Chronic Muscle Inflammation Research Articles

Nutritional interventions as modulators of the disease activity for idiopathic inflammatory myopathies: a scoping review.

Idiopathic inflammatory myopathies (IIMs) are chronic, autoimmune connective tissue diseases associated with significant morbidity and disability. Nutrients can activate the immune system and contribute to chronic low-grade inflammation (LGI). Chronic muscle inflammation leads to imbalanced pro-inflammatory and anti-inflammatory cytokines, causing inadequate nutrition, weight loss and muscle weakness during a negative cycle. Owing to its potential to modulate LGI in various diseases, the Mediterranean diet (Med Diet) has been extensively studied. This scoping review explores the nutritional implications and recommendations of the Med Diet as a treatment for immune-mediated diseases, focusing on the gaps in IIM nutritional interventions. A comprehensive literature search of the MEDLINE and EBSCO databases between September 2018 and December 2022 was performed. We identified that the Med Diet and its specific components, such as omega-3 (nω3) fatty acids, vitamin D and antioxidants, play a role in the dietary treatment of connective tissue-related autoimmune diseases. Nutritional interventions have demonstrated potential for modulating disease activity and warrant further exploration of IIMs through experimental studies. This review introduces a dietary therapeutic approach using the Med Diet and related compounds to regulate chronic inflammatory processes in IIMs. However, further clinical studies are required to evaluate the efficacy of the Med Diet in patients with IIMs. Emphasising a clinical-nutritional approach, this study encourages future research on the anti-inflammatory effects of the Med Diet on IIMs. This review highlights potential insights for managing and treating these conditions using a holistic approach.

Electromyography varies by stage in inclusion body myositis.

Inclusion body myositis (IBM) is a chronic inflammatory muscle disease that is characterized by mixed myogenic and neurogenic electromyography (EMG) findings. We investigated the association between EMG findings and the IBM stage. We included consecutive patients diagnosed with IBM based on muscle biopsy and had needle EMG performed within 1 month of biopsy. Motor unit potential waveform (MUP) in EMG and pathological findings were compared between patients in early and late phases. In total, 30 patients with biopsy-confirmed IBM and 254 muscles were included. The rate of abnormal discharge did not differ according to disease stage. There was a difference in the frequency of occurrence between myogenic suggestive MUP and neurogenic of biceps and flexor digitorum profundus in the late phase. Abnormal MUP was observed even in muscles without muscle weakness, and myogenic changes were predominant in biceps and gastrocnemius with muscle weakness. The biopsy findings on the contralateral side of the muscle where electromyography was performed revealed a tendency for muscles that exhibited myogenic origin to have more inflammatory cells and RV; however, the difference was not significant. The target muscles for EMG must be selected considering the disease stage as well. In the early stages of IBM, EMG results should be interpreted cautiously, as neurogenic suggestive pattern of MUP might also be exhibited. Contralateral electromyography findings may be helpful in selecting muscles for muscle biopsies, such as biceps and quadriceps.

Electrical impedance myography detects dystrophin-related muscle changes in mdx mice

