Cytokine storm in COVID-19 and malaria: Annals of pro-inflammatory cytokines.

Infectious diseases are affecting the people worldwide. Mostly, infectious agents activate excessive production of cytokines so called cytokine storm. Among the infectious diseases COVID-19 is one of the deadliest diseases affecting individuals all over the world, moreover, Plasmodium falciparum malaria and HIV are major killers. An excessive pro-inflammatory response is one of the major causes of pathological conditions in these diseases. It is important to investigate the pathophysiology in the infectious diseases such as COVID-19, malaria and HIV as there is no concrete therapy against them so far. Exploration of excessive pro-inflammation could be important for therapeutic intervention. In this article, an attempt has been made to analyze the pathological conditions arise due to excessive inflammatory response in COVID-19, malaria and other infectious diseases. Targeting excessive pro-inflammatory response/cytokine storm in infectious diseases could be a useful strategy.

Antineoplastic properties of zafirlukast against hepatocellular carcinoma via activation of mitochondrial mediated apoptosis.

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwideand haslimited treatment options. In view of this, zafirlukast (ZAF) was administered orally to DEN-induced HCC rats to evaluate its antineoplastic properties. ELISA, qRT-PCR and Western blot were used to determine the molecular mechanism associated with ZAF therapy for HCC. We found that HCC developed as a result of lower expression of caspases 3 and 9, but their levels returned to normal when the expression of eNOS, BAX, BAD, and Cyt C was decreased and when the expression of iNOS, Bcl-xl, and Bcl-2 was increased. Again, ZAF (80 mg/kg dose) treatment normalized the expression of caspase-mediated apoptotic factors, i.e. BAX and Bcl-2 proteins, as established through Western blot analysis. Later, 1H NMR-based serum metabolomics study revealed that levels of perturbed metabolites in DEN-induced rat serum returned to normal after ZAF administration. Altogether, the antineoplastic potential of ZAF was found to be comparable, and to some degree better, than the marketed chemotherapeutic 5-flurouracil, which may be beneficial for anti-HCC treatment from a future drug design perspective.

Exploration of copy number variation in genes related to anti-malarial drug resistance in Plasmodium falciparum.

Development of drug resistance in P. falciparum is one of the major problems associated with malaria treatment. Parasite genetic factors such as single nucleotide polymorphisms (SNPs) and copy number variations (CNV) have shown their role in drug resistance. Most of the studies have focused on the role of SNPs and drug resistance in parasite. However, it has also been shown that CNV is associated with adaptation and drug resistance in parasite. Hence, exploration of copy number polymorphism in essential genes of P. falciparum and their role in anti-malarial resistance is important. This review provides the recent information related to genetic profile of CNV marker in plasmepsin and other genes associated with drugresistanceinP. falciparum. It may be suggested that CNVs in plasmepsin genes are the major driver of piperaquine resistance. Moreover, CNVs in pfcrt and pfmdr1genes appear to play important role in adaptation and hence survival of the parasite. It may be hypothesized that targeting of CNV formation in the parasite could be beneficial for breakdown of its adaption in response to drug pressure.

Variations in host genes encoding adhesion molecules and susceptibility to falciparum malaria in India.

