Understanding the relationship between cerebellum and the frontal-cortex region of C9orf72-related amyotrophic lateral sclerosis: A comparative analysis of genetic features.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a relentlessly progressive and fatal neurodegenerative diseases for which at present no cure is available. Despite the extensive research the progress from diagnosis to prognosis in ALS and frontotemporal dementia (FTD) has been slow which represents suboptimal understanding of disease pathophysiological processes. In recent studies, several genes have been associated with the ALS and FTD diseases such as SOD1, TDP43, and TBK1, whereas the hexanucleotide GGGGCC repeat expansion (HRE) in C9orf72 gene is a most frequent cause of ALS and FTD, that has changed the understanding of these diseases. METHODS: The goal of this study was to identify and spatially determine differential gene expression signature differences between cerebellum and frontal cortex in C9orf72-associated ALS (C9-ALS), to study the network properties of these differentially expressed genes, and to identify miRNAs targeting the common differentially expressed genes in both the tissues. This study thus highlights underlying differential cell susceptibilities to the disease mechanisms in C9-ALS and suggesting therapeutic target selection in C9-ALS. RESULTS: In this manuscript, we have identified that the genes involved in neuron development, protein localization and transcription are mostly enriched in cerebellum of C9-ALS patients, while the UPR-related genes are enriched in the frontal cortex. Of note, UPR pathway genes were mostly dysregulated both in the C9-ALS cerebellum and frontal cortex. Overall, the data presented here show that defects in normal RNA processing and the UPR pathway are the pathological hallmarks of C9-ALS. Interestingly, the cerebellum showed more strong transcriptome changes than the frontal cortex. CONCLUSION: Interestingly, the cerebellum region showed more significant transcriptomic changes as compared to the frontal cortex region suggesting its active participation in the disease process. This nuanced understanding may offer valuable insights for the development of targeted therapeutic strategies aimed at mitigating disease progression in C9-ALS.

Intersection of network medicine and machine learning towards investigating the key biomarkers and pathways underlying amyotrophic lateral sclerosis: a systematic review.

BACKGROUND: Network medicine is an emerging area of research that focuses on delving into the molecular complexity of the disease, leading to the discovery of network biomarkers and therapeutic target discovery. Amyotrophic lateral sclerosis (ALS) is a complicated rare disease with unknown pathogenesis and no available treatment. In ALS, network properties appear to be potential biomarkers that can be beneficial in disease-related applications when explored independently or in tandem with machine learning (ML) techniques. OBJECTIVE: This systematic literature review explores recent trends in network medicine and implementations of network-based ML algorithms in ALS. We aim to provide an overview of the identified primary studies and gather details on identifying the potential biomarkers and delineated pathways. METHODS: The current study consists of searching for and investigating primary studies from PubMed and Dimensions.ai, published between 2018 and 2022 that reported network medicine perspectives and the coupling of ML techniques. Each abstract and full-text study was individually evaluated, and the relevant studies were finally included in the review for discussion once they met the inclusion and exclusion criteria. RESULTS: We identified 109 eligible publications from primary studies representing this systematic review. The data coalesced into two themes: application of network science to identify disease modules and promising biomarkers in ALS, along with network-based ML approaches. Conclusion This systematic review gives an overview of the network medicine approaches and implementations of network-based ML algorithms in ALS to determine new disease genes, and identify critical pathways and therapeutic target discovery for personalized treatment.

The SARS-CoV-2 targeted human RNA binding proteins network biology to investigate COVID-19 associated manifestations.

The global coronavirus disease 2019 (COVID-19) pandemic caused by the SARS-CoV-2 virus has had unprecedented social and economic ramifications. Identifying targets for drug repurposing could be an effective means to present new and fast treatments. Furthermore, the risk of morbidity and mortality from COVID-19 goes up when there are coexisting medical conditions, however, the underlying mechanisms remain unclear. In the current study, we have adopted a network-based systems biology approach to investigate the RNA binding proteins (RBPs)-based molecular interplay between COVID-19, various human cancers, and neurological disorders. The network based on RBPs commonly involved in the three disease conditions consisted of nine RBPs connecting 10 different cancer types, 22 brain disorders, and COVID-19 infection, ultimately hinting at the comorbidities and complexity of COVID-19. Further, we underscored five miRNAs with reported antiviral properties that target all of the nine shared RBPs and are thus therapeutically valuable. As a strategy to improve the clinical conditions in comorbidities associated with COVID-19, we propose perturbing the shared RBPs by drug repurposing. The network-based analysis presented hereby contributes to a better knowledge of the molecular underpinnings of the comorbidities associated with COVID-19.

