 receptor subunit alpha, macrophage colony-stimulating factor 1, and myeloperoxidase. In the sensitivity analysis, no significant pleiotropy and heterogeneity was detected.

CONCLUSION

This was the first study to reveal the causal association between cardiovascular proteins and MN. These specific cardiovascular proteins could be novel biomarkers for MN, and is helpful for timely identify the risk of other diseases that might result from MN. However, further clinical studies are needed to confirm our results.

Research Progress of Cordyceps sinensis and Its Fermented Mycelium Products on Ameliorating Renal Fibrosis by Reducing Epithelial-to-Mesenchymal Transition

Renal fibrosis is a hallmark and common outcome of various chronic kidney diseases (CKDs) and manifests pathologically as accumulation and deposition of extracellular matrix (ECM) in the kidney. Epithelial-to-mesenchymal transition (EMT) has been shown to be an important mechanism involved in renal fibrosis. Cordyceps sinensis, a traditional Chinese medicine, has long been used for the treatment of renal fibrosis. As research on the mycelium of C. sinensis progressed, a variety of medicines developed from fermented mycelium were used to treat CKD. However, their efficacies and mechanisms have not been fully summarized. In this review, five medicines developed from fermented mycelium of C. sinensis are presented. The pharmacodynamic effects of C. sinensis on different animal models of renal fibrosis are summarized. The in vitro studies and related mechanisms of C. sinensis on renal cells are detailed. Finally, the application and efficacy of these five commercial medicines that meet national standards in different types of CKD are summarized. From this review, it can be concluded that C. sinensis can alleviate various causes of renal fibrosis to some extent, and its mechanism is related to TGF-β1 dependent signaling, inhibition of inflammation, and improvement of renal function. Further research on rigorously designed, large-sample, clinically randomized controlled trial studies and detailed mechanisms should be conducted.

Cordycepin buffers anisomycin-induced fear memory deficit by restoring hippocampal BDNF

The process of memory consolidation involves the synthesis of new proteins, and interfering with protein synthesis through anisomycin can impair memory. Memory deficits due to aging and sleep disorders may also result from a reduction in protein synthesis. Rescuing memory deficits caused by protein synthesis deficiency is therefore an important issue that needs to be addressed. Our study focused on the effects of cordycepin on fear memory deficits induced by anisomycin using contextual fear conditioning. We observed that cordycepin was able to attenuate these deficits and restore BDNF levels in the hippocampus. The behavioral effects of cordycepin were dependent on the BDNF/TrkB pathway, as demonstrated by the use of ANA-12. Cordycepin had no significant impact on locomotor activity, anxiety or fear memory. Our findings provide the first evidence that cordycepin can prevent anisomycin-induced memory deficits by regulating BDNF expression in the hippocampus.

Mechanism of Cordyceps sinensis and its Extracts in the Treatment of Diabetic Kidney Disease: A Review

Diabetic kidney disease (DKD) is the major reason of chronic kidney disease (CKD)-caused end-stage renal failure (ESRF), and leads to high mortality worldwide. At present, the treatment of DKD is mainly focused on controlling the hyperglycemia, proteinuria, and hypertension, but is insufficient on the effective delay of DKD progression. Cordyceps sinensis is a kind of wild-used precious Chinese herb. Its extracts have effects of nephroprotection, hepatoprotection, neuroprotection, and protection against ischemia/reperfusion-induced injury, as well as anti-inflammatory and anti-oxidant activities. According to the theory of traditional Chinese medicine, Cordyceps sinensis can tonify the lung and the kidney. Several Chinese patent medicines produced from Cordyceps sinensis are often used to treat DKD and achieved considerable efficacy. This review summarized the clinical usage of Cordyceps sinensis, as well as its mainly biological activities including anti-hyperglycemic, anti-inflammatory, immunomodulatory, anti-oxidant, anti-fibrotic activities and regulation of apoptosis.