BackgroundThe lack of functional dystrophin protein in Duchenne muscular dystrophy (DMD) causes chronic skeletal muscle inflammation and degeneration. Therefore, the restoration of functional dystrophin levels is a fundamental approach for DMD therapy. Electrical impedance myography (EIM) is an emerging tool that provides noninvasive monitoring of muscle conditions and has been suggested as a treatment response biomarker in diverse indications. Although magnetic resonance imaging (MRI) of skeletal muscles has become a standard measurement in clinical trials for DMD, EIM offers distinct advantages, such as portability, user-friendliness, and reduced cost, allowing for remote monitoring of disease progression or response to therapy. To investigate the potential of EIM as a biomarker for DMD, we compared longitudinal EIM data with MRI/histopathological data from an X-linked muscular dystrophy (mdx) mouse model of DMD. In addition, we investigated whether EIM could detect dystrophin-related changes in muscles using antisense-mediated exon skipping in mdx mice.MethodsThe MRI data for muscle T2, the magnetic resonance spectroscopy (MRS) data for fat fraction, and three EIM parameters with histopathology were longitudinally obtained from the hindlimb muscles of wild-type (WT) and mdx mice. In the EIM study, a cell-penetrating peptide (Pip9b2) conjugated antisense phosphorodiamidate morpholino oligomer (PPMO), designed to induce exon-skipping and restore functional dystrophin production, was administered intravenously to mdx mice.ResultsMRI imaging in mdx mice showed higher T2 intensity at 6 weeks of age in hindlimb muscles compared to WT mice, which decreased at ≥ 9 weeks of age. In contrast, EIM reactance began to decline at 12 weeks of age, with peak reduction at 18 weeks of age in mdx mice. This decline was associated with myofiber atrophy and connective tissue infiltration in the skeletal muscles. Repeated dosing of PPMO (10 mg/kg, 4 times every 2 weeks) in mdx mice led to an increase in muscular dystrophin protein and reversed the decrease in EIM reactance.ConclusionsThese findings suggest that muscle T2 MRI is sensitive to the early inflammatory response associated with dystrophin deficiency, whereas EIM provides a valuable biomarker for the noninvasive monitoring of subsequent changes in skeletal muscle composition. Furthermore, EIM reactance has the potential to monitor dystrophin-deficient muscle abnormalities and their recovery in response to antisense-mediated exon skipping.

Severe myopathy in a patient with chronic neurological disease – diagnostic challenges

Polymyositis is a rare disease that belongs to the idiopathic inflammatory myopathies (IIMs) group, characterized by chronic muscle inflammation, and in rare cases a life-threatening condition due to extra-muscular involvement. Even though steroids constitute the building block of treatment of this disease, in severe cases, escalation treatment should be considered in order to obtain good clinical outcomes. We report a clinical case of a 22-year-old female who developed progressive severe systemic muscular weakness, dysphagia and dysphonia, accompanied by elevated serum muscle enzymes, positive myositis-specific antibodies, and muscle biopsy suggestive of inflammatory myopathy. The clinical features and laboratory results led us to the diagnosis of polymyositis. On additional laboratory tests the patient tested positive for Borrelia burgdorferi (Borrelia b) specific antibodies. Due to life-threatening organ involvement the immunosuppressive treatment, immunoglobulin intravenous infusion and pulse therapy with methylprednisolone were initiated and she needed nasogastric tube in order to be fed. Furthermore antibiotic treatment was administrated. The patient improved almost completely after 3 months of treatment.

Myositis Multidisciplinary Clinic in a Tertiary Referral Center.

Idiopathic inflammatory myopathies (IIM) are a rare heterogeneous group of diseases characterised by chronic skeletal muscle inflammation, but other organs are also frequently involved. IMM represent a diagnostic challenge and a multidisciplinary approach is important to ensure successful diagnosis and adequate follow-up of these patients. To describe the general functioning of our multidisciplinary myositis clinic, highlighting the benefits of multidisciplinary team management in patients with confirmed or suspected IIM and to characterise our clinical experience. Description of the organization of a dedicated multidisciplinary myositis outpatient clinic, supported by IMM specific electronic assessment tools and protocols based on our Portuguese Register - Reuma.pt. In addition, an overview of our activity between 2017 and 2022 is provided. An IIM multidisciplinary care clinic, based on a close collaboration between Rheumatologists, Dermatologists and Physiatrist is detailed in this paper. One hundred and eighty-five patients were assessed in our myositis clinic; 138 (75%) of those were female, with a median age of 58 [45-70] years. At the last appointment, 130 patients had a confirmed IIM diagnosis, and the mean disease duration was 4 [2-6] years. The most frequent diagnosis was dermatomyositis (n = 34, 26.2%), followed by antisynthetase syndrome (n = 27, 20.8%) and clinically amyopathic/paucimyopathic dermatomyositis (n = 18, 13.8%). Twenty-four patients (18.5%) were on monotherapy and 94 (72.3%) were on combination therapy. A multidisciplinary approach is important to ensure the correct diagnosis and follow-up of these patients. A myositis clinic, with a standardised practice at a tertiary hospital level, contributes to a standardization of care and opens research opportunities.

