Depression and anxiety disorders in patients with multiple sclerosis: association with neurodegeneration and neurofilaments

There is increasing evidence that neurofilament light chain (NF-L) can be considered as a biomarker for neuro-axonal damage. This polypeptide can be released into the cerebrospinal fluid (CSF) and the blood, where it can be quantified. The concentration of NF-L is elevated in patients with multiple sclerosis (MS) and psychiatric disorders. We aimed to investigate the NF-L levels in the CSF from treated MS patients and the relationship with depression or anxiety. The study involved three groups: control group (individuals without inflammation), the relapse-remitting multiple sclerosis (RRMS)-untreated group, and the RRMS-Fingo group (RRMS patients who were treated with fingolimod). MS disability was assessed by the Expanded Disability Status Scale, and depression and anxiety were evaluated by a neuropsychologist, using the Hospital Anxiety and Depression Scale, the Beck Depression Inventory-II, and the Beck Anxiety Inventory. Individual CSF samples were collected to measure NF-L levels. The results of the statistical analysis on levels of NF-L in the CSF of control subjects, RRMS-untreated patients, and RRMS-Fingo patients were significant. The relationship between depression and anxiety in RRMS-Fingo patients and NF-L levels was not statistically significant. In conclusion, MS events such as anxiety and depression appear to contribute to the onset of clinical relapses, subclinical cases, and neurodegeneration.

Neurofilament light chain in the assessment of patients with multiple sclerosis / Neurofilamento de cadeia leve na avaliação de pacientes com esclerose múltipla

ABSTRACT Multiple sclerosis (MS) is an autoimmune, inflammatory, and degenerative disease of the central nervous system. Axonal degeneration is triggered by inflammation and is the pathological substrate of progressive disability in patients with MS. Therapeutic interventions can reduce inflammatory activity, thus delaying neurodegeneration and the progression of disability. Disease activity and neurodegeneration are assessed mainly through clinical evaluation and magnetic resonance imaging. These measures lack sensitivity and accuracy, so new biomarkers are necessary. Several markers have been studied and to date the most promising is neurofilament light (NfL), a component of the axonal cytoskeleton, which is released into cerebrospinal fluid (CSF) following axonal damage. In the present study, we review the current knowledge about CSF NfL determination in MS, clinically isolated syndrome, and radiologically isolated syndrome, and critically discuss how CSF NfL measurement may contribute to therapeutic decision-making in these patients.

RESUMO A esclerose múltipla (EM) é uma doença autoimune, inflamatória e degenerativa do sistema nervoso central. A degeneração axonal é deflagrada pelo processo inflamatório e é o substrato patológico da incapacidade na EM. As intervenções terapêuticas reduzem a inflamação retardando a neurodegeneração e a progressão da incapacidade. A neurodegeneração é avaliada pelo quadro clínico e pela ressonância magnética. Estas mensurações não suficientemente acuradas, havendo necessidade de novos biomarcadores. Diversos biomarcadores têm sido estudados e, até o presente, o mais promissor é o neurofilamento de cadeia leve (NfL). O mesmo é um componente do citoesqueleto que é liberado no líquido cefalorraquidiano após injúria axonal. No presente estudo nós revisamos o conhecimento atual acerca do NfL na EM, síndrome clinica isolada e síndrome radiológica isolada, discutindo criticamente como a determinação deste biomarcador pode contribuir na tomada de decisões clínicas.

Three-vessel coronary artery disease may predict changes in biochemical brain injury markers after off-pump coronary artery bypass grafting / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Neurological injury is a frequent and important complication of coronary artery bypass grafting (CABG). Several risk factors for this type of sequela have been identified, among them aortic arch atherosclerosis. Our previous study indicated that atherosclerotic burden in coronary arteries may likewise predict postoperative neurological complications (Pawliszak et al., 2016b). We assessed the severity of this condition by using the SYNTAX score calculator. However, diagnosing angiographic three-vessel coronary artery disease (3VD) could be an even simpler method of achieving this goal.