A Systematic Review of the Biological Effects of Cordycepin

We conducted a systematic review of the literature on the effects of cordycepin on cell survival and proliferation, inflammation, signal transduction and animal models. A total of 1204 publications on cordycepin were found by the cut-off date of 1 February 2021. After application of the exclusion criteria, 791 papers remained. These were read and data on the chosen subjects were extracted. We found 192 papers on the effects of cordycepin on cell survival and proliferation and calculated a median inhibitory concentration (IC50) of 135 µM. Cordycepin consistently repressed cell migration (26 papers) and cellular inflammation (53 papers). Evaluation of 76 papers on signal transduction indicated consistently reduced PI3K/mTOR/AKT and ERK signalling and activation of AMPK. In contrast, the effects of cordycepin on the p38 and Jun kinases were variable, as were the effects on cell cycle arrest (53 papers), suggesting these are cell-specific responses. The examination of 150 animal studies indicated that purified cordycepin has many potential therapeutic effects, including the reduction of tumour growth (37 papers), repression of pain and inflammation (9 papers), protecting brain function (11 papers), improvement of respiratory and cardiac conditions (8 and 19 papers) and amelioration of metabolic disorders (8 papers). Nearly all these data are consistent with cordycepin mediating its therapeutic effects through activating AMPK, inhibiting PI3K/mTOR/AKT and repressing the inflammatory response. We conclude that cordycepin has excellent potential as a lead for drug development, especially for age-related diseases. In addition, we discuss the remaining issues around the mechanism of action, toxicity and biodistribution of cordycepin.

Protective effect of cordycepin on experimental renal ischemia/reperfusion injury in rats

AIM

To date, various molecules have been investigated to reduce the effect of renal ischemia/reperfusion (I/R) injury. However, none have yet led to clinical use. The present study aimed to investigate the protective effect of cordycepin (C) on renal I/R injury in an experimental rat model.

MATERIALS AND METHODS

Twenty-four mature Sprague Dawley female rat was randomly divided into three groups: Sham, I/R, I/R+C. All animals underwent abdominal exploration. To induce I/R injury, an atraumatic vascular bulldog clamp was applied to the right renal pedicle for 60 minutes (ischemia) and later clamp was removed to allow reperfusion in all rats, except for the sham group. In the I/R + C group, 10 mg/kg C was administered intraperitoneally, immediately after reperfusion. After 4 hours of reperfusion, the experiment was terminated with right nephrectomy. Histological studies and biochemical analyses were performed on the right nephrectomy specimens. EGTI (endothelial, glomerular, tubulointerstitial) histopathology scoring and semi-quantitative analysis of renal cortical necrosis were used for histological analyses and superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), total oxidant status (TOS) for biochemical analyses.

RESULTS

Histopathological examination of the tissue damage revealed that all kidneys in the sham group were normal. The I/R group had higher histopathological scores than the I/R + C group. In the biochemical analysis of the tissues, SOD, MDA, TOS values were found to be statistically different in the I/R group compared to the I/R + C group (p: 0.004, 0.004, 0.001 respectively).

CONCLUSIONS

Intraperitoneal cordycepin injection following ischemia preserve renal tissue against oxidative stress in a rat model of renal I/R injury.

The protective effect of Cordycepin on diabetic nephropathy through autophagy induction in vivo and in vitro

BACKGROUND

Diabetic nephropathy (DN) is one of the most serious chronic complications of diabetes mellitus (DM). Autophagy is an important physiological function for podocytes to maintain stability of intracellular environment. In this study, we planned to clarify the effect of Cordycepin, a traditional Chinese medicine, on DN and the related mechanisms.

METHODS

All rats were randomly divided into normal control group, diabetic controls, low-dose group (10 mg/kg), medium-dose group (100 mg/kg), and high-dose group (500 mg/kg). The level of cholesterol, blood sugar, triglyceride, creatinine, and urine protein was examined through an automatic biochemistry analyser. Enzyme-linked immunosorbent assay (Elisa) was used to detect the level of IL-1β, IL-6, and IL-18. HE staining was used to examine histopathologic changes. TUNEL staining was used to detected cell apoptosis. The expression of fibrosis markers α-SMA, t-TG, and TIMP-1, apoptosis-related proteins cleaved-caspase3, Bax and Bcl-2, autophagy markers Beclin1, light chain 3 (LC3)I/II, and p62 were evaluated by western blot.

RESULTS

The level of cholesterol, blood sugar, triglyceride, creatinine, and urine protein in the diabetic controls was much higher than that in the normal control group. Obvious histopathology injuries were also found in DN model group. After Cordycepin treatment, all the above indexes were improved compared with the DN group and tissue damages were also alleviated. Further studies showed that Cordycepin suppressed cell apoptosis and renal fibrosis and rescued cell autophagy in DN rat model. Moreover, the results of our in vitro experiments showed that the addition of 3-methyladenine (3-MA, specific autophagy inhibitor) successfully abolished the protective effect of Cordycepin on renal fibrosis through inducing apoptosis and renal fibrosis. The above protective effects of Cordycepin were exhibited in a dose-dependent manner.