TRIM72 Alleviates Muscle Inflammation in mdx Mice via Promoting Mitophagy-Mediated NLRP3 Inflammasome Inactivation.

Chronic muscle inflammation exacerbates the pathogenesis of Duchenne muscular dystrophy (DMD), which is characterized by progressive muscle degeneration and weakness. NLRP3 (nucleotide-binding domain and leucine-rich repeat pyrin domain containing 3) inflammasome plays a key role in the inflammatory process, and its abnormal activation leads to a variety of inflammatory or immune diseases. TRIM72 (MG53) is a protective myokine for tissue repair and regeneration. However, little is known about the potential impact of TRIM72 in the crosstalk between mitophagy and inflammatory process of DMD. Here, 10-week-old male mdx mice were injected intramuscularly with adeno-associated virus (AAV-TRIM72) to overexpress TRIM72 protein for 6 weeks. Then, skeletal muscle samples were collected, and relevant parameters were measured by histopathological analysis and molecular biology techniques. C2C12 cell line was transfected with lentivirus (LV-TRIM72) to overexpress or siRNA (si-TRIM72) to suppress the TRIM72 expression for the following experiment. Our data firstly showed that the TRIM72 expression was decreased in skeletal muscles of mdx mice. Then, we observed the increased NLRP3 inflammasome and impaired mitophagy in mdx mice compared with wild type mice. In mdx mice, administration of AAV-TRIM72 alleviated the accumulation of NLRP3 inflammasome and the consequent IL-18 and IL1β maturation by inducing autophagy, while this protective effect was reversed by chloroquine. Mitochondrial reactive oxygen species (mtROS), as a recognized activator for NLRP3 inflammasome, was attenuated by TRIM72 through the induction of mitophagy in C2C12 cells. Additionally, we proposed that the TRIM72 overexpression might promote mitophagy through both the early stage by PI3K-AKT pathway and the late stage by autolysosome fusion. In conclusion, the current study suggests that TRIM72 prevents DMD inflammation via decreasing NLRP3 inflammasomes and enhancing mitophagy. Collectively, our study provides insight into TRIM72 as a promising target for therapeutic intervention for DMD.

Changes of c-Fos expression and NADPH-d activity in claustrum induced by chronic muscle inflammation in cat (a preliminary study)

An investigation of the central mechanisms underlying muscle inflammation and musculoskeletal pain is an important step to find means for the prevention or treatment of muscle inflammation. One of the insufficiently studied brain structures involved in the transmission of nociceptive information is the claustrum (CL). Therefore, the aim of the study was to reveal changes in the patterns of Fos-immunoreactivity and NADPH-diaphoreactivity in the nucleus claustrum (CL) and additionally in the ventral putamen (Pu) during chronic inflammation of m. gastrocnemius-soleus in cat, induced by intramuscular injection of complete Freund’s adjuvant (CFA). Immunohistochemical and histochemical techniques were used to detect Fos-immunoreactive (Fos-ir) and NADPH-diaphorase reactive (NADPH-dr) neurons within studied structures. It was revealed that nine days after CFA-induced muscle inflammation the level of Fos-immunoreactivity and NADPH-d reactivity within the CL and in the ventral part of Pu increased two-fold in comparison with the control. Because the CL is reciprocally connected with many structures of the brain cortex and subcortical structures, all these structures can be pathways of transmission of nociceptive information, nevertheless, it can be assume that the central amygdala nucleus may make the main nociceptive contribution to the activation of neurons within the CL. It is known that CL is mutually related to Pu, but it was not possible to assess their mutual influence in this study. The results of the study of the Fos-ir neurons distribution in CL and Pu under conditions of long-term muscles inflammation indicate the active involvement of the mentioned structures in the formation of adaptive reactions. The increase in the number of neurons with NADPH-d reactivity in CL and Pu indicates that NO-signals play a significant role in the formation and amplification of the response to painful impulses from inflamed muscles. In addition, further research is needed to accurately identify all possible nociceptive inputs to the CL and to separate the emotional, motor, auditory, and visual components that may accompany nociceptive processes.