Morphological features and analysis of the nerve fibers in the periodontal ligament of dogs / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To identify the properties of nerve fibers of dogs by immunohistochemical staining method.</p><p><b>METHODS</b>Intact bone blocks above the inferior alveolar nerve canal were cut from the medial of the second premolar to the distal of the third premolar of healthy adult Beagle dogs of 18 months, embedded to make hard tissue sections, stained with S100 and neurofilament protein (NFP) antibodies, and finally observed the nerve distribution under the microscope.</p><p><b>RESULTS</b>The distribution of S100 positive tissue in the periodontal ligament of dogs showed the following patterns: bundles of densely gathered rings with different diameters, filaments accompanied by lumens, free endings and deep-dyeing oval lamellasome. The location of NFP positive tissue was similar to that of S100 positive tissue, but the distribution of these NFP positive filaments with various diameters showed largely as bundles, free ending and branches scattering in periodontal membrane.</p><p><b>CONCLUSIONS</b>We may firstly distinguish the structure of the nerve fibers in periodontal ligament of nerve distribution, and then judge the categories of the nerve fibers by S100 immunohistochemistry furtherly according to comparison of the thickness of neural axon by NFP immunohistochemistry, and finally distinct the function and attribute of the nerve fibers in the periodontal ligament of dogs. 
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Effect of sodium nitrite on phosphorylation of cytoskeletal proteins and spatial learning and memory in rats / 生理学报

The present study was aimed to explore the effect of sodium nitrite on cytoskeletal protein phosphorylation and spatial learning and memory in rats. Rats were served with drinking water containing sodium nitrite (100 mg/kg) for 60 days, then, the ability of spatial learning and memory of the rats was measured by Morris water maze. Phosphorylation level of tau and neurofilament, and the expression of protein phosphatase 2A (PP2A) catalytic subunit in the hippocampus were detected by immunohistochemistry and Western blot. In comparison with the rats served with normal tap water, the rats served with sodium nitrite water showed significantly longer latency to find the hidden platform in Morris water maze (P < 0.05), elevated phosphorylation level of tau and neurofilament, and decreased expression of PP2A catalytic subunit (P < 0.05). These results indicated that administration of sodium nitrite could impair the spatial learning and memory of the rats, and the hyperphosphorylation of cytoskeletal proteins and the down-regulation of PP2A might be underlying mechanisms for the impairment.

Effect of Draconis Sanguis-containing serum on NGF, BDNF, CNTF, LNGFR, TrkA, GDNF, GAP-43 and NF-H expressions in Schwann cells / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the effect of Draconis Sanguis-containing serum on the expressions of NGF, BDNF, CNTF, LNG-FR, TrkA, GDNF, GAP-43 and NF-H in Schwann cells, and investigate the possible mechanism of Draconis Sanguis to promote peripheral nerve regeneration.</p><p><b>METHOD</b>SD rats were randomly divided into 2 groups: the Draconis Sanguis group (orally administered with Draconis Sanguis-containing balm solution) and the blank group (equivoluminal balm) to prepare Draconis Sanguis-containing serum and blank control serum. Schwann cells were extracted from double sciatic nerves of three-day-old SD rats, divided into 2 groups: the Draconis Sanguis group and the blank control group, and respectively cultured with 10% Draconis Sanguis-containing serum or blank control serum. The mRNA expressions of NGF, BDNF, CNTF and other genes in Schwann cells were measured by RT-PCR analysis 48 hours later.</p><p><b>RESULT</b>Most of the Schwann cells were bipolar spindle and arranged shoulder to shoulder or end to end under the microscope and identified to be positive with the immunocytochemical method. To compare with the blank group, mRNA expressions of NGF, LNGFR, GDNF and GAP-43 significantly increased (P < 0.01). Whereas that of BDNF decreased significantly (P < 0.05), and so did that of TrkA, CNTF (P < 0.01), with no remarkable difference in NF-H-mRNA.</p><p><b>CONCLUSION</b>Traditional Chinese medicine Draconis Sanguis may show effect in nerve regeneration by up-regulating mRNA expressions of NGF, LNGFR, GDNF and GAP-43 and down-regulating mRNA expressions of TrkA, BDNF and CNTF.</p>