COVID-19 associated nervous system manifestations.

The novel coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused a global pandemic in the last year. Along with major respiratory distress, a myriad of neurological manifestations was also reported to be associated with COVID-19 patients. These cases indicate that SARS-CoV-2 can be considered as an opportunistic pathogen of the brain. SARS-CoV-2 enters the brain through the olfactory bulb, retrograde axonal transport from peripheral nerve endings, or via hematogenous or lymphatic routes. Notably, COVID-19 infection can cause or even present with different neurological features including encephalopathy, impaired consciousness, confusion, agitation, seizure, ataxia, headache, anosmia, ageusia, neuropathies, and neurodegenerative diseases. In this paper, we provide a brief review of observed neurological manifestations associated with COVID-19.

Artificial intelligence-driven drug repurposing and structural biology for SARS-CoV-2.

It has been said that COVID-19 is a generational challenge in many ways. But, at the same time, it becomes a catalyst for collective action, innovation, and discovery. Realizing the full potential of artificial intelligence (AI) for structure determination of unknown proteins and drug discovery are some of these innovations. Potential applications of AI include predicting the structure of the infectious proteins, identifying drugs that may be effective in targeting these proteins, and proposing new chemical compounds for further testing as potential drugs. AI and machine learning (ML) allow for rapid drug development including repurposing existing drugs. Algorithms were used to search for novel or approved antiviral drugs capable of inhibiting SARS-CoV-2. This paper presents a survey of AI and ML methods being used in various biochemistry of SARS-CoV-2, from structure to drug development, in the fight against the deadly COVID-19 pandemic. It is envisioned that this study will provide AI/ML researchers and the wider community an overview of the current status of AI applications particularly in structural biology, drug repurposing, and development, and motivate researchers in harnessing AI potentials in the fight against COVID-19.

Insights into the SARS-CoV-2-Mediated Alteration in the Stress Granule Protein Regulatory Networks in Humans.

The rapidly and constantly evolving coronavirus, SARS-CoV-2, imposes a great threat to human health causing severe lung disease and significant mortality. Cytoplasmic stress granules (SGs) exert anti-viral activities due to their involvement in translation inhibition and innate immune signaling. SARS-CoV-2 sequesters important SG nucleator proteins and impairs SG formation, thus evading the host response for efficient viral replication. However, the significance of SGs in COVID-19 infection remains elusive. In this study, we utilize a protein-protein interaction network approach to systematically dissect the crosstalk of human post-translational regulatory networks governed by SG proteins due to SARS-CoV-2 infection. We uncovered that 116 human SG proteins directly interact with SARS-CoV-2 proteins and are involved in 430 different brain disorders including COVID-19. Further, we performed gene set enrichment analysis to identify the drugs against three important key SG proteins (DYNC1H1, DCTN1, and LMNA) and also looked for potential microRNAs (miRNAs) targeting these proteins. We identified bexarotene as a potential drug molecule and miRNAs, hsa-miR-615-3p, hsa-miR-221-3p, and hsa-miR-124-3p as potential candidates for the treatment of COVID-19 and associated manifestations.

Targeting cathepsins: A potential link between COVID-19 and associated neurological manifestations.

Many studies have shown that the lysosomal cathepsins, especially cathepsins B/L (CTSB/L) are required for SARS-CoV-2 entry into host cells. Lysosomal proteases, cathepsins are indispensable for normal health and are involved in several brain disorders occurring at different development age periods. On the other hand, it has been well known that COVID-19 infection is largely associated with several neurological disorders. Taken together these findings and given the high levels of expression of CTSB/L in the brain, we here proposed a reasonable hypothesis about the involvement of CTSB/L in the neurological manifestations linked to COVID-19. Pharmacological inhibitions of the CTSB/L could be a potential therapeutic target to block the virus entry as well as to mitigate the brain disorders. To this end, we utilized the network-based drug repurposing analyses to identify the possible drugs that can target CTSB/L. This study identifies the molecules like cyclosporine, phenytoin, and paclitaxel as potential drugs with binding ability to the CTSB/L. Further, we have performed molecular docking and all-atom molecular dynamics (MD) simulations to investigate the stability of CTSL-drug complexes. The results showed strong and stable binding of drugs with CTSL.