990 IMMUNE-MEDIATED NECROTIZING MYOPATHY IN A PATIENT WITH MULTI-VESSEL CORONARY ARTERY DISEASE

Abstract Inflammatory muscle diseases (often referred to as “inflammatory myopathies” or “myositis”) are a group of muscle diseases characterized by chronic muscle inflammation, inflammation of tissues associated with the muscles, muscle weakness and occasionally muscle pain (depending on the specific case). Ischemic heart disease is the leading cause of cardiovascular mortality in Western countries; the underlying cause is coronary atherosclerosis, a multifactorial disease determined by the concomitant presence of classic cardiovascular risk factors and inflammation of the vessel wall. We present the case of a 60 y/o man who previously underwent CABG (LIMA for ADA e GSV for OM1) for multi-vessel CAD and then developed immune-mediated necrotizing myopathy (probably due to statin treatment) with muscle weakness and pain and with elevation of myolysis markers: in this context, he also presented a recurrence of chest pain with troponin elevation, so that it was needed the integration of functional imaging from myocardial scintigraphy and from cardiac magnetic resonance to understand that troponin elevation (and the chest pain) were due to ischemia and not to muscle damage. This case report underlines how a critical approach to imaging and a deep knowledge of pathophysiology is mandatory in cardiovascular medicine.

Role of Exosomal miR-223 in Chronic Skeletal Muscle Inflammation.

As skeletal muscle is one of the largest organs in the body, its damage can directly reflect a decline in somatic function, thus, further affecting daily life and health. Inflammation is a prerequisite for the repair of injured skeletal muscles. Chronic inflammation induced by inadequate repair in skeletal muscle aggravates tissue injury. Exosomes regulate inflammatory responses to facilitate the repair of skeletal muscle injury. Moreover, exosomal miR‐223 with high specificity is the most abundant miRNA in peripheral blood and regarded as biomarkers for inflammation post skeletal muscle injury, which warrants further investigation. Available studies have demonstrated that exosomal miR‐223 negatively correlates with TNF‐α levels in serum and regulates the canonical inflammatory NF‐κB signaling pathway. miR‐223 is a negative feedback regulator with great potential for adjusting inflammatory imbalance and promoting skeletal muscle repair. The research on the regulation of negative feedback factors in the inflammatory signaling pathway is essential in biology and medicine. Therefore, this review mainly elaborates the formation, heterogeneity and markers of exosomes and points out exosomal miR‐223 as a beneficial role in chronic skeletal muscle inflammation and can be expected to be a potential therapeutic target for skeletal muscle damage.

Inhibition of PKCθ Improves Dystrophic Heart Phenotype and Function in a Novel Model of DMD Cardiomyopathy.

Chronic cardiac muscle inflammation and subsequent fibrotic tissue deposition are key features in Duchenne Muscular Dystrophy (DMD). The treatment of choice for delaying DMD progression both in skeletal and cardiac muscle are corticosteroids, supporting the notion that chronic inflammation in the heart plays a pivotal role in fibrosis deposition and subsequent cardiac dysfunction. Nevertheless, considering the adverse effects associated with long-term corticosteroid treatments, there is a need for novel anti-inflammatory therapies. In this study, we used our recently described exercised mdx (ex mdx) mouse model characterised by accelerated heart pathology, and the specific PKCθ inhibitor Compound 20 (C20), to show that inhibition of this kinase leads to a significant reduction in the number of immune cells infiltrating the heart, as well as necrosis and fibrosis. Functionally, C20 treatment also prevented the reduction in left ventricle fractional shortening, which was typically observed in the vehicle-treated ex mdx mice. Based on these findings, we propose that PKCθ pharmacological inhibition could be an attractive therapeutic approach to treating dystrophic cardiomyopathy

