CCDC92 promotes podocyte injury by regulating PA28α/ABCA1/cholesterol efflux axis in type 2 diabetic mice.

Podocyte lipotoxicity mediated by impaired cellular cholesterol efflux plays a crucial role in the development of diabetic kidney disease (DKD), and the identification of potential therapeutic targets that regulate podocyte cholesterol homeostasis has clinical significance. Coiled-coil domain containing 92 (CCDC92) is a novel molecule related to metabolic disorders and insulin resistance. However, whether the expression level of CCDC92 is changed in kidney parenchymal cells and the role of CCDC92 in podocytes remain unclear. In this study, we found that Ccdc92 was significantly induced in glomeruli from type 2 diabetic mice, especially in podocytes. Importantly, upregulation of Ccdc92 in glomeruli was positively correlated with an increased urine albumin-to-creatinine ratio (UACR) and podocyte loss. Functionally, podocyte-specific deletion of Ccdc92 attenuated proteinuria, glomerular expansion and podocyte injury in mice with DKD. We further demonstrated that Ccdc92 contributed to lipid accumulation by inhibiting cholesterol efflux, finally promoting podocyte injury. Mechanistically, Ccdc92 promoted the degradation of ABCA1 by regulating PA28α-mediated proteasome activity and then reduced cholesterol efflux. Thus, our studies indicate that Ccdc92 contributes to podocyte injury by regulating the PA28α/ABCA1/cholesterol efflux axis in DKD.

Recent advances in radical-mediated intermolecular (4 + 2) cycloaddition.

(4 + 2) Cycloaddition plays an important role in the synthesis of versatile carbocyclic/heterocyclic compounds with its high atom- and step-economy. Additionally, with mild conditions and indispensable functional group compatibility, the radical reaction has been recognized as a useful tool in organic chemistry. Given the enormous impact of radical-mediated (4 + 2) cycloaddition processes and their promising applications, we summarize and highlight the recent works in this attractive area. On the basis of the types of radicals that initiate different (4 + 2) cycloaddition processes, we classify them into processes involving alkenyl cations or alkenyl radicals, aryl radicals, acyl radicals, alkyl radicals, and heteroatom radicals, and this review places special emphasis on the reaction design and mechanisms, which will stimulate future developments in radical-mediated intermolecular (4 + 2) cycloaddition.

ß-arrestin2 deficiency ameliorates S-100-induced autoimmune hepatitis in mice by inhibiting infiltration of monocyte-derived macrophage and attenuating hepatocyte apoptosis.

Autoimmune hepatitis (AIH) is a progressive hepatitis syndrome characterized by high transaminase levels, interface hepatitis, hypergammaglobulinemia, and the presence of autoantibodies. Misdiagnosis or delayed treatment of AIH can lead to cirrhosis or liver failure, which poses a major risk to human health. ß-Arrestin2, a key scaffold protein for intracellular signaling pathways, has been found to be involved in many autoimmune diseases such as Sjogren's syndrome and rheumatoid arthritis. However, whether ß-arrestin2 plays a role in AIH remains unknown. In the present study, S-100-induced AIH was established in both wild-type mice and ß-arrestin2 knockout (Arrb2 KO) mice, and the experiments identified that liver ß-arrestin2 expression was gradually increased, and positively correlated to serum ANA, ALT and AST levels during AIH progression. Furthermore, ß-arrestin2 deficiency ameliorated hepatic pathological damage, decreased serum autoantibody and inflammatory cytokine levels. ß-arrestin2 deficiency also inhibited hepatocyte apoptosis and prevented the infiltration of monocyte-derived macrophages into the damaged liver. In vitro experiments revealed that ß-arrestin2 knockdown suppressed the migration and differentiation of THP-1 cells, whereas ß-arrestin2 overexpression promoted the migration of THP-1 cells, which was regulated by the activation of the ERK and p38 MAPK pathways. In addition, ß-arrestin2 deficiency attenuated TNF-α-induced primary hepatocyte apoptosis by activating the Akt/GSK-3ß pathway. These results suggest that ß-arrestin2 deficiency ameliorates AIH by inhibiting the migration and differentiation of monocytes, decreasing the infiltration of monocyte-derived macrophages into the liver, thereby reducing inflammatory cytokines-induced hepatocytes apoptosis. Therefore, ß-arrestin2 may act as an effective therapeutic target for AIH.