Genomics-guided targeting of stress granule proteins G3BP1/2 to inhibit SARS-CoV-2 propagation.

SARS-CoV-2 nucleocapsid (N) protein undergoes RNA-induced phase separation (LLPS) and sequesters the host key stress granule (SG) proteins, Ras-GTPase-activating protein SH3-domain-binding protein 1 and 2 (G3BP1 and G3BP2) to inhibit SG formation. This will allow viral packaging and propagation in host cells. Based on a genomic-guided meta-analysis, here we identify upstream regulatory elements modulating the expression of G3BP1 and G3BP2 (collectively called G3BP1/2). Using this strategy, we have identified FOXA1, YY1, SYK, E2F-1, and TGFBR2 as activators and SIN3A, SRF, and AKT-1 as repressors of G3BP1/2 genes. Panels of the activators and repressors were then used to identify drugs that change their gene expression signatures. Two drugs, imatinib, and decitabine have been identified as putative modulators of G3BP1/2 genes and their regulators, suggesting their role as COVID-19 mitigation agents. Molecular docking analysis suggests that both drugs bind to G3BP1/2 with a much higher affinity than the SARS-CoV-2 N protein. This study reports imatinib and decitabine as candidate drugs against N protein and G3BP1/2 protein.

Genomics-guided identification of potential modulators of SARS-CoV-2 entry proteases, TMPRSS2 and Cathepsins B/L.

SARS-CoV-2 requires serine protease, transmembrane serine protease 2 (TMPRSS2), and cysteine proteases, cathepsins B, L (CTSB/L) for entry into host cells. These host proteases activate the spike protein and enable SARS-CoV-2 entry. We herein performed genomic-guided gene set enrichment analysis (GSEA) to identify upstream regulatory elements altering the expression of TMPRSS2 and CTSB/L. Further, medicinal compounds were identified based on their effects on gene expression signatures of the modulators of TMPRSS2 and CTSB/L genes. Using this strategy, estradiol and retinoic acid have been identified as putative SARS-CoV-2 alleviation agents. Next, we analyzed drug-gene and gene-gene interaction networks using 809 human targets of SARS-CoV-2 proteins. The network results indicate that estradiol interacts with 370 (45%) and retinoic acid interacts with 251 (31%) human proteins. Interestingly, a combination of estradiol and retinoic acid interacts with 461 (56%) of human proteins, indicating the therapeutic benefits of drug combination therapy. Finally, molecular docking analysis suggests that both the drugs bind to TMPRSS2 and CTSL with the nanomolar to low micromolar affinity. The results suggest that these drugs can simultaneously target both the entry pathways of SARS-CoV-2 and thus can be considered as a potential treatment option for COVID-19.

Simultaneous Inhibition of SARS-CoV-2 Entry Pathways by Cyclosporine.

The COVID-19 pandemic caused by SARS-CoV-2 represents a global public health emergency. The entry of SARS-CoV-2 into host cells requires the activation of its spike protein by host cell proteases. The serine protease, TMPRSS2, and cysteine proteases, Cathepsins B/L, activate spike protein and enable SARS-CoV-2 entry to the host cell through two completely different and independent pathways. Therefore, inhibiting either TMPRSS2 or cathepsin B/L may not sufficiently block the virus entry. We here hypothesized that simultaneous targeting of both the entry pathways would be more efficient to block the virus entry rather than targeting the entry pathways individually. To this end, we utilized the network-based drug repurposing analyses to identify the possible common drugs that can target both the entry pathways. This study, for the first time, reports the molecules like cyclosporine, calcitriol, and estradiol as candidate drugs with the binding ability to the host proteases, TMPRSS2, and cathepsin B/L. Next, we analyzed drug-gene and gene-gene interaction networks using 332 human targets of SARS-CoV-2 proteins. The network results indicate that, out of 332 human proteins, cyclosporine interacts with 216 (65%) proteins. Furthermore, we performed molecular docking and all-atom molecular dynamics (MD) simulations to explore the binding of drug with TMPRSS2 and cathepsin L. The molecular docking and MD simulation results showed strong and stable binding of cyclosporine A (CsA) with TMPRSS2 and CTSL genes. The above results indicate cyclosporine as a potential drug molecule, as apart from interacting with SARS-CoV-2 entry receptors, it also interacts with most of SARS-CoV-2 target host genes; thus it could potentially interfere with functions of SARS-CoV-2 proteins in human cells. We here also suggest that these antiviral drugs alone or in combination can simultaneously target both the entry pathways and thus can be considered as a potential treatment option for COVID-19.