Bilateral leg pain and unilateral calf atrophy caused by polymyositis accompanying lumbar spinal stenosis and disc herniation: a case report

Polymyositis is a subgroup of idiopathic inflammatory myopathies characterized by symmetric proximal limb weakness and chronic skeletal muscle inflammation. We herein report the first case of bilateral leg pain and unilateral calf atrophy caused by polymyositis accompanying lumbar spinal stenosis and disc herniation. A 52-year-old man presented with intermittent claudication and calf pain that had become gradually aggravated during the last 3 months. Magnetic resonance imaging showed spinal stenosis at the L3/4 and L4/5 levels and lumbar disc herniation at the L4/5 level. Preoperative laboratory investigations revealed elevated muscle enzyme concentrations. Magnetic resonance imaging also showed atrophy, fatty degeneration, and edema in both calf muscles. Histological examination showed inflammatory myositis and fibrosis in the perifascicular connective tissues. The patient was diagnosed with polymyositis. We performed decompressive laminectomy at the L3/4 and L4/5 levels and discectomy at the L4/5 level. After administration of prednisolone for 6 months and methotrexate for 3 months, the patient’s bilateral calf pain and abnormal laboratory findings improved. The combination of surgical decompression and adequate medical treatment resulted in a successful recovery. Polymyositis should be suspected in patients with lumbar spinal stenosis or lumbar disc herniation who exhibit increased muscle enzyme concentrations or lower extremity muscle atrophy.

Anoctamin 5 Knockout Mouse Model Recapitulates LGMD2L Muscle Pathology and Offers Insight Into in vivo Functional Deficits

Mutations in the Anoctamin 5 (Ano5) gene that result in the lack of expression or function of ANO5 protein, cause Limb Girdle Muscular Dystrophy (LGMD) 2L/R12, and Miyoshi Muscular Dystrophy (MMD3). However, the dystrophic phenotype observed in patient muscles is not uniformly recapitulated by ANO5 knockout in animal models of LGMD2L. Here we describe the generation of a mouse model of LGMD2L generated by targeted out-of-frame deletion of the Ano5 gene. This model shows progressive muscle loss, increased muscle weakness, and persistent bouts of myofiber regeneration without chronic muscle inflammation, which recapitulates the mild to moderate skeletal muscle dystrophy reported in the LGMD2L patients. We show that these features of ANO5 deficient muscle are not associated with a change in the calcium-activated sarcolemmal chloride channel activity or compromised in vivo regenerative myogenesis. Use of this mouse model allows conducting in vivo investigations into the functional role of ANO5 in muscle health and for preclinical therapeutic development for LGMD2L.

A network of core and subtype-specific gene expression programs in myositis.

Myositis comprises a heterogeneous group of skeletal muscle disorders which converge on chronic muscle inflammation and weakness. Our understanding of myositis pathogenesis is limited, and many myositis patients lack effective therapies. Using muscle biopsy transcriptome profiles from 119 myositis patients (spanning major clinical and serological disease subtypes) and 20 normal controls, we generated a co-expression network of 8101 dynamically regulated transcripts. This network organized the myositis transcriptome into a map of gene expression modules representing interrelated biological processes and disease signatures. Universally myositis-upregulated network modules included muscle regeneration, specific cytokine signatures, the acute phase response, and neutrophil degranulation. Universally myositis-suppressed pathways included a specific subset of myofilaments, the mitochondrial envelope, and nuclear isoforms of the anti-apoptotic humanin protein. Myositis subtype-specific modules included type 1 interferon signaling and titin (dermatomyositis), RNA processing (antisynthetase syndrome), and vasculogenesis (inclusion body myositis). Importantly, therapies exist to target influential proteins in many myositis-dysregulated modules, and nearly all modules contained understudied proteins and non-coding RNAs - many of which were extraordinarily dysregulated in myositis and may represent novel therapeutic targets. Finally, we apply our network to patient classification, finding that a deep learning algorithm trained on patient-level network "images" successfully assigned patients to clinical groups and further into molecular subclusters. Altogether, we provide a global resource to probe and contextualize differential gene expression in myositis.

