Innervation and osteoclast distribution in the inferior pharyngeal jaw of the cichlid Nile tilapia (Oreochromis niloticus)

In addition to an oral jaw, cichlids have a pharyngeal jaw, which is used for crushing and processing captured prey. The teeth and morphology of the pharyngeal jaw bones adapt to changes in prey in response to changes in the growing environment. This study aimed to explore the possible involvement of the peripheral nervous system in remodeling the cichlid pharyngeal jaw by examining the innervation of the inferior pharyngeal jaw in the Nile tilapia, Oreochromis niloticus. Vagal innervation was identified in the Nile tilapia inferior pharyngeal jaw. Double staining with tartrate-resistant acid phosphatase and immunostaining with the neuronal markers, protein gene product 9.5, and acetylated tubulin, revealed that osteoclasts, which play an important role in remodeling, were distributed in the vicinity of the nerves and were in apposition with the nerve terminals. This contact between peripheral nerves and osteoclasts suggests that the peripheral nervous system may play a role in remodeling the inferior pharyngeal jaw in cichlids.

Enhancement of angiotensin II type 1 receptor-associated protein in the paraventricular nucleus suppresses angiotensin II-dependent hypertension

The renin-angiotensin system in the brain plays a pivotal role in modulating sympathetic nerve activity and contributes to the pathogenesis of hypertension. Angiotensin II (Ang II) type 1 receptor (AT1R)-associated protein (ATRAP) promotes internalization of AT1R while suppressing pathological overactivation of AT1R signaling. However, the pathophysiological function of ATRAP in the brain remains unknown. Therefore, this study aims to investigate whether ATRAP in the paraventricular nucleus (PVN) is involved in neurogenic hypertension pathogenesis in Ang II-infused rats. The ATRAP/AT1R ratio, which serves as an indicator of tissue AT1R hyperactivity, tended to decrease within the PVN in the Ang II group than in the vehicle group. This suggests an Ang II-induced hyperactivation of the AT1R signaling pathway in the PVN. Lentiviral vectors were generated to stimulate ATRAP expression. At 6 weeks of age, rats were microinjected with LV-Venus (Venus-expressing lentivirus) or LV-ATRAP (Venus-ATRAP-expressing lentivirus). The rats were then randomly divided into four groups: (1) Vehicle/LV-Venus, (2) Vehicle/LV-ATRAP, (3) Ang II/LV-Venus, and (4) Ang II/LV-ATRAP. Two weeks after microinjection, vehicle or Ang II was administered systemically for 2 weeks. In the Ang II/LV-ATRAP group, systolic blood pressure at 1 and 2 weeks following administration was significantly lower than that in the Ang II/LV-Venus group. Furthermore, urinary adrenaline levels tended to decrease in the Ang II/LV-ATRAP group than in the Ang II/LV-Venus group. These findings suggest that enhanced ATRAP expression in the PVN suppresses Ang II-induced hypertension, potentially by suppressing hyperactivation of the tissue AT1R signaling pathway and, subsequently, sympathetic nerve activity.

Association of PDGFRA polymorphisms with the risk of corneal astigmatism in a Japanese population

Corneal astigmatism is reportedly associated with polymorphisms of the platelet-derived growth factor receptor alpha (PDGFRA) gene region in Asian populations of Chinese, Malay, and Indian ancestry and populations of European ancestry. In this study, we investigated whether these PDGFRA polymorphisms are associated with corneal astigmatism in a Japanese population. We recruited 1,535 cases with corneal astigmatism (mean corneal cylinder power across both eyes: ≤  - 0.75 diopters [D]) and 842 controls (> - 0.75 D) to genotype 13 single-nucleotide polymorphisms (SNPs) in the PDGFRA gene region. We also performed imputation analysis in the region, with 179 imputed SNPs included in the statistical analyses. The PDGFRA SNPs were not significantly associated with the cases with corneal astigmatism ≤  - 0.75 D. However, the odds ratios (ORs) of the minor alleles of SNPs in the upstream region of PDGFRA, including rs7673984, rs4864857, and rs11133315, tended to increase according to the degree of corneal astigmatism, and these SNPs were significantly associated with the cases with corneal astigmatism ≤  - 1.25 D or ≤  - 1.50 D (Pc < 0.05, OR = 1.34-1.39). These results suggest that PDGFRA SNPs play a potential role in the development of greater corneal astigmatism.

Distribution of 5HT receptors during the regeneration process after spinal cord transection in goldfish

Spinal cord injury in teleosts leads to a fibrous scar, but axons sometimes spontaneously regenerate beyond the scar. In goldfish, regenerating axons enter the scar through tubular structures and enlargement of the tubular diameter is proportional to the increase in the number of regenerating axons. During the regeneration process, mast cells containing 5-hydroxytryptamine (5HT) are recruited to the injury site, and 5HT neurons are newly generated. Here, we investigated the distribution of 5HT receptors during this process to determine their role in remodeling the fibrous scar and tubular structures. At 2 weeks after spinal cord transection (SCT) in goldfish, expression of the 5HT2A and 5HT2C receptor subtypes was observed in the ependymo-radial glial cells lining the central canal of the spinal cord. 5HT2A was expressed at the luminal surface, suggesting that it is receptive to 5HT in the cerebrospinal fluid. 5HT2C, on the other hand, was expressed around the nuclei and in the radial processes protruding from the basal surface, suggesting that it is receptive to 5HT released from nearby nerve endings. 5HT2C was also expressed in the fibrous scar where mast cells containing 5HT were abundant. 5HT1B expression was coincident with the basement membrane bordering the fibrous scar and the surrounding nervous tissue, and with the basement membrane of the tubular structure through which axons pass during regeneration. Our findings suggest that multiple 5HT receptors are involved in remodeling the injured site during the regenerative process following SCT. Ependymo-radial glial cells expressing 5HT2A and 5HT2C are involved in neurogenesis and gliogenesis, which might contribute to remodeling the fibrous scar in coordination with 5HT-containing mast cells. Coincident expression of 5HT1B with the basement membrane might be involved in remodeling the tubular structures, thereby promoting axonal regeneration.

Effects of a High-Protein Diet on Kidney Injury under Conditions of Non-CKD or CKD in Mice

Considering the prevalence of obesity and global aging, the consumption of a high-protein diet (HPD) may be advantageous. However, an HPD aggravates kidney dysfunction in patients with chronic kidney disease (CKD). Moreover, the effects of an HPD on kidney function in healthy individuals are controversial. In this study, we employed a remnant kidney mouse model as a CKD model and aimed to evaluate the effects of an HPD on kidney injury under conditions of non-CKD and CKD. Mice were divided into four groups: a sham surgery (sham) + normal diet (ND) group, a sham + HPD group, a 5/6 nephrectomy (Nx) + ND group and a 5/6 Nx + HPD group. Blood pressure, kidney function and kidney tissue injury were compared after 12 weeks of diet loading among the four groups. The 5/6 Nx groups displayed blood pressure elevation, kidney function decline, glomerular injury and tubular injury compared with the sham groups. Furthermore, an HPD exacerbated glomerular injury only in the 5/6 Nx group; however, an HPD did not cause kidney injury in the sham group. Clinical application of these results suggests that patients with CKD should follow a protein-restricted diet to prevent the exacerbation of kidney injury, while healthy individuals can maintain an HPD without worrying about the adverse effects.