Preparation of PLLA/bpV(pic) microspheres and their effect on nerve cells / 华中科技大学学报（医学）（英德文版）

In this study, we prepared PLLA/bpV(pic) microspheres, a bpV(pic) controlled release system and examined their ability to protect nerve cells and promote axonal growth. PLLA microspheres were prepared by employing the o/w single emulsification-evaporation technique. Neural stem cells and dorsal root ganglia were divided into 3 groups in terms of the treatment they received: a routine medium group (cultured in DMEM), a PLLA microsphere group (DMEM containing PLLA microspheres alone) and a PLLA/bpV(pic) group [DMEM containing PLLA/bpV(pic) microspheres]. The effects of PLLA/bpV(pic) microspheres were evaluated by the live-dead test and measurement of axonal length. Our results showed that PLLA/bpV(pic) granulation rate was (88.2±5.6)%; particle size was (16.8±3.1)%, drug loading was (4.05±0.3)%; encapsulation efficiency was (48.5±1.8)%. The release time lasted for 30 days. In PLLA/bpV(pic) microsphere group, the cell survival rate was (95.2 ±4.77)%, and the length of dorsal root ganglion (DRG) was 718±95 μm, which were all significantly greater than those in ordinary routine medium group and PLLA microsphere group. This preliminary test results showed the PLLA/bpV(pic) microspheres were successfully prepared and they could promote the survival and growth of neural cells in DRG.

Rosiglitazone improves learning and memory impairment of 3 x Tg mice / 药学学报

This study is to investigate the protective effect of rosiglitazone (RSG) against learning and memory impairment of APP/PS1/tau transgenic mice. AD mice model was replicated by using 6-month APP/PS1/tau transgenic mice. The learning and memory ability of mice was evaluated by Morris water maze and Western blotting assays was applied to measure the phosphorylation and O-glycosylation of Tau and neurofilaments (NFs) protein. The results demonstrated that RSG could reverse the learning and memory deficits of 3 x Tg mice significantly. It was also found that RSG could suppress the hyperphosphorylation of Tau and NFs protein levels and increase the glycosylation expression of Tau and NFs proteins in 3 x Tg mice brain. Together, RSG ameliorates cognitive impairments of 3 x Tg mice via the alleviation of the hyperphosphorylated Tau and NFs proteins burden in the brain.

Effect of acupuncture on proliferation and differentiation of neural stem cells in brain tissues of rats with traumatic brain injury / 中国结合医学杂志

<p><b>OBJECTIVE</b>To observe the effect of acupuncture on proliferation and differentiation of neural stem cells in brain tissues of rats with traumatic brain injuny.</p><p><b>METHODS</b>Thirty SD rats were randomly and equally allocated to the sham-operated, the model and the acupuncture groups. The traumatic brain injury model was established by the free drop method. For the rats in the acupuncture group, acupuncture was applied once a day for 7 days. Brain histotomy was carried out when treatments were completed. Immunohistochemical techniques were adopted to detect the cells that express nestin, neurofilament proteins (NF)-200 and glial fibrillary acidic proteins (GFAP), the markers of neural stem cells, neurons, astrocytes respectively.</p><p><b>RESULTS</b>Compared to the sham-operated group, the number of nestin-positive cells and NF-200-positive cells in brain tissues was decreased significantly in the model group (P < 0.01), whereas the number of GFAP-positive cells was significantly increased P<0.01). Compared to the model group, the positive cells of nestin, NF-200, GFAP in brain tissues in the acupuncture group were increased obviously (P<0.01).</p><p><b>CONCLUSIONS</b>Acupuncture can significantly increase the number of nestin-positive cells, NF-200-positive cells and GFAP-positive cells, indicating the significant increase of neural stem cells, neurons and astrocytes in number. Acupuncture can improve neuranagenesis by promoting the proliferation and differentiation of neural stem cells in brain tissues. This might be one of the mechanisms for acupuncture to treat traumatic brain injury and to promote the repair of nervous function.</p>

