CHCHD2 Thr61Ile mutation impairs F1F0-ATPase assembly in in vitro and in vivo models of Parkinson's disease

Mitochondrial dysfunction is a significant pathological alte ration that occurs in Parkinson's disease(PD),and the Thr61lle(T61I)mutation in coiled-coil helix coiled-coil helix domain containing 2(CHCHD2),a crucial mitochondrial protein,has been reported to cause Parkinson's disease.FIFO-ATPase participates in the synthesis of cellular adenosine triphosphate(ATP)and plays a central role in mitochondrial energy metabolism.However,the specific roles of wild-type(WT)CHCHD2 and T611-mutant CHCHD2 in regulating F1FO-ATPase activity in Parkinson's disease,as well as whether CHCHD2 or CHCHD2 T61I affects mitochondrial function through regulating F1FO-ATPase activity,remain unclea r.Therefore,in this study,we expressed WT CHCHD2 and T61l-mutant CHCHD2 in an MPP^(+)-induced SH-SY5Y cell model of PD.We found that CHCHD2 protected mitochondria from developing MPP^(+)-induced dysfunction.Under normal conditions,ove rexpression of WT CHCHD2 promoted F1FO-ATPase assembly,while T61I-mutant CHCHD2 appeared to have lost the ability to regulate F1FO-ATPase assembly.In addition,mass spectrometry and immunoprecipitation showed that there was an interaction between CHCHD2 and F1FO-ATPase.Three weeks after transfection with AAV-CHCHD2 T61I,we intraperitoneally injected 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine into mice to establish an animal model of chronic Parkinson's disease and found that exogenous expression of the mutant protein worsened the behavioral deficits and dopaminergic neurodegeneration seen in this model.These findings suggest that WT CHCHD2 can alleviate mitochondrial dysfunction in PD by maintaining F1F0-ATPase structure and function.

Rapamycin reverses ferroptosis by increasing autophagy in MPTP/MPP+-induced models of Parkinson's disease

Parkinson’s disease is a neurodegenerative disorder,and fe rroptosis plays a significant role in the pathological mechanism underlying Parkinson’s disease.Rapamycin,an autophagy inducer,has been shown to have neuroprotective effects in Parkinson’s disease.However,the link between rapamycin and ferroptosis in Parkinson’s disease is not entirely clear.In this study,rapamycin was administe red to a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced Parkinson’s disease mouse model and a 1-methyl-4-phenylpyridinium-induced Parkinson’s disease PC12 cell model.The results showed that rapamycin improved the behavioral symptoms of Parkinson’s disease model mice,reduced the loss of dopamine neurons in the substantia nigra pars compacta,and reduced the expression of ferroptosis-related indicators(glutathione peroxidase 4,recombinant solute carrier family 7,member 11,glutathione,malondialdehyde,and reactive oxygen species).In the Parkinson’s disease cell model,rapamycin improved cell viability and reduced ferro ptosis.The neuroprotective effect of rapamycin was attenuated by a ferroptosis inducer(methyl(1S,3R)-2-(2-chloroacetyl)-1-(4-methoxycarbonylphenyl)-1,3,4,9-tetrahyyridoindole-3-carboxylate)and an autophagy inhibitor(3-methyladenine).Inhibiting ferro ptosis by activating autophagy may be an important mechanism by which rapamycin exerts its neuroprotective effects.Therefo re,the regulation of ferroptosis and autophagy may provide a therapeutic target for drug treatments in Parkinson’s disease.

Flavanone and flavonoid hydroxylase genes regulate fiber color formation in naturally colored cotton

