The angiotensin receptor neprilysin inhibitor LCZ696 attenuates renal fibrosis via ASK1/JNK/p38 MAPK-mediated apoptosis in unilateral ureteral obstruction.

The angiotensin receptor neprilysin inhibitor LCZ696 affords superior cardioprotection and renoprotection compared with renin-angiotensin blockade monotherapy, but the underlying mechanisms remain elusive. Herein, we evaluated whether LCZ696 attenuates renal fibrosis by inhibiting ASK1/JNK/p38 mitogen-activated protein kinase (MAPK)-mediated apoptosis in a rat model of unilateral ureteral obstruction (UUO) and in vitro. Rats with UUO were treated daily for 7 days with LCZ696, valsartan, or the selective ATP competitive inhibitor of apoptosis signal-regulating kinase 1 (ASK1), GS-444217. The effects of LCZ696 on renal injury were examined by assessing the histopathology, oxidative stress, intracellular organelles, apoptotic cell death, and MAPK pathways. H2O2-exposed human kidney 2 (HK-2) cells were also examined. LCZ696 and valsartan treatment significantly attenuated renal fibrosis caused by UUO, and this was paralleled by downregulation of proinflammatory cytokines and decreased inflammatory cell influx. Intriguingly, LCZ696 had stronger effects on renal fibrosis and inflammation than valsartan. UUO-induced oxidative stress triggered mitochondrial destruction and endoplasmic reticulum stress, which resulted in apoptotic cell death; these effects were reversed by LCZ696. Both GS-444217 and LCZ696 hampered the expression of death-associated ASK1/JNK/p38 MAPKs. In H2O2-treated HK-2 cells, LCZ696 and GS-444217 increased cell viability but decreased the production of intracellular reactive oxygen species and MitoSOX and apoptotic cell death. Both agents also deactivated H2O2-stimulated activation of ASK1/JNK/p38 MAPKs. These findings suggest that LCZ696 protects against UUO-induced renal fibrosis by inhibiting ASK1/JNK/p38 MAPK-mediated apoptosis.

Nicotine exacerbates tacrolimus-induced renal injury by programmed cell death.

BACKGROUND/AIMS: Cigarette smoking is an important modifiable risk factor in kidney disease progression. However, the underlying mechanisms for this are lacking. This study aimed to assess whether nicotine (NIC), a major toxic component of cigarette smoking, would exacerbates tacrolimus (TAC)-induced renal injury. METHODS: Sprague-Dawley rats were treated daily with NIC, TAC, or both drugs for 4 weeks. The influence of NIC on TAC-caused renal injury was examined via renal function, histopathology, oxidative stress, mitochondria, endoplasmic reticulum (ER) stress, and programmed cell death (apoptosis and autophagy). RESULTS: Both NIC and TAC significantly impaired renal function and histopathology, while combined NIC and TAC treatment aggravated these parameters beyond the effects of either alone. Increased oxidative stress, ER stress, mitochondrial dysfunction, proinf lammatory and profibrotic cytokine expressions, and programmed cell death from either NIC or TAC were also aggravated by the two combined. CONCLUSION: Our observations suggest that NIC exacerbates chronic TAC nephrotoxicity, implying that smoking cessation may be beneficial for transplant smokers taking TAC.

L-Carnitine protects against tacrolimus-induced renal injury by attenuating programmed cell death via PI3K/AKT/PTEN signaling.

