OBJECTIVE: Exposure to high intensity, low frequency noise (HI-LFN) causes vibroacoustic disease (VAD), with memory deficit as a primary non-auditory symptomatic effect of VAD. However, the underlying mechanism of the memory deficit is unknown. This study aimed to characterize potential mechanisms involving morphological changes of neurons and nerve fibers in the hippocampus, after exposure to HI-LFN. METHODS: Adult wild-type and transient receptor potential vanilloid subtype 4 knockout (TRPV4^-/-) mice were used for construction of the HI-LFN injury model. The new object recognition task and the Morris water maze test were used to measure the memory of these animals. Hemoxylin and eosin and immunofluorescence staining were used to examine morphological changes of the hippocampus after exposure to HI-LFN. RESULTS: The expression of TRPV4 was significantly upregulated in the hippocampus after HI-LFN exposure. Furthermore, memory deficits correlated with lower densities of neurons and neurofilament-positive nerve fibers in the cornu ammonis 1 (CA1) and dentate gyrus (DG) hippocampal areas in wild-type mice. However, TRPV4^-/- mice showed better performance in memory tests and more integrated neurofilament-positive nerve fibers in the CA1 and DG areas after HI-LFN exposure. CONCLUSION TRPV4 up-regulation induced neurofilament positive nerve fiber injury in the hippocampus, which was a possible mechanism for memory impairment and cognitive decline resulting from HI-LFN exposure. Together, these results identified a promising therapeutic target for treating cognitive dysfunction in VAD patients.
Animals ; Mice ; TRPV Cation Channels/metabolism* ; Intermediate Filaments/metabolism* ; Hippocampus/metabolism* ; Neurons/metabolism* ; Memory Disorders/metabolism*

BACKGROUND AND PURPOSE: Neurofilament light chain (NfL) is a blood marker for neuroaxonal damage. We assessed the association between serum NfL and cerebral small vessel disease (SVD), which is highly prevalent in elderly individuals and a major cause of stroke and vascular cognitive impairment. METHODS: Using a cross-sectional design, we studied 53 and 439 patients with genetically defined SVD (Cerebral Autosomal-Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy [CADASIL]) and sporadic SVD, respectively, as well as 93 healthy controls. Serum NfL was measured by an ultrasensitive single-molecule array assay. We quantified magnetic resonance imaging (MRI) markers of SVD, i.e., white matter hyperintensity volume, lacune volume, brain volume, microbleed count, and mean diffusivity obtained from diffusion tensor imaging. Clinical characterization included neuropsychological testing in both SVD samples. CADASIL patients were further characterized for focal neurological deficits (National Institutes of Health stroke scale [NIHSS]) and disability (modified Rankin scale [mRS]). RESULTS: Serum NfL levels were elevated in both SVD samples (P < 1e-05 compared with controls) and associated with all SVD MRI markers. The strongest association was found for mean diffusivity (CADASIL, R2=0.52, P=1.2e-09; sporadic SVD, R2=0.21, P < 1e-15). Serum NfL levels were independently related to processing speed performance (CADASIL, R2=0.27, P=7.6e-05; sporadic SVD, R2=0.06, P=4.8e-08), focal neurological symptoms (CADASIL, NIHSS, P=4.2e-05) and disability (CADASIL, mRS, P=3.0e-06). CONCLUSIONS: We found serum NfL levels to be associated with both imaging and clinical features of SVD. Serum NfL might complement MRI markers in assessing SVD burden. Importantly, SVD needs to be considered when interpreting serum NfL levels in the context of other age-related diseases.
Academies and Institutes ; Aged ; Biomarkers ; Brain ; CADASIL ; Cerebral Small Vessel Diseases ; Cognition Disorders ; Complement System Proteins ; Dementia, Vascular ; Diffusion Tensor Imaging ; Humans ; Intermediate Filaments* ; Leukoencephalopathies ; Magnetic Resonance Imaging ; Neuropsychological Tests ; Stroke ; White Matter