Brain Disease Network Analysis to Elucidate the Neurological Manifestations of COVID-19.

Although COVID-19 largely causes respiratory complications, it can also lead to various extrapulmonary manifestations resulting in higher mortality and these comorbidities are posing a challenge to the health care system. Reports indicate that 30-60% of patients with COVID-19 suffer from neurological symptoms. To understand the molecular basis of the neurologic comorbidity in COVID-19 patients, we have investigated the genetic association between COVID-19 and various brain disorders through a systems biology-based network approach and observed a remarkable resemblance. Our results showed 123 brain-related disorders associated with COVID-19 and form a high-density disease-disease network. The brain-disease-gene network revealed five highly clustered modules demonstrating a greater complexity of COVID-19 infection. Moreover, we have identified 35 hub proteins of the network which were largely involved in the protein catabolic process, cell cycle, RNA metabolic process, and nuclear transport. Perturbing these hub proteins by drug repurposing will improve the clinical conditions in comorbidity. In the near future, we assumed that in COVID-19 patients, many other neurological manifestations will likely surface. Thus, understanding the infection mechanisms of SARS-CoV-2 and associated comorbidity is a high priority to contain its short- and long-term effects on human health. Our network-based analysis strengthens the understanding of the molecular basis of the neurological manifestations observed in COVID-19 and also suggests drug for repurposing.

Insights into the biased activity of dextromethorphan and haloperidol towards SARS-CoV-2 NSP6: in silico binding mechanistic analysis.

The outbreak of novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus continually led to infect a large population worldwide. SARS-CoV-2 utilizes its NSP6 and Orf9c proteins to interact with sigma receptors that are implicated in lipid remodeling and ER stress response, to infect cells. The drugs targeting the sigma receptors, sigma-1 and sigma-2, have emerged as effective candidates to reduce viral infectivity, and some of them are in clinical trials against COVID-19. The antipsychotic drug, haloperidol, exerts remarkable antiviral activity, but, at the same time, the sigma-1 benzomorphan agonist, dextromethorphan, showed pro-viral activity. To explore the potential mechanisms of biased binding and activity of the two drugs, haloperidol and dextromethorphan towards NSP6, we herein utilized molecular docking-based molecular dynamics simulation studies. Our extensive analysis of the protein-drug interactions, structural and conformational dynamics, residual frustrations, and molecular switches of NSP6-drug complexes indicates that dextromethorphan binding leads to structural destabilization and increase in conformational dynamics and energetic frustrations. On the other hand, the strong binding of haloperidol leads to minimal structural and dynamical perturbations to NSP6. Thus, the structural insights of stronger binding affinity and favorable molecular interactions of haloperidol towards viral NSP6 suggests that haloperidol can be potentially explored as a candidate drug against COVID-19. KEY MESSAGES: •Inhibitors of sigma receptors are considered as potent drugs against COVID-19. •Antipsychotic drug, haloperidol, binds strongly to NSP6 and induces the minimal changes in structure and dynamics of NSP6. •Dextromethorphan, agonist of sigma receptors, binding leads to overall destabilization of NSP6. •These two drugs bind with NSP6 differently and also induce differences in the structural and conformational changes that explain their different mechanisms of action. •Haloperidol can be explored as a candidate drug against COVID-19.

Neurological manifestations of COVID-19: available evidences and a new paradigm.

The recent pandemic outbreak of coronavirus is pathogenic and a highly transmittable viral infection caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2). In this time of ongoing pandemic, many emerging reports suggested that the SARS-CoV-2 has inimical effects on neurological functions, and even causes serious neurological damage. The neurological symptoms associated with COVID-19 include headache, dizziness, depression, anosmia, encephalitis, stroke, epileptic seizures, and Guillain-Barre syndrome along with many others. The involvement of the CNS may be related with poor prognosis and disease worsening. Here, we review the evidence of nervous system involvement and currently known neurological manifestations in COVID-19 infections caused by SARS-CoV-2. We prioritize the 332 human targets of SARS-CoV-2 according to their association with brain-related disease and identified 73 candidate genes. We prioritize these 73 genes according to their spatio-temporal expression in the different regions of brain and also through evolutionary intolerance analysis. The prioritized genes could be considered potential indicators of COVID-19-associated neurological symptoms and thus act as a possible therapeutic target for the prevention and treatment of CNS manifestations associated with COVID-19 patients.