Chondroitinase ABC Administration Facilitates Serotonergic Innervation of Motoneurons in Rats With Complete Spinal Cord Transection

Chondroitinase ABC (ChABC) is an enzyme that degrades glycosaminoglycan side-chains of chondroitin sulfate (CS-GAG) from the chondroitin sulfate proteoglycan (CSPG) core protein. Previous studies demonstrated that the administration of ChABC after spinal cord injury promotes nerve regeneration by removing CS-GAGs from the lesion site and promotes the plasticity of spinal neurons by removing CS-GAGs from the perineuronal nets (PNNs). These effects of ChABC might enhance the regeneration and sprouting of descending axons, leading to the recovery of motor function. Anatomical evidence, indicating that the regenerated axons innervate spinal motoneurons caudal to the lesion site, however, has been lacking. In the present study, we investigated whether descending axons pass through the lesion site and innervate the lumbar motoneurons after ChABC administration in rats with complete spinal cord transection (CST) at the thoracic level. At 3 weeks after CST, 5-hydroxytryptamine (5-HT) fibers were observed to enter the lesion in ChABC-treated rats, but not saline-treated rats. In addition, 92% of motoneurons in the ventral horn of the fifth lumbar segment (L5) in saline-treated rats, and 38% of those in ChABC-treated rats were surrounded by chondroitin sulfate-A (CS-A) positive structures. At 8 weeks after CST, many 5-HT fibers were observed in the ventral horn of the L5, where they terminated in the motoneurons in ChABC-treated rats, but not in saline-treated rats. In total, 54% of motoneurons in the L5 ventral horn in saline-treated rats and 39% of those in ChABC-treated rats were surrounded by CS-A-positive structures. ChABC-treated rats had a Basso, Beattie, and Bresnahan (BBB) motor score of 3.8 at 2 weeks, 7.1 at 3 weeks, and 10.3 at 8 weeks after CST. These observations suggest that ChABC administration to the lesion site immediately after CST may promote the regeneration of descending 5-HT axons through the lesion site and their termination on motoneurons at the level of caudal to the lesion site. ChABC administration might facilitate reinnervation by degrading CS-GAGs around motoneurons. Motor function of the lower limbs was significantly improved in ChABC-treated rats even before the 5-HT axons terminated on the motoneurons, suggesting that other mechanisms may also contribute to the motor function recovery.

Uncoupling protein 2 and aldolase B impact insulin release by modulating mitochondrial function and Ca2+ release from the ER

Uncoupling protein 2 (UCP2), a mitochondrial protein, is known to be upregulated in pancreatic islets of patients with type 2 diabetes (T2DM); however, the pathological significance of this increase in UCP2 expression is unclear. In this study, we highlight the molecular link between the increase in UCP2 expression in β-cells and β-cell failure by using genetically engineered mice and human islets. β-cell-specific UCP2-overexpressing transgenic mice (βUCP2Tg) exhibited glucose intolerance and a reduction in insulin secretion. Decreased mitochondrial function and increased aldolase B (AldB) expression through oxidative-stress-mediated pathway were observed in βUCP2Tg islets. AldB, a glycolytic enzyme, was associated with reduced insulin secretion via mitochondrial dysfunction and impaired calcium release from the endoplasmic reticulum (ER). Taken together, our findings provide a new mechanism of β-cell dysfunction by UCP2 and AldB. Targeting the UCP2/AldB axis is a promising approach for the recovery of β-cell function.

Early mobilization in spinal cord injury promotes changes in microglial dynamics and recovery of motor function

In the acute phase of spinal cord injury, the initial injury triggers secondary damage due to neuroinflammation, leading to the formation of cavities and glial scars that impair nerve regeneration. Following injuries to the central nervous system, early mobilization promotes the recovery of physical function. Therefore, in the present study, we investigated the effects of early mobilization on motor function recovery and neuroinflammation in rats. Early mobilization of rats with complete spinal cord transection resulted in good recovery of hindlimb motor function after 3 weeks. At 1 week after spinal cord injury, the early-mobilized rats expressed fewer inflammatory M1 microglia/macrophages and more anti-inflammatory M2 microglia. In addition, significantly more matrix metalloproteinase 2 (MMP2)-positive cells were observed at the lesion site 1 week after injury in the early-mobilized rats. Multiple labeling studies suggested that many MMP2-positive cells were M2 microglia. MMP9-positive cells that highly co-expressed GFAP were also observed more frequently in the early-mobilized rats. The density of growth-associated protein-positive structures in the lesion center was significantly higher in the early-mobilized rats at 3 weeks after spinal cord injury. The present results suggest that early mobilization after spinal cord injury reduced the production of M1 microglia/macrophages while increasing the production of M2 microglia at the lesion site. Early mobilization might also activate the expression of MMP2 in M2 microglia and MMP9 in astrocytes. These cellular dynamics might suppress neuroinflammation at the lesion site, thereby inhibiting the progression of tissue destruction and promoting nerve regeneration to recover motor function.

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Early mobilization effected on motor function recovery in spinal cord injury rat.

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Early mobilization suppressed neuroinflammation by M1 microglial reduction.

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Early mobilization activated expression of MMP2 in microglia cells.

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Inhibit of neuroinflammation resulted smaller spinal cord injury lesion center.

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Inhibit of neuroinflammation resulted increase the regenerating axon.

Postnatal development of thalamic reticular nucleus projections to the anterior thalamic nuclei in rats

The thalamic reticular nucleus (TRN) projects inhibitory signals to the thalamus, thereby controlling thalamocortical connections. Few studies have examined the development of TRN projections to the anterior thalamic nuclei with regard to axon course and the axon terminal distributions. In the present study, we used parvalbumin (PV) immunostaining to investigate inhibitory projections from the TRN to the thalamus in postnatal (P) 2- to 5-week-old rats (P14-35). The distribution of PV-positive (+) nerve fibers and nerve terminals markedly differed among the anterior thalamic nuclei at P14. Small, beaded nerve terminals were more distributed throughout the anterodorsal nucleus (AD) than in the anteroventral nucleus (AV) and anteromedial nucleus (AM). PV+ fibers traveling from the TRN to the AD were observed in the AV and AM. Nodular nerve terminals, spindle or en passant terminals, were identified on the axons passing through the AV and AM. At P21, axon bundles traveling without nodular terminals were observed, and nerve terminals were distributed throughout the AV and AM similar to the AD. At P28 and P35, the nerve terminals were evenly distributed throughout each nucleus. In addition, DiI tracer injections into the retrosplenial cortex revealed retrogradely-labeled projection neurons in the 3 nuclei at P14. At P14, the AD received abundant projections from the TRN and then projected to the retrosplenial cortex. The AV and AM seem to receive projections with distinct nodular nerve terminals from the TRN and project to the retrosplenial cortex. The projections from TRN to the AV and AM with nodular nerve terminals at P14 are probably developmental-period specific. In comparison, the TRN projections to the AD at P14 might be related to the development of spatial navigation as part of the head orientation system.

Chondroitin sulfate expression around motoneurons changes after complete spinal transection of neonatal rats

Hind limb locomotor activity spontaneously recovers after complete spinal transection (CST) in neonatal rats, but the mechanisms underlying the recovery are poorly understood. The perineuronal net (PNN) surrounding the neuronal cell bodies comprises an extracellular matrix that regulates neuronal plasticity during development. Here, we examined the expression of chondroitin sulfate (CS), a major component of the PNN, on motoneurons after CST in neonatal rats, and compared it with that in juvenile rats, in which hindlimb locomotor activity does not recover spontaneously. The spinal cord was transected at the mid-thoracic level in neonatal (postnatal day 5 [P5] and P10) and juvenile (P15 and P20) rats. Two weeks after CST, the percentage of motoneurons surrounded by chondroitin sulfate C (CS-C) - positive structures was significantly lower in rats with CST at P10 than in intact rats, and tended to be higher in rats with CST at P15 than in intact rats. The percentage of motoneurons with CS-A - positive structures was significantly lower in rats with CST at P15 than in intact rats. These findings suggest that CS-A and CS-C are differentially expressed in the PNNs in rats with CST. The decrease in CS-C - positive PNNs might facilitate the formation of new synaptic contacts to motoneurons, resulting in the recovery of the hindlimb locomotor activity in rats with CST during the neonatal period.