Accelerating the Mdx Heart Histo-Pathology through Physical Exercise.

Chronic cardiac muscle inflammation and fibrosis are key features of Duchenne Muscular Dystrophy (DMD). Around 90% of 18-year-old patients already show signs of DMD-related cardiomyopathy, and cardiac failure is rising as the main cause of death among DMD patients. The evaluation of novel therapies for the treatment of dystrophic heart problems depends on the availability of animal models that closely mirror the human pathology. The widely used DMD animal model, the mdx mouse, presents a milder cardiac pathology compared to humans, with a late onset, which precludes large-scale and reliable studies. In this study, we used an exercise protocol to accelerate and worsen the cardiac pathology in mdx mice. The mice were subjected to a 1 h-long running session on a treadmill, at moderate speed, twice a week for 8 weeks. We demonstrate that subjecting young mdx mice (4-week-old) to “endurance” exercise accelerates heart pathology progression, as shown by early fibrosis deposition, increases necrosis and inflammation, and reduces heart function compared to controls. We believe that our exercised mdx model represents an easily reproducible and useful tool to study the molecular and cellular networks involved in dystrophic heart alterations, as well as to evaluate novel therapeutic strategies aimed at ameliorating dystrophic heart pathology.

Metabolipidomic profiling reveals an age-related deficiency of skeletal muscle pro-resolving mediators that contributes to maladaptive tissue remodeling.

Specialized pro‐resolving mediators actively limit inflammation and support tissue regeneration, but their role in age‐related muscle dysfunction has not been explored. We profiled the mediator lipidome of aging muscle via liquid chromatography‐tandem mass spectrometry and tested whether treatment with the pro‐resolving mediator resolvin D1 (RvD1) could rejuvenate the regenerative ability of aged muscle. Aged mice displayed chronic muscle inflammation and this was associated with a basal deficiency of pro‐resolving mediators 8‐oxo‐RvD1, resolvin E3, and maresin 1, as well as many anti‐inflammatory cytochrome P450‐derived lipid epoxides. Following muscle injury, young and aged mice produced similar amounts of most pro‐inflammatory eicosanoid metabolites of cyclooxygenase (e.g., prostaglandin E2) and 12‐lipoxygenase (e.g., 12‐hydroxy‐eicosatetraenoic acid), but aged mice produced fewer markers of pro‐resolving mediators including the lipoxins (15‐hydroxy‐eicosatetraenoic acid), D‐resolvins/protectins (17‐hydroxy‐docosahexaenoic acid), E‐resolvins (18‐hydroxy‐eicosapentaenoic acid), and maresins (14‐hydroxy‐docosahexaenoic acid). Similar absences of downstream pro‐resolving mediators including lipoxin A4, resolvin D6, protectin D1/DX, and maresin 1 in aged muscle were associated with greater inflammation, impaired myofiber regeneration, and delayed recovery of strength. Daily intraperitoneal injection of RvD1 had minimal impact on intramuscular leukocyte infiltration and myofiber regeneration but suppressed inflammatory cytokine expression, limited fibrosis, and improved recovery of muscle function. We conclude that aging results in deficient local biosynthesis of specialized pro‐resolving mediators in muscle and that immunoresolvents may be attractive novel therapeutics for the treatment of muscular injuries and associated pain in the elderly, due to positive effects on recovery of muscle function without the negative side effects on tissue regeneration of non‐steroidal anti‐inflammatory drugs.

