Alzheimer's disease with sleep insufficiency:a cross-sectional study on correlations among clinical characteristics,orexin,its receptors,and the bloodbrain barrier

Previous studies have shown that reduced sleep duration,sleep fragmentation,and decreased sleep quality in patients with Alzheimer's disease are related to dysfunction in orexin signaling.At the same time,blood-brain barrier disruption is considered an early biomarker of Alzheimer's disease.However,currently no report has examined how changes in orexin signaling relate to changes in the blood-brain barrier of patients who have Alzheimer's disease with sleep insufficiency.This cross-sectional study included 50 patients with Alzheimer's disease who received treatment in 2019 at Beijing Tiantan Hospital.Patients were divided into two groups:those with insufficient sleep(sleep duration≤6 hours,n=19,age 61.58±8.54 years,10 men)and those with normal sleep durations(sleep duration>6 hours,n=31,age 63.19±10.09 years,18 men).Demographic variables were collected to evaluate cognitive function,neuropsychiatric symptoms,and activities of daily living.The levels of orexin,its receptor proteins,and several blood-brain barrier factors were measured in cerebrospinal fluid.Sleep insufficiency was associated with impaired overall cognitive function that spanned multiple cognitive domains.Furthermore,levels of orexin and its receptors were upregulated in the cerebrospinal fluid,and the blood–brain barrier was destroyed.Both these events precipitated each other and accelerated the progression of Alzheimer's disease.These findings describe the clinical characteristics and potential mechanism underlying Alzheimer's disease accompanied by sleep deprivation.Inhibiting the upregulation of elements within the orexin system or preventing the breakdown of the blood-brain barrier could thus be targets for treating Alzheimer's disease.

Further Discussion on the Three Methods for the Stage-Treatment of Parkinson's Disease

Based on the long-term clinical practice and scientific researches on the three methods for the stage-treatment of Parkinson＇s disease put forward by the author in the early years, this essay further discusses the division of the three stages of Parkinson＇s disease. Early stage： Appearance of the early symptoms and signs of Parkinson＇s disease, but short in duration and mild in severity, which do not affect the social communications, daily life and work of the patient; and their modified Hoehn ＆ Yahr grading is 1,0-1.5. Mid stage： With the symptoms and signs of Parkinson＇s disease getting worse and affecting the social communications, daily life and work of the patient, those who have their modified Hoehn ＆ Yahr grading 2-3 need medical treatment. Late stage： The patients have severe clinical symptoms of Parkinson＇s disease, and Levodopa preparation is insufficient for them to maintain their daily life; and their modified Hoehn ＆ Yahr grading is 4-5. The three treating methods are： TCM medical treatment adopted at the early stage; the combined treatment of Chinese and western medicine at the mid stage; and comprehensive treatment with multi-theraoies at the late stage.

Brain insulin resistance and Parkinson’s disease

Parkinson’s disease (PD) is the second most common neurodegenerative disease. Its most prominent pathological features are the loss of dopaminergic neurons in the substantia nigra pars compacta and the deposition of intraneuronal inclusions named Lewy bodies. Currently, the pathophysiological mechanisms of PD are not fully understood. Growing evidence suggests that insulin resistance, diabetes and PD share similar pathological processes. This raises the possibility that defective insulin signaling pathways contribute to the occurrence and development of PD. In this article, we firstly reviewed the evidence of insulin resistance from epidemiology, PD patients and animal models. We also explained the insulin signal pathways in central nervous system. We then showed the evidence that insulin resistance participates in the pathogenesis of PD via protein aggregation, mitochondrial dysfunction, neural inflammation and cognitive impairment. Finally, we introduced four categories of drugs that facilitate insulin signaling and their effects on neurodegeneration in PD.