CONCLUSION

Cordycepin participated in the modulation of cell apoptosis, fibrosis, and autophagy induction in DN. Our study for the first time revealed that Cordycepin had a certain therapeutic effect on DN in rats through autophagy induction.

Renal Injury during Long-Term Crizotinib Therapy

Crizotinib is highly effective against anaplastic lymphoma kinase-positive and c-ros oncogen1-positive non-small cell lung cancer. Renal dysfunction is associated with crizotinib therapy but the mechanism is unknown. Here, we report a case of anaplastic lymphoma kinase positive non-small cell lung cancer showing multiple cysts and dysfunction of the kidneys during crizotinib administration. We also present results demonstrating that long-term crizotinib treatment induces fibrosis and dysfunction of the kidneys by activating the tumor necrosis factor-α/nuclear factor-κB signaling pathway. In conclusion, this study shows the renal detrimental effects of crizotinib, suggesting the need of careful monitoring of renal function during crizotinib therapy.

Cordycepin, a Characteristic Bioactive Constituent in Cordyceps militaris, Ameliorates Hyperuricemia through URAT1 in Hyperuricemic Mice

Recently, we've reported the anti-hyperuricemic effects of Cordyceps militaris. As a characteristic compound of C. militaris, we hypothesized that cordycepin may play a role in preventing hyperurecimia. Remarkably, cordycepin produced important anti-hyperuricemic actions, decreasing SUA (serum uric acid) to 216, 210, and 203 μmol/L (P < 0.01) at 15, 30, and 60 mg/kg in comparison of hyperuricemic control (337 μmol/L), closing to normal control (202 μmol/L). Elisa, RT-PCR and western blot analysis demonstrated that the actions may be attributed to its downregulation of uric acid transporter 1 (URAT1) in kidney. Serum creatinine levels and blood urine nitrogen and liver, kidney, and spleen coefficients demonstrated that cordycepin may not impact liver, renal, and spleen functions. In addition, we used computational molecular simulation to investigate the binding mechanism of cordycepin. Of which, van der Waals interaction dominated the binding. Residues TRP290, ARG17, ALA408, GLY411, and MET147 contributed mainly on nonpolar energy. This provided the theoretical guidance to rationally design and synthesis novel URAT1 inhibitors.

Use of Ophiocordyceps sinensis (syn. Cordyceps sinensis) combined with angiotensin-converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARB) versus ACEI/ARB alone in the treatment of diabetic kidney disease: a meta-analysis

Ophiocordyceps sinensis (O. sinensis; syn. Cordyceps sinensis) has been used in clinical therapy for diabetic kidney disease (DKD) for more than 15 years. O. sinensis is a household name in china and it is available even in supermarket. However, the precise role of O. sinensis has not been fully elucidated with meta-analysis. The aim of this study was to review existing evidence on the effectiveness of O. sinensis for the treatment of DKD. We identified 60 trials involving 4288 participants. Overall, O. sinensis combined with ACEI/ARB had a better effect when compared to ACEI/ARB alone on 24 h UP (MD = -0.23 g/d, 95% CI: - 0.28 to -0.19, p < 0.00001), UAER (MD = -19.71 μg/min, 95% CI: -22.76 to -16.66, p < 0.00001), MAU (MD = -45.09 mg/d, 95% CI: -55.68 to -34.50, p < 0.00001), BUN (MD = -0.70 mmol/L, 95% CI: -1.02 to -0.39, p < 0.0001), SCr (MD = -8.37 μmol/L, 95% CI: -12.41 to -4.32, p < 0.0001), CRP (MD = -1.32 mg/L; 95% CI: -1.78 to -0.86; p < 0.00001), TG (MD = -0.51 mmol/L; 95% CI: -0.69 to -0.34, p < 0.00001), TC (MD = -0.64 mmol/L; 95% CI: -0.91 to -0.37, p < 0.00001), and SBP (MD = -2.01 mmHg; 95% CI: -3.45 to -0.58, p = 0.006). However, no effects were found for DBP, FBG, and HbA1C. This meta-analysis suggested that use of O. sinensis combined with ACEI/ARB may have a more beneficial effect on the proteinuria, inflammatory, dyslipidemia status as compared to ACEI/ARB alone in DKD III-IV stage patients, while there is no evidence that O. sinensis could improve the hyperglycemia status. However, with regard to low-quality and significant heterogeneity of included trials, to further verify the current results from this meta-analysis, long-term and well-designed RCTs with high-quality study are warranted to ascertain the long-term efficacy of O. sinensis.

