An insight to HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) pathogenesis; evidence from high-throughput data integration and meta-analysis

Cannabinoid receptors as new targets for HTLV-1 associated myelopathy (HAM/TSP) treatment

BACKGROUND/AIM

The roles of endocannabinoids are described in immune modulation and neuroprotection. HTLV-1-associated myelopathy (HAM/TSP) is an inflammatory neurodegenerative disease. Therefore, in this study, the interactions of HTLV-1 regulatory factors and host cannabinoid receptors (CBRs) were evaluated in HAM/TSP.

METHODS

Nineteen HAM/TSPs, 22 asymptomatic carriers (ACs), and 18 healthy controls (HCs) were enrolled. RNA was extracted from PBMCs and then reverse-transcribed to cDNA. The gene expression of CB1R and CB2R, as well as HTLV-1 proviral load (PVL), Tax and HTLV-1 basic leucine zipper factor (HBZ) were assessed by RT-qPCR.

RESULTS

The mean expression of CB1R in ACs (8.51 ± 2.76) was significantly higher than HAMTSPs (1.593 ± 0.74, p = 0.05) and also HCs (0.10 ± 0.039, p = 0.001). The CB2R gene expression level in ACs (2.62±0.44) was significantly higher than HAM/TSPs (0.59 ± 0.15, p = 0.001) and HCs (1.00 ± 0.2, p = 0.006). Meanwhile there was a strong correlation between CB1R and CB2R gene expression levels in the HCs and HAM/TSPs (p = 0.001). HTLV-1-Tax expression in HAM/TSPs (386 ± 104) was higher than ACs (75 ± 32) and statistically significant (p = 0.003). While HTLV-1-HBZ was only expressed in three AC subjects and five HAM/TSPs, thus it cannot be analyzed.

CONCLUSION

The up-regulation of CB2R has immunomodulatory effects in inflammatory reactions. While CB1R as a neuroprotective agent may suppress inflammatory reactions in ACs, preventing HAM/TSP. It seems that, like multiple sclerosis (MS), cannabinoid medications are beneficial in HAM/TSP.

The mirror like expression of genes involved in the FOXO signaling pathway could be effective in the pathogenesis of human lymphotropic virus type 1 (HTLV-1) through disruption of the downstream pathways

OBJECTIVES

Human lymphotropic virus type 1 (HTLV-1) is the cause of two major diseases, ATLL and HAM/TSP in a percentage of carriers. Despite progress in understanding the pathogenesis of these two diseases, the exact pathogenesis mechanism is still not well understood. High-throughput technologies have revolutionized medical research. This study aims to investigate the mechanism of pathogenesis of these two diseases using the results of high-throughput analysis of microarray datasets.

RESULTS

A total of 100 differentially expressed genes were found between ATLL and HAM/TSP. After constructing protein-protein network and further analyzing, proteins including ATM, CD8, CXCR4, PIK3R1 and CD2 were found as the hub ones between ATLL and HAM/TSP. Finding the modules of the subnetwork revealed the enrichment of two common pathways including FOXO signaling pathway and Cell cycle with two common genes including ATM and CDKN2D. Unlike ATLL, ATM gene had higher expressions in HAM/TSP patients. The expression of CDKN2D was increased in ATLL patients. The results of this study could be helpful for understanding the pathogenic mechanism of these two diseases in the same signaling pathways.

Elsberg Syndrome with Mixed Presentation as Meningitis Retention Syndrome: A Pediatric Case Report and Comprehensive Review of the Literature

Elsberg syndrome is a typically infectious syndrome that may cause acute or subacute bilateral lumbosacral radiculitis and sometimes lower spinal cord myelitis. Patients often present with various neurological symptoms involving the lower extremities, including numbness, weakness, and urinary disturbances such as retention. A 9-year-old girl with no significant past medical history presented with altered mental status, fever, urinary retention, and anuria and was found to have encephalomyelitis. An extensive diagnostic workup led to ruling out possible etiologies until identifying Elsberg syndrome. In this report, we describe a case of Elsberg syndrome caused by West Nile virus (WNV). To the best of our knowledge, this is the first reported case of its kind in the pediatric population. Utilizing PubMed and Web of Science databases, we reviewed the literature to describe the neurogenic control of the urinary system in correlation to a multitude of neurologic pathologies.

