Circulating Extracellular Vesicle-Propagated microRNA Signature as a Vascular Calcification Factor in Chronic Kidney Disease.

BACKGROUND: Chronic kidney disease (CKD) accelerates vascular calcification via phenotypic switching of vascular smooth muscle cells (VSMCs). We investigated the roles of circulating small extracellular vesicles (sEVs) between the kidneys and VSMCs and uncovered relevant sEV-propagated microRNAs (miRNAs) and their biological signaling pathways. METHODS AND RESULTS: We established CKD models in rats and mice by adenine-induced tubulointerstitial fibrosis. Cultures of A10 embryonic rat VSMCs showed increased calcification and transcription of osterix (Sp7), osteocalcin (Bglap), and osteopontin (Spp1) when treated with rat CKD serum. sEVs, but not sEV-depleted serum, accelerated calcification in VSMCs. Intraperitoneal administration of a neutral sphingomyelinase and biogenesis/release inhibitor of sEVs, GW4869 (2.5 mg/kg per 2 days), inhibited thoracic aortic calcification in CKD mice under a high-phosphorus diet. GW4869 induced a nearly full recovery of calcification and transcription of osteogenic marker genes. In CKD, the miRNA transcriptome of sEVs revealed a depletion of 4 miRNAs, miR-16-5p, miR-17~92 cluster-originated miR-17-5p/miR-20a-5p, and miR-106b-5p. Their expression decreased in sEVs from CKD patients as kidney function deteriorated. Transfection of VSMCs with each miRNA-mimic mitigated calcification. In silico analyses revealed VEGFA (vascular endothelial growth factor A) as a convergent target of these miRNAs. We found a 16-fold increase in VEGFA transcription in the thoracic aorta of CKD mice under a high-phosphorus diet, which GW4869 reversed. Inhibition of VEGFA-VEGFR2 signaling with sorafenib, fruquintinib, sunitinib, or VEGFR2-targeted siRNA mitigated calcification in VSMCs. Orally administered fruquintinib (2.5 mg/kg per day) for 4 weeks suppressed the transcription of osteogenic marker genes in the mouse aorta. The area under the curve of miR-16-5p, miR-17-5p, 20a-5p, and miR-106b-5p for the prediction of abdominal aortic calcification was 0.7630, 0.7704, 0.7407, and 0.7704, respectively. CONCLUSIONS: The miRNA transcriptomic signature of circulating sEVs uncovered their pathologic role, devoid of the calcification-protective miRNAs that target VEGFA signaling in CKD-driven vascular calcification. These sEV-propagated miRNAs are potential biomarkers and therapeutic targets for vascular calcification.

Evaluation of the risk factors predicting thrombotic complications associated with intravenous immunoglobulin therapy in neuroimmunological diseases.

Intravenous immunoglobulin (IVIg) therapy is increasingly used for various conditions that include neuroimmunological disorders, such as chronic inflammatory demyelinating polyneuropathy, Guillain-Barré syndrome, myasthenia gravis, and myositis. Although IVIg therapy is considered a relatively safe treatment, previous studies have reported thrombotic complications associated with IVIg (TCI). The precise mechanisms and associated risk factors have not been fully elucidated to date. Three of our patients experienced TCI. Although immobility is one of the most common risk factors for venous thrombosis, all three patients could walk without assistance; their modified Rankin Scale (mRS) scores were 2. We assessed the clinical characteristics of these patients and compared their data with that of 65 patients who received IVIg from the years 2000 to 2019 without experiencing TCI to identify associated risk factors. The frequency of TCI among patients with neuroimmunological disorders at our hospital was 4.4% (3/68 patients). There were no significant differences between the patients with and without TCI regarding their mean age (69.7 vs 58.0 years, p = 0.244), percentage of females (66.7% vs 45.6%, p = 0.588), mean body mass index (22.67 vs 22.16, p = 0.878), mean mRS score (2.22 vs 2.00, p = 0.658), and use of oral prednisolone (66.7% vs 13.8%, p = 0.0658). Interestingly, the D-dimer levels of two of the patients with TCI were not elevated before treatment. Sixteen patients received anticoagulant therapy during IVIg treatment, and none suffered from TCI. As our analysis suggested, it might be important to monitor D-dimer levels before and after IVIg to help prevent and detect TCI.

Next-generation sequencing-based small RNA profiling of cerebrospinal fluid exosomes.