Aristolochic Acid Induces Renal Fibrosis and Senescence in Mice

The kidney is one of the most susceptible organs to age-related impairments. Generally, renal aging is accompanied by renal fibrosis, which is the final common pathway of chronic kidney diseases. Aristolochic acid (AA), a nephrotoxic agent, causes AA nephropathy (AAN), which is characterized by progressive renal fibrosis and functional decline. Although renal fibrosis is associated with renal aging, whether AA induces renal aging remains unclear. The aim of the present study is to investigate the potential use of AAN as a model of renal aging. Here, we examined senescence-related factors in AAN models by chronically administering AA to C57BL/6 mice. Compared with controls, the AA group demonstrated aging kidney phenotypes, such as renal atrophy, renal functional decline, and tubulointerstitial fibrosis. Additionally, AA promoted cellular senescence specifically in the kidneys, and increased renal p16 mRNA expression and senescence-associated β-galactosidase activity. Furthermore, AA-treated mice exhibited proximal tubular mitochondrial abnormalities, as well as reactive oxygen species accumulation. Klotho, an antiaging gene, was also significantly decreased in the kidneys of AA-treated mice. Collectively, the results of the present study indicate that AA alters senescence-related factors, and that renal fibrosis is closely related to renal aging.

Expression of matrix metalloproteinases during axonal regeneration in the goldfish spinal cord

Spinal cord injury in fish produces fibrous scar, but spontaneous axonal regeneration beyond the scar sometimes occurs. A previous study revealed that regenerating axons enter the scar through tubular structures with laminin, and that an increased number of axons within the tube is coincident with enlargement of the tube diameter and reduction of the fibrous scar area. The present study investigated the expression of matrix metalloproteinases (MMPs) that might play a role in the degradation of the extracellular matrix in fibrous scar tissue and in the remodeling of tubular structures. Spinal hemisection produced fibrous scar tissue in the lesion center, surrounded by nervous tissue. Two weeks after spinal lesioning, MMP-9 was expressed in some regenerating axons in the fibrous scar tissue. MMP-14 was expressed in the regenerating axons, as well as in glial processes in the fibrous scar tissue. MMP-2 was suggested to be expressed in mast cells in the fibrous scar. The mast cells were in contact with fibroblasts, and in close proximity to the basement membrane of tubular structures surrounding the regenerating axons. The present findings suggest that several MMPs are involved in axon regenerating processes following spinal cord injury in goldfish. MMP-9 and MMP-14 expressed in the regenerating axons might degrade extracellular matrix and support axonal growth deep into the fibrous scar tissue. MMP-14 expressed in glial cells and MMP-2 expressed in mast cells might also provide a beneficial environment for axonal regeneration, leading to successful motor recovery.

The use of angiotensin receptor blockers is associated with greater recovery of cardiac function than angiotensin-converting-enzyme inhibitors among patients with dilated cardiomyopathy

Background

We previously showed that angiotensin-converting-enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB) were associated with heart failure with recovered ejection fraction (HFrecEF) in patients with dilated cardiomyopathy (DCM). However, the different effects of these drugs on cardiac reverse remodeling have not been fully elucidated. The aim of this study was to assess comparative effectiveness of ACEi versus ARB on recovery of left ventricular ejection fraction (LVEF) among patients with DCM.

Methods

We analyzed the clinical personal records of DCM, a national database of Japanese Ministry of Health, Labour and Welfare, from 2003 to 2014. Patients with LVEF &lt;40% and on either ACEi or ARB were included. Eligible patients were divided into two groups according to the use of ACEi or ARB. A one-to-one propensity case-matched analysis was used. A propensity score was estimated by fitting a logistic-regression model which adjusted for age, sex, duration of HF, NYHA functional class (I-II vs. III-IV), systolic blood pressure, diastolic blood pressure, heart rate, atrial fibrillation, pacing, left bundle branch block, LVEF, hypertension, diabetes mellitus, hyperuricemia, chronic kidney disease, B-type natriuretic peptide (BNP), beta-blockers, mineralocorticoid receptor antagonists, loop diuretics, thiazides, digitalis, amiodarone, and oral inotropes. The primary outcome was defined as LVEF ≥40% at 3 years of follow-up.

Results

Out of 4,618 eligible patients, 2,238 patients received ACEi and 2,380 patients received ARB. Propensity score matching yielded 1,341 pairs. Mean age was 56.0 years and 2,041 (76.1%) was male. Mean LVEF was 27.6%, and median duration of HF was 1 year. The primary outcome was observed more frequently in ARB group than in ACEi group (59.8% vs. 54.1%; odds ratio [OR] 1.26; 95% confidence interval [CI] 1.08–1.47; P=0.003). The change in LVEF from baseline to 3 years of follow-up was greater in ARB group than in ACEi group (15.8±0.4 vs. 14.0±0.4%, P=0.002). In the ACEi group, 946 patients (70.6%) continued to receive ACEi at 3 years of follow-up, while 1,088 patients (81.3%) continued to receive ARB in the ARB group. Per-protocol analysis consistently showed that ARB increased the prevalence of HFrecEF (62.0% vs. 54.0%; OR 1.39; 95% CI 1.17–1.66; P&lt;0.001). Subgroup analysis showed that ARB increased frequency of HFrecEF regardless systolic blood pressure, heart rate, LVEF, chronic kidney disease, and concomitant use of beta-blockers and mineralocorticoid receptor antagonists.

Conclusions

The use of ARB was associated with HFrecEF more frequently than ACEi among patients with DCM and reduced LVEF.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Health Sciences Research Grants from the Japanese Ministry of Health, Labour and Welfare (Comprehensive Research on Cardiovascular Diseases)Japan Agency for Medical Research and Development (AMED) grant

Practical Arachnoid Anatomy for the Technical Consideration of Galen Complex Dissection: Cadaveric and Clinical Evaluation

BACKGROUND

The occipital transtentorial approach (OTA) is a very useful but challenging approach to expose the pineal region because the deep-seated arachnoid membranes usually fold and extend over the great vein of Galen (GVG), leading to dense and poor visibility. In addition, the practical aspects of arachnoid anatomy are not well understood. We aimed to develop a safe surgical procedure for the OTA according to the practical aspects of arachnoid anatomy.

METHODS

The procedure is shown through an illustrative video of surgery and cadaver. Five cadavers were analyzed for their arachnoid structures and the surgical procedures via the OTA, in strict compliance with legal and ethical requirements.

RESULTS

All cadavers showed a 2-layered arachnoid structure-one belonging to the occipital lobe, and the other to the cerebellum. According to our cadaveric analysis, the arachnoid attachment of the tentorial apex can be peeled bluntly, with an average distance of 10.2 mm. For our clinical presentation, a pineal tumor with hydrocephalus was detected in a 14-year-old boy. While using the OTA and expanding the deep surgical field, we detached the membrane from the tentorial apex and bluntly peeled it to reveal the deep veins. Finally, gross total removal of the tumor was achieved.

CONCLUSIONS

A 2-layered arachnoid structure interposes the GVG from above and below the tentorium. The arachnoid membrane below the tentorium can be peeled off bluntly from the GVG to the attachment bundle limited by the penetrating veins. This detachment technique is useful for safe enlargement of the surgical field for the OTA.

Chondroitin sulfate expression around spinal motoneurons during postnatal development in rats

Perineuronal nets are extracellular matrix structures that surround neuronal cell bodies and their proximal dendrites in the central nervous system. Chondroitin sulfate proteoglycans, which contain chondroitin sulfates (CSs) are major components of perineuronal nets. CSs are considered to have inhibitory roles in neural plasticity, although the effects differ according to their sulfation pattern. In the present study, we investigated the expression of the CS subtypes CS-A and CS-C surrounding spinal motoneurons in different postnatal periods to explore the potential influence of altered CS sulfation patterns on spinal development. CS-A-positive structures were observed around motoneurons in the cervical, thoracic, and lumbar segments as early as postnatal day (P) 5. Most motoneurons were covered with CS-A-positive structures during the first 2 postnatal weeks. The percentage of motoneurons covered with CS-A-positive structures decreased after P20, becoming lower than 70% in the cervical, and lumber segments after P35. CS-C-positive structures were occasionally observed around motoneurons during the first 2 postnatal weeks. The percentage of motoneurons covered with CS-C-positive structures increased after P20, becoming significantly higher after P25 than before P20. The expression pattern of Wisteria Floribunda agglutinin-positive structures around motoneurons was similar to that of the CS-C-positive structures. The present findings revealed that CS-A and CS-C are differentially expressed in the extracellular matrix surrounding motoneurons. The altered sulfation pattern with increased CS-C expression is associated with the maturation of perineuronal nets and might lead to changes in the motoneuron plasticity.