Nontraumatic Spinal Cord Injury: Epidemiology, Etiology and Management

The spinal cord is a conduit within the central nervous system (CNS) that provides ongoing communication between the brain and the rest of the body, conveying complex sensory and motor information necessary for safety, movement, reflexes, and optimization of autonomic function. After a traumatic spinal cord injury (SCI), supraspinal influences on the peripheral nervous system and autonomic nervous system (ANS) are disrupted, leading to spastic paralysis, sympathetic blunting, and parasympathetic dominance, resulting in cardiac dysrhythmias, systemic hypotension, bronchoconstriction, copious respiratory secretions, and uncontrolled bowel, bladder, and sexual dysfunction. This article outlines the pathophysiology of the less reported nontraumatic SCI (NTSCI), its classification, its influence on sensory/motor function, and introduces the probable comorbidities associated with SCI that will be discussed in more detail in the accompanying manuscripts of this special issue. Finally, management strategies for NTSCI will be provided.

Coevolution of HTLV-1-HBZ, Tax, and proviral load with host IRF-1 and CCNA-2 in HAM/TSP patients

Background HTLV-1-associated myelopathy (HAM/TSP) is a progressive neurodegenerative inflammatory condition of HTLV-1 infection. Viral-host interactions are a significant contributor to the symptoms of HTLV-1-associated diseases. Therefore, in this study, the expression of the main regulatory viral factors and proviral load (PVL) and two host transcription molecules were evaluated in HAM/TSP patients. Materials and methods The study population included 17 HAM/TSP patients, 20 asymptomatic carriers (ACs), and 19 healthy controls (HCs). RNA and DNA were extracted from PBMCs for assessment of the gene expressions and PVL assessment using RT-qPCR and TaqMan method. Results HTLV-1-PVL was higher in HAM/TSPs (395.80 ± 99.69) than ACs (92.92 ± 29.41) (P = 0.001). The Tax expression in HAM/TSPs (7.8 ± 5.7) was strongly higher than ACs (0.06 ± 0.04) (P = 0.02), while HTLV-1-HBZ was only increased around three times in HAM/TSPs (3.17), compared to ACs (1.20) and not significant. The host IRF1 expression in HAM/TSPs (0.4 ± 0.31) was higher than ACs (0.09 ± 0.05) (P = 0.02) and also HCs (0.16 ± 0.07) (P = 0.5), but lower in ACs than HCs (p = 0.01). Although, in HAM/TSPs (0.13 ± 0.09) and ACs (0.03 ± 0.02) CCNA-2 expression was statistically fewer than HCs (0.18 ± 0.06) (P = 0.03, P = 0.001, respectively), in HAM/TSP was higher than ACs (P = 0.1), but did not meet a 95% confidence interval. Conclusion The study showed that HTLV-1-PVL and Tax, along with host IRF-1, could be considered biomarkers in HAM/TSP development. Furthermore, IRF-1, as an essential transcription factor, can be considered a pivotal target in HAM/TSPs treatment.

Exploration of mRNAs and miRNA classifiers for various ATLL cancer subtypes using machine learning

Background

Adult T-cell Leukemia/Lymphoma (ATLL) is a cancer disease that is developed due to the infection by human T-cell leukemia virus type 1. It can be classified into four main subtypes including, acute, chronic, smoldering, and lymphoma. Despite the clinical manifestations, there are no reliable diagnostic biomarkers for the classification of these subtypes.

Methods

Herein, we employed a machine learning approach, namely, Support Vector Machine-Recursive Feature Elimination with Cross-Validation (SVM-RFECV) to classify the different ATLL subtypes from Asymptomatic Carriers (ACs). The expression values of multiple mRNAs and miRNAs were used as the features. Afterward, the reliable miRNA-mRNA interactions for each subtype were identified through exploring the experimentally validated-target genes of miRNAs.

Results

The results revealed that miR-21 and its interactions with DAAM1 and E2F2 in acute, SMAD7 in chronic, MYEF2 and PARP1 in smoldering subtypes could significantly classify the diverse subtypes.

