The understanding of molecular pathogenesis of clinical states enables for early diagnosis and/or effective management of the disease. In an investigation of molecular pathogenesis or adaptation in cardiovascular disease, the blood samples of patients diagnosed for different categories of cardiovascular disease were obtained from Punjab Institute of Cardiology, Lahore. These categories included myocardial infarction, angina pectoris, cardiomyopathy, valvular heart disease and rheumatic heart disease. Blood samples of the healthy subjects of comparable age group with an absent history of cardiac ailment were also collected for the control comparison. The sera of all categories were separated and used for the study of the protein profile with sodium dodecyle sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The gels were stained with coomassie blue. After distaining the gels were photographed and their images were stored for protein quantification by Gene Genius Bio-imaging Gel Documentation System. This provides the data of molecular weight and percent raw -volume for each of the fraction. The protein fractions that showed significant variations were separated by using the technique of electroblotting and electroelution and run on isoelectric focusing (IEF) in second dimension to determine the isoelectric points.
In the patients of Q-wave myocardial infarction apolipoprotein B (270 kDa) exhibited significant elevation of 86 % compared to control subjects. However, apolipoprotein A-I (23 kDa) and transthyretin (14 kDa) reduced significantly by 54 % and 31 % respectively in these patients compared to the healthy subjects. The fraction of 17 kDa was also found to be reduced by 30 % in Q-wave myocardial infarction patients compared to the healthy subjects.
In non Q-wave myocardial infarction group apolipoprotein B (270 kDa) showed 56 % significant increase compared to normal subjects. On the other hand apolipoprotein A-I (23 kDa) and 1ransthyretin (14 kDa) showed reduction of 31 % and 27 % respectively in patients compared to the control subjects. Another protein fraction of 28 kDa expressed 26 % lower intensity in non Q-wave myocardial infarction group compared to the healthy group.
The patients of angina pectoris group exhibited 30 % increase of apolipoprotein B (270 kDa) and 25 % decline of apolipoprotein A-I (23 kDa) compared tp control group.
In the group of cardiomyopathy patients apolipoprotein B (270 kDa), ceruloplasmin (135 kDa), apolipoprotein A-I (23 kDa) and transthyretin (14 kDa) were found to be significantly enhanced by 58 %, 25 %, 28 % and 78 % respectively compared to healthy subjects.
In the patients of valvular heart disease apolipoprotein B (270 kDa), alpha-2 macroglobulin (190 kDa), ceruloplasmin (135 kDa) and immunoglobulin heavy chain (100 kDa) expressed significant increase by 45 %, 42 %,25 % and 75 % respectively compared to normal subjects.
In rheumatic heart disease group apolipoprotein B (270 kDa), alpha-2 macroglobulin (190 kDa), ceruloplasmin (135 kDa) and immunoglobulin (100 kDa) was found to be elevated by 34 %, 39 %, 27 % and 27 % respectively compared to control subjects. A fraction of 23.5 kDa had expressed weakly in 70 % of the patients of rheumatic heart disease, not expressed in control subjects.
Sequential sampling of the patients of myocardial infarction demonstrated that most of the protein fractions showed maximum intensity - 48 hours in 80-90 % patients and expressed the pattern of declining intensity over the subsequent hours.However, the fraction of 24 kDa and transthyretin (14 kDa) exhibited highest intensity 120 hours. Fraction of 23.5 kDa occasionally appeared - 24 hours, reached maximum value - 48 hours, declined in the next 24 hours and ultimately disappeared. These changes in protein levels at different timings might be used to determine the time of attack of myocardial infarction.
The present study has demonstrated significant variations (enhancement and reduction) in some proteins in different categories of cardiovascular disease detected by using a very sensitive technique of electrophoresis, two-dimensional gel electrphoresis (2-DE), a widely used technique for protein analysis. These variations in proteins may be used for the diagnosis of different categories of cardiovascular disease and also for the early diagnosis of different types of cardiovascular disease particularly in asymptomatic patients. Improvement in the technique of electrophoresis, particularly two-dimensional gel electrophoresis, is also suggested for the further understanding of cardiovascular disease and its diagnosis on better developed methodology in our Pakistani population.