BACKGROUND AND PURPOSE: A few groups have suggested that activated cytokines and nitrosative stress are closely involved in the pathogenesis of different demyelinating disorders induced by the neuroinflammatory destruction of neurons. The purpose of this study was to elucidate the associations of cytokines and S-nitrosothiols (RSNO) with the severity of neurodegeneration during relapse in demyelinating disorders of the central nervous system. METHODS: We measured levels of interleukin-6 (IL-6), erythropoietin, RSNO, and phosphorylated neurofilament heavy chain (pNfh) in cerebrospinal fluid (CSF) samples obtained from patients with different demyelinating disorders: multiple sclerosis (MS, n=52), acute disseminated encephalomyelitis (ADEM, n=9), and neuromyelitis optica spectrum disorders (NMOSD) with aquaporin-4 immunoglobulin G (AQP4-IgG, n=12). We compared these levels with those measured in a control group (n=24). RESULTS: We found that IL-6 in CSF was elevated in NMOSD with AQP4-IgG and ADEM patients as well as in MS patients after the destruction of soluble IL-6. Erythropoietin levels were lower in MS, while RSNO levels were higher in NMOSD with AQP4-IgG and MS patients than in the control group. CSF pNfh levels were elevated in MS and ADEM patients. CONCLUSIONS: These results confirm that IL-6 is activated in different demyelinating disorders, with this elevation being more prominent in the CSF of NMOSD with AQP4-IgG and ADEM patients. Moreover, S-nitrosylation is activated in demyelinating disorders with spinal-cord injury and neurodegeneration in these patients. However, we found no correlation between these biochemical markers, and so we could not confirm whether IL-6-mediated nitric oxide production is involved in spinal-cord lesions.
Biomarkers ; Central Nervous System* ; Cerebrospinal Fluid ; Cytokines ; Demyelinating Diseases* ; Encephalomyelitis, Acute Disseminated ; Erythropoietin ; Humans ; Immunoglobulin G ; Interleukin-6* ; Intermediate Filaments ; Multiple Sclerosis ; Neuromyelitis Optica ; Neurons ; Nitric Oxide ; Recurrence ; S-Nitrosothiols*

The synaptic contacts of cochlear afferent fibers (CAFs) with inner hair cells (IHCs) are spatially segregated according to their firing properties. CAFs also exhibit spatially segregated vulnerabilities to noise. The CAF fibers contacting the modiolar side of IHCs tend to be more vulnerable. Noise vulnerability is thought to be due to the absence of neuroprotective mechanisms in the modiolar side contacting CAFs. In this study, we investigated whether the expression of neuroprotective Ca²⁺-buffering proteins is spatially segregated in CAFs. The expression patterns of calretinin, parvalbumin, and calbindin were examined in rat CAFs using immunolabeling. Calretinin-rich fibers, which made up ~50% of the neurofilament (NF)-positive fibers, took the pillar side course and contacted all IHC sides. NF-positive and calretinin-poor fibers took the modiolar side pathway and contacted the modiolar side of IHCs. Both fiber categories juxtaposed the C-terminal binding protein 2 (CtBP2) puncta and were contacted by synaptophysin puncta. These results indicated that the calretinin-poor fibers, like the calretinin-rich ones, were afferent fibers and probably formed functional efferent synapses. However, the other Ca²⁺-buffering proteins did not exhibit CAF subgroup specificity. Most CAFs near IHCs were parvalbumin-positive. Only the pillar-side half of parvalbumin-positive fibers coexpressed calretinin. Calbindin was not detected in any nerve fibers near IHCs. Taken together, of the Ca²⁺-buffering proteins examined, only calretinin exhibited spatial segregation at IHC-CAF synapses. The absence of calretinin in modiolar-side CAFs might be related to the noise vulnerability of the fibers.
Animals ; Calbindin 2* ; Calbindins ; Carrier Proteins ; Fires ; Hair Cells, Auditory, Inner ; Intermediate Filaments ; Nerve Fibers ; Noise* ; Rats ; Sensitivity and Specificity ; Synapses ; Synaptophysin