Conclusions

Considering the high accuracy of the constructed model, the identified mRNAs and miRNA are proposed as the potential therapeutic targets and the prognostic biomarkers for various ATLL subtypes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09540-1.

Glutathione reductase system changes in HTLV-1 infected patients

During chronic HTLV-1 infections oxidative stress occurs and contributes in viral pathogenesis. Glutaredoxin (Grx) system is one of the most effective antioxidant components. The system maintains the cellular redox and scavenges reactive oxygen species through the function of glutathione reductase (GR) enzyme, NADPH and reduced glutathione (GSH). This study was performed to investigate potential changes in GR gene expression and activity as well as GSH level, and their association with the viral load in HTLV-1 infection. Forty HTLV-1 seropositive patients divided into two groups: asymptomatic carriers (N = 20) and HAM/TSP (N = 20) with the same number of age and sex-matched healthy controls were recruited in this study. GR cellular gene expression and viral load in PBMCs were determined using Real-time PCR Technique. Enzyme activity and GSH level in sera were measured by commercial kits based on manufacturer's provided protocols. GR gene expression and GR enzyme activity, as well as GSH level, were significantly lower in HTLV-1 patients. A negative correlation between viral load and GR gene expression/enzyme activity was observed in HAM/TSP group. Similarly, a negative relationship between viral load and GSH levels was observed in both carrier and HAM/TSP groups. We also found that in profound complicated condition of HTLV-1 infection, HAM/TSP, Grx system components activity was significantly decreased compared to the controls. Such observation was not the case in clinically healthy HTLV-1 carriers. These findings may shed a light on the conditions contributing in pathogenesis of the complications and exacerbation of the disease in the HAM/TSP cases.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13337-022-00758-y.

Identification of dysregulated pathways underlying HTLV-1-associated myelopathy/tropical spastic paraparesis through co-expression network analysis

Human T cell lymphotropic virus-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a pathogen-caused disease which is associated with the progressive neurological disorder. HAM/TSP affects the expression level of several proteins and dysregulates some biological pathways. To identify the interaction patterns among expressed genes in HAM/TSP patients, weighted gene co-expression network analysis (WGCNA) was applied. Three microarray datasets regarding HAM/TSP were merged, and the co-expression network was constructed among genes. A total of 38 modules were identified. Three preserved modules in HAM/TSP in comparison to the healthy subjects which also had the most connected proteins and enriched in the biological pathways were selected. These modules were enriched in pathways related to immune systems, cell cycle, viral infection, and neuronal systems. Moreover, the involvement of novel immunological-related proteins including C1QB, GBP5, PSME1, SERPING1, and UBE2C; neurological-related proteins including TUBA4A, TUBB8, and TP63; and also proteins including TRPC6, PRKG2, OPRD1, PRKACA, and TUBB4A involved in the cGMP-PKG signaling pathway, thyroid hormone synthesis, and recruitment of mitotic centrosome proteins and complexes were found. Therefore, tracing these proteins and the identified modules can shed light on the pathogenesis mechanism of HAM/TSP and help to find potential therapeutic targets. However, further experimental validation should be performed to confirm the proposed functional players.

Comprehensive high-throughput meta-analysis of differentially expressed microRNAs in transcriptomic datasets reveals significant disruption of MAPK/JNK signal transduction pathway in Adult T-cell leukemia/lymphoma

Background

Human T-lymphotropic virus 1 (HTLV-1) infection may lead to the development of Adult T-cell leukemia/lymphoma (ATLL). To further elucidate the pathophysiology of this aggressive CD4+ T-cell malignancy, we have performed an integrated systems biology approach to analyze previous transcriptome datasets focusing on differentially expressed miRNAs (DEMs) in peripheral blood of ATLL patients.

Methods

Datasets GSE28626, GSE31629, GSE11577 were used to identify ATLL-specific DEM signatures. The target genes of each identified miRNA were obtained to construct a protein-protein interactions network using STRING database. The target gene hubs were subjected to further analysis to demonstrate significantly enriched gene ontology terms and signaling pathways. Quantitative reverse transcription Polymerase Chain Reaction (RTqPCR) was performed on major genes in certain pathways identified by network analysis to highlight gene expression alterations.