Transplantation of fibrin-thrombin encapsulated human induced neural stem cells promotes functional recovery of spinal cord injury rats through modulation of the microenvironment

Recent studies have mostly focused on engraftment of cells at the lesioned spinal cord,with the expectation that differentiated neurons facilitate recovery.Only a few studies have attempted to use transplanted cells and/or biomaterials as major modulators of the spinal cord injury microenvironment.Here,we aimed to investigate the role of microenvironment modulation by cell graft on functional recovery after spinal cord injury.Induced neural stem cells reprogrammed from human peripheral blood mononuclear cells,and/or thrombin plus fibrinogen,were transplanted into the lesion site of an immunosuppressed rat spinal cord injury model.Basso,Beattie and Bresnahan score,electrophysiological function,and immunofluorescence/histological analyses showed that transplantation facilitates motor and electrophysiological function,reduces lesion volume,and promotes axonal neurofilament expression at the lesion core.Examination of the graft and niche components revealed that although the graft only survived for a relatively short period(up to 15 days),it still had a crucial impact on the microenvironment.Altogether,induced neural stem cells and human fibrin reduced the number of infiltrated immune cells,biased microglia towards a regenerative M2 phenotype,and changed the cytokine expression profile at the lesion site.Graft-induced changes of the microenvironment during the acute and subacute stages might have disrupted the inflammatory cascade chain reactions,which may have exerted a long-term impact on the functional recovery of spinal cord injury rats.

Properties of oscillatory neuronal activity in the basal ganglia and thalamus in patients with Parkinson’s disease

Background:The cardinal features of Parkinson’s disease(PD)are bradykinesia,rigidity and rest tremor.Abnormal activity in the basal ganglia is predicted to underlie the mechanism of motor symptoms.This study aims to characterize properties of oscillatory activity in the basal ganglia and motor thalamus in patients with PD.Methods:Twenty-nine patients with PD who underwent bilateral or unilateral electrode implantation for subthalamic nucleus(STN)DBS(n=11),unilateral pallidotomy(n=9)and unilateral thalamotomy(n=9)were studied.Microelectrode recordings in the STN,globus pallidus internus(GPi)and ventral oral posterior/ventral intermediate of thalamus(Vop/Vim)were performed.Electromyography of the contralateral limbs was recorded.Single unit characteristics including interspike intervals were analyzed.Spectral and coherence analyses were assessed.Mean spontaneous firing rate(MSFR)of neurons was calculated.Analysis of variance and χ^(2) test were performed.Results:Of 76 STN neurons,39.5% were 4–6 Hz band oscillatory neurons and 28.9% were β frequency band(βFB)oscillatory neurons.The MSFR was 44.2±7.6 Hz.Of 62 GPi neurons,37.1% were 4–6 Hz band oscillatory neurons and 27.4% were βFB neurons.The MSFR was 80.9±9.6 Hz.Of 44 Vop neurons,65.9% were 4–6 Hz band oscillatory neurons and 9%were βFB neurons.The MSFR was 24.4±4.2 Hz.Of 30 Vim oscillatory neurons,70% were 4–6 Hz band oscillatory neurons and 13.3% were β FB neurons.The MSFR was 30.3±3.6 Hz.Further analysis indicated that proportion of βFB oscillatory neurons in STN and GPi was higher than that of similar neurons in the Vop and Vim(P<0.05).Conversely,the proportion of 4–6 Hz band oscillatory neurons and tremor related neurons in the Vim and Vop was higher than that of STN and GPi(P<0.05).The highest MSFR was for GPi oscillatory neurons whereas the lowest MSFR was for Vop oscillatory neurons(P<0.005).Conclusion:The alterations in neuronal activity in basal ganglia play a critical role in generation of parkinsonism.β oscillatory activity is more prominent in basal ganglia than in thalamus suggesting that the activity likely results from dopaminergic depletion.While both basal ganglia and thalamus have tremor activity,the thalamus appears to play a more important role in tremor production,and basal ganglia β oscillatory activity might be the trigger.