MicroRNAs (miRNAs), particularly those found in human body fluids, have been suggested as potential biomarkers. Among various body fluids, the cerebrospinal fluid (CSF) shows promise as a profiling target for diagnosis and monitoring of neurological diseases. However, relevant genome-scale studies are limited and no studies have profiled exosomal miRNAs in CSF. Therefore, we conducted a next-generation sequencing-based genome-wide survey of small RNAs in the exosomal and non-exosomal (supernatant) fractions of healthy human CSF as well as serum in each donor. We observed miRNA enrichment in the exosomal fractions relative to the supernatant fractions of both CSF and serum. We also observed substantial differences in exosomal miRNA profiles between CSF and serum. Half of the reported brain miRNAs were found in CSF exosomal fractions. In particular, miR-1911-5p, specifically expressed in brain tissue, was detected in CSF but not in serum, as confirmed by digital PCR in three additional donors. Our data suggest that the brain is a major source of CSF exosomal miRNAs. Here we provide the important evidence that exosomal miRNAs in CSF may reflect brain pathophysiology.

Spreading of amyotrophic lateral sclerosis lesions--multifocal hits and local propagation?

OBJECTIVE: To investigate whether or not the lesions in sporadic amyotrophic lateral sclerosis (ALS) originate from a single focal onset site and spread contiguously by prion-like cell-to-cell propagation in the rostrocaudal direction along the spinal cord, as has been hypothesised (the 'single seed and simple propagation' hypothesis). METHODS: Subjects included 36 patients with sporadic ALS and initial symptoms in the bulbar, respiratory or upper limb regions. Abnormal spontaneous activities in needle electromyography (nEMG)-that is, fibrillation potentials, positive sharp waves (Fib/PSWs) or fasciculation potentials (FPs)-were compared among the unilateral muscles innervated by different spinal segments, especially between the T10 and L5 paraspinal muscles, and between the vastus medialis and biceps femoris. Axon length and the proportion of muscle fibre types, which are both related to motoneuronal vulnerability in ALS, are similar in the paired muscles. RESULTS: Fourteen of 36 patients showed a non-contiguous distribution of nEMG abnormalities from the onset site, with skipping of intermediate segments. In eight of them, the non-contiguous pattern was evident between paired muscles with the same motoneuronal vulnerability. The non-contiguously affected lumbosacral lesions involved motoneuron columns horizontally or radially proximate to one another, appearing to form a cluster in four of the eight patients. FPs, known to precede Fib/PSWs, were shown more frequently than Fib/PSWs in all the lumbosacral segments but L5, suggesting that 2nd hits occur at L5 and then spread to other lumbosacral segments. CONCLUSIONS: In sporadic ALS, the distribution of lower motoneuron involvement cannot be explained by the 'single seed and simple propagation' hypothesis alone. We propose a 'multifocal hits and local propagation' hypothesis instead.

Serum amyloid A level is increased in neuromyelitis optica and atypical multiple sclerosis with smaller T2 lesion volume in brain MRI.

Serum amyloid A (SAA) is known to promote the development of T helper 17 cells (Th17) and can be a critical mediator of disease pathogenesis. We analyzed SAA levels in 40 patients with multiple sclerosis (MS) and related disorders, and 10 with non-inflammatory neurological disease (NIND) as controls. We found that SAA levels were significantly increased in neuromyelitis optica (NMO) patients and relapsing and remitting MS (RRMS) patients showing atypical phenotype with spinal cord lesions and smaller T2 lesion volume in brain MRI, resembling NMO. Therefore, SAA levels can be associated with clinical phenotypes in MS and NMO.

Myotonic dystrophy and lipoma: a new association.

A 58-year-old man developed muscle weakness and had more than 1,000 CTG repeats in the myotonin protein kinase gene. He was diagnosed as having myotonic dystrophy. At the time of diagnosis, a large tumor was detected in his abdominal cavity on CT scan examination. He died from pneumonia 6 years later. At autopsy, the abdominal tumor was diagnosed as a lipoma. Several types of tumor have been reported to be associated with myotonic dystrophy type 1; however, this is the first detailed clinical case demonstrating the possible relationship between myotonic dystrophy and lipoma.

Aortic dissection as a possible cause of pure transient global amnesia: a case report and literature review.

A 55-year-old man suddenly developed anterograde and retrograde amnesia. His colleagues witnessed the onset of the episode and reported that 2 h before the onset of the amnesic attack the patient transiently became pale. Physical examination was unremarkable and neurological examination revealed no focal neurological sign although a laboratory investigation revealed leukocytosis. Pure transient global amnesia (TGA) was diagnosed. The anterograde amnesia resolved 20 h after onset, but the causes of his transient paleness precedent to TGA and leukocytosis were unclear. Thirty-four hours after onset, the patient complained of sudden back pain and radiological studies revealed aortic dissection (AD; Stanford type B). We emphasize AD as a rare cause of pure TGA, because TGA in itself often has a benign natural history, but AD can be life-threatening if undiagnosed. The precedent pain, transient systemic symptoms, and leukocytosis can be red flags suggesting AD as an etiology of TGA.