Therapeutic approaches to drug targets in atherosclerosis

AbstractNon-communicable diseases such as cancer, atherosclerosis and diabetes are responsible for major social and health burden as millions of people are dying every year. Out of which, atherosclerosis is the leading cause of deaths worldwide. The lipid abnormality is one of the major modifiable risk factors for atherosclerosis. Both genetic and environmental components are associated with the development of atherosclerotic plaques. Immune and inflammatory mediators have a complex role in the initiation and progression of atherosclerosis. Understanding of all these processes will help to invent a range of new biomarkers and novel treatment modalities targeting various cellular events in acute and chronic inflammation that are accountable for atherosclerosis. Several biochemical pathways, receptors and enzymes are involved in the development of atherosclerosis that would be possible targets for improving strategies for disease diagnosis and management. Earlier anti-inflammatory or lipid-lowering treatments could be useful for alleviating morbidity and mortality of atherosclerotic cardiovascular diseases. However, novel drug targets like endoglin receptor, PPARα, squalene synthase, thyroid hormone analogues, scavenger receptor and thyroid hormone analogues are more powerful to control the process of atherosclerosis. Therefore, the review briefly focuses on different novel targets that act at the starting stage of the plaque form to the thrombus formation in the atherosclerosis

TCF7L2 gene polymorphisms do not predict susceptibility to diabetes in tropical calcific pancreatitis but may interact with SPINK1 and CTSB mutations in predicting diabetes

<p>Abstract</p> <p>Background</p> <p>Tropical calcific pancreatitis (TCP) is a type of chronic pancreatitis unique to developing countries in tropical regions and one of its important features is invariable progression to diabetes, a condition called fibro-calculous pancreatic diabetes (FCPD), but the nature of diabetes in TCP is controversial. We analysed the recently reported type 2 diabetes (T2D) associated polymorphisms in the <it>TCF7L2 </it>gene using a case-control approach, under the hypothesis that <it>TCF7L2 </it>variants should show similar association if diabetes in FCPD is similar to T2D. We also investigated the interaction between the <it>TCF7L2 </it>variants and N34S <it>SPINK1 </it>and L26V <it>CTSB </it>mutations, since they are strong predictors of risk for TCP.</p> <p>Methods</p> <p>Two polymorphisms rs7903146 and rs12255372 in the <it>TCF7L2 </it>gene were analyzed by direct sequencing in 478 well-characterized TCP patients and 661 healthy controls of Dravidian and Indo-European ethnicities. Their association with TCP with diabetes (FCPD) and without diabetes was tested in both populations independently using chi-square test. Finally, a meta analysis was performed on all the cases and controls for assessing the overall significance irrespective of ethnicity. We dichotomized the whole cohort based on the presence or absence of N34S <it>SPINK1 </it>and L26V <it>CTSB </it>mutations and further subdivided them into TCP and FCPD patients and compared the distribution of <it>TCF7L2 </it>variants between them.</p> <p>Results</p> <p>The allelic and genotypic frequencies for both <it>TCF7L2 </it>polymorphisms, did not differ significantly between TCP patients and controls belonging to either of the ethnic groups or taken together. No statistically significant association of the SNPs was observed with TCP or FCPD or between carriers and non-carriers of N34S <it>SPINK1 </it>and L26V <it>CTSB </it>mutations. The minor allele frequency for rs7903146 was different between TCP and FCPD patients carrying the N34S <it>SPINK1 </it>variant but did not reach statistical significance (OR = 1.59, 95% CI = 0.93–2.70, P = 0.09), while, <it>TCF7L2</it><it/>variant showed a statistically significant association between TCP and FCPD patients carrying the 26V allele (OR = 1.69, 95% CI = 1.11–2.56, P = 0.013).</p> <p>Conclusion</p> <p>Type 2 diabetes associated <it>TCF7L2 </it>variants are not associated with diabetes in TCP. Since, <it>TCF7L2 </it>is a major susceptibility gene for T2D, it may be hypothesized that the diabetes in TCP patients may not be similar to T2D. Our data also suggests that co-existence of <it>TCF7L2 </it>variants and the <it>SPINK1 </it>and <it>CTSB </it>mutations, that predict susceptibility to exocrine damage, may interact to determine the onset of diabetes in TCP patients.</p