The cytoskeleton consists of 3 filamentous components: intermediate filaments, microtubules, and actin filaments. Actin filaments continuously assemble and disassemble far out of equilibrium to adapt cells in response to external stimuli. Actin filaments organization and dynamic are controlled by a multitude of actin-binding proteins including actin-bundling proteins. L-plastin, expressed abundantly in lymphocytes and monocytes, is an actin-bundling protein that roles in immune defense and in metastatic invasion of cancer cells. The actin-bundling activity of L-plastin is regulated not only by intracellular calcium concentration, but by phosphorylation of Ser5. The actin-bundling activity of L-pastin decreases by increased calcium concentration but is promoted by phosphorylation of Ser5. The morphology changes and motility of cells requires continuous remodeling of actin filaments which demands the sensitive nature of L-plastin to Ca2+-signal, phosphorylation of Ser5, and probably additional regulation. This review briefly describes the structure and regulation of L-plastin, and roles for L-plastin in cancer invasion and in macrophages.
Actin Cytoskeleton ; Calcium ; Cytoskeleton ; Intermediate Filaments ; Lymphocytes ; Macrophages* ; Microfilament Proteins ; Microtubules ; Monocytes ; Phosphorylation

Tobacco smoking has been identified as an important factor in premature skin aging to detect the histological changes occurred in adult male guinea pig thin skin under the influence of low and high doses of nicotine; which constitutes approximately 0.6%–3.0% of the dry weight of tobacco. Fifteen adult male pigmented guinea pigs were equally divided into three groups: group I, control; group IIA, low dose nicotine treated; 3 mg/kg subcutaneously for 4 weeks; and group IIB, high dose nicotine treated; 6 mg/kg subcutaneously for 4 weeks. Specimens from the back thin skin were processed for light and electron microscopy. Nicotine administration revealed flattened dermo-epidermal junction and reduced rete ridges formation. Collagen bundles were disorganized with increased spaces between them. A reduction in the amount of elastic fibers in the dermis were also observed compared to group I. Ultrastructurally, keratinocytes had hyperchromatic nuclei, intracytoplasmic vacuoles, disruption of desmosomal junctions, irregular tonofilaments distribution, and increased inter-cellular spaces. These changes were more pronounced with high dose nicotine administration. The epidermal thickness was reduced in low dose nicotine administration. But, high dose nicotine administration revealed increased epidermal thickness compared to the control group. Nicotine induced structural changes of adult male guinea pig thin skin. These changes were more pronounced with high dose nicotine administration.
Adult* ; Animals ; Collagen ; Dermis ; Elastic Tissue ; Guinea Pigs* ; Guinea* ; Humans ; Intermediate Filaments ; Keratinocytes ; Male* ; Microscopy, Electron ; Nicotine* ; Skin Aging ; Skin* ; Smoking ; Tobacco ; Vacuoles

