MicroRNA 320a Predicts Chronic Axial and Widespread Pain Development Following Motor Vehicle Collision in a Stress-Dependent Manner

MicroRNAs as potential biomarkers for diagnosis of post-traumatic stress disorder

Post-traumatic stress disorder is a mental disorder caused by exposure to severe traumatic life events. Currently, there are no validated biomarkers or laboratory tests that can distinguish between trauma survivors with and without post-traumatic stress disorder. In addition, the heterogeneity of clinical presentations of post-traumatic stress disorder and the overlap of symptoms with other conditions can lead to misdiagnosis and inappropriate treatment. Evidence suggests that this condition is a multisystem disorder that affects many biological systems, raising the possibility that peripheral markers of disease may be used to diagnose post-traumatic stress disorder. We performed a PubMed search for microRNAs (miRNAs) in post-traumatic stress disorder (PTSD) that could serve as diagnostic biomarkers and found 18 original research articles on studies performed with human patients and published January 2012 to December 2023. These included four studies with whole blood, seven with peripheral blood mononuclear cells, four with plasma extracellular vesicles/exosomes, and one with serum exosomes. One of these studies had also used whole plasma. Two studies were excluded as they did not involve microRNA biomarkers. Most of the studies had collected samples from adult male Veterans who had returned from deployment and been exposed to combat, and only two were from recently traumatized adult subjects. In measuring miRNA expression levels, many of the studies had used microarray miRNA analysis, miRNA Seq analysis, or NanoString panels. Only six studies had used real time polymerase chain reaction assay to determine/validate miRNA expression in PTSD subjects compared to controls. The miRNAs that were found/validated in these studies may be considered as potential candidate biomarkers for PTSD and include miR-3130-5p in whole blood; miR-193a-5p, -7113-5p, -125a, -181c, and -671-5p in peripheral blood mononuclear cells; miR-10b-5p, -203a-3p, -4488, -502-3p, -874-3p, -5100, and -7641 in plasma extracellular vesicles/exosomes; and miR-18a-3p and -7-1-5p in blood plasma. Several important limitations identified in the studies need to be taken into account in future studies. Further studies are warranted with war veterans and recently traumatized children, adolescents, and adults having PTSD and use of animal models subjected to various stressors and the effects of suppressing or overexpressing specific microRNAs.

Novel insights into the molecular mechanisms underlying anti-nociceptive effect of myricitrin against reserpine-induced fibromyalgia model in rats: Implication of SIRT1 and miRNAs

ETHNOPHARMACOLOGICAL RELEVANCE

Manilkara zapota (L.) P. Royen, also termed sapodilla or chikoo, is a significant plant in ethnomedicine because of its long history of traditional medical applications. In diverse cultures, sapodilla is believed to protect against oxidative stress, inflammation, and some chronic diseases because of its high antioxidant content. The naturally occurring antioxidant myricitrin (MYR) flavonoid is primarily found in the leaves and other plant parts of sapodilla and it is well-known for having therapeutic qualities and possible health advantages.

AIM OF THE STUDY

To appraise the possible impact of MYR on a rat model of reserpine-induced fibromyalgia (FM) and explore its mechanism of action.

MATERIALS AND METHODS

Isolation and identification of MYR with more than 99% purity from Manilkara zapota leaves were primarily done and confirmed through chromatographic and spectrophotometric techniques. To develop FM model, reserpine (RSP) was injected daily (1 mg/kg, s.c.) for three successive days. Then, MYR (10 mg/kg, i.p.) and pregabalin (PGB, 30 mg/kg, p.o.) were given daily for another five days. Behavioral changes were assessed through open field test (OFT), hot plate test, and forced swimming test (FST). Further analyses of different brain parameters and signaling pathways were performed to assess monoamines levels, oxidative stress, inflammatory response, apoptotic changes as well as silent information regulator 1 (SIRT1) and micro RNAs (miRNAs) expressions.