OGT Regulates Hematopoietic Stem Cell Maintenance via PINK1-Dependent Mitophagy

O-linked N-acetylglucosamine (O-GlcNAc) transferase (OGT) is a unique enzyme introducing O-GlcNAc moiety on target proteins, and it critically regulates various cellular processes in diverse cell types. However, its roles in hematopoietic stem and progenitor cells (HSPCs) remain elusive. Here, using Ogt conditional knockout mice, we show that OGT is essential for HSPCs. Ogt is highly expressed in HSPCs, and its disruption induces rapid loss of HSPCs with increased reactive oxygen species and apoptosis. In particular, Ogt-deficient hematopoietic stem cells (HSCs) lose quiescence, cannot be maintained in vivo, and become vulnerable to regenerative and competitive stress. Interestingly, Ogt-deficient HSCs accumulate defective mitochondria due to impaired mitophagy with decreased key mitophagy regulator, Pink1, through dysregulation of H3K4me3. Furthermore, overexpression of PINK1 restores mitophagy and the number of Ogt-deficient HSCs. Collectively, our results reveal that OGT critically regulates maintenance and stress response of HSCs by ensuring mitochondrial quality through PINK1-dependent mitophagy.

The nationwide registry of hospitalized heart failure patients in Japan: Japanese Registry Of Acute Decompensated Heart Failure (JROADHF)

Background and aim

Heart failure (HF) is a growing healthcare problem worldwide. This study aimed to describe clinical characteristics and long-term outcomes of HF patients in Japan.

Methods and results

JROADHF (the Japanese Registry Of Acute Decompensated Heart Failure) is a retrospective, multicentre, nationwide observational database of 13,238 patients hospitalized due to HF in 128 hospitals randomly selected from Japanese Circulation Society (JCS)-certified teaching hospitals during 2013. At inclusion, demographic and clinical data were collected from medical records with linkage to a nationwide claim-based database, the Japanese Diagnosis Procedure Combination (DPC). Patients were followed up to 5 years after discharge at each participating site. Patients were old as the median age of 81 years and women were older (74.8±12.8 vs 81.6±11.1 y.o). Mean left ventricular ejection fraction (LVEF) was 47%, and 45% were HF with preserved ejection fraction of &gt;50% (HFpEF). Causes of HF included ischemic in 27%, valvular in 19%, arrhythmia in 17%, and hypertensive in 16%. Median length of hospital stay was 18 days and in-hospital mortality was 7.7%. All-cause mortality during 1 and 4 years were 22.3% and 48.4%, respectively. Hospitalization rates due to HF within 1 and 4 years were as high as 30.5 and 48.4%, respectively.

Conclusions

Contemporary nationwide registry revealed that hospitalized HF patients were elder and had more HFpEF, and their prognosis was still poor compared to the data shown in prior registries.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Japan Agency for Medical Research and Development (AMED) Practical Research Project for Life-Style related Diseases including Cardiovascular Diseases and Diabetes Mellitus

Use of direct oral anticoagulants is associated with better long-term outcomes in patients with atrial fibrillation and heart failure as compared with vitamin K antagonists

Background

Direct oral anticoagulants (DOACs) have been shown to be safe and effective in patients with atrial fibrillation (AF) as compared with warfarin, a vitamin K antagonist. However, the safety and efficacy of DOACs in patients with AF and heart failure (HF) have been unclear.

Purpose

The purpose of this study was to determine whether DOACs can improve long-term outcomes in patients with AF and HF as compared with warfarin.

Methods

We analyzed the JROADHF registry, which was a multicenter registry of patients hospitalized for the worsening HF in Japan. Baseline data were collected during the episode of index hospitalization from April 2013 to March 2014. Follow-up data were collected up to 4.5 years after the index hospitalization. Patients with AF and creatinine clearance ≥15 ml/min/1.73m2 were included. Valvular heart disease, congenital heart disease, and constrictive pericarditis were excluded. Eligible patients were divided into two groups according to the use of warfarin or DOACs. The primary outcome was defined as all-cause death. The secondary outcomes were defined as cardiovascular death, composite of all-cause death or cardiovascular hospitalization, and composite of stroke death or stroke related hospitalization. A one to one propensity case-matched analysis was used. Complete case analysis and multiple imputation analysis were also conducted as sensitivity analyses.

Results

Out of the 14,847 patients in this registry, 2,175 had AF, creatinine clearance ≥15 ml/min/1.73m2 and discharged alive. Propensity score matching yielded 475 pairs. In matching cohort, mean age was 76.5 years and 513 (54.0%) was male. Mean left ventricular ejection fraction was 48.6±16.4%. During a mean follow-up of 3.2 years, patients with DOACs had a lower incidence rate of all-cause death than those with warfarin (75.2 vs. 99.9 death per 1000 patient-years; rate ratio (RR) 0.75; 95% confidence interval [CI] 0.59–0.96; P=0.022). The incidence of cardiovascular death tended to be lower in DOAC group (30.9 vs. 43.1; incidence rate ratio 0.72; 95% CI 0.49–1.04; P=0.081). There were no significant differences in the incidence of composite of all cause death or cardiovascular hospitalization (252.3 vs. 269.4; RR 0.94; 95% CI 0.79–1.11; P=0.45) or composite of stroke death or stroke related hospitalization (13.1 vs. 16.7; RR 0.79; 95% CI 0.39–1.59; P=0.50). Cox regression model showed that DOAC was associated with lower mortality than warfarin (hazard ratio (HR) 0.75; 95% CI 0.59–0.96; P=0.023). Complete case analysis (HR 0.78; 95% CI 0.63–0.98; P=0.035) and multiple imputation analysis (HR 0.78; 95% CI 0.68–0.84; P&lt;0.001) also showed the same results. A restricted cubic spline analysis demonstrated that the effectiveness of DOACs over warfarin waned with age, and DOACs were effective in patients younger than 80 years old.

Conclusion

Use of DOACs was associated with better long-term outcome in patients with HF as compared with warfarin.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Japan Agency for Medical Research and Development

Artificial intelligence-based analysis of payment system data can predict one-year mortality of hospitalized patients with heart failure

Background

Individual risk stratification is fundamental in the care of heart failure (HF) patients. However, the prediction performance of risk scores, such as MAGGIC and SHFM, is not adequate and, more importantly, they need additional predictors including various biomarkers, imaging data, and environmental factors. Data from a case-mix payment system including diagnosis and procedures with outcomes can be used to develop the risk prediction models, allowing the use of big data for a more accurate prediction of mortality.

Purpose

This study aimed to develop artificial intelligence (AI) models for predicting 1-year mortality in patients hospitalized due to HF.

Methods

We analyzed the data from 10175 patients enrolled in the Japanese Registry Of Acute Decompensated Heart Failure (JROADHF). Candidate variables included the data obtained from a payment system introduced by the Japanese government, the Diagnosis Procedure Combination (DPC), which included each patient profile (age, sex, height, weight), principal diagnosis for hospitalization, comorbidities, procedures, length of hospital stay, and discharge status. They did not include clinical data available from patients such as vital status, laboratory data including bio-makers, electrocardiographic and echocardiographic data. The collected data were divided into the training set and the validation set (80%: 20%). With the training set, 5 AI models (logistic regression, random forest, support vector machine, neural network, and ensemble classifier) learned the one-year mortality results. AI models were evaluated by using the validation set with ROC analysis. The training and validation steps were repeated 10 times with different seed values to calculate the C-statistic of each model. We also identified the predictors for one-year prognosis acquired from the AI models.

Results

At 1-year of follow-up, a total of 1727 patients had died (17%). Among the machine learning models, the ensemble classifier showed the highest C-statistic of 0.76 (95% confidence interval: 0.75 to 0.77) for predicting mortality. Top predictors acquired from the random forest classifier was ADL (Barthel Index) at discharge, age, body mass index, and length of hospital stay.

