Inhibition of inflammation using diacerein markedly improved renal function in endotoxemic acute kidney injured mice

Background

Inflammation is an important pathogenic component of endotoxemia-induced acute kidney injury (AKI), finally resulting in renal failure. Diacerein is an interleukin-1β (IL-1β) inhibitor used for osteoarthritis treatment by exerting anti-inflammatory effects. This study aims to investigate the effects of diacerein on endotoxemia-induced AKI.

Methods

Male C57BL/6 mice were intraperitoneally injected with lipopolysaccharide (LPS, 10 mg/kg) for 24 h prior to diacerein treatment (15 mg/kg/day) for another 48 h. Mice were examined by histological, molecular and biochemical approaches.

Results

LPS administration showed a time-dependent increase of IL-1β expression and secretion in kidney tissues. Diacerein treatment normalized urine volume and osmolarity, reduced blood urea nitrogen (BUN), fractional excretion of sodium (FENa), serum creatinine and osmolarity, and protected renal function in an endotoxemic AKI mice model. In the histopathologic study, diacerein also improved renal tubular damage such as necrosis of the tubular segment. Moreover, diacerein inhibited LPS-induced increase of inflammatory cytokines, such as IL-1β, tumor necrosis factor-α, monocyte chemoattractant protein-1 and nitric oxide synthase 2. In addition, LPS administration markedly decreased aquaporin 1 (AQP1), AQP2, AQP3, Na,K-ATPase α1, apical type 3 Na/H exchanger and Na-K-2Cl cotransporter expression in the kidney, which was reversed by diacerein treatment. We also found that diacerein or IL-1β inhibition prevented the secretion of inflammatory cytokines and the decrease of AQP and sodium transporter expression induced by LPS in HK-2 cells.

Conclusion

Our study demonstrates for the first time that diacerein improves renal function efficiently in endotoxemic AKI mice by suppressing inflammation and altering tubular water and sodium handing. These results suggest that diacerein may be a novel therapeutic agent for the treatment of endotoxemic AKI.

     

Curcumin inhibits neuronal and vascular degeneration in retina after ischemia and reperfusion injury

Background

Neuron loss, glial activation and vascular degeneration are common sequelae of ischemia-reperfusion (I/R) injury in ocular diseases. The present study was conducted to explore the ability of curcumin to inhibit retinal I/R injury, and to investigate underlying mechanisms of the drug effects.

Methodology/Principal Findings

Different dosages of curcumin were administered. I/R injury was induced by elevating the intraocular pressure for 60 min followed by reperfusion. Cell bodies, brn3a stained cells and TUNEL positive apoptotic cells in the ganglion cell layer (GCL) were quantitated, and the number of degenerate capillaries was assessed. The activation of glial cells was measured by the expression level of GFAP. Signaling pathways including IKK-IκBα, JAK-STAT1/3, ERK/MAPK and the expression levels of β-tubulin III and MCP-1 were measured by western blot analysis. Pre-treatment using 0.01%–0.25% curcumin in diets significantly inhibited I/R-induced cell loss in GCL. 0.05% curcumin pre-treatment inhibited I/R-induced degeneration of retinal capillaries, TUNEL-positive apoptotic cell death in the GCL, brn3a stained cell loss, the I/R-induced up-regulation of MCP-1, IKKα, p-IκBα and p-STAT3 (Tyr), and down-regulation of β-tubulin III. This dose showed no effect on injury-induced GFAP overexpression. Moreover, 0.05% curcumin administered 2 days after the injury also showed a vaso-protective effect.

Conclusions/Significance

Curcumin protects retinal neurons and microvessels against I/R injury. The beneficial effects of curcumin on neurovascular degeneration may occur through its inhibitory effects on injury-induced activation of NF-κB and STAT3, and on over-expression of MCP-1. Curcumin may therefore serve as a promising candidate for retinal ischemic diseases.     

Curcumin modulates eukaryotic initiation factors in human lung adenocarcinoma epithelial cells