Hepatocyte growth factor-modified adipose tissue-derived stem cells improve erectile function in streptozotocin-induced diabetic rats

TGFβ1-Smad signaling pathway is closely related to various tissues fibrosis. Hepatocyte growth factor (HGF) has been shown to antagonize TGFβ1-Smad signaling and may improve kidney tissue fibrosis in diabetic models. Penile fibrosis is a pathological condition which occurs during diabetic erectile dysfunction (ED). The aim of this study was to examine the effect of the treatment of ED in diabetic rats with a combination of HGF and adipose tissue-derived stem cells (ADSC). In this diabetes model, rats were injected intraperitoneally with 60 mg streptozotocin (STZ) to induce diabetes. Three months later, the diabetic rats were divided into a negative control(NC) group, an ADSC-treated group and an ADSC + HGF-treated group while normal rats were assigned into a sham group. Rats in the sham and NC groups were injected in the corpus cavernosum with phosphate-buffered saline, while rats in the other groups were injected with either ADSC or ADSC + HGF. One month later, erectile function was examined in each group and penile tissues were collected for experiments. The expression of smooth muscle actin (SMA) and platelet-endothelial cell adhesion molecule-1 (PECAM-1) was analyzed by Western blotting. The smooth muscle and collagen deposition in corpus cavernosum was evaluated by Masson staining, while endothelial changes were assessed immunohistochemically. Cell apoptosis was detected by the TdT-mediated dUTP nick-end labeling (TUNEL) assay. The results revealed that ADSC alone can significantly improve erectile function in diabetic rats, but in combination with HGF the improvement was more prominent, showing higher content of smooth muscle and endothelial cells and lower cell apoptotic index in corpus cavernosum. Treatment with HGF can significantly enhance the beneficial effect of ADSC on erectile function in diabetic rats, and this effect might be closely related to the down-regulation of TGFβ1-Smad signaling.

Curcumin ameliorates renal fibrosis by inhibiting local fibroblast proliferation and extracellular matrix deposition

Renal fibrosis is mainly characterized by activation and proliferation of interstitial fibroblasts and by excessive synthesis and accumulation of extracellular matrix (ECM) components, including fibronectin (FN) and collagen. This study investigated the effects of curcumin on proliferation of renal interstitial fibroblasts and their underlying mechanisms in vivo and in vitro. ECM components were visualized by Sirius red and immunohistochemistry staining and quantified by western blot analysis in mice with unilateral ureteral obstruction (UUO). Duplex staining for proliferating cell nuclear antigen and α-smooth muscle actin (α-SMA), as well as MTT and flow cytometry assays, were performed to measure fibroblast proliferation. Protein expression of phosphorylated Smad2/3 (p-Smad2/3) and peroxisome proliferator-activated receptor-γ (PPAR-γ) were assessed by western blotting. Curcumin treatment decreased the accumulation of type I collagen and FN in the kidney of animals with UUO. Activation of rat renal interstitial fibroblasts (NRK-49F) was induced by TGF-β1. Curcumin treatment inhibited fibroblast proliferation and the cell cycle was arrested in the G1 phase. Curcumin treatment upregulated the expression of PPAR-γ and downregulated the expression of p-Smad2/3. These results suggest that curcumin treatment ameliorates renal fibrosis by reducing fibroblast proliferation and ECM accumulation mediated by PPAR-γ and Smad-dependent TGF-β1 signaling.

Cordycepin prevented IL-β-induced expression of inflammatory mediators in human osteoarthritis chondrocytes

PURPOSE

Cordycepin, a nucleoside derivative isolated from Cordyceps, has been reported to exert anti-inflammatory, antitumor, antidiabetic and renoprotective effects. Osteoarthritis (OA) is a degenerative joint disease with an inflammatory component that drives the degradation of cartilage extracellular matrix. This study aimed to assess the effects of cordycepin on human OA chondrocytes.

