Recent advances on the development of NO-releasing molecules (NORMs) for biomedical applications

Nitric oxide (NO) is an important biological messenger as well as a signaling molecule that participates in a broad range of physiological events and therapeutic applications in biological systems. However, due to its very short half-life in physiological conditions, its therapeutic applications are restricted. Efforts have been made to develop an enormous number of NO-releasing molecules (NORMs) and motifs for NO delivery to the target tissues. These NORMs involve organic nitrate, nitrite, nitro compounds, transition metal nitrosyls, and several nanomaterials. The controlled release of NO from these NORMs to the specific site requires several external stimuli like light, sound, pH, heat, enzyme, etc. Herein, we have provided a comprehensive review of the biochemistry of nitric oxide, recent advancements in NO-releasing materials with the appropriate stimuli of NO release, and their biomedical applications in cancer and other disease control.

Differential expression of TLR4 in patients of coronary artery disease with and without traditional cardiovascular risk factors

Funding Acknowledgements

Type of funding sources: None.

Background

Atherosclerosis is inherently an inflammatory process, with a complex interplay of inflammatory markers. It is established that these inflammatory markers play an important role in patients of Coronary Artery Disease(CAD) with traditional cardiovascular risk factors. However, the role of inflammation in the atherosclerotic process in patients of CAD without traditional risk factors is still not clearly known.

Purpose

Our purpose was to determine whether in patients of CAD without traditional risk factors, TLR4(Toll like receptor 4) expression as a marker of inflammation is similar to that in patients of CAD with traditional risk factors.

Materials and Methods

This observational cross sectional study was done between July’20 to Dec’21. Equal number of patients of CAD with and without traditional cardiovascular risk factors undergoing Coronary Artery Bypass Grafting (CABG) were enrolled. The risk factors considered were Hypertension, Diabetes, Dyslipidemia, Obesity and Addiction to Tobacco and/or Alcohol. A minimum of two punch biopsy samples of aortic tissue was taken from each subject undergoing CABG. Immunohistochemistry for TLR4, was done in Ventana BenchMark GX System. The primary TLR4 antibody was procured from reputed source.

Results

The presence or absence of TLR4 expression was associated significantly with the Syntax scores (37.40±4.74 vs 29.5±8.71; p value=0.036), total Cholesterol (187±35.06mg/dL vs 130±35.69 mg/dL ;p value 0.010) and LDL cholesterol (118.86±28.12mg/dL vs 64.21±25.61 mg/dL; p value 0.003). TLR4 expression, however, was not significantly associated with the number of coronary vessels involved (p=0.298). TLR4 expression was also not significantly associated with any other individual risk factors. However, when the traditional risk factors were considered in combination, TLR4 expression was associated significantly with the number of risk factors present(p=0.029) the strongest being in those having 4 traditional risk factors. The level of TLR4 expression gradually declined with the decrease in the number of risk factors, having mostly weak or negative expression in patients without any traditional risk factors.

Conclusion

Patients with CAD without any traditional risk factors, had a less severe coronary artery disease as manifested by lower Syntax scores, and had lower degree of TLR4 expression. Patients with CAD with traditional risk factors had more severe coronary artery disease as evidenced by higher Syntax scores, and had higher degree of TLR4 expression proportional to the number of traditional risk factors present. Thus, differential TLR4 expression in CAD patients with and without traditional risk factors indicated a difference in inflammatory state between the two groups and warrants further investigation.

MicroRNA 155:145 ratio as a marker of atherogenic tilt manifested across different age groups and risk factor profiles

Funding Acknowledgements

Type of funding sources: None.

Background

 Differential expression of microRNAs is critical in the genesis and progression of atherosclerosis. MiR145 has atheroprotective role through improved homeostasis of smooth muscle cells (SMC). MiR155 is pro-atherogenic due to its suppression of Bcl6, which antagonises NF-κB and modulates macrophages.

Purpose

  Our purpose was to determine if the differential expression of miR 155 & 145 (expressed as miR 155:145 ratio) across various age groups and risk factor profiles correlates with atherosclerotic cardiovascular disease (ASCVD).

Materials and Methods

  This observational cross-sectional study was done between Feb"19 & Jan"20 on 108 patients divided equally into 3 age groups: <18, 18-45 & >45yrs. Family history (of ASCVD or risk factors) and risk factor profile were assessed in all 3 groups; and in the latter two, presence or absence of ASCVD was additionally evaluated by coronary angiogram and/or carotid IMT. MiR155 & 145 were measured in all by RT-PCR, & the results were then compared after calculating the ratio.

Results

 miR 155:145 ratio was significantly increased in <18yrs aged subjects with a positive family history(p = 0.001). Multivariate regression analysis revealed a significant positive correlation of miR155:145 with family history of risk factors or ASCVD in this group(p < 0.001).

In the 18-45yrs age group, the miR 155:145 ratio was found to be significantly increased in patients with diabetes(p = 0.037) and significant coronary artery disease(CAD) as determined by Syntax score(p < 0.001). In multivariate regression analysis, a significant positive correlation was found between miR 155:145 and Syntax score(p < 0.001) – a ratio of 155:145 > 1 implied a greater chance of CAD, with increased numerical values correlating with increased severity of disease as evidenced by Syntax score; and a ratio < 1 decreased the chances of significant CAD considerably. A positive association was also discovered for this ratio with hypertension, diabetes, tobacco exposure and a combination of multiple risk factors, but none of them were statistically significant.

In the age group of >45 yrs, regression analysis revealed a statistically insignificant positive association of the miR 155:145 ratio with Syntax score, hypertension, dyslipidaemia and a combination of risk factors.

Conclusion

 MiR 155:145, when >1, can point towards an ‘atherogenic tilt’, and greater increase in the ratio numerically may denote more severe disease, as indicated by a positive association with Syntax Score. This atherogenic tilt occurs very early in life, even before 18 years with significant family history. Above 18 years, with addition of other risk factors, this tilt is further compounded, and correlated well with Syntax score and such risk factors. Therefore, miR 155:145 ratio may help in identifying the individuals at risk for development of clinically significant CAD and can be utilised for development of future therapeutic strategies as well as prognostication. Abstract Figure 1  Abstract Figure 2

Proteinuria is an independent risk factor for ischemic stroke among diabetic patients

This study was done to assess the relationship between proteinuria and ischemic stroke in subjects with diabetes mellitus, and to determine whether proteinuria is an independent risk factor for stroke. This comparative study was conducted in Mymensingh Medical College Hospital from January 2009 to June 2010. It was done to establish the relationship between proteinuria (Microalbuminuria) and ischemic stroke among diabetic patients. Other risk factors were also assessed. Patients were divided in Group A - diabetic patients with ischemic stroke (n=50) and Group B diabetic patients without stroke (n=50). Mean age of the Group A & B were 60.16±8.33 and 57.19±7.73 years (p=0.068). Mean Blood sugar (2 hours after Break Fast) was 14.68±4.32mmol/L in Group A and 14.75±4.02mmol/L in Group B (p>0.05). Albumin Creatinine ratio was abnormal in 84.0% in Group A and 22.0% in Group A (p=0.001) [Odds ratio (95%CI) = 18.61 (6.78-51.09)]. Logistic regression analysis has also shown that microalbuminuria (ACR) is an independent risk factor for ischemic stroke (p=0.001), [Odds ratio (95%CI) = 19.811(5.915-66.348)]. In diabetic patients increased urinary protein is a risk factor for stroke. Estimation of urinary protein (Microalbuminuria) may be used as a predictor for ischemic stroke in patients with diabetes.