BACKGROUND: Host adhesion molecules play a significant role in the pathogenesis of Plasmodium falciparum malaria and changes in their structure or levels in individuals can influence the outcome of infection. The aim of this study was to investigate the association of SNPs of three adhesion molecule genes, ICAM1, PECAM1 and CD36, with severity of falciparum malaria in a malaria-endemic and a non-endemic region of India. METHODS: The frequency distribution of seven selected SNPs of ICAM1, PECAM1 and CD36 was determined in 552 individuals drawn from 24 populations across India. SNP-disease association was analysed in a case-control study format. Genotyping of the population panel was performed by Sequenom mass spectroscopy and patient/control samples were genotyped by SNaPshot method. Haplotypes and linkage disequilibrium (LD) plots were generated using PHASE and Haploview, respectively. Odds-ratio (OR) for risk assessment was estimated using EpiInfotrade mark version 3.4. RESULTS: Association of the ICAM1 rs5498 (exon 6) G allele and the CD36 exon 1a A allele with increased risk of severe malaria was observed (severe versus control, OR = 1.91 and 2.66, P = 0.02 and 0.0012, respectively). The CD36 rs1334512 (-53) T allele as well as the TT genotype associated with protection from severe disease (severe versus control, TT versus GG, OR = 0.37, P = 0.004). Interestingly, a SNP of the PECAM1 gene (rs668, exon 3, C/G) with low minor allele frequency in populations of the endemic region compared to the non-endemic region exhibited differential association with disease in these regions; the G allele was a risk factor for malaria in the endemic region, but exhibited significant association with protection from disease in the non-endemic region. CONCLUSION: The data highlights the significance of variations in the ICAM1, PECAM1 and CD36 genes in the manifestation of falciparum malaria in India. The PECAM1 exon 3 SNP exhibits altered association with disease in the endemic and non-endemic region.

QSAR modeling, docking and ADMET studies for exploration of potential anti-malarial compounds against Plasmodium falciparum.

Development of resistance in the Plasmodium falciparum to Artemisinin, the most effective anti-malarial compound, threatens malaria elimination tactics. To gain more efficacious Artemisinin derivatives, QSAR modeling and docking was performed. In the present study, 2D-QSAR model and molecular docking were used to evaluate the Artemisinin compounds and to reveal their binding modes and structural basis of inhibitory activity. Moreover, ADMET-related descriptors have been calculated to predict the pharmacokinetic properties of the effective compounds. The correlation expressed as coefficient of determination (r2) and prediction accuracy expressed in the form of cross-validated r2 (q2) of QSAR model are found 0.9687 and 0.9586, respectively. Total 239 descriptors have been included in the study as independent variables. The four chemical descriptors, namely radius of gyration, mominertia Z, SssNH count and SK Average have been found to be well correlated with anti-malarial activities. The model was statistically robust and has good predictive power which could be employed for virtual screening of proposed anti-malarial compounds. QSAR and docking results revealed that studied compounds exhibit good anti-malarial activities and binding affinities. The outcomes could be useful for the design and development of the potent inhibitors which after optimization can be potential therapeutics for malaria.

Chemokine genetic polymorphism in human health and disease.

Chemokine receptor-ligand interaction regulates transmigration of lymphocytes and monocytes from circulation to the inflammatory sites. CC chemokine receptors, chemokine receptor 2(CCR2) and 5 (CCR5) are important in recruitment of immune cells as well as non-immune cells under pathological condition. CCR2, CCR5 and their ligands (CCL2 and CCL5) are major contributor to the autoimmune and inflammatory diseases and cancer. Currently studies are being done to explore genetic variations in chemokine genes and their involvement in diseases that could make clear disease severity and deaths. Conflicting results of studies in different populations and diseases promoted to investigate chemokines genetic polymorphisms in miscellaneous diseases. This study is aimed to evaluate the influence of chemokines genetic polymorphisms in pathogenesis and outcome of prevalent non infectious diseases. Present study demonstrates the likely role played by genetic variations in drug response and evolution. Moreover this study highlights chemokine as therapeutic target and diagnostic biomarker in pathological condition.

Impact of genetic variations in C-C chemokine receptors and ligands on infectious diseases.

Chemokine receptors and ligands are crucial for extensive immune response against infectious diseases such as malaria, leishmaniasis, HIV and tuberculosis and a wide variety of other diseases. Role of chemokines are evidenced in the activation and regulation of immune cell migration which is important for immune response against diseases. Outcome of disease is determined by complex interaction among pathogen, host genetic variability and surrounding milieu. Variation in expression or function of chemokines caused by genetic polymorphisms could be associated with attenuated immune responses. Exploration of chemokine genetic polymorphisms in therapeutic response, gene regulation and disease outcome is important. Infectious agents in human host alter the expression of chemokines via epigenetic alterations and thus contribute to disease pathogenesis. Although some fragmentary data are available on chemokine genetic variations and their contribution in diseases, no unequivocal conclusion has been arrived as yet. We therefore, aim to investigate the association of CCR5-CCL5 and CCR2-CCL2 genetic polymorphisms with different infectious diseases, transcriptional regulation of gene, disease severity and response to therapy. Furthermore, the role of epigenetics in genes related to chemokines and infectious disease are also discussed.