Reducing immunosuppressant-related complications using conventional drugs is an efficient therapeutic strategy. L-carnitine (LC) has been shown to protect against various types of renal injury. In this study, we investigated the renoprotective effects of LC in a rat model of chronic tacrolimus (TAC) nephropathy. SD rats were injected with TAC (1.5 mg · kg-1 · d-1, sc) for 4 weeks. Renoprotective effects of LC were assessed in terms of renal function, histopathology, oxidative stress, expression of inflammatory and fibrotic cytokines, programmed cell death (pyroptosis, apoptosis, and autophagy), mitochondrial function, and PI3K/AKT/PTEN signaling. Chronic TAC nephropathy was characterized by severe renal dysfunction and typical histological features of chronic nephropathy. At a molecular level, TAC markedly increased the expression of inflammatory and fibrotic cytokines in the kidney, induced oxidative stress, and led to mitochondrial dysfunction and programmed cell death through activation of PI3K/AKT and inhibition of PTEN. Coadministration of LC (200 mg · kg-1 · d-1, ip) caused a prominent improvement in renal function and ameliorated histological changes of kidneys in TAC-treated rats. Furthermore, LC exerted anti-inflammatory and antioxidant effects, prevented mitochondrial dysfunction, and modulated the expression of a series of apoptosis- and autophagy-controlling genes to promote cell survival. Human kidney proximal tubular epithelial cells (HK-2 cells) were treated with TAC (50 µg/mL) in vitro, which induced production of intracellular reactive oxygen species and expression of an array of genes controlling programmed cell death (pyroptosis, apoptosis, and autophagy) through interfering with PI3K/AKT/PTEN signaling. The harmful responses of HK-2 cells to TAC were significantly attenuated by cotreatment with LC and the PI3K inhibitor LY294002 (25 µM). In conclusion, LC treatment protects against chronic TAC nephropathy through interfering the PI3K/AKT/PTEN signaling.

Exogenous pancreatic kininogenase protects against renal fibrosis in rat model of unilateral ureteral obstruction.

Tissue kallikrein has protective function against various types of injury. In this study, we investigated whether exogenous pancreatic kininogenase (PK) conferred renoprotection in a rat model of unilateral ureteral obstruction (UUO) and H2O2-treated HK-2 cells in vitro. SD rats were subjected to UUO surgery, then PK (7.2 U/g per day, ip) was administered for 7 or 14 days. After the treatment, rats were euthanized; the obstructed kidneys were harvested for further examination. We found that PK administration significantly attenuated interstitial inflammation and fibrosis, and downregulated the expression of proinflammatory (MCP-1, TLR-2, and OPN) and profibrotic (TGF-ß1 and CTGF) cytokines in obstructed kidney. UUO-induced oxidative stress, closely associated with excessive apoptotic cell death and autophagy via PI3K/AKT/FoxO1a signaling, which were abolished by PK administration. We further showed that PK administration increased the expression of bradykinin receptors 1 and 2 (B1R and B2R) mRNA and the production of NO and cAMP in kidney tissues. Coadministration with either B1R antagonist (des-Arg9-[Leu8]-bradykinin) or B2R antagonist (icatibant) abrogated the renoprotective effects of PK, and reduced the levels of NO and cAMP in obstructed kidney. In H2O2-treated HK-2 cells, addition of PK (6 pg/mL) significantly decreased ROS production, regulated the expression of oxidant and antioxidant enzymes, suppressed the expression of TGF-ß1 and MCP-1, and inhibited cell apoptosis. Our data demonstrate that PK treatment protects against the progression of renal fibrosis in obstructed kidneys.

Streptomyces tremellae sp. nov., isolated from a culture of the mushroom Tremella fuciformis.