Results

High-throughput in silico analysis revealed 9 DEMs hsa-let-7a, hsa-let-7g, hsa-mir-181b, hsa-mir-26b, hsa-mir-30c, hsa-mir-186, hsa-mir-10a, hsa-mir-30b, and hsa-let-7f between ATLL patients and healthy donors. Further analysis revealed the first 5 of DEMs were directly associated with previously identified pathways in the pathogenesis of HTLV-1. Network analysis demonstrated the involvement of target gene hubs in several signaling cascades, mainly in the MAPK pathway. RT-qPCR on human ATLL samples showed significant upregulation of EVI1, MKP1, PTPRR, and JNK gene vs healthy donors in MAPK/JNK pathway.

Discussion

The results highlighted the functional impact of a subset dysregulated microRNAs in ATLL on cellular gene expression and signal transduction pathways. Further studies are needed to identify novel biomarkers to obtain a comprehensive mapping of deregulated biological pathways in ATLL.

Deciphering microRNA-mRNA regulatory network in adult T-cell leukemia/lymphoma; the battle between oncogenes and anti-oncogenes

Adult T-cell leukemia/lymphoma (ATLL) is virus-caused cancer that originates from the infection by human T-cell leukemia virus type 1. ATLL dysregulates various biological pathways related to the viral infection and cancer progression through the dysexpression of miRNAs and mRNAs. In this study, the potential regulatory subnetworks were constructed aiming to shed light on the pathogenesis mechanism of ATLL. For this purpose, two mRNA and one miRNA expression datasets were firstly downloaded from the GEO database. Next, the differentially expressed genes and miRNAs (DEGs and DE-miRNAs, respectively), as well as differentially co-expressed gene pairs (DCGs), were determined. Afterward, common DEGs and DCGs targeted by experimentally validated DE-miRNAs were explored. The oncogenic and anti-oncogenic miRNA-mRNA regulatory subnetworks were then generated. The expression levels of four genes and two miRNAs were examined in the blood samples by qRT-PCR. The members of three oncogenic/anti-oncogenic subnetworks were generally enriched in immune, virus, and cancer-related pathways. Among them, FZD6, THBS4, SIRT1, CPNE3, miR-142-3p, and miR-451a were further validated by real-time PCR. The significant up-regulation of FZD6, THBS4, and miR-451a as well as down-regulation of CPNE3, SIRT1, and miR-142-3p were found in ATLL samples than normal samples. The identified oncogenic/anti-oncogenic subnetworks are pieces of the pathogenesis puzzle of ATLL. The ultimate winner is probably an oncogenic network that determines the final fate of the disease. The identified genes and miRNAs are proposed as novel prognostic biomarkers for ATLL.

Immunopathogenesis and Cellular Interactions in Human T-Cell Leukemia Virus Type 1 Associated Myelopathy/Tropical Spastic Paraparesis

HTLV-1-Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP) is a neuropathological disorder in 1–3% of individuals infected with Human T-lymphotropic virus 1 (HTLV-1). This condition is characterized by progressive spastic lower limb weakness and paralysis, lower back pain, bladder incontinence, and mild sensory disturbances resembling spinal forms of multiple sclerosis. This disease also causes chronic disability and is therefore associated with high health burden in areas where HTLV-1 infection is endemic. Despite various efforts in understanding the virus and discovery of novel diagnostic markers, and cellular and viral interactions, HAM/TSP management is still unsatisfactory and mainly focused on symptomatic alleviation, and it hasn’t been explained why only a minority of the virus carriers develop HAM/TSP. This comprehensive review focuses on host and viral factors in association with immunopathology of the disease in hope of providing new insights for drug therapies or other forms of intervention.

