Apoptosis signal-regulating kinase 1 inhibition attenuates human airway smooth muscle growth and migration in chronic obstructive pulmonary disease.

Increased airway smooth muscle (ASM) mass is observed in chronic obstructive pulmonary disease (COPD), which is correlated with disease severity and negatively affects lung function in these patients. Thus, there is clear unmet clinical need for finding new therapies which can target airway remodeling and disease progression in COPD. Apoptosis signal-regulating kinase 1 (ASK1) is a ubiquitously expressed mitogen-activated protein kinase (MAPK) kinase kinase (MAP3K) activated by various stress stimuli, including reactive oxygen species (ROS), tumor necrosis factor (TNF)-α, and lipopolysaccharide (LPS) and is known to regulate cell proliferation. ASM cells from COPD patients are hyperproliferative to mitogens in vitro However, the role of ASK1 in ASM growth is not established. Here, we aim to determine the effects of ASK1 inhibition on ASM growth and pro-mitogenic signaling using ASM cells from COPD patients. We found greater expression of ASK1 in ASM bundles of COPD lung when compared with non-COPD. Pre-treatment of ASM cells with highly selective ASK1 inhibitor, TC ASK 10 resulted in a dose-dependent reduction in mitogen (FBS, PDGF, and EGF; 72 h)-induced ASM growth as measured by CyQUANT assay. Further, molecular targetting of ASK1 using siRNA in ASM cells prevented mitogen-induced cell growth. In addition, to anti-mitogenic potential, ASK1 inhibitor also prevented TGFß1-induced migration of ASM cells in vitro Immunoblotting revealed that anti-mitogenic effects are mediated by C-Jun N-terminal kinase (JNK) and p38MAP kinase-signaling pathways as evident by reduced phosphorylation of downstream effectors JNK1/2 and p38MAP kinases, respectively, with no effect on extracellular signal-regulated kinase (ERK) 1/2 (ERK1/2). Collectively, these findings establish the anti-mitogenic effect of ASK1 inhibition and identify a novel pathway that can be targetted to reduce or prevent excessive ASM mass in COPD.

Synthesis and anti-inflammatory activity of novel triazole hybrids of (+)-usnic acid, the major dibenzofuran metabolite of the lichen Usnea longissima.

(+)-Usnic acid ((R)-2,6-diacetyl-7,9-dihydroxy-8,9b-dimethyl-1,3(2H,9bH)-dibenzo-furandione), a dibenzofuran isolated from the lichen Usnea longissima, has been chemically transformed to synthesize a series of sixteen novel triazole analogs by click chemistry approach. The synthesized compounds were tested for their anti-inflammatory potential against the cytokines TNF-[Formula: see text] and IL-1[Formula: see text] in U937 cell lines. The bromo enamines (2a, 2b), azido enamines (3a, 3b) and triazole analogs (4f, 4g, 4h, 5f, 5g and 5h) exhibited promising anti-inflammatory activity against TNF-[Formula: see text] with [Formula: see text] values ranging from 1.40 to 5.70 [Formula: see text]M. Most significantly, the [Formula: see text] values of compounds 5f (1.40 [Formula: see text]M) and 5h (1.88 [Formula: see text]M) are the lowest among the compounds tested and found close to that of standard prednisolone. Hence, these two compounds can be considered as lead molecules for further fine tuning to make highly potent anti-inflammatory therapeutic agents.

Autophagy and airway fibrosis: Is there a link?

In the past decade, an emerging process named "autophagy" has generated intense interest in many chronic lung diseases. Tissue remodeling and fibrosis is a common feature of many airway diseases, and current therapies do not prevent or reverse these structural changes. Autophagy has evolved as a conserved process for bulk degradation and recycling of cytoplasmic components to maintain basal cellular homeostasis and healthy organelle populations in the cell. Furthermore, autophagy serves as a cell survival mechanism and can also be induced by chemical and physical stress to the cell. Accumulating evidence demonstrates that autophagy plays an essential role in vital cellular processes, including tissue remodeling. This review will discuss some of the recent advancements made in understanding the role of this fundamental process in airway fibrosis with emphasis on airway remodeling, and how autophagy can be exploited as a target for airway remodeling in asthma and chronic obstructive pulmonary disease.

Chromium-induced nephrotoxicity and ameliorative effect of carvedilol in rats: Involvement of oxidative stress, apoptosis and inflammation.

Nephrotoxicity is a major adverse effect of chromium poisoning. In the present study, we investigated the potential renoprotective effect and underlying mechanisms of carvedilol, a non-specific ß-adrenergic blocker using rat model of potassium dichromate-induced nephrotoxicity. Rats were pretreated with carvedilol (10mg/kg) for 21days. A single subcutaneous injection of potassium dichromate (15mg/kg, s.c.) resulted in a significant increase in the levels of blood urea nitrogen and serum creatinine, markers related to oxidative stress, nitrosative stress, apoptosis and inflammation accompanied with histopathological changes in kidney tissues. Exploration of the underlying renoprotective mechanisms of carvedilol revealed that carvedilol attenuated nuclear translocation and DNA binding activity of NF-κB (p65) in kidney tissues. The serum levels of TNF-α and the renal expression of iNOS and tissue nitrites were significantly decreased in carvedilol plus potassium dichromate administered rats. Carvedilol pretreatment significantly attenuated the potassium dichromate-induced DNA damage, decreased the p53, Bax and cleaved caspase-3 expression and increased the Bcl-2 expression. Moreover, pretreatment with carvedilol significantly restored the renal tissue antioxidant and mitochondrial respiratory enzyme activities and decreased the elevated lipid peroxidation biomarkers to normal. These results were further supported and confirmed by histopathological findings. In conclusion, the findings of the present study demonstrated that carvedilol is an effective chemoprotectant against potassium dichromate-induced nephrotoxicity in rats.

Antioxidant, hepatoprotective and cytotoxic effects of icetexanes isolated from stem-bark of Premna tomentosa.

The study investigates the antioxidant, hepatoprotective and antiproliferative effects of novel icetexane diterpenoids (ice 1-4) isolated from hexane extract of stem bark of Premna tomentosa. A549, HT-29, MCF-7, MDA-MB-231, A431 cells were used to assess the antiproliferative activity by MTT assay. Cell death induced by apoptosis was determined by morphological assessment studies using acridine orange/ethidium bromide staining (dual staining), mitochondrial potential measurement by JC-1 staining, and cell cycle analysis by propidium iodide staining method by Muse cell analyser. Anti oxidant activity was investigated by in vitro assays such as DPPH, nitric oxide and superoxide scavenging activities. Hepatoprotective activity was determined in vitro with HepG2 cells and in vivo by tBHP induced hepatic damage mice model. Based on the in vitro cytotoxic assays and morphological assessment studies using fluorescence microscopic study (acridine orange and ethidium bromide double staining) and mitochondrial potential measurements, it was found that ice 2 and 3 possess good antiproliferative effect via mitochondrial mediated apoptosis in human lung and breast cancer cells. Results of in vitro antioxidant studies demonstrated that ice-4 has showed good antioxidant activity. The restoration of serum levels of SGOT, SGPT and ALKP, liver GSH status and reduction or inhibition of lipid peroxidation in liver of tBHP intoxicated mice after administration of ice-4 at dose of 250mg/kg indicated its potential use for hepatoprotective activity.