A novel actinomycete strain, designated Js-1T, was isolated from Tremella fuciformis collected from Gutian, Fujian Province, in southeastern China. The taxonomic status of this strain was determined by a polyphasic approach, which demonstrated that the novel strain was a member of the genus Streptomyces. The cell walls of this strain were found to contain ll-diaminopimelic acid, muramic acid and glycine. An analysis of whole-cell hydrolysates revealed that no characteristic sugar was present. The key identified menaquinones were MK-9 (H6) and MK-9 (H8), while the diagnostic polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylmethylethanolamine and phosphatidylglycerol. The main cellular fatty acids were anteiso-C15 : 0, iso-C15 : 0, C16 : 0 and iso-C16 : 0. An analysis of an almost complete 16S rRNA gene sequence showed that the strain shared the highest levels of sequence similarity with Streptomyces sannanensisKC-7038T (97.87 %), Streptomyces hebeiensis YIM 001T (97.84 %), Streptomyces pathocidini NBRC 13812T (97.80 %), Streptomyces cocklensis BK168T (97.25 %), Streptomyces coerulescens NBRC 12758T (97.12 %), Streptomyces aurantiogriseus NBRC 12842T (97.06 %) and Streptomyces rimosussubsp. rimosus ATCC 10970T (97.04 %). The DNA G+C content of the genomic DNA of strain Js-1T was 70.1 mol%. Furthermore, DNA-DNA hybridization tests revealed that the relatedness values between strain Js-1T and the most closely related species ranged from 15.10 to 47.20 %. Based on its phenotypic and genotypic characteristics, strain Js-1T (=CCTCC M 2011365T=JCM 30846T) is considered to represent a novel species within the genus Streptomyces, which we classified as Streptomycestremellae sp. nov.

[Prevention and Treatment of Atherosclerosis by Three Different Chinese Medical Compounds: a Mechanism Study].

OBJECTIVE: To study the effect of Buyang Huanwu Decoction (BHD), Xuefu Zhuyu Decoction (XZD), and Sijunzi Decoction (SD) contained serums on expressions of Toll-like receptor 4 (TLR4)/nuclear factor (NF)-κB signals, lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), tumor necrosis factor-α (TNF-α), vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and to explore possible anti-atherosclerotic mechanisms. METHODS: Twenty New Zealand rabbits were divided into 4 groups at random, i.e., the normal control group, the BHD group (6.7 g/kg), the XZD group (3.6 g/kg), and the SD group (1.6 g/kg), 5 in each group. All medication lasted for 7 successive days. Two h after the final medication, about 50 mL blood was withdrawn from rabbit heart for preparing serums. Human umbilical vein endothelial cell ECV304 were cultured in vitro for 18 h and randomly divided into the blank control group, the model group, the Western medicine (WM) control group, the BHD group, the XZD group, and the SD group at random. ECV304, except in the blank control group, were stimulated with lipopolysaccharide (LPS) for 2 h. Those in the WM control group and CM groups were treated respectively with corresponding CM contained serum for 24 h. Finally gene and protein expressions of TLR4, myeloid differentiation factor 88 (MyD88), tumor necrosis factor receptor-associated factor-6 (TRAF-6), NF-κB, LOX-1, TNF-α, ICAM-1, and VCAM-1 were detected by fluorescent quantitative PCR and Western blot. RESULTS: Compared with the blank control group, mRNA expressions of TLR4, MyD88, TRAF-6, NF-KB, LOX-1 , TNF-cx, ICAM-1, and VCAM-1 increased significantly; protein expressions of TLR4, NF-κB, LOX-1, TNF-α, ICAM-1, and VCAM-1 also increased significantly in the model group (P < 0.01). Compared with the model group, mRNA and protein expressions of each index could be significantly inhibited in the BHD group, the XZD group, and the WM control group (P < 0.05). Besides, mRNA and protein expressions of each index could be significantly elevated more in the BHD group and the XZD group than in the WM control group (P < 0.05). No statistical difference existed in each index between the SD group and the rest groups (P > 0.05). CONCLUSIONS: The mechanism of BHD and XZD for fighting against atherosclerosis might be associated with inhibiting TLR4/NF-κB signal transduction pathway and expressions of its downstream inflammatory factors such as LOX-1, TNF-α, ICAM-1, and VCAM-1. But SD showed no associated effect on atherosclerosis.

[Effects of yiqi huoxue compound contained drug serum on the expressions of toll-like receptor 4 and downstream signal transduction pathway, and LOX-1, TNF-alpha, ICAM-1 in the human vein endothelial cells].