Heme oxygenase-1 (HO-1) is a stress-responsive enzyme that modulates the immune response and oxidative stress associated with spinal cord injury (SCI). This study aimed to investigate neuronal regeneration via transplantation of mesenchymal stromal cells (MSCs) overexpressing HO-1. Canine MSCs overexpressing HO-1 were generated by using a lentivirus packaging protocol. Eight beagle dogs with experimentally-induced SCI were divided into GFP-labeled MSC (MSC-GFP) and HO-1-overexpressing MSC (MSC-HO-1) groups. MSCs (1 × 10⁷ cells) were transplanted at 1 week after SCI. Spinal cords were harvested 8 weeks after transplantation, after which histopathological, immunofluorescence, and western blot analyses were performed. The MSC-HO-1 group showed significantly improved functional recovery at 7 weeks after transplantation. Histopathological results showed fibrotic changes and microglial cell infiltration were significantly decreased in the MSC-HO-1 group. Immunohistochemical (IHC) results showed significantly increased expression levels of HO-1 and neuronal markers in the MSC-HO-1 group. Western blot results showed significantly decreased expression of tumor necrosis factor-alpha, interleukin-6, cycloogygenase 2, phosphorylated-signal transducer and activator of transcription 3, and galactosylceramidase in the MSC-HO-1 group, while expression levels of glial fibrillary acidic protein, β3-tubulin, neurofilament medium, and neuronal nuclear antigen were similar to those observed in IHC results. Our results demonstrate that functional recovery after SCI can be promoted to a greater extent by transplantation of HO-1-overexpressing MSCs than by normal MSCs.
Animals ; Blotting, Western ; Dogs ; Fluorescent Antibody Technique ; Galactosylceramidase ; Glial Fibrillary Acidic Protein ; Heme Oxygenase-1* ; Heme* ; Interleukin-6 ; Intermediate Filaments ; Lentivirus ; Mesenchymal Stromal Cells* ; Neurons ; Oxidative Stress ; Product Packaging ; Regeneration ; Spinal Cord Injuries* ; Spinal Cord* ; Transducers ; Tumor Necrosis Factor-alpha

Our study aims to explore the effects of lentivirus-mediated microRNA-124 (miR-124) gene-modified bone marrow mesenchymal stem cell (BMSC) transplantation on the repair of spinal cord injury (SCI) in rats. BMSCs were isolated from the bone marrow of rats. The target gene miR-124 was identified using a luciferase-reporter gene assay. Seventy-two rats were selected for construction of the SCI model, and the rats were randomly divided into the blank group, sham group, SCI group, negative control (NC) group, overexpressed miR-124 group and si-PDXK group. The mRNA expression of miR-124 and the mRNA and protein expression of pyridoxal kinase (PDXK) were detected by quantitative real-time polymerase chain reaction and western blotting. The locomotor capacity of the rats was evaluated using the Basso, Beattie and Bresnahan (BBB) scale. Brdu, neuron-specific enolase (NSE), neurofilament (NF) and microtubule-associated protein 2 (MAP2) were detected using immunohistochemistry. The expression levels of thyrotropin-releasing hormone (TRH), prostacyclin (PGI2) and gangliosides (GM) were measured using an enzyme-linked immunosorbent assay. PDXK was identified as the target gene of miR-124. The overexpressed miR-124 group exhibited higher miR-124 expression than the SCI, NC and si-PDXK groups. Compared with the SCI and NC groups, the PDXK expression was downregulated in the overexpressed miR-124 and si-PDXK groups, and the BBB scores were significantly increased 7, 21 and 35 days after transplantation. The double-labeled positive cell densities (Brdu+NSE/NF/MAP2) and the expression levels of TRH, PGI2 and GM in the overexpressed miR-124 group were significantly higher than those in the NC and SCI groups. These results indicated that miR-124 targeted PDXK to accelerate the differentiation of BMSCs into neurocytes and promote SCI repair.
Animals ; Blotting, Western ; Bone Marrow* ; Bromodeoxyuridine ; Cell Count ; Enzyme-Linked Immunosorbent Assay ; Epoprostenol ; Gangliosides ; Immunohistochemistry ; Intermediate Filaments ; Mesenchymal Stem Cell Transplantation* ; Mesenchymal Stromal Cells* ; Microtubule-Associated Proteins ; Phosphopyruvate Hydratase ; Pyridoxal Kinase ; Rats* ; Real-Time Polymerase Chain Reaction ; RNA, Messenger ; Spinal Cord Injuries* ; Spinal Cord* ; Thyrotropin-Releasing Hormone