Impaired Rho GTPase activation abrogates cell polarization and migration in macrophages with defective lipolysis

Infiltration of monocytes and macrophages into the site of inflammation is critical in the progression of inflammatory diseases such as atherosclerosis. Cell migration is dependent on the continuous organization of the actin cytoskeleton, which is regulated by members of the small Rho GTPase family (RhoA, Cdc42, Rac) that are also important for the regulation of signal transduction pathways. We have recently reported on reduced plaque formation in an atherosclerotic mouse model transplanted with bone marrow from adipose triglyceride lipase-deficient (Atgl−/−) mice. Here we provide evidence that defective lipolysis in macrophages lacking ATGL, the major enzyme responsible for triacylglycerol hydrolysis, favors an anti-inflammatory M2-like macrophage phenotype. Our data implicate an as yet unrecognized principle that insufficient lipolysis influences macrophage polarization and actin polymerization, resulting in impaired macrophage migration. Sustained phosphorylation of focal adhesion kinase [due to inactivation of its phosphatase by elevated levels of reactive oxygen species (ROS)] results in defective Cdc42, Rac1 and RhoA activation and in increased and sustained activation of Rac2. Inhibition of ROS production restores the migratory capacity of Atgl−/− macrophages. Since monocyte and macrophage migration are a prerequisite for infiltrating the arterial wall, our results provide a molecular link between lipolysis and the development of atherosclerosis

<i style="mso-bidi-font-style:normal">In vitro</i> anthelmintic efficacy of ethno-medicinal plant <i style="mso-bidi-font-style:normal">Annona reticulata </i>L.<i style="mso-bidi-font-style:normal"> </i>roots<i style="mso-bidi-font-style:normal"> </i>against Indian earthworms (<i style="mso-bidi-font-style:normal">Pheretima posthuma</i>)

152-157The present study was envisaged to evaluate the ethno-medical claims of Annona reticulata L.<i style="mso-bidi-font-style: normal"> roots for anthelmintic efficacy in vitro in comparison with the standard chemotherapeutic agent, albendazole on adult Indian earthworms (Pheretima posthuma). The efficacy was evaluated by monitoring gross visual motility, paralysis and mortality time and new software based tool, PASS (Prediction of Activity Spectra for Substances). Literature confirmed that roots of the plant are rich in aporphine alkaloids and acetogenins. Therefore, study includes investigation and correlation of the biological activity spectrum of the aporphine alkaloids and acetogenins using PASS with in vitro anthelmintic activity. In vitro anthelmintic trials of extract was conducted at 20, 40, 60 mg/mL. The extract was found to be effective at all concentrations but a more significant result was at concentration 60 mg/mL. This could be due to synergistic effect of both the phytoconstituents. However, exact mechanism of action need to be studied

In vitro anthelmintic efficacy of ethno-medicinal plant Annona reticulata L. roots against Indian earthworms (Pheretima posthuma)

The present study was envisaged to evaluate the ethno-medical claims of Annona reticulata L. roots for anthelmintic efficacy in vitro in comparison with the standard chemotherapeutic agent, albendazole on adult Indian earthworms (Pheretima posthuma). The efficacy was evaluated by monitoring gross visual motility, paralysis and mortality time and new software based tool, PASS (Prediction of Activity Spectra for Substances). Literature confirmed that roots of the plant are rich in aporphine alkaloids and acetogenins. Therefore, study includes investigation and correlation of the biological activity spectrum of the aporphine alkaloids and acetogenins using PASS with in vitro anthelmintic activity. In vitro anthelmintic trials of extract was conducted at 20, 40, 60 mg/mL. The extract was found to be effective at all concentrations but a more significant result was at concentration 60 mg/mL. This could be due to synergistic effect of both the phytoconstituents. However, exact mechanism of action need to be studied

Antioxidant, antimicrobial activity and in silico PASS prediction of Annona reticulata Linn. root extract

