Biology subjects

Khan, M. A.-A.-K.

Publications and source records attributed to Khan, M. A.-A.-K..

6 recordsLinked to original sources

bioRxiv2020

Host transcriptional responses and SARS-CoV-2 isolates from the nasopharyngeal samples of Bangladeshi COVID-19 patients

As the COVID-19 pandemic progresses, fatality and cases of new infections are also increasing at an alarming rate. SARS-CoV-2 follows a highly variable course and it is becoming more evident that individuals immune system has a decisive influence on the progression of the disease. However, the detailed underlying molecular mechanisms of the SARS-CoV-2 mediate disease pathogenesis are largely unknown. Only a few host transcriptional responses in COVID-19 have been reported so far from the Western world, but no such data has been generated from the South-Asian region yet to correlate the conjectured lower fatality around this part of the globe. In this context, we aimed to perform the transcriptomic profiling of the COVID-19 patients from Bangladesh along with the reporting of the SARS-CoV-2 isolates from these patients. Moreover, we performed a comparative analysis to demonstrate how differently the various SARS-CoV-2 infection systems are responding to the viral pathogen. We detected a unique missense mutation at 10329 position of ORF1ab gene, annotated to 3C like proteinase, which is found in 75% of our analyzed isolates; but is very rare globally. Upon the functional enrichment analyses of differentially modulated genes, we detected a similar host induced response reported earlier; this response was mainly mediated by the innate immune system, interferon stimulation, and upregulated cytokine expression etc. in the Bangladeshi patients. Surprisingly, we did not perceive the induction of apoptotic signaling, phagosome formation, antigen presentation and production, hypoxia response within these nasopharyngeal samples. Furthermore, while comparing with the other SARS-CoV-2 infection systems, we spotted that lung cells trigger the more versatile immune and cytokine signaling which was several folds higher compared to our reported nasopharyngeal samples. We also observed that lung cells did not express ACE2 in a very high amount as suspected, however, the nasopharyngeal cells are found overexpressing ACE2. But the amount of DPP4 expression within the nasal samples was significantly lower compared to the other cell types. Surprisingly, we observed that lung cells express a very high amount of integrins compared to the nasopharyngeal samples, which might suggest the putative reasons for an increased amount of viral infections in the lungs. From the network analysis, we got clues on the probable viral modulation for the overexpression of these integrins. Our data will provide valuable insights in developing potential studies to elucidate the roles of ethnicity effect on the viral pathogenesis, and incorporation of further data will enrich the search of an effective therapeutics.

genomics↗

bioRxiv2020

Perversely expressed long noncoding RNAs can alter host response and viral proliferation in SARS-CoV-2 infection

BackgroundSince December 2019, the world is experiencing an unprecedented crisis due to a novel coronavirus, SARS-CoV-2. Owing to poor understanding of pathogenicity, the virus is eluding treatment and complicating recovery. Regulatory roles of long non-coding RNAs (lncRNAs) during viral infection and associated antagonism of host antiviral immune responses has become more evident in last decade. To elucidate possible functions of lncRNAs in the COVID-19 pathobiology, we have utilized RNA-seq dataset of SARS-CoV-2 infected lung epithelial cells. ResultsOur analyses uncover 21 differentially expressed lncRNAs whose functions are broadly involved in cell survival and regulation of gene expression. By network enrichment analysis we find that these lncRNAs can directly interact with differentially expressed protein-coding genes ADAR, EDN1, KYNU, MALL, TLR2 and YWHAG; and also AKAP8L, EXOSC5, GDF15, HECTD1, LARP4B, LARP7, MIPOL1, UPF1, MOV10 and PRKAR2A, host genes that interact with SARS-CoV-2 proteins. These genes are involved in cellular signaling, metabolism, immune response and RNA homeostasis. Since lncRNAs have been known to sponge microRNAs and protect expression of upregulated genes, we also identified 9 microRNAs that are induced in viral infections; however, some lncRNAs are able to block their usual suppressive effect on overexpressed genes and consequently contribute to host defense and cell survival. ConclusionsOur investigation determines that deregulated lncRNAs in SARS-CoV-2 infection are involved in viral proliferation, cellular survival, and immune response, ultimately determining disease outcome and this information could drive the search for novel RNA therapeutics as a treatment option.