Conclusion

By using AI-based analysis of a national case-mix payment system data, the present risk stratification model could predict the one-year mortality of hospitalized HF patients without any quantitative laboratory and physiological data. Furthermore, the present results could emphasize the advantage of this approach using the claim-based data that are routinely collected in a usual daily practice with no need to collect any additional information.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Japan Agency for Medical Research and Development

Distribution of mRNA for GPR143, a receptor of 3,4-L-dihydroxyphenylalanine, and of immunoreactivities for nicotinic acetylcholine receptors in the nigrostriatal and mesolimbic regions

Nicotine exerts its reinforcing actions by activating nicotinic acetylcholine receptors (nAChRs), but the detailed mechanisms remain unclear. Nicotine releases 3, 4-dihydroxyphenylalanine (DOPA), a neurotransmitter candidate in the central nervous system. Here, we investigated the distribution of GPR143, a receptor of DOPA, and nAChR subunits in the nigrostriatal and mesolimbic regions. We found GPR143 mRNA-positive cells in the striatum and nucleus accumbens. Some of them were surrounded by tyrosine hydroxylase (TH)-immunoreactive fibers. There were some GPR143 mRNA-positive cells coexpressing TH, and nAChR subunit α4 or α7 in the substantia nigra and ventral tegmental area. These findings suggest that DOPA-GPR143 signaling may be involved in the nicotine action in the nigrostriatal and mesolimbic dopaminergic systems.

Proteomic analysis of exosome-enriched fractions derived from cerebrospinal fluid of amyotrophic lateral sclerosis patients

Exosomes contain many proteins associated with neurodegenerative diseases. To identify new candidate biomarkers and proteins associated with amyotrophic lateral sclerosis (ALS), we performed liquid chromatography-tandem mass spectrometry proteomic analysis of exosome-enriched fractions isolated from cerebrospinal fluid (CSF) of sporadic ALS patients using gel filtration chromatography. Proteomic data revealed that three proteins were increased and 11 proteins were decreased in ALS patients. The protein with the greatest increase in exosome-enriched fractions of CSF derived from ALS was novel INHAT repressor (NIR), which is closely associated with nucleolar function. By immunohistochemical analysis, we found that NIR was reduced in the nucleus of motor neurons in ALS patients. Our results demonstrate the potential utility of our methodology for proteomic analysis of CSF exosomes and suggest that nucleolar stress might play a role in sporadic ALS pathogenesis through the dysfunction of NIR.

Assessment of the subcutaneous degradation process of insoluble hyaluronic acid in rats

Insoluble hyaluronic acid (IHA) may prevent adhesions by forming a physical barrier during the period when postoperative adhesions form. This study was performed to verify the changes that a solid IHA membrane undergoes as it is degraded in vivo, and to ascertain the swelling rate of IHA required for it to function as a physical barrier during the postoperative adhesion formation period. Nine female WI rats weighing 300-400 g were used. Discs 8 mm in diameter were cut out of dry IHA membranes made of IHA with a swelling rate (wet weight/dry weight) of either 2.47 (high-swelling IHA) or 1.94 (low-swelling IHA). They were placed in saline to swell and then washed with saline before subcutaneous implantation in four pockets in each rat. The high-swelling IHA started to degrade more rapidly than the low-swelling IHA. There was no evidence of degradation of the low-swelling IHA until day 7, but once it had started, the speed of degradation tended to be similar to that of the high-swelling IHA. The present results showed that, when IHA is implanted subcutaneously in rats, it is degraded over time in a phased process. The swelling rate required for the use of IHA as a postoperative adhesion barrier was also suggested.

Neonatal spinal injury induces de novo projections of primary afferents to the lumbosacral intermediolateral nucleus in rats

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Neonatal spinal injury induces dextran amine-labeled primary afferent projections to the sacral intermediolateral nucleus.

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Dextran amine-labeled afferent fibers form varicose terminals on the parasympathetic preganglionic neurons.

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Dextran amine tends to be incorporated preferentially in dorsal root ganglion neurons with myelinated fibers.

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De novo projections of myelinated afferents might contribute to the recovery of micturition following neonatal spinal injury.

Complete spinal transection in adult rats results in poor recovery of hind limb function and severe urinary bladder dysfunction. Neonatal rats with spinal cord transection, however, exhibit spontaneous and significant recovery of micturition control. A previous study in which biotinylated-dextran amine (BDA) was used as an anterograde tracer demonstrated that primary afferent fibers from the fifth lumbar dorsal root ganglion (DRG) project more strongly and make more terminals in the ventral horn after neonatal spinal cord transection at the mid-thoracic level. In the present study, we injected BDA into the sixth lumbar (L6) DRG of neonatally spinalized rats to label primary afferent fibers that include visceral afferents. The labeled fibers projected to the intermediolateral nucleus (IML) in the intermediate zone on ipsilateral side of the L6 spinal segment, whereas no projections to the IML were observed in sham-operated or intact rats. The BDA-labeled fibers of neonatally spinalized rats formed varicose terminals on parasympathetic preganglionic neurons in the IML. These findings suggest that some primary afferent projections from the L6 DRG to the IML appear after neonatal spinal cord transection, and these de novo projections might contribute to the recovery of autonomic function such as micturition following spinal cord injury in the neonatal stage.

Chondroitin Sulfate Expression in Perineuronal Nets After Goldfish Spinal Cord Lesion

Perineuronal nets (PNNs) surrounding neuronal cell bodies regulate neuronal plasticity during development, but their roles in regeneration are unclear. In the PNNs, chondroitin sulfate (CS) is assumed to be involved in inhibiting contact formation. Here, we examined CS expression in PNNs in the ventral horn of a goldfish hemisected spinal cord in which descending axons regenerate beyond the lesion to connect with distal spinal neurons. In intact fish, chondroitin sulfate A (CS-A)–positive PNNs accounted for 5.0% of HuC/D-immunoreactive neurons, and 48% of choline acetyltransferase (ChAT)-immunoreactive neurons. At 2, 4 and 8 weeks after spinal hemisection, CS-A–positive PNNs accounted for 8.4%–9.9% of HuC/D-immunoreactive neurons, and 50%–60% of ChAT-immunoreactive neurons, which was not significantly different from intact fish. Chondroitin sulfate C (CS-C)–positive PNNs accounted for 6.4% of HuC/D-immunoreactive neuron, and 67% of ChAT-immunoreactive neurons in intact fish. At 2, 4 and 8 weeks after spinal hemisection, CS-C–positive PNNs accounted for 7.9%, 5.5% and 4.3%, respectively, of HuC/D-immunoreactive neurons, and 65%, 52% and 42%, respectively, of ChAT-immunoreactive neurons, demonstrating a significant decrease at 4 and 8 weeks after spinal hemisection. Among ventral horn neurons that received descending axons labeled with tetramethylrhodamine dextran amine (RDA) applied at the level of the first spinal nerve, CS-A–positive PNNs accounted for 53% of HuC/D-immunoreactive neurons. At 2 and 4 weeks after spinal hemisection, CS-A–positive PNNs accounted for 57% and 56% of HuC/D-immunoreactive neurons, which was not significantly different from intact fish. CS-C–positive PNNs, accounted for 48% of HuC/D-immunoreactive neurons that received RDA-labeled axons. At 2 and 4 weeks after spinal hemisection, CS-C–positive PNNs significantly decreased to 22% of the HuC/D-immunoreactive neurons, and by 4 weeks after spinal hemisection they had returned to 47%. These findings suggest that CS expression is maintained in the PNNs after spinal cord lesion, and that the descending axons regenerate to preferentially terminate on neurons not covered with CS-C–positive PNNs. Therefore, CS-C in the PNNs possibly inhibits new contact with descending axons, and plasticity in the spinal neurons might be endowed by downregulation of CS-C in the PNNs in the regeneration process after spinal hemisection in goldfish.