Hemoglobin Degrading Proteases of Plasmodium falciparum as Antimalarial Drug Targets.

Plasmepsins, falcipains and aminopeptidases are Plasmodium falciparum proteases involved in human host hemoglobin degradation and other processes like erythrocyte invasion and rupture. Antimalarial drug resistance and natural selection in parasite are important reasons that create the urgent need of novel targets and lead compounds to overcome the burden of malaria. This report explored progress of the study covering proteases and their inhibitors specific to hemoglobin degradation. Additionally, in silico predicted antimalarial targets, balancing selection and drug-protein interaction are included.

Exploring putative molecular mechanisms of human pyruvate kinase enzyme deficiency and its role in resistance against Plasmodium falciparum malaria.

Malaria is the third most prevalent cause of global mortality and is an interesting case of evolutionary selection. In response to high frequency of malaria infection, several host genetic factors have been selected, such as Hemoglobin variants, Glucose-6-phosphate dehydrogenase (G6PD) deficiency and pyruvate kinase deficiency. Among these popular host genetic factors, deficiency of pyruvate kinase enzyme is one of the most important factor that provide resistance against malaria. Regulation of this enzyme at the level of transcription is important and several factors may play crucial role in regulation of this enzyme. DNA sequence variation and epigenetic factors modifying transcriptional regulation of gene have been explored in context of several diseases. In the present study, we explored the factors modifying transcription regulation of pyruvate kinase gene with the help of Bioinformatics tools. On the basis of our predictions we hypothesize that any factor that reduces the availability (level) or activity of pyruvate kinase enzyme must play a strong role in resistance to malaria. Thus, factors reducing the activity (loss of function) or level of pyruvate kinase have been selected to provide resistance against malaria primarily in endemic regions.

Exploring Drug Targets in Isoprenoid Biosynthetic Pathway for Plasmodium falciparum.

Emergence of rapid drug resistance to existing antimalarial drugs in Plasmodium falciparum has created the need for prediction of novel targets as well as leads derived from original molecules with improved activity against a validated drug target. The malaria parasite has a plant plastid-like apicoplast. To overcome the problem of falciparum malaria, the metabolic pathways in parasite apicoplast have been used as antimalarial drug targets. Among several pathways in apicoplast, isoprenoid biosynthesis is one of the important pathways for parasite as its multiplication in human erythrocytes requires isoprenoids. Therefore targeting this pathway and exploring leads with improved activity is a highly attractive approach. This report has explored progress towards the study of proteins and inhibitors of isoprenoid biosynthesis pathway. For more comprehensive analysis, antimalarial drug-protein interaction has been covered.

Antimalarial drug targets and drugs targeting dolichol metabolic pathway of Plasmodium falciparum.

Because of mutation and natural selection, development of drug resistance to the existing antimalarial is the major problem in malaria treatment. This problem has created an urgent need of novel antimalarial drug targets as well as lead compounds. The important characteristic of malaria is that it shows the phenomenon of balanced polymorphisms. Several traits have been selected in response to disease pressure. Therefore such factors must be explored to understand the pathogenesis of malaria infection in human host. Apicoplast, hub of metabolism is present in Plasmodium falciparum (causative agent of falciparum malaria) having similarities with plant plastid. Among several pathways in apicoplast, Dolichol metabolic pathway is one of the most important pathway and has been known to play role in parasite survival in the human host. In P.falciparum, a phosphorylated derivative of Dolichol participates in biosynthesis of glycoproteins. Several proteins of this pathway play role in post translational modifications of proteins involved in the signal transduction pathways, regulation of DNA replication and cell cycle. This pathway can be used as antimalarial drug target. This report has explored progress towards the study of proteins and inhibitors of Dolichol metabolic pathway. For more comprehensive analysis, the host genetic factors and drug-protein interaction have been covered.