Impact of amino acid substitution in the kinase domain of Bruton tyrosine kinase and its association with X-linked agammaglobulinemia.

X-linked agammaglobulinemia (XLA) is a rare disease that affects the immune system, characterized by a serial development of bacterial infection from the onset of infantile age. Bruton tyrosine kinase (BTK) is a non-receptor cytoplasmic kinase that plays a crucial role in the B-lymphocyte maturation. The altered expression, mutation and/or structural variations of BTK are responsible for causing XLA. Here, we have performed extensive sequence and structure analyses of BTK to find deleterious variations and their pathogenic association with XLA. First, we screened the pathogenic variations in the BTK from a pool of publicly available resources, and their pathogenicity/tolerance and stability predictions were carried out. Finally, two pathogenic variations (E589G and M630K) were studied in detail and subjected to all-atom molecular dynamics simulation for 200 ns. Intramolecular hydrogen bonds (H-bonds), secondary structure, and principal component analysis revealed significant conformational changes in variants that support the structural basis of BTK dysfunction in XLA. The free energy landscape analysis revealed the presence of multiple energy minima, suggests that E589G brings a large destabilization and consequently unfolding behavior compared to M630K. Overall, our study suggests that amino acid substitutions, E589G, and M630K, significantly alter the structural conformation and stability of BTK.

Targeting hub genes and pathways of innate immune response in COVID-19: A network biology perspective.

The current pandemic of 2019 novel coronavirus disease (COVID-19) caused by a novel virus strain, 2019-nCoV/SARS-CoV-2 have posed a serious threat to global public health and economy. It is largely unknown how the human immune system responds to this infection. A better understanding of the immune response to SARS-CoV-2 will be important to develop therapeutics against COVID-19. Here, we have used transcriptomic profile of human alveolar adenocarcinoma cells (A549) infected with SARS-CoV-2 and employed a network biology approach to generate human-virus interactome. Network topological analysis discovers 15 SARS-CoV-2 targets, which belongs to a subset of interferon (IFN) stimulated genes (ISGs). These ISGs (IFIT1, IFITM1, IRF7, ISG15, MX1, and OAS2) can be considered as potential candidates for drug targets in the treatments of COVID-19. We have identified significant interaction between ISGs and TLR3 agonists, like poly I: C, and imiquimod, and suggests that TLR3 agonists can be considered as a potential drug for drug repurposing in COVID-19. Our network centric analysis suggests that moderating the innate immune response is a valuable approach to target COVID-19.

Virtual high-throughput screening of natural compounds in-search of potential inhibitors for protection of telomeres 1 (POT1).

Communicated by Ramaswamy H. Sarma.

Genome wide identification and characterization of microsatellite markers in black pepper (Piper nigrum): A valuable resource for boosting genomics applications.

Black pepper is one of the most valued and widely used spices in the world and dominates multi-billion dollar global spices trade. India is amongst the major producers, consumers and exporters of black pepper. In spite of its commercial and cultural importance, black pepper has received meagre attention in terms of generation of genomic resources. Availability of markers distributed throughout the genome would facilitate and accelerate genetic studies, QTL identification, genetic enhancement and crop improvement in black pepper. In this perspective, the sequence information from the recently sequenced black pepper (Piper nigrum) genome has been used for identification and characterisation of Simple Sequence Repeats (SSRs). Total 69,126 SSRs were identified from assembled genomic sequence of P. nigrum. The SSR frequency was 158 per MB making it, one SSR for every 6.3 kb in the assembled genome. Among the different types of microsatellite repeat motifs, dinucleotides were the most abundant (48.6%), followed by trinucleotide (23.7%) and compound repeats (20.62%). A set of 85 SSRs were used for validation, of which 74 produced amplification products of expected size. Genetic diversity of 30 black pepper accessions using 50 SSRs revealed four distinct clusters. Further, the cross species transferability of the SSRs was checked in nine other Piper species. Out of 50 SSRs used, 19 and 31 SSRs were amplified in nine and seven species, respectively. Thus the identified SSRs may have application in other species of the genus Piper where genome sequence is not available yet. Present study reports the first NGS based genomic SSRs in black pepper and thus constitute a valuable resource for a whole fleet of applications in genetics and plant breeding studies such as genetic map construction, QTL identification, map-based gene cloning, marker-assisted selection and evolutionary studies in Piper nigrum and related species.