A Focal Cooling Method for the Cervical Spinal Cord: A Percutaneous Approach to the Dorsal Neck in Dogs

For the treatment of acute cervical spinal cord injuries, a local epidural cooling system using a percutaneous technique was proposed. In this animal study, regional low temperature was obtained stably in the cervical epidural space (CED) without decreasing temperatures at the rectum and the thoracic epidural space. Three stainless steel tubes were inserted percutaneously using the lateral approach into 3 serial interspinous spaces of the neck of 12 beagles under radiographic guidance. Two temperature probes were inserted into the CEDs at the level of the middle cooling tube. A third temperature probe was inserted into the epidural space at the Th13 level. A fourth temperature probe was placed in the rectum as a control. Iced water was circulated in the cooling tubes for 60 minutes. Temperatures were monitored every 10 seconds for 90 minutes, with the minimum temperatures during the period being recorded. The mean minimum temperatures recorded in the dorsal CED (min-CED-dorsal), the lateral CED (min-CED-lateral), the Th13 epidural space (min-T13ED), and the rectum (min-rectum), were 16.0 ± 0.6°C, 22.6 ± 1.6°C, 35.4 ± 0.2°C, and 35.5 ± 0.2°C, respectively. There was a statistically significant difference between the mean min-CED-dorsal and min-rectum temperatures (p < 0.0001). The method introduced above was effective in reducing cervical epidural temperature selectively.

Regulation of axonal regeneration by the level of function of the endogenous Nogo receptor antagonist LOTUS

Axonal regeneration in the adult mammalian central nervous system is limited in part by the non-permissive environment, including axonal growth inhibitors such as the Nogo-A protein. How the functions of these inhibitors can be blocked remains unclear. Here, we examined the role of LOTUS, an endogenous Nogo receptor antagonist, in promoting functional recovery and neural repair after spinal cord injury (SCI), as well as axonal regeneration after optic nerve crush. Wild-type untreated mice show incomplete but substantial intrinsic motor recovery after SCI. The genetic deletion of LOTUS delays and decreases the extent of motor recovery, suggesting that LOTUS is required for spontaneous neural repair. The neuronal overexpression of LOTUS in transgenic mice promotes motor recovery after SCI, and recombinant viral overexpression of LOTUS enhances retinal ganglion cell axonal regeneration after optic nerve crush. Thus, the level of LOTUS function titrates axonal regeneration.

Chondroitin sulfates do not impede axonal regeneration in goldfish spinal cord

Chondroitin sulfate proteoglycans produced in glial scar tissue are a major inhibitory factor for axonal regeneration after central nervous system injury in mammals. The inhibition is largely due to chondroitin sulfates, whose effects differ according to the sulfation pattern. In contrast to mammals, fish nerves spontaneously regenerate beyond the scar tissue after spinal cord injury, although the mechanisms that allow for axons to pass through the scar are unclear. Here, we used immunohistochemistry to examine the expression of two chondroitin sulfates with different sulfation variants at the lesion site in goldfish spinal cord. The intact spinal cord was immunoreactive for both chondroitin sulfate-A (CS-A) and chondroitin sulfate-C (CS-C), and CS-A immunoreactivity overlapped extensively with glial processes positive for glial fibrillary acidic protein. At 1week after inducing the spinal lesion, CS-A immunoreactivity was observed in the cell bodies and extracellular matrix, as well as in glial processes surrounding the lesion center. At 2weeks after the spinal lesion, regenerating axons entering the lesion center overtook the CS-A abundant area. In contrast, at 1week after lesion induction, CS-C immunoreactivity was significantly decreased, and at 2weeks after lesion induction, CS-C immunoreactivity was observed along the regenerating axons entering the lesion center. The present findings suggest that after spinal cord injury in goldfish, chondroitin sulfate proteoglycans are deposited in the extracellular matrix at the lesion site but do not form an impenetrable barrier to the growth of regenerating axons.

Fiber Connections of the Caudal Corpus Cerebelli, with Special Reference to the Intrinsic Circuitry, in a Teleost (Oreochromis niloticus)

The caudal part of the corpus cerebelli of Nile tilapia can be divided into dorsal and ventral regions. The granule cell layer of the dorsal (dGL) and ventral (vGL) regions of the caudal corpus cerebelli is known to receive indirect inputs from the telencephalon relayed by the nucleus paracommissuralis. The descending pathways are topographically organized, and the dGL and vGL receive inputs from different dorsal telencephalic parts. The caudal corpus cerebelli, in turn, projects extracerebellar efferents. However, it remains unknown how the descending telencephalic inputs are processed within the cerebellum. Therefore, the present study investigated intrinsic connections of the caudal corpus cerebelli by injecting neural tracers into the molecular layer of dorsal and ventral regions. Injections of tracers into the ventral molecular layer resulted in labeled cells in the vGL and the ganglionic layer of the ventral corpus. The axonal trajectories from labeled cells in the ganglionic layer were analyzed in detail via single-axon reconstructions, which suggested that the terminal portions were confined to the ganglionic layer of the dorsal corpus. No labeled terminals were observed outside the caudal corpus cerebelli. Tracer applications to the dorsal molecular layer resulted in labeled cells not only in the ganglionic layer and the granule cell layer of the dorsal corpus but also in the ganglionic layer of the ventral corpus. The latter finding confirms the presence of intrinsic projections from the ventral region to the dorsal region in the caudal corpus cerebelli. We further revealed that the intrinsic projection neurons are Purkinje cells by immunohistochemistry for zebrin II (aldolase C), which is a marker of Purkinje cells, combined with tracer injections into the dorsal corpus. Unlike injections into the ventral corpus, injections into the dorsal corpus resulted in labeled terminals in extracerebellar structures, such as the nucleus of the medial longitudinal fascicle and reticular formation. The present study suggests that indirect inputs from different telencephalic parts received and processed by distinct regions of caudal corpus cerebelli are sent out of the corpus through the efferent neurons in the dorsal corpus.

Clinical classification of 103 Japanese patients with Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is the commonest cause of flaccid paralysis worldwide. Miller Fisher syndrome (MFS) is a variant of GBS characterized by ophthalmoplegia and ataxia. Together GBS and MFS form a continuum of discrete and overlapping subtypes, the frequency of which remains unknown. We retrospectively analysed the clinical features (antecedent symptoms, pattern of neurological weakness or ataxia, presence of hypersomnolence) of 103 patients at a single hospital in Japan. Patients were then classified according to new diagnostic criteria (Wakerley et al., 2014). Laboratory data (neurophysiology and anti-ganglioside antibody profiles) were also analysed. According to the new diagnostic criteria, the 103 patients could be classified as follows: classic GBS 73 (71%), pharyngeal-cervical-brachial weakness 2 (2%), acute pharyngeal weakness 0 (0%), paraparetic GBS 1 (1%), bifacial weakness with paraesthesias 1 (1%), polyneuritis cranialis 0 (0%), classic MFS 18 (17%), acute ophthalmoparesis 1 (1%), acute ptosis 0 (0%), acute mydriasis 0 (0%), acute ataxic neuropathy 1 (1%), Bickerstaff brainstem encephalitis 3 (3%), acute ataxic hypersomnolence 0 (0%), GBS and MFS overlap 1 (1%), GBS and Bickerstaff brainstem encephalitis overlap 1 (1%), MFS and pharyngeal-cervical-brachial weakness overlap 1 (1%). Application of the new clinical diagnostic criteria allowed accurate retrospective diagnosis and classification of GBS and MFS subtypes.

Compensatory projections of primary sensory fibers in lumbar spinal cord after neonatal thoracic spinal transection in rats

Complete spinal transection in adult rats results in poor recovery of hind limb function, whereas significant spontaneous recovery can occur following spinal cord transection in rat neonates. The mechanisms underlying the recovery, however, are poorly understood. Recent studies in rodents suggested that the recovery is not due to axonal regeneration, but rather due to reorganization of the neural circuits in the spinal cord below the injury site, including central pattern generators. Few studies have reported histological evidence for changes in the primary sensory fibers or terminals. Thus, in the present study, we transected spinal cords of rats at thoracic level 8 at postnatal day 5. Four weeks after the injury, biotinylated-dextran amine (BDA), an anterograde tracer, was injected into the dorsal root ganglion of the lumbar spinal cord to examine the localization of sensory fibers and their terminal buttons in the spinal cord. BDA-positive axons in the rat spinal cord following neonatal spinal transection (neo ST) were longer than those in sham-operated or normal rats. The number of terminal buttons was also higher in spinal cords of neo ST rats compared with sham-operated or normal rats. These findings suggest that sensory fibers project more strongly and make more synapses following neo ST to compensate for the lack of supraspinal projections.