genomics↗

bioRxiv2020

SARS-CoV-2 mutations altering regulatory properties: deciphering host's and virus's perspectives

Since the first recorded case of the SARS-CoV-2, it has acquired several mutations in its genome while spreading throughout the globe. However, apart from some changes in protein coding, functional importance of these mutations in disease pathophysiology are still largely unknown. In this study, we investigated the significance of these mutations both from the hosts and viruss perspective by analyzing the host miRNA binding and viruss internal ribosome entry site (IRES), respectively. Strikingly, we observed that due to the acquired mutations, host miRNAs bind differently compared to the reference; where few of the miRNAs lost and few gained the binding affinity for targeting the viral genome. Moreover, functional enrichment analysis suggests that targets of both of these gained and lost miRNAs might be involved in various host immune signaling pathways. Also, we sought to shed some insights on the impacts of mutations on the IRES structure of SARS-CoV-2. Remarkably, we detected that three particular mutations in the IRES can disrupt its secondary structure which can further make the virus less functional. These results could be valuable in exploring the functional importance of the mutations of SARS-CoV-2 and could provide novel insights into the differences observed different parts of the world.

genomics↗

bioRxiv2020

SARS-CoV-2 proteins exploit host's genetic and epigenetic mediators for the annexation of key host signaling pathways that confers its immune evasion and disease pathophysiology

The constant rise of the death toll and cases of COVID-19 has made this pandemic a serious threat to human civilization. Understanding of host-SARS-CoV-2 interaction in viral pathogenesis is still in its infancy. In this study we aimed to correlate how SARS-CoV-2 utilizes its proteins for tackling the host immune response; parallelly, how host epigenetic factors might play a role in this pathogenesis was also investigated. We have utilized a blend of computational and knowledgebase approach to elucidate the interplay between host and SARS-CoV-2. Integrating the experimentally validated host interactome proteins and differentially expressed host genes due to SARS-CoV-2 infection, we have taken a blend of computational and knowledgebase approach to delineate the interplay between host and SARS-CoV-2 in various signaling pathways. Also, we have shown how host epigenetic factors are involved in the deregulation of gene expression. Strikingly, we have found that several transcription factors and other epigenetic factors can modulate some immune signaling pathways, helping both host and virus. We have identified miRNA hsa-miR-429 whose transcription factor was also upregulated and targets were downregulated and this miRNA can have pivotal role in suppression of host immune responses. While searching for the pathways in which viral proteins interact with host proteins, we have found pathways like-HIF-1 signaling, autophagy, RIG-I signaling, Toll-like receptor signaling, Fatty acid oxidation/degradation, Il-17 signaling etc significantly associated. We observed that these pathways can be either hijacked or suppressed by the viral proteins, leading to the improved viral survival and life-cycle. Moreover, pathways like-Relaxin signaling in lungs suggests aberration by the viral proteins might lead to the lung pathophysiology found in COVID-19. Also, enrichment analyses suggest that deregulated genes in SARS-CoV-2 infection are involved in heart development, kidney development, AGE-RAGE signaling pathway in diabetic complications etc. might suggest why patients with comorbidities are becoming more prone to SARS-CoV-2 infection. Our results suggest that SARS-CoV-2 integrates its proteins in different immune signaling pathway and other cellular signaling pathways for developing efficient immune evasion mechanisms, while leading the host to more complicated disease condition. Our findings would help in designing more targeted therapeutic interventions against SARS-CoV-2.

systems biology↗

bioRxiv2020

Epigenetic regulator miRNA pattern differences among SARS-CoV, SARS-CoV-2 and SARS-CoV-2 world-wide isolates delineated the mystery behind the epic pathogenicity and distinct clinical characteristics of pandemic COVID-19