RESULTS

From High-Performance Liquid Chromatography (HPLC) analysis, the methanol extract of sapodilla leaves contains 166.17 μg/ml of MYR. Results of behavioral tests showed a significant improvement in RSP-induced nociceptive stimulation, reduced locomotion and exploration and depressive-like behavior by MYR. Biochemical analyses showed that MYR significantly ameliorated the RSP-induced imbalance in brain monoamine neurotransmitters. In addition, MYR significantly attenuated oxidative stress elicited by RSP via up-regulating nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) protein expressions, enhancing superoxide dismutase (SOD) and catalase (CAT) activities, and reducing malondialdehyde (MDA) content in brain. The RSP-provoked inflammatory response was also diminished by MYR treatment as shown by a significant decreased NOD-like receptor protein 3 (NLRP3) inflammasome expression along with reduced levels of interleukin 1 beta (IL-1β) and nuclear factor-κB (NF-κB). Furthermore, the anti-apoptotic activity of MYR was demonstrated by a marked rise in Bcl-2-associated X protein (BAX)/B cell lymphoma-2 (Bcl-2) ratio by lowering Bcl-2 while increasing BAX levels. In addition, MYR treatment significantly boosted the expression of SIRT1 deacetylase in RSP-treated animals. Interestingly, molecular docking showed the ability of MYR to form a stable complex in the binding site of SIRT1. Regarding miRNAs, MYR effectively ameliorated RSP-induced changes in miR-320 and miR-107 gene expressions.

CONCLUSION

Our findings afford new insights into the anti-nociceptive profile of MYR in the RSP-induced FM model in rats. The underlying mechanisms involved direct binding and activation of SIRT1 to influence different signaling cascades, including Nrf2 and NF-κB/NLRP3 together with modulation of miRNAs. However, more in-depth studies are needed before proposing MYR as a new clinically relevant drug in the management of FM.

Identifying microRNAs Possibly Implicated in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Fibromyalgia: A Review

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and fibromyalgia (FM) are chronic syndromes of unknown etiology, accompanied by numerous symptoms affecting neurological and physical conditions. Despite frequent revisions of the diagnostic criteria, clinical practice guidelines are often outdated, leading to underdiagnosis and ineffective treatment. Our aim was to identify microRNA (miRNA) biomarkers implicated in pathological mechanisms underlying these diseases. A comprehensive literature review using publicly accessible databases was conducted. Interesting miRNAs were extracted from relevant publications on ME/CFS and/or FM, and were then linked to pathophysiological processes possibly manifesting these chronic diseases. Dysregulated miRNAs in ME/CFS and FM may serve as promising biomarkers for these diseases. Key identified miRNAs, such as miR-29c, miR-99b, miR-128, miR-374b, and miR-766, were frequently mentioned for their roles in immune response, mitochondrial dysfunction, oxidative stress, and central sensitization, while miR-23a, miR-103, miR-152, and miR-320 were implicated in multiple crucial pathological processes for FM and/or ME/CFS. In summary, both ME/CFS and FM seem to share many dysregulated biological or molecular processes, which may contribute to their commonly shared symptoms. This miRNA-based approach offers new angles for discovering molecular markers urgently needed for early diagnosis or therapeutics to tackle the pathology of these medically unexplained chronic diseases.

Sarcopenia and the management of spinal disease in the elderly

Sarcopenia, generally defined by the loss of skeletal mass and function, may disproportionately affect elderly individuals and heavily influence spinal disease. Muscle atrophy is associated with myriad clinical problems, including thoracic kyphosis, increased sagittal vertical axis (SVA), spinal implant failures, and postoperative complications. As such, the aim of this narrative review is to synthesize pertinent literature detailing the intersection between sarcopenia and the impact of sarcopenia on the management of spine disease. Specifically, we focus on the domains of etiology, diagnosis and assessment, impact on the cervical and lumbar spine, spinal augmentation procedures, neoplastic disease, whiplash injury, and recovery/prevention. A narrative review was conducted by searching the PubMed and Google Scholar databases from inception to July 12, 2024, for any cohort studies, systematic reviews, or randomized controlled trials. Case studies and conference abstracts were excluded. Diagnosis of sarcopenia relies on the assessment of muscle strength and quantity/quality. Strength may be assessed using clinical tools such as gait speed, timed up and go (TUG) test, or hand grip strength, whereas muscle quantity/quality may be assessed via computed tomography (CT scan), magnetic resonance imaging (MRI), and dual-energy X-ray absorptiometry (DXA scan). Sarcopenia has a generally negative impact on the clinical course of those undergoing cervical and lumbar surgery, and may be predictive of mortality in those with neoplastic spinal disease. In addition, severe acceleration-deceleration (whiplash) injuries may result in cervical extensor muscle atrophy. Intervention and recovery measures include nutrition or exercise therapy, although the evidence for nutritional intervention is lacking. Sarcopenia is a widely prevalent pathology in the advanced-age population, in which the diagnostic criteria, impact on spinal pathology, and recovery/prevention measures remain understudied. However, further understanding of this therapeutically challenging pathology is paramount, as surgical outcome may be heavily influenced by sarcopenia status.