GPR97 deficiency ameliorates renal interstitial fibrosis in mouse hypertensive nephropathy.

Hypertensive nephropathy (HTN) ranks as the second-leading cause of end-stage renal disease (ESRD). Accumulating evidence suggests that persistent hypertension injures tubular cells, leading to tubulointerstitial fibrosis (TIF), which is involved in the pathogenesis of HTN. G protein-coupled receptors (GPCRs) are implicated in many important pathological and physiological processes and act as important drug targets. In this study, we explored the intrarenal mechanisms underlying hypertension-associated TIF, and particularly, the potential role of GPR97, a member of the adhesion GPCR subfamily, in TIF. A deoxycorticosterone acetate (DOCA)/salt-induced hypertensive mouse model was used. We revealed a significantly upregulated expression of GPR97 in the kidneys, especially in renal tubules, of the hypertensive mice and 10 patients with biopsy-proven hypertensive kidney injury. GPR97-/- mice showed markedly elevated blood pressure, which was comparable to that of wild-type mice following DOCA/salt treatment, but dramatically ameliorated renal injury and TIF. In NRK-52E cells, we demonstrated that knockdown of GPR97 suppressed the activation of TGF-ß signaling by disturbing small GTPase RhoA-mediated cytoskeletal reorganization, thus inhibiting clathrin-mediated endocytosis of TGF-ß receptors and subsequent Smad activation. Collectively, this study demonstrates that GPR97 contributes to hypertension-associated TIF at least in part by facilitating TGF-ß signaling, suggesting that GPR97 is a pivotal intrarenal factor for TIF progression under hypertensive conditions, and therapeutic strategies targeting GPR97 may improve the outcomes of patients with HTN.

TFEB, a master regulator of autophagy and biogenesis, unexpectedly promotes apoptosis in response to the cyclopentenone prostaglandin 15d-PGJ2.

Transcriptional factor EB (TFEB), a master regulator of autophagy and lysosomal biogenesis, is generally regarded as a pro-survival factor. Here, we identify that besides its effect on autophagy induction, TFEB exerts a pro-apoptotic effect in response to the cyclopentenone prostaglandin 15-deoxy-∆-12,14-prostaglandin J2 (15d-PGJ2). Specifically, 15d-PGJ2 promotes TFEB translocation from the cytoplasm into the nucleus to induce autophagy and lysosome biogenesis via reactive oxygen species (ROS) production rather than mTORC1 inactivation. Surprisingly, TFEB promotes rather than inhibits apoptosis in response to 15d-PGJ2. Mechanistically, ROS-mediated TFEB translocation into the nucleus transcriptionally upregulates the expression of ATF4, which is required for apoptosis elicited by 15d-PGJ2. Additionally, inhibition of TFEB activation by ROS scavenger N-acetyl cysteine or inhibition of protein synthesis by cycloheximide effectively compromises ATF4 upregulation and apoptosis in response to 15d-PGJ2. Collectively, these results indicate that ROS-induced TFEB activation exerts a novel role in promoting apoptosis besides its role in regulating autophagy in response to 15d-PGJ2. This work not only evidences how TFEB is activated by 15d-PGJ2, but also unveils a previously unexplored role of ROS-dependent activation of TFEB in modulating cell apoptosis in response to 15d-PGJ2.

Lemairamin, isolated from the Zanthoxylum plants, alleviates pain hypersensitivity via spinal α7 nicotinic acetylcholine receptors.