Changes in autophagy-related protein levels in nervous tissues of hens with tri-ortho-cresyl phosphate-induced delayed neuropathy / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the changes in the levels of autophagy-related proteins, Atg1, Atg5, and Beclin1, in organophosphate-induced delayed neuropathy (OPIDN) caused by tri-ortho-cresyl phosphate (TOCP), and to investigate the molecular pathogenic mechanism of OPIDN.</p><p><b>METHODS</b>Thirty adult Roman hens were randomly and equally divided into control group and 1, 5, 10, and 21 d intoxication groups. Each hen in the intoxication group was administered TOCP by gavage at a single dose of 750 mg/kg, while each hen in the control group was administered the same volume of corn oil. The hens were killed at the corresponding time points, and their tibial nerves and spinal cords were collected. The levels of Atg1, Atg5, and Beclin1 in the tibial nerves and spinal cords were measured by immunoblotting.</p><p><b>RESULTS</b>Compared with those in the control group, the levels of Atg1 in tibial nerves decreased by 29.8%, 64.4%, 43.5%, and 19.8% at 1, 5, 10, and 21 d, respectively, after intoxication ((P < 0.05); the levels of Atg5 in tibial nerves decreased by 36.8%, 49.6%, 51.2%, and 31.5% at 1, 5, 10, and 21 d, respectively, after intoxication (P < 0.05); the levels of Beclin1 in tibial nerves decreased by 68.5%, 66.3%, and 32.2% at 1, 5, and 10 d, respectively, after intoxication (P < 0.05). Compared with those in the control group, the levels of Atg1 in spinal cords decreased by 23.5%, 48.7%, and 20% at 1, 5, and 10 d, respectively, after intoxication (P < 0.05); the levels of Atg5 in spinal cords decreased by 32.7%, 51.5%, 47.3%, and 39.6% at 1, 5, 10, and 21 d, respectively, after intoxication (P < 0.05); the levels of Beclin1 in spinal cords decreased by 28.9%, 50.2%, 43.2%, and 28.3% at 1, 5, 10, and 21 d, respectively, after intoxication (P < 0.05).</p><p><b>CONCLUSION</b>The intoxication of TOCP is associated with the significant changes in the levels of autophagy-related proteins in the nervous tissues of hens, which might be involved in the pathogenesis of OPIDN.</p>

Effect of 2,5-hexanedione on light-molecular-weight neurofilaments (NF-L) degradation of rat nerve tissues / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effect of 2,5-hexanedione (HD) on degradation of low-molecular-weight neurofilaments (NF-L) in nervous tissue of rats, and to explore the molecular mechanism of n-hexane neuropathy.</p><p><b>METHODS</b>Fifty male Wistar rats were randomly divided into one-week poisoning group (n = 10), two-week poisoning group (n = 10), three-week poisoning group (n = 10), four-week poisoning group (n = 10), and control group (n = 10). In the four poisoning groups, a rat model of n-hexane neuropathy was established by intraperitoneal injection of HD (400 mg/kg/d). The change in the sciatic nerve ultrastructure of each rat was observed under an electron microscope. The progression of HD-induced peripheral neuropathy was evaluated using a gait scoring system. The degradation rates of NF-L in the sciatic nerve and spinal cord of each rat were measured by Western Blotting.</p><p><b>RESULTS</b>The rats showed decrease in muscle strength and abnormal gait after two weeks of HD poisoning and mild or moderate paralysis after four weeks of HD poisoning. The sciatic nerve showed degenerative change, according to electron microscope observation. Compared with the control group, the two-week poisoning group, three-week poisoning group, and four-week poisoning group had the NF-L degradation rates decreased by 25.8%, 70.4%, and 69.7%, respectively, in the supernatant fraction of sciatic nerve, and by 14.7%, 64.6%, and 67.3%, respectively, in the sediment fraction of sciatic nerve, all showing a significant difference (P < 0.01). Compared with the control group, the one-week poisoning group had the NF-L degradation rate decreased by 33.87% in the supernatant fraction of spinal cord, the four-week poisoning group had the NF-L degradation rate increased by 16.2% in the supernatant fraction of spinal cord, and the one-week poisoning group and two-week poisoning group had the NF-L degradation rates decreased by 46.3% and 13.0% in the sediment fraction of spinal cord, all showing a significant difference (P < 0.01).</p><p><b>CONCLUSION</b>HD poisoning significantly inhibits NF-L degradation in the sciatic nerve, which may be associated with NF degeneration and accumulation in the axons of patients with n-hexane neuropathy.</p>