The Impact of Micro RNA-320a Serum Level on Severity of Symptoms and Cerebral Processing of Pain in Patients with Fibromyalgia

OBJECTIVES

The aim of this work was to explore the expression of miR-320a level in fibromyalgia patients in comparison to healthy controls, and to clarify its impact on the severity of symptoms and the cerebral processing of pain assessed by middle latency somatosensory evoked potentials (SSEPs).

DESIGN

Case-control study.

SETTING

Rheumatology and Neurology outpatient clinics.

SUBJECTS

Seventy-four fibromyalgia patients and seventy-four normal healthy controls.

METHODS

The included patients were subjected to detailed history taking, assessment of severity of fibromyalgia symptoms using the Fibromyalgia Impact Questionnaire Revised (FIQR), assessment of pain intensity using the Neuropathic Pain Symptom Inventory (NPSI), measurement of the serum level of miR-320a in addition to of measurement peak latencies and amplitudes of middle latency SSEPs.

RESULTS

Fibromyalgia patients had significantly higher micro-RNA-320a levels (0.907 ± 0.022) in comparison to controls (0.874 ± 0.015) (P-value < .001). The mean values of micro-RNA-320a levels were significantly higher in fibromyalgia patients with insomnia, chronic fatigue syndrome, persistent depressive disorder, and primary headache disorder than those without (P-value = .024, <.001, .006, .036 respectively). There were statistically significant positive correlations between micro-RNA-320a levels, and disease duration, FIQR, and NPSI total scores (P-value <0.001, 0.003, 0.002 respectively). There were no statistically significant correlations between micro-RNA-320a levels and middle latency SSEPs.

DISCUSSION

Micro-RNA-320a level is significantly upregulated in fibromyalgia patient. It has a crucial impact on the severity of symptoms but not related to the cerebral processing of pain.

Expression and Biological Functions of miRNAs in Chronic Pain: A Review on Human Studies

Chronic pain is a major public health problem and an economic burden worldwide. However, its underlying pathological mechanisms remain unclear. MicroRNAs (miRNAs) are a class of small noncoding RNAs that post-transcriptionally regulate gene expression and serve key roles in physiological and pathological processes. This review aims to synthesize the human studies examining miRNA expression in the pathogenesis of chronic primary pain and chronic secondary pain. Additionally, to understand the potential pathophysiological impact of miRNAs in these conditions, an in silico analysis was performed to reveal the target genes and pathways involved in primary and secondary pain and their differential regulation in the different types of chronic pain. The findings, methodological issues and challenges of miRNA research in the pathophysiology of chronic pain are discussed. The available evidence suggests the potential role of miRNA in disease pathogenesis and possibly the pain process, eventually enabling this role to be exploited for pain monitoring and management.

MicroRNA 320a and Membrane Antigens as Tools to Evaluate the Pathophysiology of Platelets Stored in Blood Banks

Our research group, through the analysis of miRNomes in platelet concentrates (PCs) stored in blood banks, identified and validated the miR-127 and miR-320a miRNAs as biomarkers of platelet storage lesions (PSLs) in PCs. In order to validate the miRNAs 127 and 320a methodologically, as PSL biomarkers in a large number of PC bags, we also evaluated important immunological markers involved in the platelet activation/aggregation process—the CD62P receptor (P-selectin), the surface glycoproteins (GP) IIb/IIIa, and the purinergic P2Y12 receptor—via flow cytometry. The miRNAs miR-127 and miR-320a were quantified by real-time quantitative PCR (RT-qPCR). To carry out this study, 500 collection tubes were used at the upper edge of the PC bags containing platelets. Each tube was divided into seven equal parts (totaling 3500 samples) for platelet analysis from 7 different storage days, where the 1st day represents the high-quality control, and the 7th day corresponds to the low-quality control of the platelets. After analyzing all parameters during storage days, it was concluded that the relative quantification of miR-320a below 0.50 and the CD62P receptor below 27.92% are reliable indicators of the absence of storage lesions in blood banks. We believe that the values found in the expression of the CD62P receptor legitimize the use of the miR-320a and miR-127 miRNAs to build a kit capable of accurately measuring whether the stored platelets are suitable for transfusion.