Extracellular Vesicles in HTLV-1 Communication: The Story of an Invisible Messenger

Human T-cell lymphotropic virus type 1 (HTLV-1) infects 5-10 million people worldwide and is the causative agent of adult T-cell leukemia/lymphoma (ATLL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) as well as other inflammatory diseases. A major concern is that the most majority of individuals with HTLV-1 are asymptomatic carriers and that there is limited global attention by health care officials, setting up potential conditions for increased viral spread. HTLV-1 transmission occurs primarily through sexual intercourse, blood transfusion, intravenous drug usage, and breast feeding. Currently, there is no cure for HTLV-1 infection and only limited treatment options exist, such as class I interferons (IFN) and Zidovudine (AZT), with poor prognosis. Recently, small membrane-bound structures, known as extracellular vesicles (EVs), have received increased attention due to their potential to carry viral cargo (RNA and proteins) in multiple pathogenic infections (i.e., human immunodeficiency virus type I (HIV-1), Zika virus, and HTLV-1). In the case of HTLV-1, EVs isolated from the peripheral blood and cerebral spinal fluid (CSF) of HAM/TSP patients contained the viral transactivator protein Tax. Additionally, EVs derived from HTLV-1-infected cells (HTLV-1 EVs) promote functional effects such as cell aggregation which enhance viral spread. In this review, we present current knowledge surrounding EVs and their potential role as immune-modulating agents in cancer and other infectious diseases such as HTLV-1 and HIV-1. We discuss various features of EVs that make them prime targets for possible vehicles of future diagnostics and therapies.

Expression changes of cytotoxicity and apoptosis genes in HTLV-1-associated myelopathy/tropical spastic paraparesis patients from the perspective of system virology

Although human T-cell lymphotropic virus type-1 (HTLV-1) was the first retrovirus among human pathogens to be identified, insufficient information on the pathogenesis of HTLV-1 infection means that no precise mechanism has yet been provided for HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Based on previous studies, it was found that apoptosis and inflammation stimulation were among the most important mechanisms underlying HAM/TSP. The present study provides an in-silico analysis of the microarray data related to HAM/TSP patients. Expression changes of the genes responsible for cytotoxicity and apoptosis processes of HAM/TSP patients and asymptomatic carriers were investigated. Expression of the genes involved in cytotoxicity and apoptosis in HAM/TSP patients was decreased; hence, a model was proposed indicating that the spread of immune responses in HAM/TSP may be due to expression of HTLV-1 virulence factors and the resistance of HTLV-1-infected cells to apoptosis.

Molecular targeting of PD-1 signaling pathway as a novel therapeutic approach in HTLV-1 infection

HTLV-1, the first human oncogenic retrovirus, is a type C retrovirus that belongs to the Deltaretrovirus genus. The HTLV-1 genome has 8.5 kbp length, and consists of major genes such as gag, pol, pro, env, and pX region. This retrovirus is considered as one of the most deadly infectious agent for peripheral-blood mononuclear cells (PBMC). The infection of HTLV-1 can lead to dangerous complications, such as infective dermatitis (ID), uveitis, arthritis, lymphadenitis, arthropathies, Sjögren's Syndrome (SS), and particularly HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) or Adult T-Cell Leukemia Lymphoma (ATLL). At the moment, Zidovudine (AZT) plus IFN-α is the only treatment available for HTLV-1 infections. Based on scientific studies, alongside the therapeutic regimens, intrinsic mechanisms also play a determinant role in reducing the signs of disease. Programmed cell death-1 (PD-1) signaling pathway, one of the most important checkpoints, has recently received interest, such as the development of a novel generation of anti-tumors. In the present study, we discuss the role of PD-1 signaling pathway in HTLV-1 infection as well as its application as a novel approach for treatment of HTLV-1 infections.

What is the role of the thioredoxin antioxidant complex in relation to HAM/TSP?

We have little information about the definite role of the thioredoxin antioxidant complex system during viral infection, particularly during human T-cell lymphotropic virus type 1 (HTLV-1) infection and the HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) state. Therefore, we conducted comprehensive next-generation sequencing (NGS) analysis to determine Trx system expression changes in three categories of subjects: sero-negative HTLV-1 individuals, asymptomatic HTLV-1 people and HAM/TSP patients. We found that Trx capacity is reduced in the HAM/TSP state compared to healthy individuals, which indicates increasing inflammation and reduction of apoptosis, which might contribute to the progression of inflammation in the spinal cord, which in turn may develop into the HAM/TSP state.