Detailed molecular mechanism of SARS-CoV-2 pathogenesis is still elusive to address its deadlier nature and to design effective theraputics. Here, we present our study elucidating the interplay between the SARS-CoV and SARS-CoV-2 viruses; and hosts miRNAs, an epigenetic regulator, as a mode of pathogenesis, and enlightened how the SARS-CoV and SARS-CoV-2 infections differ in terms of their miRNA mediated interactions with host and its implications in the disease complexity. We have utilized computational approaches to predict potential host and viral miRNAs, and their possible roles in different important functional pathways. We have identified several putative host antiviral miRNAs that can target the SARS viruses, and also SARS viruses encoded miRNAs targeting host genes. In silico predicted targets were also integrated with SARS infected human cells microarray and RNA-seq gene expression data. Comparison of the host miRNA binding profiles on 67 different SARS-CoV-2 genomes from 24 different countries with respective countrys normalized death count surprisingly uncovered some miRNA clusters which are associated with increased death rates. We have found that induced cellular miRNAs can be both a boon and a bane to the host immunity, as they have possible roles in neutralizing the viral threat, parallelly, they can also function as proviral factors. On the other hand, from over representation analysis, interestingly our study revealed that although both SARS-CoV and SARS-CoV-2 viral miRNAs could target broad immune signaling pathways; only some of the SARS-CoV-2 miRNAs are found to uniquely target some immune signaling pathways like-autophagy, IFN-I signaling etc, which might suggest their immune-escape mechanisms for prolonged latency inside some hosts without any symptoms of COVID-19. Further, SARS-CoV-2 can modulate several important cellular pathways which might lead to the increased anomalies in patients with comorbidities like-cardiovascular diseases, diabetes, breathing complications, etc. This might suggest that miRNAs can be a key epigenetic modulator behind the overcomplications amongst the COVID-19 patients. Our results support that miRNAs of host and SARS-CoV-2 can indeed play a role in the pathogenesis which can be further concluded with more experiments. These results will also be useful in designing RNA therapeutics to alleviate the complications from COVID-19.

genomics↗

bioRxiv2020

Lung biopsy cells transcriptional landscape from COVID-19 patient stratified lung injury in SARS-CoV-2 infection through impaired pulmonary surfactant metabolism

Clinical management of COVID-19 is still complicated due to the lack of therapeutic interventions to reduce the breathing problems, respiratory complications and acute lung injury - which are the major complications of most of the mild to critically affected patients and the molecular mechanisms behind these clinical features are still largely unknown. In this study, we have used the RNA-seq gene expression pattern in the COVID-19 affected lung biopsy cells and compared it with the effects observed in typical cell lines infected with SARS-CoV-2 and SARS-CoV. We performed functional overrepresentation analyses using these differentially expressed genes to signify the processes/pathways which could be deregulated during SARS-CoV-2 infection resulting in the symptomatic impairments observed in COVID-19. Our results showed that the significantly altered processes include inflammatory responses, antiviral cytokine signaling, interferon responses, and interleukin signaling etc. along with downmodulated processes related to lungs functionality like-responses to hypoxia, lung development, respiratory processes, cholesterol biosynthesis and surfactant metabolism. We also found that the viral protein interacting hosts proteins involved in similar pathways like: respiratory failure, lung diseases, asthma, and hypoxia responses etc., suggesting viral proteins might be deregulating the processes related to acute lung injury/breathing complications in COVID-19 patients. Protein-protein interaction networks of these processes and map of gene expression of deregulated genes revealed that several viral proteins can directly or indirectly modulate the host genes/proteins of those lung related processes along with several host transcription factors and miRNAs. Surfactant proteins and their regulators SPD, SPC, TTF1 etc. which maintains the stability of the pulmonary tissue are found to be downregulated through viral NSP5, NSP12 that could lead to deficient gaseous exchange by the surface films. Mitochondrial dysfunction owing to the aberration of NDUFA10, NDUFAF5, SAMM50 etc. by NSP12; abnormal thrombosis in lungs through atypical PLAT, EGR1 functions by viral ORF8, NSP12; dulled hypoxia responses due to unusual shift in HIF-1 downstream signaling might be the causative elements behind the acute lung injury in COVID-19 patients. Our study put forward a distinct mechanism of probable virus induced lung damage apart from cytokine storm and advocate the need of further research for alternate therapy in this direction.

genomics↗