Curcumin, a polyphenolic compound, is the active component of Curcuma longa and has been extensively investigated as an anticancer drug that modulates multiple pathways. Eukaryotic initiation factors (eIFs) have been known to play important roles in translation initiation, which controls cell growth and proliferation. Little is known about the effects of curcumin on eIFs in lung cancer. The objective of this study was to exam the curcumin cytotoxic effect and modulation of two major rate-limiting translation initiation factors, including eIF2α and eIF4E protein expression levels in lung adenocarcinoma epithelial cell line A549. Cytotoxicity was measured by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and protein changes were determined by Western blot. A549 cells were treated with 0–240 μM curcumin for 4–96 h. The inhibitory effects of curcumin on cytotoxicity were dose- and time-dependent (P < 0.001). The 50% inhibitory curcumin concentrations (IC50s) at 24, 48, 72, and 96 h were 93, 65, 40, and 24 μM, respectively. Protein expressions of eIF2α, eIF4E, Phospho-4E-BP1 were down-regulated, while Phospho-eIF2α and Phospho-eIF4E were up-regulated after A549 cells were treated with 20 and 40 μM curcumin for 24 h. In addition, the effects of curcumin on these protein expression changes followed a significant dose-response (P < 0.05, trend test). These findings suggest that curcumin could reduce cell viability through prohibiting the initiation of protein synthesis by modulating eIF2α and eIF4E.     

Inhibitory effect of curcumin on liver injury in a murine model of endotoxemic shock

The effect of curcumin on lipopolysaccharide/d-galactosamine (LPS/GalN)-induced acute shock model of liver injury was examined in mice. The simultaneous administration of LPS (5–20 μg kg⁻¹, i.p.) and GalN (700 mg kg⁻¹, i.p.) markedly increased the serum tumor necrosis factor-α (TNF-α), glutamic oxaloacetic transaminase/glutamic pyruvic transaminase (GOT/GPT), and massive hepatic necrosis and inflammation, leading to 100% lethality. Pre-administration of curcumin (100 mg kg⁻¹, i.p.) 3 h before induction with LPS/GalN imparted a large extent of protection against acute elevation in serum TNF-α and serum GOT/GPT. Hepatic necrosis and lethality caused by LPS/GalN was also greatly reduced by curcumin treatment. The results demonstrated that curcumin could protect mice from LPS/GalN-induced hepatic injury and inflammation through blockading TNF-α production, eventually raising the survival rate of septic-shock-induced mice.     

Oral glucosamine increases expression of transforming growth factor β1 (TGFβ1) and connective tissue growth factor (CTGF) mRNA in rat cartilage and kidney: implications for human efficacy and toxicity

Glucosamine is used for alleviating pain in osteoarthritis. Clinical trials have reported that glucosamine has equivocal efficacy. Glucosamine is also used in cell cultures to stimulate hexosamine flux and protein O-glycosylation, but at many-fold greater concentrations than those in human plasma following oral dosing. Lean Zucker rats were dosed orally for 6 weeks with glucosamine hydrochloride at doses (0–600 mg/kg/day) that produced peak serum concentrations of <1–35 μM, spanning the human exposure range. Relative expression of both TGFβ1 and CTGF mRNA were significantly increased up to 2.3-fold in liver, kidney and articular cartilage when evaluated 4 h after final dose. Apparent threshold serum glucosamine (C_max) concentration required to increase TGFβ1 expression in cartilage was 10–20 μM. These increases were associated with significant increases in UDP-N-acetylglucosamine concentrations suggesting increased hexosamine flux. Both TGFβ1 and CTGF are mediators of chondrocyte proliferation and cartilage repair. Study demonstrates that oral glucosamine doses that produce clinically relevant serum glucosamine concentrations can induce tissue TGFβ1 and CTGF expression in vivo and provides a mechanistic rationale for reported beneficial effects of glucosamine therapy. Induction of renal TGFβ1 and CTGF mRNA suggests that potential sclerotic side-effects may occur following consumption of potent glucosamine preparations.     

Curcumin Improves Outcomes and Attenuates Focal Cerebral Ischemic Injury via Antiapoptotic Mechanisms in Rats

Curcumin, a member of the curcuminoid family of compounds, is a yellow colored phenolic pigment obtained from the powdered rhizome of C. longa Linn. Recent studies have demonstrated that curcumin has protective effects against cerebral ischemia/reperfusion injury. However, little is known about its mechanism. In the present study, we tested the effects of curcumin in focal cerebral ischemia in rats and the possible mechanisms. Adult male Sprague–Dawley rats were treated with curcumin (100, 300 and 500 mg/kg) administered intraperitoneally after 60 min of occlusion (beginning of reperfusion). Neurological score and infarct volume were assessed at 24 and 72 h. Oxidative stress was evaluated by malondialdehyde assay and the apoptotic mechanisms were studied by Western blotting. Curcumin treatment significantly reduced infarct volume and improved neurological scores at different time points compared with the vehicle-treated group. Curcumin treatment decreased malondialdehyde levels, cytochrome c, and cleaved caspase 3 expression and increased mitochondrial Bcl-2 expression. Inhibition of oxidative stress with curcumin treatment improves outcomes after focal cerebral ischemia. This neuroprotective effect is likely exerted by antiapoptotic mechanisms.     