Recurrent laryngeal nerve (RLN) injury can result in unilateral or bilateral vocal cords paralysis, thereby causing a series of complications, such as hoarseness and dyspnea. However, the repair of RLN remains a great challenge in current medicine. This study aimed to develop human umbilical mesenchymal stem cells (HuMSCs) and nerve growth factor (NGF)-loaded heparinized collagen scaffolds (HuMSCs/NGF HC-scaffolds) and evaluate their potential in the repair of RLN injury. HuMSCs/NGF HC-scaffolds were prepared through incorporating HuMSCs and NGF into heparinized collagen scaffolds that were prefabricated by freeze-drying in a template. The resulting scaffolds were characterized by FTIR, SEM, porosity, degradation in vitro, NGF release in vitro and bioactivity. A rabbit RLN injury model was constructed to appraise the performance of HuMSCs/NGF HC-scaffolds for nerve injury repair. Electrophysiology, histomorphology and diagnostic proteins expression for treated nerves were checked after application of various scaffolds. The results showed that the composite scaffolds with HuMSCs and NGF were rather helpful for the repair of broken RLN. The RLN treated with HuMSCs/NGF HC-scaffolds for 8 weeks produced a relatively normal electromyogram, and the levels of calcium-binding protein S100, neurofilament and AchE pertinent to nerve were found to be close to the normal ones but higher than those resulted from other scaffolds. Taken together, HuMSCs/NGF HC-scaffolds exhibited a high score on the nerve injury repair and may be valuable for the remedy of RLN injury.
Collagen* ; Dyspnea ; Electrophysiology ; Heparin* ; Hoarseness ; Humans* ; In Vitro Techniques ; Intermediate Filaments ; Mesenchymal Stromal Cells* ; Nerve Growth Factor* ; Paralysis ; Porosity ; Recurrent Laryngeal Nerve Injuries* ; Recurrent Laryngeal Nerve* ; Spectroscopy, Fourier Transform Infrared ; Umbilical Cord* ; Vocal Cords

Fetal development of the face involves a specific type of cornification in which keratinocytes provide a mass or plug to fill a cavity. The epithelial-mesenchymal interaction was likely to be different from that in the usual skin. We examined expression of intermediate filaments and other mesenchymal markers beneath cornification in the fetal face. Using sections from 5 mid-term human fetuses at 14–16 weeks, immunohistochemistry was conducted for cytokeratins (CK), vimentin, nestin, glial fibrilary acidic protein, desmin, CD34, CD68 and proliferating cell nuclear antigen (PCNA). Fetal zygomatic skin was composed of a thin stratum corneum and a stratum basale (CK5/6+, CK14+, and CK19+) and, as the intermediate layer, 2–3 layered large keratinocytes with nucleus. The basal layer was lined by mono-layered mesenchymal cells (CD34+ and nestin+). Some of basal cells were PCNA-positive. In the keratinocyte plug at the external ear and nose, most cell nuclei expressed PCNA, CK5/6, CK14, and CK19. Vimentin-positive mesenchymal cells migrated into the plug. The PCNA-positive nucleus as well as mesenchymal cell migration was not seen in the lip margin in spite of the thick keratinocyte layer. The lingual epithelium were characterized by the CK7-positive stratum corneum as well as the thick mesenchymal papilla. CD68-positive macrophages were absent in the epidermis/epithelium. Being different from usual cornification of the skin, loss of a mesenchymal monolayer as well as superficial migration of mesenchymal cells might connect with a specific differentiation of keratinocyte to provide a plug at the fetal nose and ear.
Cell Movement ; Cell Nucleus ; Desmin ; Ear ; Ear, External ; Epidermis* ; Epithelium* ; Fetal Development ; Fetus ; Humans* ; Immunohistochemistry ; Intermediate Filaments ; Keratinocytes ; Keratins ; Lip ; Macrophages ; Nestin ; Nose ; Proliferating Cell Nuclear Antigen ; Skin ; Vimentin