METHODS

In this study, human OA chondrocytes were pretreated with cordycepin at 10, 50 or 100 μM and subsequently stimulated with interleukin-1β (IL-1β) (5 ng/ml) for 24 h. Production of prostaglandin E2 (PGE2) and nitric oxide (NO) were evaluated by the Griess reaction and an enzyme-linked immunosorbent assay (ELISA). Gene expression of matrix metalloproteinase (MMP)-13, IL-6, inducible nitric oxide synthase (iNOS) and cyclo-oxygenase (COX-2) was measured by real-time polymerase chain reaction (PCR). MMP-13 and IL-6 proteins in culture medium were determined using cytokine-specific ELISA. Western immunoblotting was used to analyse the iNOS and COX-2 protein production in culture medium. Nuclear factor kappa-B (NF-κB) activity regulation was explored using Western immunoblotting.

RESULTS

Pretreatment with cordycepin significantly inhibited the production of PGE2 and NO induced by IL-1β. Cordycepin also significantly decreased the IL-1β-stimulated gene expression and production of MMP-13, IL-6, iNOS and COX-2 in OA chondrocytes. Pretreatment with cordycepin attenuated IL-1β-induced activation of NF-κB by suppressing degradation of its inhibitory protein nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκB-α) in the cytoplasm.

CONCLUSIONS

We show for the first time the anti-inflammatory activity of cordycepin in human OA chondrocytes. Thus, with this unique profile of actions, cordycepin may prove to be a potentially attractive and new therapeutic/preventive agent for OA.

Hydrogen-rich saline ameliorates renal injury induced by unilateral ureteral obstruction in rats

Hydrogen has been demonstrated to have effective protection against tissue injuries caused by oxidative stress, inflammation, and apoptosis. This study investigated the efficacy of hydrogen-rich saline (HS) on the prevention of renal injury induced by unilateral ureteric obstruction (UUO) in rats. Male Sprague-Dawley rats were divided randomly into 4 groups: sham group, UUO group, UUO+saline group, and UUO+HS group. UUO was induced by ligation of the left ureter. 5ml/kg HRSS or saline was administered beginning 1day after UUO and for 10days thereafter. Rats were killed at 10days after UUO. Left kidneys were excised immediately for the tissue histologic examinations and biochemical assays. Renal injury scores in the UUO group and the UUO+saline group were significantly higher compared with those in the sham group. However, administration of HS significantly reduced the injury score. Apoptosis index was significantly increased in UUO group and the UUO+saline group. HS treatment also reduced the apoptosis index. Interstitial fibrosis and macrophage infiltration were obvious in UUO kidneys. However, HS treatment significantly reduced the fibrosis and infiltration of macrophage in UUO kidneys. Significant increase in the MDA level and decrease in the SOD activity were observed in UUO group and the UUO+saline group. MDA level of UUO+HS group was significantly reduced. In addition, SOD activity of was significantly improved after treatment of HS. The data provide a biochemical and histologic basis for HS acting as a novel therapeutic strategy for preventing the renal injury induced by UUO.

Blockade of Smad signaling by 3'-deoxyadenosine: a mechanism for its anti-fibrotic potential

Cordyceps militaris has been used in Eastern countries for the treatment of various diseases including chronic kidney diseases. However, there are no reports that identified its active entities and molecular mechanisms underlying its therapeutic effectiveness. 3'-Deoxyadenosine is a major nucleoside derivative isolated from C. militaris. Some reports suggested that both C. militaris and 3'-deoxyadenosine have anti-inflammatory and anti-fibrotic effects. In the present report, we investigated whether and how 3'-deoxyadenosine interferes with fibrogenic processes in the kidney. For this purpose, we examined effects of 3'-deoxyadenosine on the expression of collagens triggered by transforming growth factor-β (TGF-β1) and bone morphogenetic protein-4 (BMP-4), especially focusing on the regulation of Smad signaling in vitro and in vivo. We found that 3'-deoxyadenosine suppressed expression of collagens induced by TGF-β1 and BMP-4 dose dependently. This suppression occurred at the transcriptional level and was correlated with blunted activation of the CAGA box and the BMP-responsive element. The suppressive effect on the TGF-β/BMP signaling was mediated mainly by adenosine transporter and partially by the A3 adenosine receptor, but not A1/A2 adenosine receptors. 3'-Deoxyadenosine reduced levels of both phosphorylated and total Smad proteins (Smad1, 2 and 3) dose dependently. It was mainly ascribed to transcriptional suppression, but not to enhanced protein degradation and eIF2α-mediated translational suppression. Consistent with the in vitro results, in vivo administration with 3'-deoxyadenosine reduced the levels of phosphorylated and total Smad proteins, as well as the levels of Smad mRNAs, in the kidney subjected to unilateral ureteral obstruction. It was associated with blunted induction of type I collagen and α-smooth muscle actin, a decrease in the number of interstitial myofibroblasts and reduced fibrotic area. These results suggest that 3'-deoxyadenosine interferes with the TGF-β and BMP signaling via downregulation of Smads, which may underlie the anti-fibrotic effect of this agent. 3'-Deoxyadenosine may be useful for therapeutic intervention in various TGF-β-related fibrotic disorders.