OBJECTIVE: To investigate the effects of Yiqi Huoxue Compound (YHC) contained drug serum on the expressions of TLR4 and its downstream signal transduction pathway and LOX-1, TNF-alpha, ICAM-1 in human umbilical vein endothelial cells (HUVECs), and to study its possible anti-atherosclerosis (AS) mechanism. METHODS Twenty New Zealand rabbits were divided into 4 groups in random, i. e., the normal control group, the high concentration group, the middle concentration group, and the low concentration group, 5 in each group. Normal saline was given to rabbits in the normal control group by gastrogavage. High, middle, and low concentration of YHC was respectively given to rabbits in the rest 3 groups by gastrogavage for 7 successive days. The blood was withdrawn from the heart 2 h after the last gastrogavage. The serum was isolated after centrifuge. HUVECs was in vitro cultured and then randomly divided into 6 groups, i. e., the normal control group, the model group, the Western medicine control group, the high, middle, and low YHC groups. HUVECs were stimulated with LPS for 2 h, and then treated with high, middle, and low YHC contained serum. HUVECs were collected 24 h later. The gene expressions of TLR4, MyD88, TRAF-6, TRAM, TRIF, NF-kappaB, LOX-1, TNF-alpha, and ICAM-1 were detected using fluorescent quantitative PCR. The protein expressions of TLR4, MyD88, TRAF-6, and LOX-1 were determined using Western blot method. RESULTS: After HUVECs were stimulated by LPS, the expressions of TLR4, MyD88, TRAF-6, TRAM, TRIF, NF-kappaB, LOX-1, TNF-alpha, and ICAM-1 were enhanced, showing statistical difference when compared with the vehicle control group (P < 0.01). YHC contained serum significantly decreased the higher expressions of TLR4, MyD88, TRAF-6, NF-kappaB, LOX-1, TNF-alpha, and ICAM-1, showing statistical difference when compared with the model group (P < 0.05). CONCLUSIONS: YHC could inhibit the TLR signal transduction pathway and the expressions of LOX-1, TNF-alpha, and ICAM-1. These might be one of the mechanisms for treating various immune inflammatory diseases and preventing AS.

[Isolation and identification of a bacterial strain JS018 capable of degrading several kinds of organophosphate pesticides].

Organophosphate pesticides are used widely all over the world and play an important role in plant pest control. However these pesticides are considered as pollutants and harmful to human health. To search for microorganisms that can degrade organophosphate pesticides with high efficiency, a bacterial strain, coded as JS018, was isolated and screened from the soil in the vicinity of Shanming Pesticides Factory, Shanming, Fujian. Laboratory tests showed that the bacterium could degrade several kinds of organophosphate pesticides, such as Parathion-methyl and phoxin. The strain's degrading rates on phoxin, Parathion-methyl, hostathion and dichlorvos in LB liquid fermentation medium for 36 h were 99%, 96%, 80.4% and 69.0% respectively. The bacterial colonies on LB plate appeared shiny and pale-pink in color. The bacteria were Gram-negative coccoids, 0.5 - 0.7 microm in diameter. They grew well at 30 - 38 degrees C and pH 7.0 - 9.0. The optimal temperature and pH for cell growth was 32 degrees C and pH 7.5 - 8.0, respectively. They did not grow in medium containing 6% or more NaCl. The antibiotic susceptibility tests showed that the strain was resistant to ampicillin, penicillin and lincomycin. It was sensitive to kanamycin, tetracycline and gentamicin. Laboratory tests also showed that the strain could ferment D-glucose, trehalose, melezitose and ethanol. It was negative in the production of indole and hydrogen sulfide. It could not liquefy gelatin, utilize citrate, nor ferment L-arabinose, sucrose, D-mannitol, D-xylose, fructose, D-galactose, maltose or lactose. The catalase, urease and nitrate reduction were positive. Based on its morphological, physiological and biochemical properties as well as the 16S rDNA sequence analysis result, the strain was tentatively identified as Roseomonas sp.