Features of pathological changes in the non-myelin sheath of rats with experimental autoimmune encephalomyelitis / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the pathological changes in the non-myelin sheath by observing histological damages to the neurofilament protein and apoptosis of neurons in rats with experimental autoimmune encephalomyelitis (EAE).</p><p><b>METHODS</b>Forty-eight Wistar rats were randomly divided into two groups: control and EAE (24 rats in each group). Behavioral changes were observed. Inflammation reactions and demyelination were observed by hematoxylin eosin staining and LOYEZ staining.The level of neurofilament was detected by immunohistochemistry. Apoptosis of the neuron in the spinal cord was detected by TUNEL.</p><p><b>RESULTS</b>Behavioral and histological results confirmed that the model of EAE rats was prepared successfully. In the EAE group, typical morphological features of axonal damage (sparsed axonal density, axonal distortion, axonal transection and even axonal disappearance) were found from the seventh day after immunization and the morphological changes were the most obvious on the fourteenth day. Neurofilament density in the EAE group was significantly lower than in the control group (P<0.01) at 7, 14 and 21 days after immunization. The neuronal apoptosis index in the EAE group at 7, 14 and 21 days after immunization was significantly higher than in the control group (P<0.01).</p><p><b>CONCLUSIONS</b>In addition to inflammatory demyelination, axonal damage and neuronal apoptosis can be observed in the early stage of EAE. Pathological changes may be associated with neurological dysfunction.</p>

Magnetic resonance diffusion tensor imaging for diagnosis of pyramidal tract damage in rats / 法医学杂志

OBJECTIVE@#To explore the applicability of magnetic resonance diffusion tensor imaging (DTI) for diagnosis of pyramidal tract damage in rats.@*METHODS@#Marmarou's model was set up, followed by DTI scanning at 3, 12, 24 and 72 h post trauma to acquire the dispersion parameter of bilateral pyramidal tracts. Moreover, axonal varicosities per square millimeter and the percentage of positive area of axons demonstrated by beta-amyloid precursor protein (beta-APP) immunostaining were obtained, as well as the mean density and sum density of neurofilament (NF) 68 immunostaining.@*RESULTS@#Axial diffusivity (AD), fraction anisotropy (FA) and relative anisotropy (RA) in the pyramidal tract were significantly and continuously reduced and reached to the bottom at 72h post trauma (P < 0.05) in accord with the gradient of axonal damage verified by beta-APP and NF68 immunostaining. Furthermore, the changes of AD, FA and RA showed a significant negative correlation with the beta-APP immunohistochemical results.@*CONCLUSION@#DTI has important value for early diagnosis in pyramidal tract damage.

Neurochemical Properties of Dental Primary Afferent Neurons

The long belief that dental primary afferent (DPA) neurons are entirely composed of nociceptive neurons has been challenged by several anatomical and functional investigations. In order to characterize non-nociceptivepopulation among DPA neurons, retrograde transport fluorescent dye was placed in upper molars of rats and immunohistochemical detection of peripherin and neurofilament 200 in the labeled trigeminal ganglia was performed. As the results, majority ofDPA neurons were peripherin-expressing small-sized neurons, showing characteristic ofnociceptive C-fibers. However, 25.7% of DPA were stained with antibody against neurofilament 200, indicating significant portion of DPA neurons are related to large myelinated Abeta fibers. There were a small number of neurons thatexpressed both peripherin and neurofilament 200, suggestive of Adelta fibers. The possible transition of neurochemical properties by neuronal injury induced by retrograde labeling technique was ruled out by detection of minimal expression of neuronal injury marker, ATF-3. These results suggest that in addition to the large population of C-fiber-related nociceptive neurons, a subset of DPA neurons is myelinated large neurons, which is related to low-threshold mechanosensitive Abeta fibers. We suggest that these Abeta fiber-related neurons might play a role as mechanotransducers of fluid movement within dentinal tubules.