Granulocyte-macrophage colony stimulating factor is anabolic and interleukin-1β is catabolic for rat articular chondrocytes

Objective: To study the effects of GM-CSF and IL-1β, both implicated in tissue damage in arthritis, on articular chondrocyte proliferation and metabolism, and to explore their agonist/antagonist effects. Methods: Chondrocytes were obtained from 1-month-old rats. First-passage monolayers were incubated for 24 h with or without GM-CSF and/or IL-1β, and labeled with ³H-thymidine, ³⁵S–SO₄ and ¹⁴C-proline. Proteoglycan and collagen synthesis were analyzed by liquid chromatography and SDS–PAGE. Gene expression was measured by RT-PCR. Results: IL-1β exerts potent, and GM-CSF weak, inhibitory effects on DNA synthesis. GM-CSF strongly stimulates, and IL-1β inhibits, proteoglycan and collagen synthesis. IL-1β suppresses the effect of GM-CSF, and increases the release of radioactive molecules from pre-labeled cartilage fragments; GM-CSF decreases the IL-1β-induced effect. Interestingly, both cytokines induce the expression of each other’s gene. Conclusions: IL-1β appears to be a catabolic and anti-anabolic agent for chondrocytes, whereas GM-CSF is mainly anabolic, and blocks the IL-1β-induced catabolic effect. It is postulated that both agents are implicated in inflammation: IL-1β promotes tissue catabolism and destruction, whereas GM-CSF enhances tissue reconstruction.     

Local expression of interferon-alpha and interferon receptors in cervical intraepithelial neoplasia

Purpose  

The present study evaluated mRNA expression of interferon-alpha (IFN-α), IFN-α receptor subunits (IFNAR-1 and IFNAR-2) and an IFN-stimulated gene encoding the enzyme 2′,5′-oligoadenylate synthetase (2′5′OAS) in biopsies on patients with varying grades of cervical intraepithelial neoplasia (CIN I, II and III).     

Replicated associations of <Emphasis Type="Italic">TNFAIP3</Emphasis>, <Emphasis Type="Italic">TNIP1</Emphasis> and <Emphasis Type="Italic">ETS1</Emphasis> with systemic lupus erythematosus in a southwestern Chinese population

Introduction  

Recent genome-wide and candidate gene association studies in large numbers of systemic lupus erythematosus (SLE) patients have suggested approximately 30 susceptibility genes. These genes are involved in three types of biological processes, including immune complex processing, toll-like receptor function and type I interferon production, and immune signal transduction in lymphocytes, and they may contribute to the pathogenesis of SLE. To better understand the genetic risk factors of SLE, we investigated the associations of seven SLE susceptibility genes in a Chinese population, including FCGR3A, FCGR2A, TNFAIP3, TLR9, TREX1, ETS1 and TNIP1.     

Analysis of key genes and signaling pathways involved in Helicobacter pylori‐associated gastric cancer based on The Cancer Genome Atlas database and RNA sequencing data

Background

Helicobacter pylori (H. pylori) infection is associated with the development of gastric cancer, although the mechanism is unclear. Herein, this study aimed to clarify the key genes and signaling pathways involved in H. pylori pathogenesis based on The Cancer Genome Atlas (TCGA) database and RNA sequencing analysis.

Materials and Methods

Forty‐nine gastric cancer samples (16 with H. pylori and 33 without H. pylori) and 35 cancer‐adjacent normal samples from TCGA database were analyzed by bioinformatics. The differentially expressed genes between H. pylori‐positive and H. pylori‐negative patients were verified in 18 gastric cancer (GC) samples (9 with H. pylori and 9 without H. pylori), which were analyzed using RNA sequencing. Survival analysis was carried out to explore associations between the differentially expressed genes and prognosis. Bioinformatics analysis was performed to determine the signaling pathways associated with H. pylori.

Results

The baseline level of clinical features from TCGA database and RNA sequencing showed no differences between the H. pylori‐positive and H. pylori‐negative GC groups (P > 0.05). TP53 was shown to be upregulated in the H. pylori‐positive group in both TCGA database and RNA sequencing data, which also showed higher expression in the GC tissues than in adjacent normal tissues (P < 0.05). CCDC151, CHRNB2, GMPR2, HDGFRP2, and VSTM2L were shown to be downregulated in the H. pylori‐positive group by both TCGA database and RNA sequencing, which also showed lower expression in the GC tissues than in adjacent normal tissues (P < 0.05). GC patients with low expression levels of HDGFRP2 had a poor prognosis (P < 0.05). Thirty‐three signaling pathways and 10 biological processes were found to be positively associated with H. pylori infection (P < 0.05, FDR < 0.05).