Microbial infections and diseases are frequently associated with several pathogenic strains of bacteria and fungi. Plants of the reticulata genus are a notable source of new therapeutic agents including antioxidant and antimicrobial. This study reports the antioxidant and antimicrobial activities of methanolic root extract of Annona reticulata Linn. The antioxidant property of extract was evaluated using DPPH free radical scavenging and hydrogen peroxide assay. Antibacterial tests were performed using the agar cup method whereas Poison plate method was used to assess sensitivity of fungal strains. The biological potential of major phytoconstituents as antimicrobial agent was screened by new software based tool, PASS. The dose dependent scavenging was observed at concentrations 20, 40, 60, 80 and 100 μg/ml which were compared to ascorbic acid. The probable activity (Pa) of neoannonin using PASS was found to be 0.541. The extract was significantly active against all strains of bacteria but the largest zone of inhibition was found against B. cereus. Predominant growth reduction was observed in fungi Tricoderma viride and Candida albicans. The results indicate that the extract show potential as a source of new antimicrobial drug and may impart health benefits by its antioxidant property

Sodium thiosulfate ameliorates oxidative stress and preserves renal function in hyperoxaluric rats

BACKGROUND: Hyperoxaluria causes crystal deposition in the kidney, which leads to oxidative stress and to injury and damage of the renal epithelium. Sodium thiosulfate (STS, Na2S2O3) is an anti-oxidant, which has been used in human medicine for decades. The effect of STS on hyperoxaluria-induced renal damage is not known. METHODS: Hyperoxaluria and renal injury were induced in healthy male Wistar rats by chronic exposure to ethylene glycol (EG, 0.75%) in the drinking water for 4 weeks. The treatment effects of STS, NaCl or Na2SO4 were compared. Furthermore, the effects of STS on oxalate-induced oxidative stress were investigated in vitro in renal LLC-PK1 cells. RESULTS: Chronic EG exposure led to hyperoxaluria, oxidative stress, calcium oxalate crystalluria and crystal deposition in the kidneys. Whereas all tested compounds significantly reduced crystal load, only STS-treatment maintained tissue superoxide dismutase activity and urine 8-isoprostaglandin levels in vivo and preserved renal function. In in vitro studies, STS showed the ability to scavenge oxalate-induced ROS accumulation dose dependently, reduced cell-released hydrogen peroxide and preserved superoxide dismutase activity. As a mechanism explaining this finding, STS was able to directly inactivate hydrogen peroxide in cell-free experiments. CONCLUSIONS: STS is an antioxidant, which preserves renal function in a chronic EG rat model. Its therapeutic use in oxidative-stress induced renal-failure should be considered

Oxidant-antioxidant status.

<p>The activities of the two antioxidant enzymes (A) Superoxide dismutase (SOD), and (B) Catalase (CAT) were determined in renal tissue at time point 4 weeks in the control, EG, EG+STS, EG+SC and EG+SS animal group. SOD activity was preserved with STS treatment; (C) Urinary 8-Isoprostaglandin levels were elevated in the EG-exposed animals and maintained in the normal range only in STS-treated animals. The changes and significance levels are with reference to the EG group. The data are means ± SD from 7–8 animals per group. *p< 0.05, **p < 0.01, ***p < 0.001.</p

α-SMA stain of kidney tissue.

<p>The groups are (A) control, (B) EG-exposed, (C) EG+STS-exposed, (D) EG+SC-exposed, (E) EG+SS-exposed animals. The α -SMA stain was markedly increased in EG-exposed animals but decreased in all treatment groups. The significance levels are with reference to the EG group. The data are means ± SD from 7–8 animals per group. *p< 0.05, **p < 0.01, ***p < 0.001.</p

ED-1 stain of kidney tissue.

<p>The groups are (A) control, (B) EG-exposed, (C) EG+STS-exposed, (D) EG+SC-exposed, (E) EG+SS-exposed animal groups. The ED-1 stain was markedly increased in EG-exposed animals but decreased in all treatment groups. The significance levels are with reference to the EG group. The data are means ± SD from 7–8 animals per group. ***p < 0.001.</p