Pain is common after sexual assault and posttraumatic arousal/reactivity symptoms mediate the development of new or worsening persistent pain

ABSTRACT

Clinically significant new or worsening pain (CSNWP) is a common, yet often overlooked, sequelae of sexual assault. Little is known regarding factors influencing the development of CSNWP in sexual assault survivors. The current study used data from a recently completed prospective study to evaluate whether posttraumatic alterations in arousal and reactivity in the early aftermath of sexual assault influence the transition from acute to clinically significant new or worsening persistent pain. Women ≥ 18 years of age (n = 706) presenting for emergency care after sexual assault to 13 emergency care sites were enrolled in the study. Women completed assessments at the time of presentation as well as at 1 week (n = 706, 100%) and 6 weeks (n = 630, 91%). Nearly 70% of women reported CSNWP at the time of emergency care (n = 475, 69%), which persisted to 6 weeks in approximately 2 in 5 survivors (n = 248, 41%). A structural equation model adjusted for age, race, past trauma exposure, and preassault pain levels suggested that posttraumatic alterations in arousal/reactivity symptoms 1 week after assault partially mediated the transition from acute to persistent CSNWP. A significant portion (41%) of women sexual assault survivors develop CSNWP 6 weeks postassault. Posttraumatic arousal/reactivity symptoms in the early aftermath of assault contribute to CSNWP development; such symptoms are potential targets for secondary preventive interventions to reduce chronic postassault pain.

Expression of Selected microRNAs in Migraine: A New Class of Possible Biomarkers of Disease?

Preliminary but convergent findings suggest a role for microRNAs (miRNAs) in the generation and maintenance of chronic pain and migraine. Initial observations showed that serum levels of miR-382-5p and miR-34a-5p expression were increased in serum during the migraine attack, with miR-382-5p increasing in the interictal phase as well. By contrast, miR-30a-5p levels were lower in migraine patients compared to healthy controls. Of note, antimigraine treatments proved to be capable of influencing the expression of these miRNAs. Altogether, these observations suggest that miRNAs may represent migraine biomarkers, but several points are yet to be elucidated. A major concern is that these miRNAs are altered in a broad spectrum of painful and non-painful conditions, and thus it is not possible to consider them as truly “migraine-specific” biomarkers. We feel that these miRNAs may represent useful tools to uncover and define different phenotypes across the migraine spectrum with different treatment susceptibilities and clinical features, although further studies are needed to confirm our hypothesis. In this narrative review we provide an update and a critical analysis of available data on miRNAs and migraines in order to propose possible interpretations. Our main objective is to stimulate research in an area that holds promise when it comes to providing reliable biomarkers for theoretical and practical scientific advances.

Detection of Sepsis in Platelets Using MicroRNAs and Membrane Antigens

The present study proposes to legitimize in sepsis a characteristic found in platelets that suffer storage lesions in blood banks, which is the increased expression of miRNA miR-320a in relation to miR-127. Under physiologically normal conditions, an inverse relationship is observed. The aim of this study was to verify whether the analysis of miR-320a and miR-127 expression in platelets could detect a decrease in their viability and function due to the presence of pathogens in the blood of patients hospitalized in the Intensive Care Unit. We also investigated the expression of membrane antigens sensitive to platelet activation. Of the 200 patients analyzed, only those who developed sepsis (140) were found to have a higher relative quantity of miR-320a than that of miR-127. This characteristic and the increased expression of membrane antigens P2Y12, CD62P, CD41, and CD61 showed a significant association (p < 0.01) with all types of sepsis evaluated in this study. Additionally, 40% of patients hospitalized for sepsis had negative results for the first cultures. We conclude that analysis of miR-127 and miR-320a expression combined with membrane antigens evaluation, in association with the available clinical and diagnostic parameters, are important tools to detect the onset of sepsis.

microRNA let-7i-5p mediates the relationship between muscle fat infiltration and neck pain disability following motor vehicle collision: a preliminary study