Experimentally induced spine osteoarthritis in rats leads to neurogenic inflammation within neurosegmentally linked myotomes

Naturally occurring spine osteoarthritis is clinically associated with the manifestation of chronic inflammatory muscle (myofascial) disease. The purpose of this study was to investigate the causal association between experimentally induced spine osteoarthritis and neurogenic inflammatory responses within neurosegmentally linked myotomes. Wistar Kyoto rats were randomly assigned to spine facet compression surgery (L4-L6) or sham surgery. Animals exposed to facet compression surgery demonstrated radiographic signs of facet-osteoarthritis (L4-L6 spinal levels) and sensory changes (allodynia, thermal hyperalgesia) at 7, 14 and 21days post-intervention, consistent with the induction of central sensitization; no radiologic or sensory changes were observed after sham surgery. Increased levels of proinflammatory biomarkers including substance P (SP), calcitonin gene related peptide (CGRP), protease-activated receptor-2 (PAR2) and calcium/calmodulin dependent protein kinase II (CaMKII) were observed post-surgery within neurosegmentally-linked rectus femoris (L2-L5) muscle when compared to the non-segmentally linked biceps brachii (C4-C7) muscle; no differences were observed between muscles in the sham surgery group. These findings offer novel insight into the potential role of spine osteoarthritis and neurogenic inflammatory mechanisms in the pathophysiology of chronic inflammatory muscle (myofascial) disease.

Cellular senescence-mediated exacerbation of Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a progressive disease characterised by chronic muscle degeneration and inflammation. Our previously established DMD model rats (DMD rats) have a more severe disease phenotype than the broadly used mouse model. We aimed to investigate the role of senescence in DMD using DMD rats and patients. Senescence was induced in satellite cells and mesenchymal progenitor cells, owing to the increased expression of CDKN2A, p16- and p19-encoding gene. Genetic ablation of p16 in DMD rats dramatically restored body weight and muscle strength. Histological analysis showed a reduction of fibrotic and adipose tissues invading skeletal muscle, with increased muscle regeneration. Senolytic drug ABT263 prevented loss of body weight and muscle strength, and increased muscle regeneration in rats even at 8 months—the late stage of DMD. Moreover, senescence markers were highly expressed in the skeletal muscle of DMD patients. In situ hybridization of CDKN2A confirmed the expression of it in satellite cells and mesenchymal progenitor cells in patients with DMD. Collectively, these data provide new insights into the integral role of senescence in DMD progression.

Pharmacological Aspects of Phyllanthus fraternus Standardized Extract (Rich in Lignans and Tannins) as a Pain Modulator

Background: The standardized extracts of P. fraternus were previously reported by us for its anti-inflammatory, analgesic, and anti-arthritic biological potentials. However, we have not reported for a consequence of P. fraternus on chronic inflammatory muscle hyperalgesia. Herein, we have demonstrated chronic pain modulating effect of standardized extracts of P. fraternus. Materials and Methods: Firstly, we have collected various parts of P. fraternus plant including the dried stems, leaves, and roots. In order to produce chronic inflammations, we further allowed injection to the left gastrocnemius muscle belly of rats with a freshly prepared solution of 3% carrageenan in normal saline (100µL). Thermal/heat hyperalgesia, mechanical hyperalgesia and muscle circumferences were determined in the current experimental model. In order to estimate, chronic pain modulating potential of P. fraternus, we have also studied histopathological studies and measurement of prostaglandin E-2 (PGE2). Results: After administration of 3% carrageenan intramuscular injection, we investigated the chronic thermal and mechanical hypersensitivity of aforementioned test sample i.e. standardized extracts of P. fraternus in terms of adopting 2 gradual dosings of 200 and 400 mg/kg (administered intraperitoneally) from day 14th to 22nd. From our study, we observed significant antihyperalgesic activity; when we allowed administering standardized extracts of P. fraternus intraperitoneally. Conclusion: To conclude, we have investigated the antihyperalgesic and anti-inflammatory potentials of standardized extracts of P. fraternus. These effects might be having mediation via supraspinal or spinal neuronal mechanisms, and mainly observed due to evidence of PGE2 inhibitions.