Anti-GQ1b antibody syndrome: anti-ganglioside complex reactivity determines clinical spectrum

BACKGROUND AND PURPOSE

Anti-GQ1b antibodies have been found in patients with Miller Fisher syndrome as well as its related conditions. Our aim was to identify the mechanism by which autoantibodies produce various clinical presentations in 'anti-GQ1b antibody syndrome'.

METHODS

Immunoglobulin G antibodies to ganglioside complex (GSC) of GQ1b or GT1a with GM1, GD1a, GD1b or GT1b were tested in sera from patients with anti-GQ1b (n = 708) or anti-GT1a (n = 696) IgG antibodies. Optical densities of the single anti-GQ1b or anti-GT1a antibodies were used as reference (100%), and those of anti-GSC antibodies were expressed in percentages to reference. The relationships between anti-GSC antibody reactivity and the corresponding clinical features were assessed by multivariate logistic regression analysis.

RESULTS

Ophthalmoplegia and hypersomnolence were significantly associated with complex-attenuated anti-GQ1b and anti-GT1a antibodies. Ataxia was associated with GD1b- and GT1b-enhanced anti-GQ1b antibodies or GM1-enhanced anti-GT1a antibodies. Bulbar palsy was associated with GT1b-enhanced anti-GQ1b antibodies. Neck weakness was associated with GD1a-enhanced anti-GQ1b antibodies. Arm weakness was associated with GD1b-enhanced anti-GQ1b and GD1a-enhanced anti-GT1a antibodies. Leg weakness was associated with GD1a-enhanced anti-GQ1b and anti-GT1a antibodies.

CONCLUSIONS

Differences in fine specificity of anti-GQ1b antibodies are associated with clinical features, possibly due to the different expression of gangliosides in different parts of the nervous system.

Spinal cord stimulation modulates supraspinal centers of the descending antinociceptive system in rats with unilateral spinal nerve injury

BACKGROUND

The descending antinociceptive system (DAS) is thought to play crucial roles in the antinociceptive effect of spinal cord stimulation (SCS), especially through its serotonergic pathway. The nucleus raphe magnus (NRM) in the rostral ventromedial medulla is a major source of serotonin [5-hydroxytryptamine (5-HT)] to the DAS, but the role of the dorsal raphe nucleus (DRN) in the ventral periaqueductal gray matter is still unclear. Moreover, the influence of the noradrenergic pathway is largely unknown. In this study, we evaluated the involvement of these serotonergic and noradrenergic pathways in SCS-induced antinociception by behavioral analysis of spinal nerve-ligated (SNL) rats. We also investigated immunohistochemical changes in the DRN and locus coeruleus (LC), regarded as the adrenergic center of the DAS, and expression changes of synthetic enzymes of 5-HT [tryptophan hydroxylase (TPH)] and norepinephrine [dopamine β-hydroxylase (DβH)] in the spinal dorsal horn.

RESULTS

Intrathecally administered methysergide, a 5-HT1- and 5-HT2-receptor antagonist, and idazoxan, an α2-adrenergic receptor antagonist, equally abolished the antinociceptive effect of SCS. The numbers of TPH-positive serotonergic and phosphorylated cyclic AMP response element binding protein (pCREB)-positive neurons and percentage of pCREB-positive serotonergic neurons in the DRN significantly increased after 3-h SCS. Further, the ipsilateral-to-contralateral immunoreactivity ratio of DβH increased in the LC of SNL rats and reached the level seen in naïve rats, even though the number of pCREB-positive neurons in the LC was unchanged by SNL and SCS. Moreover, 3-h SCS did not increase the expression levels of TPH and DβH in the spinal dorsal horn.

CONCLUSIONS

The serotonergic and noradrenergic pathways of the DAS are involved in the antinociceptive effect of SCS, but activation of the DRN might primarily be responsible for this effect, and the LC may have a smaller contribution. SCS does not potentiate the synthetic enzymes of 5HT and norepinephrine in the neuropathic spinal cord.

Role of nerve growth factor-tyrosine kinase receptor A signaling in paclitaxel-induced peripheral neuropathy in rats

The mechanisms underlying paclitaxel-induced peripheral neuropathy remain unknown. Nerve growth factor (NGF) is a representative neurotrophic factor that maintains neuronal function, promotes survival, and mediates neuropathic pain. We investigated expression levels of NGF and its receptors in the dorsal root ganglia (DRG) and spinal dorsal horn (DH) following paclitaxel treatment. Intraperitoneal (I.P.) administration of paclitaxel induced significant mechanical hypersensitivity and cold allodynia in rats, significantly increased the expression of NGF and its receptor tyrosine kinase receptor A (trkA) in the DRG, and increased NGF expression in the DH. In contrast, paclitaxel treatment did not alter the mRNA levels of NGF or its receptors in the DRG, DH, sciatic nerve, or hindpaw skin. Moreover, expression of NEDD4-2, a negative regulator of trkA, was significantly increased in the DRG of paclitaxel-treated rats. Intrathecal (I.T.) administration of the tyrosine kinase receptor inhibitor k252a significantly alleviated mechanical hypersensitivity in paclitaxel-treated rats. Our results suggest that NGF-trkA signaling is involved in mechanical allodynia in paclitaxel-induced neuropathy.

Hepatic triglyceride lipase plays an essential role in changing the lipid metabolism in genotype 1b hepatitis C virus replicon cells and hepatitis C patients

AIM

Recently, several studies have shown the existence of associations between lipoprotein profiles and hepatitis C virus (HCV), although only a limited amount of information is available about the mechanisms underlying the changes in the lipoprotein profiles associated with HCV. In this study, we investigated the association between lipoprotein profile, classified according to the particle size, and lipoprotein metabolism.

METHODS

We used four kinds of cells for this experiment; full-length genome HCV RNA replicon cells (OR6), sub-genomic HCV RNA replicon cells (sO), and OR6c cells and sOc cells, which were the same cell lines treated with interferon-α. The triglyceride (TG) levels in the lipoprotein subclasses of the culture medium were measured by high-performance liquid chromatography. The mRNA expression levels of several molecules associated with lipoprotein metabolism were measured in the OR6, OR6c, sO and sOc cells. To confirm some of the results obtained using the in vitro system, liver biopsy samples obtained from the patients were also examined.

RESULTS

The content of TG in the large low-density lipoprotein (LDL) and medium LDL in the culture medium was increased only in the OR6 cells. The hepatic triglyceride lipase (HTGL) mRNA expression levels were lower in the OR6 cells than in the OR6c cells (P < 0.01). Examination of the HTGL expression levels in the patients' livers revealed a decrease in HTGL expression in the chronic hepatitis C liver as compared with that in the chronic hepatitis B or non-alcoholic steatohepatitis liver (P < 0.01).

CONCLUSION

We showed that HCV inhibits HTGL production in hepatocytes, inducing a change of the lipoprotein profile.

Anatomical study of superior cluneal nerve entrapment

OBJECT

Entrapment of the superior cluneal nerve (SCN) in an osteofibrous tunnel in the space surrounded by the iliac crest and the thoracolumbar fascia is a cause of low-back pain (LBP). Several anatomical and surgical reports describe SCN entrapment as a cause of LBP, and a recent clinical study reported that patients with suspected SCN disorder constitute approximately 10% of the patients suffering from LBP and/or leg symptoms. However, a detailed anatomical study of SCN entrapment is rare. The purpose of this study was to investigate the courses of SCN branches and to ascertain the frequency of SCN entrapment.