Conclusions

These results indicate that some genes (TP53, CCDC151, CHRNB2, GMPR2, HDGFRP2, VSTM2L) and previously unidentified signaling pathways (eg, the Hippo signaling pathway) might play an important role in H. pylori‐associated GC.     

Integrated miRNA and mRNA expression profiling of mouse mammary tumor models identifies miRNA signatures associated with mammary tumor lineage

Background  

MicroRNAs (miRNAs) are small, non-coding, endogenous RNAs involved in regulating gene expression and protein translation. miRNA expression profiling of human breast cancers has identified miRNAs related to the clinical diversity of the disease and potentially provides novel diagnostic and prognostic tools for breast cancer therapy. In order to further understand the associations between oncogenic drivers and miRNA expression in sub-types of breast cancer, we performed miRNA expression profiling on mammary tumors from eight well-characterized genetically engineered mouse (GEM) models of human breast cancer, including MMTV-H-Ras, -Her2/neu, -c-Myc, -PymT, -Wnt1 and C3(1)/SV40 T/t-antigen transgenic mice, BRCA1 ^fl/fl ;p53 ^+/-;MMTV-cre knock-out mice and the p53 ^fl/fl ;MMTV-cre transplant model.     

Past vegetation dynamics in the Yellowstone region highlight the vulnerability of mountain systems to climate change

Aim

Reconstruct the long‐term ecosystem dynamics of the region across an elevational gradient as they relate to climate and local controls. In particular, we (1) describe the dominant conifers' history; (2) assess changes in vegetation composition and distribution; and (3) note periods of abrupt change versus stability as means of better understanding vegetation responses to environmental variability.

Location

Greater Yellowstone Ecosystem (GYE; USA).

Time period

16.5 ka bp ‐present.

Major taxa studied

Juniperus, Picea, Abies, Pinus, Pseudotsuga.

Methods

The vegetation reconstruction was developed from 15 pollen records. Results were interpreted based on modern pollen–vegetation relationships estimated from a suite of regression‐based approaches.

Results

Calibrated pollen data suggest that late‐glacial vegetation, dominated by shrubs and Juniperus, lacks a modern counterpart in the area. Picea, Abies and Pinus expanded at 16 ka bp in association with postglacial warming and co‐occurred in mixed‐conifer parkland/forest after 12 ka bp . This association along with Pinus contorta forest, which was present after 9 ka bp , has persisted with little change at middle and high elevations to the present day. This stability contrasts with the dynamic history of plant communities at low elevations, where shifts between parkland, steppe and forest over the last 8,000 years were likely driven by variations in effective moisture and fire.

Main conclusions

The postglacial vegetation history of the GYE highlights the dynamic nature of mountain ecosystems and informs on their vulnerability to future climate change: (1) most of the conifers have been present in the area for >12,000 years and survived climate change by adjusting their elevational ranges; (2) some plant associations have exhibited stability over millennia as a result of nonclimatic controls; and (3) present‐day forest cover is elevationally more compressed than at any time in history, probably due to the legacy of the Medieval Climate Anomaly and the Little Ice Age.     

Segmental identity and cerebellar granule cell induction in rhombomere 1

Background  

Cerebellar granule cell precursors are specifically generated within the hindbrain segment, rhombomere 1, which is bounded rostrally by the midbrain/hindbrain isthmus and caudally by the boundary of the Hoxa2 expression domain. While graded signals from the isthmus have a demonstrable patterning role within this region, the significance of segmental identity for neuronal specification within rhombomere 1 is unexplored. We examined the response of granule cell precursors to the overexpression of Hoxa2, which normally determines patterns of development specific to the hindbrain. How much does the development of the cerebellum, a midbrain/hindbrain structure, reflect its neuromeric origin as a hindbrain segment?     