Persistent neck-pain disability (PNPD) is common following traumatic stress exposures such as motor vehicle collision (MVC). Substantial literature indicates that fat infiltration into neck muscle (MFI) is associated with post-MVC PNPD. However, little is known about the molecular mediators underlying this association. In the current study, we assessed whether microRNA expression signatures predict PNPD and whether microRNA mediate the relationship between neck MFI and PNPD. A nested cohort of 43 individuals from a longitudinal study of MVC survivors, who provided blood (PAXgene RNA) and underwent magnetic resonance imaging (MRI), were included in the current study. Peritraumatic microRNA expression levels were quantified via small RNA sequencing, neck MFI via MRI, and PNPD via the Neck Disability Index two-weeks, three-months, and twelve-months following MVC. Repeated measures regression models were used to assess the relationship between microRNA and PNPD and to perform mediation analyses. Seventeen microRNA predicted PNPD following MVC. One microRNA, let-7i-5p, mediated the relationship between neck MFI and PNPD. Peritraumatic blood-based microRNA expression levels predict PNPD following MVC and let-7i-5p might contribute to the underlying effects of neck MFI on persistent disability. In conclusion, additional studies are needed to validate this finding.

MicroRNA profiling of the pig periaqueductal grey (PAG) region reveals candidates potentially related to sex-dependent differences

Background

MicroRNAs indirectly orchestrate myriads of essential biological processes. A wide diversity of miRNAs of the neurodevelopmental importance characterizes the brain tissue, which, however, exhibits region-specific miRNA profile differences. One of the most conservative regions of the brain is periaqueductal grey (PAG) playing vital roles in significant functions of this organ, also those observed to be sex-influenced. The domestic pig is an important livestock species but is also believed to be an excellent human model. This is of particular importance for neurological research because of the similarity of pig and human brains as well as difficult access to human samples. However, the pig PAG profile has not been characterized so far. Moreover, molecular bases of sex differences connected with brain functioning, including miRNA expression profiles, have not been fully deciphered yet.

Methods

Thus, in this study, we applied next-generation sequencing to characterize pig PAG expressed microRNAs. Furthermore, we performed differential expression analysis between females and males to identify changes of the miRNA profile and reveal candidates underlying sex-related differences.

Results

As a result, known brain-enriched, and new miRNAs which will expand the available profile, were identified. The downstream analysis revealed 38 miRNAs being differentially expressed (DE) between female and male samples. Subsequent pathway analysis showed that they enrich processes vital for neuron growth and functioning, such as long-term depression and axon guidance. Among the identified sex-influenced miRNAs were also those associated with the PAG physiology and diseases related to this region.

Conclusions

The obtained results broaden the knowledge on the porcine PAG miRNAome, along with its dynamism reflected in different isomiR signatures. Moreover, they indicate possible mechanisms associated with sex-influenced differences mediated via miRNAs in the PAG functioning. They also provide candidate miRNAs for further research concerning, i.e., sex-related bases of physiological and pathological processes occurring in the nervous system.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13293-020-00343-2.

Vitamin D insufficiency increases risk of chronic pain among African Americans experiencing motor vehicle collision

African Americans experience an increased burden of motor vehicle collision (MVC), post-MVC musculoskeletal pain, and vitamin D insufficiency. In this prospective multicenter study, we tested the hypothesis that African Americans (n = 133) presenting to the emergency department after MVC with low peritraumatic vitamin D levels would have worse chronic musculoskeletal pain outcomes compared to individuals with sufficient vitamin D. Vitamin D levels were assessed in the early aftermath of MVC through enzyme-linked immunosorbent assay, and pain severity was assessed using the 0 to 10 numeric rating scale at 6 weeks, 6 months, and 1 year. In repeated-measures analysis, African American MVC survivors with vitamin D insufficiency experienced more severe chronic pain (β = 1.18, P = 0.031). In secondary analyses, we assessed for evidence that the effect of vitamin D on post-MVC pain outcomes is mediated, at least in part, by the influence of vitamin D on genetic variants in genes involved in immune system regulation (IL-10 and NLRP3). Genotyping was performed using a genome-wide microarray using collected DNA samples. Secondary analyses suggest that the effect of vitamin D on post-MVC pain outcomes may be influenced by genetic variation in IL-10 and NLRP3. Further studies are needed to assess the impact of vitamin D insufficiency on pain outcomes in African Americans experiencing MVC and other common trauma exposures, to assess factors affecting this relationship, and to assess the efficacy of administering vitamin D in the immediate aftermath of MVC to prevent chronic pain. Such low-cost, nonopioid interventions are urgently needed to address chronic pain development after MVC.