QSAR and docking based semi-synthesis and in vivo evaluation of artemisinin derivatives for antimalarial activity.

To screen the active antimalarial novel artemisinin derivatives, a QSAR modeling approach was used. QSAR model showed high correlation (r(2)= 0.83 and rCV(2)= 0.81) and indicated that Connectivity Index (order 1, standard), Connectivity Index (order 2, standard), Dipole Moment (debye), Dipole Vector X (debye) and LUMO Energy (eV) well correlate with activity. High binding likeness on antimalarial target plasmepsin was detected through molecular docking. Active artemisinin derivatives showed significant activity and indicated compliance with standard parameters of oral bioavailability and ADMET. The active artemisinin derivatives namely, ß-Artecyclopropylmether HMCP (A3), ß- Artepipernoylether (PIP-1) (A4) and 9-(ß-Dihydroartemisinoxy)methyl anthracene (A5) were semi-synthesized and characterized based on its (1)H and (13)C NMR spectroscopic data and later activity tested in vivo on mice infected with multidrug resistant strain of P. yoelii nigeriensis. Predicted results were successfully validated by in vivo experiments.

Antimalarial drugs and drug targets specific to fatty acid metabolic pathway of Plasmodium falciparum.

Plasmodium falciparum, a causitive agent of malaria, is the third most prevalent factor for mortility in the world. Falciparum malaria is an example of evolutionary and balancing selection. Because of mutation and natural selection, the parasite has developed resistance to most of the existing drugs. Under such circumstances, there is a growing need to develop new molecular targets in P. falciparum. A four membrane bound organelles called apicoplast, very much similar to that of chloroplast of plants, have been found in parasite. Therefore, the proteins involved in metabolic pathways of apicoplasts are important drug targets. Among the pathways in apicoplast, fatty acid biosynthetic pathway is the most important metabolic pathway in P. falciparum. Several studies have explored the role of different proteins involved in this pathway and antimalarial compounds against this target. In this review, we have studied the role of different proteins in fatty acid metabolism and designing, synthesis and evaluation of compounds against the targets identified in fatty acid metabolic pathway.

QSAR, docking and ADMET studies of artemisinin derivatives for antimalarial activity targeting plasmepsin II, a hemoglobin-degrading enzyme from P. falciparum.

This work presents the development of quantitative structure activity relationship (QSAR) model to predict the antimalarial activity of artemisinin derivatives. The structures of the molecules are represented by chemical descriptors that encode topological, geometric, and electronic structure features. Screening through QSAR model suggested that compounds A24, A24a, A53, A54, A62 and A64 possess significant antimalarial activity. Linear model is developed by the multiple linear regression method to link structures to their reported antimalarial activity. The correlation in terms of regression coefficient (r(2)) was 0.90 and prediction accuracy of model in terms of cross validation regression coefficient (rCV(2)) was 0.82. This study indicates that chemical properties viz., atom count (all atoms), connectivity index (order 1, standard), ring count (all rings), shape index (basic kappa, order 2), and solvent accessibility surface area are well correlated with antimalarial activity. The docking study showed high binding affinity of predicted active compounds against antimalarial target Plasmepsins (Plm-II). Further studies for oral bioavailability, ADMET and toxicity risk assessment suggest that compound A24, A24a, A53, A54, A62 and A64 exhibits marked antimalarial activity comparable to standard antimalarial drugs. Later one of the predicted active compound A64 was chemically synthesized, structure elucidated by NMR and in vivo tested in multidrug resistant strain of Plasmodium yoelii nigeriensis infected mice. The experimental results obtained agreed well with the predicted values.

Deletion of the APOBEC3B gene strongly impacts susceptibility to falciparum malaria.