Motor neuron replacement therapy for amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis is a motor neuron degenerative disease that is also known as Lou Gehrig’s disease in the United States,Charcot’s disease in France,and motor neuron disease in the UK.The loss of motor neurons causes muscle wasting,paralysis,and eventually death,which is commonly related to respiratory failure,within 3-5 years after onset of the disease.Although there are a limited number of drugs approved for amyotrophic lateral sclerosis,they have had little success at treating the associated symptoms,and they cannot reverse the course of motor neuron degeneration.Thus,there is still a lack of effective treatment for this debilitating neurodegenerative disorder.Stem cell therapy for amyotrophic lateral sclerosis is a very attractive strategy for both basic and clinical researchers,particularly as transplanted stem cells and stem cell-derived neural progenitor/precursor cells can protect endogenous motor neurons and directly replace the lost or dying motor neurons.Stem cell therapies may also be able to re-establish the motor control of voluntary muscles.Here,we review the recent progress in the use of neural stem cells and neural progenitor cells for the treatment of amyotrophic lateral sclerosis.We focus on MN progenitor cells derived from fetal central nervous system tissue,embryonic stem cells,and induced pluripotent stem cells.In our recent studies,we found that transplanted human induced pluripotent stem cell-derived motor neuron progenitors survive well,differentiate into motor neurons,and extend axons into the host white matter,not only in the rostrocaudal direction,but also along motor axon tracts towards the ventral roots in the immunodeficient rat spinal cord.Furthermore,the significant motor axonal extension after neural progenitor cell transplantation in amyotrophic lateral sclerosis models demonstrates that motor neuron replacement therapy could be a promising therapeutic strategy for amyotrophic lateral sclerosis,particularly as a variety of stem cell derivatives,including induced pluripotent stem cells,are being considered for clinical trials for various diseases.

Suppression of astrocytic autophagy by αB-crystallin contributes to α-synuclein inclusion formation

Background:Parkinson’s disease(PD)is characterized by a chronic loss of dopaminergic neurons and the presence of proteinaceous inclusions(Lewy bodies)within some remaining neurons in the substantia nigra.Recently,astroglial inclusion body has also been found in some neurodegenerative diseases including PD.However,the underlying molecular mechanisms of how astroglial protein aggregation forms remain largely unknown.Here,we investigated the contribution ofαB-crystallin(CRYAB),a small heat shock protein,inα-synuclein inclusion formation in astrocytes.Methods:Small interfering RNA(siRNA)-mediated CRYAB(siCRYAB)knockdown or CRYAB overexpression was performed to investigate the impact of CRYAB on the autophagy in human glioblastoma cell line U251 cells.Coimmunoprecipitation(co-IP)and immunoblotting were used to dissect the interaction among multiple proteins.The clearance ofα-synuclein in vitro was evaluated by immunocytochemistry.CRYAB transgenic mice and transgenic mice overexpressing A30P mutant form of humanα-synuclein were used to examine the influence of CRYAB toα-synuclein accumulation in vivo.Results:We found that knockdown of CRYAB in U251 cells or primary cultured astrocytes resulted in a marked augmentation of autophagy activity.In contrast,exogenous CRYAB disrupted the assembly of the BAG3-HSPB8-HSC70 complex via binding with BAG3,thereby suppressing the autophagy activity.Furthermore,CRYAB-regulated autophagy has relevance to PD pathogenesis.Knockdown of CRYAB remarkably promoted cytoplasmic clearance ofα-synuclein preformed fibrils(PFFs).Conversely,selective overexpression of CRYAB in astrocytes markedly suppressed autophagy leading to the accumulation of α-synuclein aggregates in the brain of transgenic mice expressing humanα-synuclein A30P mutant.Conclusions:This study reveals a novel function for CRYAB as a natural inhibitor of astrocytic autophagy and shows that knockdown of CYRAB may provide a therapeutic target against proteinopathies such as synucleinopathies.

自体诱导神经干细胞来源的多巴胺能神经前体细胞完成首例帕金森病患者脑内移植

Parkinson's disease(PD)is the second most common neurodegenerative disease,affecting around 1.0%of the population over 65 years of age[1].In China,there are estimated to be more than 3 million PD patients,with each year about 100,000 PD patients being newly diagnosed.Along with China stepping into an aging society,it was estimated that in 2030,there would be around 5 million PD patients in China alone,which would create huge socioeconomic burdens on patients and their families.