Lemairamin (also known as wgx-50), is isolated from the pericarps of the Zanthoxylum plants. As an agonist of α7 nicotinic acetylcholine receptors (α7nAChRs), it can reduce neuroinflammation in Alzheimer's disease. This study evaluated its antinociceptive effects in pain hypersensitivity and explored the underlying mechanisms. The data showed that subcutaneous lemairamin injection dose-dependently inhibited formalin-induced tonic pain but not acute nociception in mice and rats, while intrathecal lemairamin injection also dose-dependently produced mechanical antiallodynia in the ipsilateral hindpaws of neuropathic and bone cancer pain rats without affecting mechanical thresholds in the contralateral hindpaws. Multiple bi-daily lemairamin injections for 7 days did not induce mechanical antiallodynic tolerance in neuropathic rats. Moreover, the antinociceptive effects of lemairamin in formalin-induced tonic pain and mechanical antiallodynia in neuropathic pain were suppressed by the α7nAChR antagonist methyllycaconitine. In an α7nAChR antagonist-reversible manner, intrathecal lemairamin also stimulated spinal expression of IL-10 and ß-endorphin, while lemairamin treatment induced IL-10 and ß-endorphin expression in primary spinal microglial cells. In addition, intrathecal injection of a microglial activation inhibitor minocycline, anti-IL-10 antibody, anti-ß-endorphin antiserum or µ-opioid receptor-preferred antagonist naloxone was all able to block lemairamin-induced mechanical antiallodynia in neuropathic pain. These data demonstrated that lemairamin could produce antinociception in pain hypersensitivity through the spinal IL-10/ß-endorphin pathway following α7nAChR activation.

The spinal microglial IL-10/ß-endorphin pathway accounts for cinobufagin-induced mechanical antiallodynia in bone cancer pain following activation of α7-nicotinic acetylcholine receptors.

BACKGROUND: Cinobufagin is the major bufadienolide of Bufonis venenum (Chansu), which has been traditionally used for the treatment of chronic pain especially cancer pain. The current study aimed to evaluate its antinociceptive effects in bone cancer pain and explore the underlying mechanisms. METHODS: Rat bone cancer model was used in this study. The withdrawal threshold evoked by stimulation of the hindpaw was determined using a 2290 CE electrical von Frey hair. The ß-endorphin and IL-10 levels were measured in the spinal cord and cultured primary microglia, astrocytes, and neurons. RESULTS: Cinobufagin, given intrathecally, dose-dependently attenuated mechanical allodynia in bone cancer pain rats, with the projected Emax of 90% MPE and ED50 of 6.4 µg. Intrathecal cinobufagin also stimulated the gene and protein expression of IL-10 and ß-endorphin (but not dynorphin A) in the spinal cords of bone cancer pain rats. In addition, treatment with cinobufagin in cultured primary spinal microglia but not astrocytes or neurons stimulated the mRNA and protein expression of IL-10 and ß-endorphin, which was prevented by the pretreatment with the IL-10 antibody but not ß-endorphin antiserum. Furthermore, spinal cinobufagin-induced mechanical antiallodynia was inhibited by the pretreatment with intrathecal injection of the microglial inhibitor minocycline, IL-10 antibody, ß-endorphin antiserum and specific µ-opioid receptor antagonist CTAP. Lastly, cinobufagin- and the specific α-7 nicotinic acetylcholine receptor (α7-nAChR) agonist PHA-543613-induced microglial gene expression of IL-10/ß-endorphin and mechanical antiallodynia in bone cancer pain were blocked by the pretreatment with the specific α7-nAChR antagonist methyllycaconitine. CONCLUSIONS: Our results illustrate that cinobufagin produces mechanical antiallodynia in bone cancer pain through spinal microglial expression of IL-10 and subsequent ß-endorphin following activation of α7-nAChRs. Our results also highlight the broad significance of the recently uncovered spinal microglial IL-10/ß-endorphin pathway in antinociception.

Effects of UV-B radiation on the survival, egg hatchability and transcript expression of antioxidant enzymes in a high-temperature adapted strain of Neoseiulus barkeri.

