Innovation in pathogenesis and management of aortic aneurysm

Aortic aneurysm(AA)refers to the persistent dilatation of the aorta,exceeding three centimeters.Investigating the pathophysiology of this condition is important for its prevention and management,given its responsibility for more than 25000 deaths in the United States.AAs are classified based on their location or morphology.various pathophysiologic pathways including inflammation,the immune system and atherosclerosis have been implicated in its development.Inflammatory markers such as transforming growth factorβ,interleukin-1β,tumor necrosis factor-α,matrix metalloproteinase-2 and many more may contribute to this phenomenon.Several genetic disorders such as Marfan syndrome,Ehler-Danlos syndrome and Loeys-Dietz syndrome have also been associated with this disease.Recent years has seen the investigation of novel management of AA,exploring the implication of different immune suppressors,the role of radiation in shrinkage and prevention,as well as minimally invasive and newly hypothesized surgical methods.In this narrative review,we aim to present the new contributing factors involved in pathophysiology of AA.We also highlighted the novel management methods that have demonstrated promising benefits in clinical outcomes of the AA.

The role of ERK1/2 signaling pathway in coronary microembolization-induced rat myocardial inflammation and injury

Objectives In this work,we explore the effect of atorvastatin on myocardial apoptosis and caspase-8 acti- vation after coronary microembolization(CME) in rats. Methods Fifty rats were randomly divided into five groups; the coronary microembolization(CME) group,the sham-operated (sham) control group,the gastric lavage control group, the atorvastatin lavage group,and the caspasse-8 inhibitor (N-acetyl-Ile-Glu-Thr-Asp-CHO,abbreviated as CHO) group,with 10 rats for each group.A microembolization ball was injected through the left ventricle for constructing the CME model.Animals in the sham control group were given an injection of physiological saline instead of the microembolization ball.Seven days before the operation,the atorvastatin group underwent gastric lavage with 20 mg/kg of atorvastatin once a day.Gastric lavage control animals underwent gastric lavage with an equivalent dose of physiological saline instead of the atorvastatin.Animals in the CHO group were given an intraperitoneal injection of 10 mg/kg of CHO 30 min before the operation.Six hours after the operation,cardiac ultrasonic detection was conducted on each group to measure the cardiac function indexes.TUNEL(Terminal-deoxynucleoitidyl transferase mediated dUTP nick end labeling) assays were used to measure myocardial apoptosis,and western blots were used to quantify the expression levels of activated caspase-3 and -8.Results(1) The echocardiographic parameters showed that,compared to the sham control animals,the left ventricular ejection fraction(LVEF) of the CME group was significantly decreased(P【0.05).In addition, cardiac sonography revealed a decrease in the left ventricular shortening fraction(FS) and cardiac output(CO), but an increase in the left ventricular end-diastolic dimension (LVEDd).Compared to the CME group,the atorvastatin and CHO groups exhibited significantly improved cardiac function (P【0.05).(2) When compared with the sham control,the myocardical apoptotic rate of the CME group,as well as the levels of activated caspase-3 and-8,increased significantly (P【0.05).The myocardial apoptotic rate,as well as the levels of activated caspase-3 and caspase-8 in the atorvastatin and CHO groups,decreased significandy(P【0.05) in comparison to the CME group.Conclusions The atorvastatin pretreatment clearly suppressed post-CME myocardial apoptosis and improved cardiac function.The most likely mechanism for these effects is the blockade of the myocardial death receptor -mediated apoptosis pathway.

Berberine Relieves Insulin Resistance via the Cholinergic Anti-inflammatory Pathway in HepG2 Cells