The relation between local and distal muscle fat infiltration in chronic whiplash using magnetic resonance imaging

The objective of this study was to investigate the relationship between fat infiltration in the cervical multifidi and fat infiltration measured in the lower extremities to move further into understanding the complex signs and symptoms arising from a whiplash trauma. Thirty-one individuals with chronic whiplash associated disorders, stratified into a mild/moderate group and a severe group, together with 31 age- and gender matched controls were enrolled in this study. Magnetic resonance imaging was used to acquire a 3D volume of the neck and of the whole-body. Cervical multifidi was used to represent muscles local to the whiplash trauma and all muscles below the hip joint, the lower extremities, were representing widespread muscles distal to the site of the trauma. The fat infiltration was determined by fat fraction in the segmented images. There was a linear correlation between local and distal muscle fat infiltration (p<0.001, r² = 0.28). The correlation remained significant when adjusting for age and WAD group (p = 0.009) as well as when correcting for age, WAD group and BMI (p = 0.002). There was a correlation between local and distal muscle fat infiltration within the severe WAD group (p = 0.0016, r² = 0.69) and in the healthy group (p = 0.022, r² = 0.17) but not in the mild/moderate group (p = 0.29, r² = 0.06). No significant differences (p = 0.11) in the lower extremities’ MFI between the different groups were found. The absence of differences between the groups in terms of lower extremities’ muscle fat infiltration indicates that, in this particular population, the whiplash trauma has a local effect on muscle fat infiltration rather than a generalized.

Cutting to the Pathophysiology Chase: Translating Cutting-Edge Neuroscience to Rehabilitation Practice in Sports-Related Concussion Management

Mild traumatic brain injury, or concussion, is a common sports injury. Concussion involves physical injury to brain tissue and vascular and axonal damage that manifests as transient and often nonspecific clinical symptoms. Concussion diagnosis is challenging, and the relationship between brain injury and clinical symptoms is unclear. The purpose of this commentary was to translate cutting-edge neuroscience to rehabilitation practice. We (1) highlight potential biomarkers that may improve our understanding of concussion and its recovery, (2) explain why researchers must address the paucity of concussion research in female athletes, and (3) present female-specific factors that should be accounted for in future studies. Integrating objective, quantitative measures of concussion pathophysiology with concussion history, genetics, and genomics will help caregivers identify concussed athletes, tailor recovery protocols, and protect athletes from potential long-term effects of cumulative head impact. J Orthop Sports Phys Ther 2019;49(11):811-818. Epub 1 Jun 2019. doi:10.2519/jospt.2019.8884.

Whiplash-Associated Dysphagia: Considerations of Potential Incidence and Mechanisms

Non-specific self-reports of dysphagia have been described in people with whiplash-associated disorders (WAD) following motor vehicle collision (MVC); however, incidence and mechanistic drivers remain poorly understood. Alterations in oropharyngeal dimensions on magnetic resonance imaging (MRI), along with heightened levels of stress, pain, and changes in stress-dependent microRNA expression (e.g., miR-320a) have been also associated with WAD, suggesting multi-factorial issues may underpin any potential swallowing changes. In this exploratory paper, we examine key biopsychosocial parameters in three patients with persistent WAD reporting swallowing change and three nominating full recovery after whiplash with no reported swallowing change. Parameters included (1) oropharyngeal volume with 3D MRI, (2) peritraumatic miR-320a expression, and (3) psychological distress. These factors were explored to highlight the complexity of patient presentation and propose future considerations in relation to a potential deglutition disorder following WAD. The three participants reporting changes in swallowing all had smaller oropharyngeal volumes at < 1 week and at 3 months post injury and lower levels of peritraumatic miR-320a. At 3 months post MVC, oropharyngeal volumes between groups indicated a large effect size (Hedge's g = 0.96). Higher levels of distress were reported at both time points for those with persistent symptomatology, including self-reported dysphagia, however, this was not featured in those nominating recovery. This paper considers current evidence for dysphagia as a potentially under-recognized feature of WAD and highlights the need for future, larger-scaled, multidimensional investigation into the incidence and mechanisms of whiplash-associated dysphagia.