Biological control of spider mites in hot and dry weather is a serious technical issue. A high-temperature adapted strain (HTAS) of the predatory mite Neoseiulus barkeri Hughes was selected from its conventional strain (CS), via long-term heat acclimation and frequent heat hardenings in our previous studies. However, the environment of high temperature is usually associated with enhanced ultraviolet (UV) radiation. In the present study, the physiological effects of UV-B radiation on survival rate and egg damage of N. barkeri were investigated, as well as the activities and expression profiles of antioxidant enzymes to UV-B radiation stress. UV-B radiation had deleterious effects on egg hatchability and survival of N. barkeri. Adults of the HTAS strain were less UV-B resistant than those of the CS strain; they also had lower levels of enzymatic activity of superoxide dismutase (SOD) and catalase against oxidative damage and weaker upregulation of SOD genes. The mRNA expression of three SOD genes of CS adult females immediately increased whereas that of HTAS showed almost no difference under UV-B stress for 1 h. The results showed the HTAS of N. barkeri had lower fitness under UV-B stress compared with the CS of N. barkeri. These results suggested that long-term heat acclimation may exert a profound impact on the developmental physiology of N. barkeri.

Chitosan elicitation of Isatis tinctoria L. hairy root cultures for enhancing flavonoid productivity and gene expression and related antioxidant activity.

Elicitation for phytochemical enhancement via cost-effective elicitors can overcome the limitation of commercial application faced by plant cell and organ culture technology. Chitosan is a natural, low-cost, and nontoxic elicitor that can trigger plant defense responses with the concomitant enhancement in phytochemical biosynthesis. In this work, the elicitation of Isatis tinctoria L. hairy root cultures by chitosan was conducted to enhance the production of pharmacologically active flavonoids. In comparison with control (2.31 ±â€¯0.29 mg/g DW), a 7.08-fold enhancement of total flavonoids (16.35 ±â€¯0.88 mg/g DW) was achieved in 24 day-old I. tinctoria hairy root cultures elicited by 150 mg/L chitosan for 36 h. Interestingly, the multiple hydroxyl-substituted flavonoids (rutin, quercetin, isorhamnetin, and isoliquiritigenin) were noticed to increase significantly in chitosan-elicited I. tinctoria hairy root cultures. Moreover, the transcription of associated genes involved in flavonoid biosynthesis pathway was significantly up-regulated underlying chitosan elicitation, among which chalcone synthase and flavonoid 3'-hydroxylase might play an important role in flavonoid enhancement. Additionally, extracts from chitosan-elicited I. tinctoria hairy root cultures exhibited higher antioxidant activities with lower IC50 values as compared with control. Overall, a cost-effective strategy via the simple chitosan elicitation is provided here to enhance the production of high-added value flavonoids in I. tinctoria hairy root cultures, which paves the way toward the successful commercialization of this in vitro culture system in the future.

Neuroprotective Natural Products for the Treatment of Parkinson's Disease by Targeting the Autophagy-Lysosome Pathway: A Systematic Review.

The autophagy-lysosome pathway (ALP) is a primary means by which damaged organelles and long-lived proteins are removed from cells and their components recycled. Impairment of the ALP has been found to be linked to the pathogenesis of Parkinson's disease (PD), a chronic neurodegenerative disorder characterized by the accumulation of protein aggregates and loss of dopaminergic neurons in the midbrain. In recent years, some active compounds derived from plants have been found to regulate the ALP and to exert neuroprotective effects in experimental models of PD, raising the possibility that autophagy enhancement may be an effective therapeutic strategy in PD treatment. In this review, we summarize recent findings of natural products that enhance ALP and thereby protect against PD. Research articles were retrieved from PubMed using relevant keywords in combination. Papers related to the topic were identified, and then the reliability of the experiments was assessed in terms of methodology. The results suggest that targeting the ALP with natural products is a promising strategy for PD treatment. However, risk of bias exists in some studies due to the defective methodology. Rigorous experimental design following the guidelines of autophagy assays, molecular target identification and in vivo efficacy evaluation is critical for the development of ALP enhancers for PD treatment in future studies. Copyright © 2017 John Wiley & Sons, Ltd.