Histopathologic Observations of Eyes in Exenterated Orbits After Neoadjuvant Intra-Arterial Cytoreductive Chemotherapy for Adenoid Cystic Carcinoma of the Lacrimal Gland.

To assess whether exenteration specimens obtained after neoadjuvant intra-arterial cytoreductive chemotherapy (IACC) for adenoid cystic carcinoma of the lacrimal gland demonstrate significant ocular histopathologic alterations that might preclude future pursuit of globe-preserving therapy. Retrospective histopathologic analysis of globes in IACC-treated exenteration specimens among the same cohort of patients whose survival outcomes have been reported. Twenty patients had specimens available. Nineteen globes revealed no abnormalities of the iris, ciliary body, lens, retinal pigment epithelium, choroid, or chorioretinal vasculature. Eighteen globes showed no optic nerve abnormalities. One globe from a patient who refused exenteration until adenoid cystic carcinoma recurrence supervened demonstrated optic nerve edema with a peripapillary hemorrhage and cotton wool spot, as well as hemorrhage and necrosis within an extraocular muscle. Eighteen globes showed no retinal abnormalities attributable to intra-arterial chemotherapy. Three globes showed incidental retinal findings: 2 globes contained 1 to 2 small peripheral retinal hemorrhages and 1 had a pigmented retinal hole. Seven demonstrated mild, chronic extraocular muscle inflammation, and 13 had unremarkable musculature. The single patient who received IACC via the internal carotid rather than the external carotid artery developed ophthalmic artery occlusion with orbital apex syndrome prior to exenteration, and diffuse necrosis and hemorrhage were evident histopathologically. Neoadjuvant IACC does not cause significant histopathologic damage to key ocular structures or compromise visual function in patients receiving intra-arterial chemotherapy through the external carotid artery. However, delivering chemotherapy through the internal carotid artery may result in visually significant thrombotic vascular events. The generally benign histopathological findings in these exenteration specimens support the concept of IACC delivery through the external carotid system as the cornerstone of a future globe-preserving strategy for lacrimal gland adenoid cystic carcinoma.

A Stromal Progenitor and ILC2 Niche Promotes Eosinophilia in Skeletal Muscle

Chronic muscle inflammation contributes to the pathogenesis of Duchenne muscular dystrophy (DMD), a lethal muscle disorder attributed to dystrophin gene mutations. However, the function and regulation of eosinophilia, an unappreciated facet of type II innate immunity in dystrophic muscle, remain poorly understood. Here, we report the novel observation that group 2 innate lymphoid cells (ILC2s) are present in skeletal muscle and are the principal regulators of muscle eosinophilia during muscular dystrophy. Eosinophils were elevated in DMD patients and dystrophic mice, along with the major eosinophil survival factor, interleukin-5 (IL-5). ILC2s were present in healthy skeletal muscle, were activated and expanded in number during muscular dystrophy in mice, and were the sole source of IL-5. Muscle ILC2s were expanded by IL-33, which was upregulated in dystrophic muscle and was predominantly produced by fibro/adipogenic progenitor cells (FAPs). Exogenous IL-33 also promoted muscle eosinophilia, which was further augmented by combined treatment with IL-2 complex (IL-2c). The deletion of ILC2s in dystrophic mice prevented eosinophilia and mitigated the IL-33/IL-2c-mediated increase of muscle eosinophils and IL-5 expression. Our findings establish that interactions between FAPs and ILC2s regulate type II innate immunity in dystrophic muscle and promote muscle eosinophilia during muscular dystrophy.