METHODS

Branches of the SCN were dissected in 109 usable specimens (54 on the right side and 55 on the left side) obtained in 59 formalin-preserved cadavers (average age at death 84.8 years old). All branches were exposed at the points where they perforated the thoracolumbar fascia. The presence or absence of an osteofibrous tunnel was ascertained and, if present, the entrapment of the branches in the tunnel was determined.

RESULTS

Of 109 specimens, 61 (56%) had at least 1 branch running through an osteofibrous tunnel. Forty-two medial (39%), 30 intermediate (28%), and 14 lateral (13%) SCN branches passed through such a tunnel. Of these, only 2 medial branches had obvious entrapment in an osteofibrous tunnel. There were several patterns for the SCN course through the tunnel: medial branch only (n = 25), intermediate branch only (n = 11), lateral branch only (n = 4), medial and intermediate branches (n = 11), medial and lateral branches (n = 2), intermediate and lateral branches (n = 4), and all branches (n = 4).

CONCLUSIONS

Several anatomical variations of the running patterns of SCN branches were detected. Entrapment was seen only in the medial branches. Although obvious entrapment of the SCN is rare, it may cause LBP.

Unfolded protein response pathways regulate Hepatitis C virus replication via modulation of autophagy

Background

Hepatitis C virus (HCV) induces endoplasmic reticulum (ER) stress which, in turn, activates the unfolding protein response (UPR). UPR activates three distinct signalling pathways. Additionally, UPR induces autophagy (UPR-autophagy pathways). On the other hand, it has become clear that some positive-single-strand RNA viruses utilize autophagy. Some groups have used the siRNA silencing approach to show that autophagy is required for HCV RNA replication. However, the mechanism of induction of the UPR-autophagy pathways remain unclear in the cells with HCV.

Method and results: we used a genome-length HCV RNA (strain O of genotype 1b) replication system (OR6) in hepatoma cells (HuH-7-derived OR6 cells). As control, we used OR6c cells from which the HCV genome had been removed by treatment with interferon-α. The UPR-autophagy pathways were activated to a greater degree in the OR6 cells as compared to the OR6c cells. Rapamycin, mTOR-independent autophagy inducer, activated HCV replication in the OR6 cells. On the other hand, HCV replication in the cells was inhibited by 3-methyladenine (3-MA), which is an inhibitor of autophagy. Salubrinal (Eukaryotic Initiation Factor 2(eIF2)-alpha phosphatase inhibitor), 3-ethoxy-5, 6-dibromosalicylaldehyde (X-box binding protein-1 (XBP-1) splicing inhibitor) and sp600125 (c-Jun N-terminal kinases (JNK) inhibitor) inhibited HCV replication and autophagy. Additionally, HCV replication and autophagy were inhibited more strongly by combination of these inhibitors.

Conclusion

Our results suggest that UPR-autophagy pathways exert an influence on HCV replication. Therefore, control these pathways may serve as a novel therapeutic strategy against replication of HCV.

Retrograde tracing technique for neonatal animals

Tract tracing is a fundamental technique in neuroanatomy for examining fiber connections in the nervous system. After the introduction of horseradish peroxidase 40 years ago, many tracing substances have been used for neuroanatomical studies on various nervous systems. Here, we described retrograde tracing techniques using multiple fluorescent tracers, which make it possible to detect axonal collaterals. This technique is useful to study the development of axonal trajectories, as well as regenerative and compensatory mechanisms of animals that undergo neural damage at early stages.

Increased migration of IgA lymphocytes to VIP nerve fibers after DSS-induced colitis

Immunoglobulin-positive lymphocytes are present close to vasoactive intestinal polypeptide-positive (VIP(+)) nerve fibers in the lamina propria of the intestinal tract, and have an important role in mucosal defense. The number of immunoglobulin A-positive (IgA(+)) cells close to the epithelial basement membrane and nerve fibers is increased by the administration of lipopolysaccharides, which induce IgA secretion into the intestinal lumen. The relationship between immunoglobulin-positive lymphocytes and the VIP(+) nerve fibers during inflammation, such as in inflammatory bowel disease, however, is not well known. The morphological relationship between immunoglobulin-positive cells and the basement membrane or the VIP(+) nerve fibers in the colon was examined using double immunofluorescent labeling in an inflammatory bowel disease mouse model created by oral administration of dextran sodium sulfate (DSS). DSS administration induced goblet cell loss, crypt loss, intestinal epithelium deformation and infiltration of inflammatory cells in the mucosa. In the colon, the number and percentage of IgA(+) lymphocytes close to the basement membrane and the VIP(+) nerve fibers in the lamina propria increased after DSS administration, in parallel with the pathologic progress in the inflamed tissue. On the other hand, the percentage of immunoglobulin G-positive (IgG(+)) lymphocytes close to the basement membrane and the VIP(+) nerve fibers decreased, although the total number of IgG(+) lymphocytes in the lamina propria increased. We suggest that the immunoglobulin-producing lymphocytes and enteric nerve fibers in the colon normally have a close morphological relationship, and that this relationship is reinforced in a cell-specific manner during inflammation.

Islet-1 expression in thoracic spinal motor neurons in prenatal mouse

The LIM homeodomain protein Islet-1, an embryonic marker for motoneurons in the spinal cord, has been reported to be heterogeneously expressed among motoneuron groups in mouse. In the present study, we examined Islet-1 expression in the thoracic and rostral lumbar spinal cord in prenatal mice. In the thoracic spinal cord at embryonic day 12.5 (E12.5) and E13.5, strong Islet-1 immunoreactivity was observed in the lateral group of the ventral horn, whereas weaker immunoreactivity was observed in the ventral group. Strong Islet-1 immunoreactivity was also observed in the intermediolateral area and more medial part of the intermediate zone. In the rostral lumbar spinal cord at E12.5 and E13.5, strong Islet-1 immunoreactivity was observed in the lateral group of the ventral horn, and in the intermediolateral nucleus, whereas weaker immunoreactivity was observed in the ventral, and dorsolateral groups. At E14.5, the number of Islet-1 immunoreactive neurons was reduced in the spinal cord, but the distribution pattern was similar to that at E12.5 and E13.5. At E15.5, Islet-1 immunoreactivity was almost completely confined to the intermediolateral area. Some weakly immunoreactive neurons were observed in the ventral horn. The findings of the present study indicated that Islet-1 expression at embryonic stages differs among the motoneuron groups in the thoracic and rostral lumbar spinal cord.

Immune responses to porphyromonas gingivalis infection suppress systemic inflammatory response in experimental murine model

Periodontitis is a localized infectious disease caused by periodontopathic bacteria such as Porphyromonas gingivalis (P. gingivalis), and the severity correlates to significance of immune responses. Recently, it has been reported that periodontitis is associated with the development of systemic disease such as diabetes and atherosclerosis because of increasing invasion of oral pathogens to the circulation. However, the association between local and systemic infectious responses is still unclear. In the present study, we examined the differences of biological responses in animals with or without bacterial infection. After Balb/c mice were infected subcutaneously with live P. gingivalis W83, serum, skin and liver were collected according to experimental protocol. The skin and liver tissues were observed pathologically by haematoxylin-eosin staining, and serum IL-6 levels were measured using ELISA method. Throughout the experimental period, conditions of the mice were observed continuously. As expected, severe infiltration of leukocytes were observed at inflamed skin corresponding to the number of bacterial challenges. Although no inflammatory appearance of skin was observed, serum IL-6 levels were increased dramatically (P <0.01, Student's t-test) and liver tissues were injured in the mice without bacterial challenge. Interestingly, although severe inflammatory appearance of the skin was observed, serum IL-6 levels were not increased and no inflammatory responses were observed in the liver of the 3-times bacterially challenged group. Importantly, immunoglobulin G against P. gingivalis W83 was detected in the blood of mice with 3-times bacterial challenge corresponding to improvement of weight loss and survival. In conclusion, although multiple infections develop severe localized inflammation, the immune system should be sufficient to protect the systemic inflammatory responses.