Differences in the miRNA signatures of chronic musculoskeletal pain patients from neuropathic or nociceptive origins

BACKGROUND

The quality of life for millions of people worldwide is affected by chronic pain. In addition to the effect of chronic pain on well-being, chronic pain has also been associated with poor health conditions and increased mortality. Due to its multifactorial origin, the classification of pain types remains challenging. MicroRNAs (miRNA) are small molecules that regulate gene expression. They are released into the bloodstream in a stable manner under normal and pathological conditions and have been described as potential biomarkers. In the present study, we aimed to investigate whether pain may induce an aberrant, specific dysregulation of miRNA expression, depending on the origin of the pain.

METHODS AND FINDINGS

To do so, we measured the expression changes of 184 circulating miRNAs (c-miRNAs) in the plasma samples of patients with different origins of chronic musculoskeletal pain. After statistical analyses, we identified seven c-miRNA candidates that were differentially expressed depending on the nociceptive or neuropathic origin of the pain. We then developed a two c-miRNA signature (hsa-miR-320a and hsa-miR-98-5p) that was able to correctly classify the pain type of 70% of the patients from the validation set.

CONCLUSIONS

In conclusion, circulating miRNAs are promising biomarkers to identify and characterize the chronic pain type and to further improve its clinical management.

Are Magnetic Resonance Imaging Technologies Crucial to Our Understanding of Spinal Conditions?

Persistent spinal (traumatic and nontraumatic) pain is common and contributes to high societal and personal costs globally. There is an acknowledged urgency for new and interdisciplinary approaches to the condition, and soft tissues, including skeletal muscles, the spinal cord, and the brain, are rightly receiving increased attention as important biological contributors. In reaction to the recent suspicion and questioned value of imaging-based findings, this paper serves to recognize the promise that the technological evolution of imaging techniques, and particularly magnetic resonance imaging, is allowing in characterizing previously less visible morphology. We emphasize the value of quantification and data analysis of several contributors in the biopsychosocial model for understanding spinal pain. Further, we highlight emerging evidence regarding the pathobiology of changes to muscle composition (eg, atrophy, fatty infiltration), as well as advancements in neuroimaging and musculoskeletal imaging techniques (eg, fat-water imaging, functional magnetic resonance imaging, diffusion imaging, magnetization transfer imaging) for these important soft tissues. These noninvasive and objective data sources may complement known prognostic factors of poor recovery, patient self-report, diagnostic tests, and the "-omics" fields. When combined, advanced "big-data" analyses may assist in identifying associations previously not considered. Our clinical commentary is supported by empirical findings that may orient future efforts toward collaborative conversation, hypothesis generation, interdisciplinary research, and translation across a number of health fields. Our emphasis is that magnetic resonance imaging technologies and research are crucial to the advancement of our understanding of the complexities of spinal conditions. J Orthop Sports Phys Ther 2019;49(5):320-329. Epub 26 Mar 2019. doi:10.2519/jospt.2019.8793.

A Functional riboSNitch in the 3' Untranslated Region of FKBP5 Alters MicroRNA-320a Binding Efficiency and Mediates Vulnerability to Chronic Post-Traumatic Pain