Anti-cataractogenic effect of curcumin and aminoguanidine against selenium-induced oxidative stress in the eye lens of Wistar rat pups: An in vitro study using isolated lens

The aim of this study was to investigate whether curcumin and aminoguanidine (AG) prevent selenium-induced cataractogenesis in vitro. On postpartum day 8, transparent isolated lens were incubated in 24 well plates containing Dulbecco's Modified Eagle Medium (DMEM). Isolated lens of group I were incubated with DMEM medium alone. Group II: lenses incubated in DMEM containing 100 μM sodium selenite; group III: lenses incubated in DMEM containing 100 μM sodium selenite and 100 μM curcumin; group IV: lenses incubated in DMEM containing 100 μM sodium selenite and 200 μM curcumin; group V: lenses incubated in DMEM containing 100 μM sodium selenite and 100 μM AG; group V: lenses incubated in DMEM containing 100 μM sodium selenite and 200 μM AG. On day 12, cataract development was graded using an inverted microscope and the lenses were analyzed for enzymic as well as non-enzymic antioxidants, lipid peroxidation (LPO), nitric oxide (NO), superoxide anion (O₂⁻) and hydroxyl radical generation (OH) and inducible nitric oxide synthase (iNOS) activity by Western blotting and RT-PCR. All control lenses in group I were clear (0). In groups II and III, all isolated lenses developed cataract with variation in levels (+++ or ++), whereas isolated lenses from groups IV, V and VI were clear (0). In agreement to this, a decrease in antioxidants and increased free radical generation and also iNOS expression were observed in selenium exposed lenses when compared to other groups. AG (100 μM) was found to be more effective in anti-cataractogenic effect than curcumin (200 μM). Curcumin and AG suppressed selenium-induced oxidative stress and cataract formation in isolated lens from Wistar rat pups, possibly by inhibiting depletion of enzymic as well as non-enzymic antioxidants, and preventing uncontrolled generation of free radicals and also by inhibiting iNOS expression. Our results implicate a major role for curcumin and AG in preventing cataractogenesis in selenite-exposed lenses, wherein AG was found to be more potent.     

Alterative effects of an oral alginate extract on experimental rabbit osteoarthritis

Background

Osteoarthritis (OA) is a common joint disease that causes disabilities in elderly. However, few agents with high efficacy and low side effects have been developed to treat OA. In this study, we evaluated the effects of the alginate extract named CTX in OA cell and rabbit models.

Results

CTX was formulated by hydrolyzing sodium alginate polymers with alginate lyase and then mixing with pectin. HPLC was used to analyze the CTX content. Human chondrosarcoma SW1353 cells treated with interleukin-1β were used as OA model cells to investigate the effects of CTX on chondrocyte inflammation and anabolism. CTX at concentrations up to 1000 μg/ml exerted low cytotoxicity. It inhibited the gene expression of proinflammatory matrix metalloproteinases (MMPs) including MMP1, MMP3 and MMP13 in a dose-dependent manner and increased the mRNA level of aggrecan, the major proteoglycan in articular cartilage, at 1000 μg/ml. Thirteen-week-old New Zealand White rabbits underwent a surgical anterior cruciate ligament transection and were orally treated with normal saline, glucosamine or CTX for up to 7 weeks. Examinations of the rabbit femur and tibia samples demonstrated that the rabbits taking oral CTX at a dosage of 30 mg/kg/day suffered lesser degrees of articular stiffness and histological cartilage damage than the control rabbits.

Conclusions

The gene expression profiles in the cell and the examinations done on the rabbit cartilage suggest that the alginate extract CTX is a pharmaco-therapeutic agent applicable for OA therapy.     

<Emphasis Type="Italic">Shewanella oneidensis</Emphasis>: a new and efficient System for Expression and Maturation of heterologous [Fe-Fe] Hydrogenase from <Emphasis Type="Italic">Chlamydomonas reinhardtii</Emphasis>

Background  

The eukaryotic green alga, Chlamydomonas reinhardtii, produces H₂ under anaerobic conditions, in a reaction catalysed by a [Fe-Fe] hydrogenase HydA1. For further biochemical and biophysical studies a suitable expression system of this enzyme should be found to overcome its weak expression in the host organism. Two heterologous expression systems used up to now have several advantages. However they are not free from some drawbacks. In this work we use bacterium Shewanella oneidensis as a new and efficient system for expression and maturation of HydA1 from Chlamydomonas reinhardtii.     

The T box regulatory element controlling expression of the class I lysyl-tRNA synthetase of <Emphasis Type="Italic">Bacillus cereus</Emphasis> strain 14579 is functional and can be partially induced by reduced charging of asparaginyl-tRNA<Superscript>Asn</Superscript>

Background  

Lysyl-tRNA synthetase (LysRS) is unique within the aminoacyl-tRNA synthetase family in that both class I (LysRS1) and class II (LysRS2) enzymes exist. LysRS1 enzymes are found in Archaebacteria and some eubacteria while all other organisms have LysRS2 enzymes. All sequenced strains of Bacillus cereus (except AH820) and Bacillus thuringiensis however encode both a class I and a class II LysRS. The lysK gene (encoding LysRS1) of B. cereus strain 14579 has an associated T box element, the first reported instance of potential T box control of LysRS expression.