Screening the proteins of organophosphoms ester-induced delayed neurotoxicity in the cerebral tissue of hens exposed to tri-ortho-cresyl phosphate / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To screen the proteins with differential expression levels in the cerebral tissue of hens exposed to tri-ortho-cresyl phosphate (TOCP), and to provide target proteins for studying the mechanism of organophosphoms ester-induced delayed neurotoxicity (OPIDN).</p><p><b>METHODS</b>Thirty two adult Roman hens were randomly divided into four groups: TOCP group was exposed to 1000 mg/kg TOCP, PMSF group was exposed to 40 mg/kg PMSF, PMSF plus TOCP group was exposed to 40 mg/kg PMSF and after 24 h exposed to 1000 mg/kg TOCP, control group was exposed to normal saline. All hens exposed to chemicals by gastro-intestine for 5 days were sacrificed, and the cerebral tissue were dissected and homogenized in ice bath. Total proteins extracted from the cerebral tissue were separated by isoelectric focusing as the first dimension and SDS-PAGE as the second dimension. The 2-DE maps were visualized after silver staining and analyzed by Image Master 2D software. At last ,the expressed protein spots were identified by Mass spectrometry.</p><p><b>RESULTS</b>From total proteins in TOCP group, the PMSF plus TOCP group and PMSF group, 1185, 1294 and 1063 spots were detected, respectively. One thousand three hundred thirty two spots from total proteins in control group were detected. The match rates of protein spots in TOCP group, the PMSF plus TOCP group and PMSF group were 78.32 %, 79.56 % and 80.93%, respectively. There were 235 protein spots with differential expression levels between TOCP group and control group, which included 158 up regulation spots and 77 down regulation spots. According to the PMSF features, there were 102 spots with differential expression levels between TOCP group and control group and without differential expression levels between TOCP group and PMSF plus TOCP group, among them there were 13 spots with 4 fold differential expression levels between TOCP group and control group and without differential expression levels between TOCP group and PMSF group. Seven protein spots (homer-1b, Destrin, heat shock protein 70, eukaryotic translation initiation factors, proteasome alpha1 subunit, lactate dehydrogenase B, glutamine synthetase) were detected by Mass spectrometry.</p><p><b>CONCLUSION</b>There are 112 protein spots with differential expression levels of the cerebral tissue in TOCP group, which may be related to OPIDN, among them 13 protein spots with differential expression levels are associated closely with OPIDN. Seven protein spots detected by Mass spectrometry may be related to the mechanism induced by OPIDN.</p>

Lipomatosis of nerve: a clinicopathologic analysis of 15 cases / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the clinicopathologic features of lipomatosis of nerve (NLS).</p><p><b>METHODS</b>The clinical, radiologic and pathologic features were analyzed in 15 cases of NLS.</p><p><b>RESULTS</b>There were a total of 10 males and 5 females. The age of patients ranged from 4 to 42 years (mean age = 22.4 years). Eleven cases were located in the upper limbs and 4 cases in the lower limbs. The median nerve was the most common involved nerve. The patients typically presented before 30 years of age (often at birth or in early childhood) with a soft and slowly enlarging mass in the limb, with or without accompanying motor and sensory deficits. Some cases also had macrodactyly and carpal tunnel syndrome. MRI showed the presence of fatty tissue between nerve fascicles, resembling coaxial cable in axial plane and assuming a spaghetti-like appearance in coronal plane. On gross examination, the affected nerve was markedly increased in length and diameter. It consisted of a diffusely enlarged greyish-yellow lobulated fusiform beaded mass within the epineural sheath. Histologically, the epineurium was infiltrated by fibrofatty tissue which separated, surrounded and compressed the usually normal-appearing nerve fascicles, resulting in perineural septation of nerve fascicles and microfascicle formation. The infiltration sometimes resulted in concentric arrangement of perineural cells and pseudo-onion bulb-like hypertrophic changes. The perineurial cells might proliferate, with thickening of collagen fibers, degeneration and atrophic changes of nerve bundles. Immunohistochemical study showed that the nerve fibers expressed S-100 protein, neurofilament and CD56 (weak). The endothelial cells and dendritic fibers were highlighted by CD34. The intravascular smooth muscle cells were positive for muscle-specific actin.</p><p><b>CONCLUSIONS</b>NLS is a rare benign soft tissue tumor of peripheral nerve. The MRI findings are characteristic. A definitive diagnosis can be made with histologic examination of tissue biopsy.</p>