Previous studies have shown that common variants of the gene coding for FK506-binding protein 51 (FKBP5), a critical regulator of glucocorticoid sensitivity, affect vulnerability to stress-related disorders. In a previous report, FKBP5 rs1360780 was identified as a functional variant because of its effect on gene methylation. Here we report evidence for a novel functional FKBP5 allele, rs3800373. This study assessed the association between rs3800373 and post-traumatic chronic pain in 1607 women and men from two ethnically diverse human cohorts. The molecular mechanism through which rs3800373 affects adverse outcomes was established via in silico, in vivo, and in vitro analyses. The rs3800373 minor allele predicted worse adverse outcomes after trauma exposure, such that individuals with the minor (risk) allele developed more severe post-traumatic chronic musculoskeletal pain. Among these individuals, peritraumatic circulating FKBP5 expression levels increased as cortisol and glucocorticoid receptor (NR3C1) mRNA levels increased, consistent with increased glucocorticoid resistance. Bioinformatic, in vitro, and mutational analyses indicate that the rs3800373 minor allele reduces the binding of a stress- and pain-associated microRNA, miR-320a, to FKBP5 via altering the FKBP5 mRNA 3'UTR secondary structure (i.e., is a riboSNitch). This results in relatively greater FKBP5 translation, unchecked by miR-320a. Overall, these results identify an important gene-miRNA interaction influencing chronic pain risk in vulnerable individuals and suggest that exogenous methods to achieve targeted reduction in poststress FKBP5 mRNA expression may constitute useful therapeutic strategies.SIGNIFICANCE STATEMENT FKBP5 is a critical regulator of the stress response. Previous studies have shown that dysregulation of the expression of this gene plays a role in the pathogenesis of chronic pain development as well as a number of comorbid neuropsychiatric disorders. In the current study, we identified a functional allele (rs3800373) in the 3'UTR of FKBP5 that influences vulnerability to chronic post-traumatic pain in two ethnic cohorts. Using multiple complementary experimental approaches, we show that the FKBP5 rs3800373 minor allele alters the secondary structure of FKBP5 mRNA, decreasing the binding of a stress- and pain-associated microRNA, miR-320a. This results in relatively greater FKBP5 translation, unchecked by miR-320a, increasing glucocorticoid resistance and increasing vulnerability to post-traumatic pain.

How Do We Meet the Challenge of Whiplash?

A previous special issue of JOSPT (October 2016) discussed whiplash in terms of the clinical problems and current research surrounding prevention, biomechanics of injury, emergent care, imaging advancements, recovery pathways and prognosis, pathogenesis of posttrauma pain, acute and chronic management, and new predictive clinical tools. While great strides have been made in the field of whiplash and are continuing in earnest, a key group of clinicians and academics have recognized that inconsistent outcomes in published literature hamper our ability to meaningfully synthesize research findings, leading to results of systematic reviews that provide very few concrete clinical recommendations. We are optimistic that improved outcomes for people with whiplash-associated disorder (WAD) are attainable in the near future, as interdisciplinary research efforts continue to align internationally, new mechanisms are identified and explored, and advanced statistical techniques allow complex questions to be answered in clinically meaningful ways. J Orthop Sports Phys Ther 2017;47(7):444-446. doi:10.2519/jospt.2017.0106.

An Integrated Model of Chronic Whiplash-Associated Disorder

Synopsis The development of persistent symptoms following whiplash injury from a motor vehicle collision is common and contributes substantially to societal and personal costs. The popular Quebec Task Force classification system of whiplash-associated disorders (WADs) was meant to function as a prognostic and intervention decision aid, but its usefulness has been questioned. Emerging evidence highlights the heterogeneity of WAD by demonstrating physical and psychological impairments that are unique to those who develop persistent symptoms. These impairments are not recognized in the Quebec Task Force classification system. The purpose of this clinical commentary is to describe an integrated model that focuses on how psychological and neurobiological factors interact with, and are influenced by, existing personal and environmental factors to contribute to the development of chronic WAD. The model has been developed through more than 20 years of work in the field, consultation with experts, in-depth synthesis of existing evidence, and new evidence from the authors' own research programs. A subtheme is that a point of convergence currently exists between the psychological, physiological, and social determinants of health literature that can further explain the complex presentation of WAD. The new model is proposed to orient future research toward more interdisciplinary efforts across nontraditional fields, including data scientists and consumers, to clarify the WAD condition. J Orthop Sports Phys Ther 2017;47(7):462-471. Epub 16 Jun 2017. doi:10.2519/jospt.2017.7455.

Whiplash Continues Its Challenge

There have been many advances in the management of neck pain disorders, but a personal frustration as a clinician and researcher in the field is that the incidence of full recovery following a whiplash injury as a result of a motor vehicle crash has not increased and, subsequently, the rate of transition to chronic neck pain has not lessened. The commentaries in this special issue reflect the multifaceted nature of whiplash-associated disorders and the wide-ranging research in the field. While management of whiplash, especially the challenge of lessening the rate of transition to chronicity, has yet to be achieved, the picture is becoming clearer. This should give great confidence and some hope to individuals with whiplash-associated disorders who have long-term pain and functional disability that after the next decade of research and clinical development, the outcomes following whiplash are likely to be vastly improved. J Orthop Sports Phys Ther 2016;46(10):815-817. doi:10.2519/jospt.2016.0112.