Hirsutella sinensis mycelium suppresses interleukin-1β and interleukin-18 secretion by inhibiting both canonical and non-canonical inflammasomes

Cordyceps sinensis is a medicinal mushroom used for centuries in Asian countries as a health supplement and tonic. Hirsutella sinensis-the anamorphic, mycelial form of C. sinensis-possesses similar properties, and is increasingly used as a health supplement. Recently, C. sinensis extracts were shown to inhibit the production of the pro-inflammatory cytokine IL-1β in lipopolysaccharide-treated macrophages. However, the molecular mechanism underlying this process has remained unclear. In addition, whether H. sinensis mycelium (HSM) extracts also inhibit the production of IL-1β has not been investigated. In the present study, the HSM extract suppresses IL-1β and IL-18 secretion, and ATP-induced activation of caspase-1. Notably, we observed that HSM not only reduced expression of the inflammasome component NLRP1 and the P2X7R but also reduced the activation of caspase-4, and ATP-induced ROS production. These findings reveal that the HSM extract has anti-inflammatory properties attributed to its ability to inhibit both canonical and non-canonical inflammasomes.

Cordycepin (3'-deoxyadenosine) attenuates age-related oxidative stress and ameliorates antioxidant capacity in rats

Free radical-induced oxidative damage is considered to be the most important consequence of the aging process. The activities and capacities of antioxidant systems of cells decline with increased age, leading to the gradual loss of pro-oxidant/antioxidant balance and resulting in increased oxidative stress. Our investigation was focused on the effects of cordycepin (3'-deoxyadenosine) on lipid peroxidation and antioxidation in aged rats. Age-associated decline in the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), reduced glutathione (GSH), vitamin C and vitamin E, and elevated levels of malondialdehyde (MDA) were observed in the liver, kidneys, heart and lungs of aged rats, when compared to young rats. Furthermore, serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), urea, and creatinine were found to be significantly elevated in aged rats compared to young rats. Aged rats receiving cordycepin treatment show increased activity of SOD, CAT, GPx, GR and GST, and elevated levels of GSH, and vitamins C and E such that the values of most of these parameters did not differ significantly from those found in young rats. In addition, the levels of MDA, AST, ALT, urea and creatinine became reduced upon administration of cordycepin to aged rats. These results suggest that cordycepin is effective for restoring antioxidant status and decreasing lipid peroxidation in aged rats.

Activation of ERK-p53 and ERK-mediated phosphorylation of Bcl-2 are involved in autophagic cell death induced by the c-Met inhibitor SU11274 in human lung cancer A549 cells

SU11274, a small molecule inhibitor of c-Met, was reported to induce apoptosis in human non-small-cell lung cancer (NSCLC) cells. However, SU11274-mediated autophagy in NSCLC cells has rarely been reported. The aim of this study was to elucidate the molecular mechanisms mediating SU11274-induced autophagy in NSCLC A549 cells. Here we reported that SU11274-induced autophagy was accompanied with an increase in the conversion of LC3-I to LC3-II and up-regulation of Beclin-1 expression. Subsequently, we also found that small interfering RNA against c-Met induced A549 cell autophagy while promotion of c-Met by hepatocyte growth factor (HGF) suppressed A549 cell autophagy. Inhibition of autophagy by 3-methyladenine (3-MA) suppressed SU11274-induced cell death, suggesting that SU11274-induced autophagy caused cell death. Further study showed that ERK and p53 were activated after SU11274 treatment. Interruption of ERK and p53 activities decreased SU11274-induced autophagy, and blocking of ERK by the specific inhibitor PD98059 suppressed SU11274-induced p53 activation. Moreover, ERK activation upregulated Beclin-1 expression through induction of Bcl-2 phosphorylation, but p53 did not induce Bcl-2 phosphorylation. In conclusion, inhibition of c-Met induced autophagic cell death, which was associated with ERK-p53 activation and ERK-mediated Bcl-2 phosphorylation in A549 cells.