Phosphatidylinositol phosphates directly bind to neurofilament light chain (NF-L) for the regulation of NF-L self assembly

Phosphatidylinositol phosphates (PtdInsPs) are ubiquitous membrane phospholipids that play diverse roles in cell growth and differentiation. To clarify the regulation mechanism acting on neurofilament light chain (NF-L) self assembly, we examined the effects of various PtdInsPs on this process. We found that PtdInsPs, including PI(4,5)P2, directly bind to the positively charged Arg54 of murine NF-L, and this binding promotes NF-L self assembly in vitro. Mutant NF-L (R53A/R54A) proteins lacking binding affinity to PtdInsPs did not have the same effect, but the mutant NF-L proteins showed greater self assembly than the wild-type in the absence of any PtdInsP. These results collectively suggest that Arg54 plays a pivotal role in NF-L self assembly by binding with PtdInsPs.

Cellular expression of (R127W)HSPB1 and its co-localization with neurofilament light chain / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To observe the cellular expression of (R127W) HSPB1 and its influence on neurofilament light chain (NFL) self-assembly and co-localization with NFL.</p><p><b>METHODS</b>Eukaryotic expression vectors pEGFPN1-(wt) HSPB1 and pEGFPN1- (R127W) HSPB1 were constructed. Hela cells were transiently transfected with pEGFPN1-(wt) HSPB1 or pEGFPN1- (R127W) HSPB1 and observed under a confocal microscope. Hela cells were also transiently co-transfected with Pcl-NFL and pEGFPN1-(wt)HSPB1, or pCL-NFL and pEGFPN1-(R127W)HSPB1. The self-assembly of NFL was observed and the co-localization study of HSPB1/ (R127W)HSPB1 with NFL was carried out in these two cell models by immunofluorescence technique.</p><p><b>RESULTS</b>The aggregates formed by EGFP-(R127W)HSPB1 predominantly located around the nucleus, and EGFP-(wt)HSPB1 showed diffusion pattern in Hela cells. When co expressed with EGFP-(wt)HSPB1, NFL formed homogeneous structure in cytosol. When co-expressed with EGFP-(R127W)HSPB1, however, NFL had amorphous staining pattern predominantly consisting of NFL aggregates, and NFL co-localized with (R127W)HSPB1 in these aggregates.</p><p><b>CONCLUSION</b>The R127W mutant of HSPB1 may have reduced capacity to serve as a chaperone to prevent aggregate formation, and fail to correctly organize the neurofilament network. Dysfunction of the axon cytoskeleton and axon transport may be the primary mechanism of R127W mutation of HSPB1 in the pathogenesis of Charcot-Marie-Tooth disease.</p>

Composite Pheochromocytoma or Paraganglioma of Adrenal Gland: A Case Report with Immunohistochemical Studies and Electron Microscopic Examination

Composite pheochromocytoma or paraganglioma of the adrenal gland is a well-recognized, yet extremely rare tumor with only one case reported in Korea. We report a case of incidentally found composite pheochromocytoma and ganglioneuroma of the adrenal gland in a 44-year-old female composed of intermingled components of pheochromocytom, ganglioneuroma, and cells with intermediate features. On immunohistochemical staining, the pheochromocytoma component was positive for synaptophysin and chromogranin, but negative for S-100 protein. Staining for the S-100 protein revealed sustentacular cells which formed a peripheral coat around the "Zellballen" and Schwann cells. The Fontana-Masson stain defined neuromelanin granules of ganglion cells and the ganglion cells expressed neural markers such as neurofilament proteins. Ultrastructural findings revealed pheochromocytes with a round or ovoid nucleus and occasionally prominent nucleolus containing numerous adrenaline and noradrenaline granules.