APOBEC3B, a gene involved in innate response, exhibits insertion-deletion polymorphism across world populations. We observed the insertion allele to be nearly fixed in malaria endemic regions of sub-Saharan Africa as well as populations with high malaria incidence in the past. This prompted us to investigate the possible association of the polymorphism with falciparum malaria. We studied the distribution of APOBEC3B, in 25 diverse Indian populations comprising of 500 samples and 176 severe or non-severe Plasmodium falciparum patients and 174 ethnically-matched uninfected individuals from a P. falciparum endemic and a non-endemic region of India. The deletion frequencies ranged from 0% to 43% in the Indian populations. The frequency of the insertion allele strikingly correlated with the endemicity map of P. falciparum malaria in India. A strong association of the deletion allele with susceptibility to falciparum malaria in the endemic region (non-severe vs. control, Odds ratio=4.96, P value=9.5E(-06); severe vs. control, OR=4.36, P value=5.76E(-05)) was observed. Although the frequency of deletion allele was higher in the non-endemic region, there was a significant association of the homozygous deletion genotype with malaria (OR=3.17, 95% CI=1.10-10.32, P value=0.0177). Our study also presents a case for malaria as a positive selection force for the APOBEC3B insertion and suggests a major role for this gene in innate immunity against malaria.

Distinct cytokine profiles define clinical immune response to falciparum malaria in regions of high or low disease transmission.

The immune effector response to Plasmodium falciparum infection involves a finely-tuned interplay between different cell types and cytokines. However, the processes by which they mediate the development of clinical immunity, in areas of different endemicity, are poorly understood. We analyzed circulating levels of pro-inflammatory (TNF, IFN-γ, IL-12, IL-16) and anti-inflammatory (IL-4, IL-10, IL-13) cytokines in control and patient groups drawn from a P. falciparum-endemic and a non-endemic region of India. The endemic region control population exhibited a lower pro- to anti-inflammatory cytokine ratio, indicating a shift towards a high basal Th2 response. Levels of IL-10 contributed most towards the region-specific difference in basal cytokine response. IL-10 was also the strongest predictor of disease in the endemic region, while IL-12, along with IL-10 and IL-6, contributed most to disease outcome in the non-endemic region. A low, mean IFN-γ/IL-10 ratio was associated with disease severity in the endemic region (p < 0.0001). In contrast, a low mean IL-12/IL-10 ratio correlated with disease outcome in the non-endemic region (p < 0.0001). In the endemic region, IL-13 correlated negatively with IFN-γ in severe patients (Spearman's ρ: -0.49; p : 0.013), while in the non-endemic region, IL-13 correlated negatively with IL-6 in severe malaria patients (Spearman's ρ: -0.485; p : 0.001). In conclusion, levels of pro- and anti-inflammatory cytokines and the relative balance between the Th1 and Th2 response, illustrates how populations residing in areas of varying disease endemicity may respond to P. falciparum-induced immune challenge.

CR1 levels and gene polymorphisms exhibit differential association with falciparum malaria in regions of varying disease endemicity.

Complement receptor 1 (CR1/CD35) levels on erythrocytes and related CR1 polymorphisms have been associated with response to falciparum malaria in populations inhabiting malaria-endemic regions. Differences in disease association profiles of its low expression alleles have been observed in populations from different regions of the world. We analyzed the influence of CR1 levels and associated SNPs on susceptibility/resistance to falciparum malaria in Indian populations. Two CR1 SNPs [exon 22 (A/G) and intron 27 (A/T)] define the low expression (L) CR1 allele in populations inhabiting a Plasmodium falciparum-endemic and a nonendemic region of India. Populations of the endemic region have very low red blood cell surface CR1 levels and higher frequencies of the exon 22 and intron 27 mutant L alleles. Whereas low CR1 levels correlated with susceptibility to severe malaria in the nonendemic region, high CR1 levels were associated with manifestation of disease in the endemic region. In addition, the exon 22 L allele was a risk factor for severe malaria in the nonendemic region. Absence of correlation between levels of tumor necrosis factor-alpha, interferon-gamma, and interleukin-6 with CR1 levels in patients with severe disease indicated that RBC CR1 levels in individuals are not the major determinants of pro-inflammatory cytokine release during infection. Our results are interpreted in the context of differences in the pathogenesis of severe malaria in the malaria-endemic and nonendemic region.