Proteomic analysis of CHIKV-infected human fibroblast-like synoviocytes: Identification of host factors potentially associated with CHIKV replication and cellular pathogenesis

Unveiling Actin Cytoskeleton Role in Mediating Chikungunya-Associated Arthritis: An Integrative Proteome-Metabolome Study

Background: Chikungunya is a zoonotic disease caused by the Chikungunya virus (CHIKV), primarily transmitted to humans through infected Aedes mosquitoes. The infection is characterized by symptoms such as high fever, musculoskeletal pain, polyarthritis, and a rash, which can lead to severe complications such as encephalitis, meningitis, and even fatalities. While many disease manifestations resemble those of other viral infections, chronic arthritis caused by CHIKV is unique, and its molecular mechanisms remain ill-defined. Materials and Methods: Proteomics data from both cellular and patient levels of CHIKV infection were curated from PubMed and screened using inclusion and exclusion criteria. Patient serum proteomics data obtained from P RIDE underwent reanalysis using Proteome Discoverer 2.2. Enrichment and protein-protein interaction network analysis were conducted on differentially expressed proteins from both serum and cellular datasets. Metabolite data from CHIKV-infected patients were further retrieved, and their protein binding partners were identified using BindingDB. The protein-metabolite interaction pathway was further developed using MetaboAnalyst. Results: The proteomics data analysis revealed differential expression of proteins involved in critical host mechanisms, such as cholesterol metabolism and mRNA splicing, during CHIKV infection. Consistent upregulation of two actin cytoskeleton proteins, TAGLN2 and PFN1, was noted in both serum and cellular datasets, and their upregulations are associated with arthritis. Furthermore, alterations in purine metabolism were observed in the integrative proteome-metabolome analysis, correlating with cytoskeletal remodelling. Conclusion: Collectively, this integrative view sheds light on the involvement of actin cytoskeleton remodeling proteins and purine metabolic pathways in the development of arthritis during CHIKV infection.

A Review of Omics Studies on Arboviruses: Alphavirus, Orthobunyavirus and Phlebovirus

Since the intricate and complex steps in pathogenesis and host-viral interactions of arthropod-borne viruses or arboviruses are not completely understood, the multi-omics approaches, which encompass proteomics, transcriptomics, genomics and metabolomics network analysis, are of great importance. We have reviewed the omics studies on mosquito-borne viruses of the Togaviridae, Peribuyaviridae and Phenuiviridae families, specifically for Chikungunya, Mayaro, Oropouche and Rift Valley Fever viruses. Omics studies can potentially provide a new perspective on the pathophysiology of arboviruses, contributing to a better comprehension of these diseases and their effects and, hence, provide novel insights for the development of new antiviral drugs or therapies.

An E3 Ubiquitin Ligase Scaffolding Protein Is Proviral during Chikungunya Virus Infection in Aedes aegypti

Chikungunya virus (CHIKV) is a reemerging alphavirus causing chikungunya disease (CHIKD) and is transmitted to humans by Aedes mosquitoes. The virus establishes an intricate balance of cellular interactions that ultimately helps in its replication and dodges cellular immune response. In an attempt to identify cellular host factors required during CHIKV replication in Aag2 cells, we performed global transcriptomics of CHIKV-infected Aag2 cells, and further, we compared this library with the Drosophila RNAi Screening Center (DRSC) database and identified transcripts that were regulated in Aedes aegypti during CHIKV infection. These analyses revealed specific pathways, such as ubiquitin-related pathways, proteolysis pathways, protein catabolic processes, protein modification, and cellular protein metabolic processes, involved during replication of the virus. Loss-of-function assays of selected candidates revealed their proviral or antiviral characteristics upon CHIKV infection in A. aegypti-derived Aag2 cells. Further validations identified that the ubiquitin proteasomal pathway is required for CHIKV infection in A. aegypti and that an important member of this family of proteins, namely, AeCullin-3 (Aedes ortholog of human cullin-3), is a proviral host factor of CHIKV replication in Aag2 cells.

IMPORTANCE Arboviruses cause several diseases in humans and livestock. Vector control is the main strategy for controlling diseases transmitted by mosquitoes. In this context, it becomes paramount to understand how the viruses replicate in the vector for designing better transmission blocking strategies. We obtained the global transcriptome signature of A. aegypti cells during CHIKV infection, and in order to obtain the maximum information from these data sets, we further utilized the well-characterized Drosophila system and arrived upon a set of transcripts and their pathways that affect A. aegypti cells during CHIKV infection. These analyses and further validations reveal that important pathways related to protein degradation are actively involved during CHIKV infection in A. aegypti and are mainly proviral. Targeting these molecules may provide novel approaches for blocking CHIKV replication in A. aegypti.

Enhanced contextual fear memory in peroxiredoxin 6 knockout mice is associated with hyperactivation of MAPK signaling pathway

Fear dysregulation is one of the symptoms found in post-traumatic stress disorder (PTSD) patients. The functional abnormality of the hippocampus is known to be implicated in the development of such pathology. Peroxiredoxin 6 (PRDX6) belongs to the peroxiredoxin family. This antioxidant enzyme is expressed throughout the brain, including the hippocampus. Recent evidence reveals that PRDX6 plays an important role in redox regulation and the modulation of several signaling molecules involved in fear regulation. Thus, we hypothesized that PRDX6 plays a role in the regulation of fear memory. We subjected a systemic Prdx6 knockout (Prdx6-/-) mice to trace fear conditioning and observed enhanced fear response after training. Intraventricular injection of lentivirus-carried mouse Prdx6 into the 3rd ventricle reduced the enhanced fear response in these knockout mice. Proteomic analysis followed by validation of western blot analysis revealed that several proteins in the MAPK pathway, such as NTRK2, AKT, and phospho-ERK1/2, cPLA2 were significantly upregulated in the hippocampus of Prdx6-/- mice during the retrieval stage of contextual fear memory. The distribution of PRDX6 found in the astrocytes was also observed throughout the hippocampus. This study identifies PRDX6 as a participant in the regulation of fear response. It suggests that PRDX6 and related molecules may have important implications for understanding fear-dysregulation associated disorders like PTSD.