Berberine（BBR） is an isoquinoline alkaloid extracted from Rhizoma coptidis and has been used for treating type 2 diabetes mellitus（T2DM） in China. The development of T2 DM is often associated with insulin resistance and impaired glucose uptake in peripheral tissues. In this study, we examined whether BBR attenuated glucose uptake dysfunction through the cholinergic anti-inflammatory pathway in Hep G2 cells. Cellular glucose uptake, quantified by the 2-[N-（7-Nitrobenz-2-oxa-1,3-diazol-4-yl）-amino]-2-deoxy-D-glucose（2-NBDG）, was inhibited by 21% after Hep G2 cells were incubated with insulin（10-6 mol/L） for 36 h. Meanwhile, the expression of alpha7 nicotinic acetylcholine receptor（α7n ACh R） protein was reduced without the change of acetylcholinesterase（ACh E） activity. The level of interleukin-6（IL-6） in the culture supernatant, the ratio of phosphorylated I-kappa-B kinase-β（IKKβ） Ser181/IKKβ and the expression of nuclear factor-kappa B（NF-κB） p65 protein were also increased. However, the treatment with BBR enhanced the glucose uptake, increased the expression of α7n ACh R protein and inhibited ACh E activity. These changes were also accompanied with the decrease of the ratio of p IKKβ Ser181/IKKβ, NF-κB p65 expression and IL-6 level. Taken together, these results suggest that BBR could enhance glucose uptake, and relieve insulin resistance and inflammation in Hep G2 cells. The mechanism may be related to the cholinergic anti-inflammatory pathway and the inhibition of ACh E activity.

Kynurenine pathway metabolism and neuroinflammatory disease

Immune-mediated activation of tryptophan（TRYP） catabolism via the kynurenine pathway（KP） is a consistent finding in all inflammatory disorders.Several studies by our group and others have examined the neurotoxic potential of neuroreactive TRYP metabolites,including quinolinic acid（QUIN） in neuroinflammatory neurological disorders,including Alzheimer＇s disease（AD）,multiple sclerosis,amylotropic lateral sclerosis（ALS）,and AIDS related dementia complex（ADC）.Our current work aims to determine whether there is any benefit to the affected individuals in enhancing the catabolism of TRYP via the KP during an immune response.Under physiological conditions,QUIN is metabolized to the essential pyridine nucleotide,nicotinamide adenine dinucleotide（NAD＋）,which represents an important metabolic cofactor and electron transporter.NAD＋ also serves as a substrate for the DNA ‘nick sensor＇ and putative nuclear repair enzyme,poly（ADP-ribose） polymerase（PARP）.Free radical initiated DNA damage,PARP activation and NAD＋ depletion may contribute to brain dysfunction and cell death in neuroinflammatory disease.

Mangiferin ameliorates insulin resistance by inhibiting inflammation and regulatiing adipokine expression in adipocytes under hypoxic condition

Adipose tissue hypoxia has been recognized as the initiation of insulin resistance syndromes. The aim of the present study was to investigate the effects of mangiferin on the insulin signaling pathway and explore whether mangiferin could ameliorate insulin resistance caused by hypoxia in adipose tissue. Differentiated 3 T3-L1 adipocytes were incubated under normal and hypoxic conditions, respectively. Protein expressions were analyzed by Western blotting. Inflammatory cytokines and HIF-1-dependent genes were tested by ELISA and q-PCR, respectively. The glucose uptake was detected by fluorescence microscopy. HIF-1α was abundantly expressed during 8 h of hypoxic incubation. Inflammatory reaction was activated by up-regulated NF-κB phosphorylation and released cytokines like IL-6 and TNF-α. Glucose uptake was inhibited and insulin signaling pathway was damaged as well. Mangiferin substantially inhibited the expression of HIF-1α. Lactate acid and lipolysis, products released by glycometabolism and lipolysis, were also inhibited. The expression of inflammatory cytokines was significantly reduced and the damaged insulin signaling pathway was restored to proper functional level. The glucose uptake of hypoxic adipocytes was promoted and the dysfunction of adipocytes was relieved. These results showed that mangiferin could not only improve the damaged insulin signaling pathway in hypoxic adipocytes, but also ameliorate inflammatory reaction and insulin resistance caused by hypoxia.

Contribution of CXCL16 / CXCR6 pathway activated by inflammation to atherosclerosis in patients with end-stage renal disease

Objective To investigate the effects of CXC chemokine ligand 16(CXCL16)/CXC chemokine receptor 6(CXCR6)pathway on cholesterol accumulation of atherosclerosis in the radial artery of end-stage renal disease(ESRD)patients under inflammatory stress and further to investigate its potential mechanisms modulated by purinergic receptor P2X ligandgated ion channel