Using naturally colored cotton(NCC)can eliminate dyeing,printing and industrial processing,and reduce sewage discharge and energy consumption.Proanthocyanidins(PAs),the primary coloration components in brown fibers,are polyphenols formed by oligomers or polymers of flavan-3-ol units derived from anthocyanidins.Three essential structural genes for flavanone and flavonoid hydroxylation encoding flavanone-3-hydroxylase(F3H),flavonoid 3’-hydroxylase(F3’H)and flavonoid 3’5’-hydroxylase(F3’5’H)are initially committed in the flavonoid biosynthesis pathway to produce common precursors.The three genes were all expressed predominantly in developing fibers of NCCs,and their expression patterns varied temporally and spatially among NCC varieties.In GhF3Hi,GhF3’Hi and GhF3’5’Hi silenced lines of NCC varieties XC20 and ZX1,the expression level of the three genes decreased in developing cotton fiber,negatively correlated with anthocyanidin content and fiber color depth.Fiber color depth and type in RNAi lines changed with endogenous gene silencing efficiency and expression pattern,the three hydroxylase genes functioned in fiber color formation.GhF3H showed functional differentiation among NCC varieties and GhF3’H acted in the accumulation of anthocyanin in fiber.Compared with GhF3’H,GhF3’5’H was expressed more highly in brown fiber with a longer duration of expression and caused lighter color of fibers in GhF3’5’H silenced lines.These three genes regulating fiber color depth and type could be used to improve these traits by genetic manipulation.

Single-nuclei RNA sequencing uncovers heterogenous transcriptional signatures in Parkinson's disease associated with nuclear receptor-related factor 1 defect

Previous studies have found that deficiency in nuclear receptor-related factor 1(Nurr1),which participates in the development,differentiation,survival,and degeneration of dopaminergic neurons,is associated with Parkinson s disease,but the mechanism of action is perplexing.Here,we first asce rtained the repercussion of knocking down Nurr1 by pe rforming liquid chromatography coupled with tandem mass spectrometry.We found that 231 genes were highly expressed in dopaminergic neurons with Nurr1 deficiency,14 of which were linked to the Parkinson’s disease pathway based on Kyoto Encyclopedia of Genes and Genomes analysis.To better understand how Nurr1 deficiency autonomously invokes the decline of dopaminergic neurons and elicits Parkinson’s disease symptoms,we performed single-nuclei RNA sequencing in a Nurr1 LV-shRNA mouse model.The results revealed cellular heterogeneity in the substantia nigra and a number of activated genes,the preponderance of which encode components of the major histocompatibility Ⅱ complex.Cd74,H2-Ab1,H2-Aα,H2-Eb1,Lyz2,Mrc1,Slc6α3,Slc47α1,Ms4α4b,and Ptprc2 were the top 10 diffe rentially expressed genes.Immunofluorescence staining showed that,after Nurr1knockdown,the number of CD74-immunoreactive cells in mouse brain tissue was markedly increased.In addition,Cd74 expression was increased in a mouse model of Parkinson’s disease induced by treatment with 6-hydroxydopamine.Ta ken togethe r,our res ults suggest that Nurr1 deficiency results in an increase in Cd74 expression,thereby leading to the destruction of dopaminergic neuro ns.These findings provide a potential therapeutic target for the treatment of Parkinson’s disease.

成年SD大鼠嗅球中几种蛋白的免疫组化分布研究

对成年SD大鼠嗅球中tyrosinehydroxylase、calbindinD-28K、calretinin、parvalbumin及olfactorymarkerprotein几种蛋白进行了免疫组化分布的研究.结果表明:tyrosinehydroxylase主要出现在嗅球的小球层,在外网织层有很少的阳性细胞;calbindinD-28K主要出现在小球层,在外网织层和内网织层很少;calretinin在小球层、外网织层、僧帽细胞层、内网织层、粒细胞层都有分布,嗅神经层无阳性;parvalbumin在外网织层最明显,僧帽细胞层中有少量,在小球层很少;olfactorymarkerprotein只出现在嗅神经层和小球层.此研究结果与前人的相关研究结果基本接近,但也存在一些差异.

基于保护剂筛选及优化策略提高苯丙氨酸羟化酶热稳定性

苯丙氨酸羟化酶(Phenylalanine hydroxylase,PAH)具有治疗苯丙酮尿症(phenylketonuria,PKU)的潜在药用价值,而热稳定性和储存稳定性差是限制其应用的重要因素。文中考察了多种保护剂对PAH热稳定性的影响,表明添加10%的甘油可将PAH在50℃处理10 min的酶活保留率提高3.1倍,达到(98.3±0.8)%,同时海藻糖、棉籽糖和甘露醇均能将PAH酶活保留率提高到78%以上。鉴于甘油在临床应用过程中可能出现不良反应,对后3种保护剂进行正交实验,获得最佳复合保护剂组合:2.5 mmol/L甘露醇、1 mmol/L棉籽糖和1.5 mmol/L海藻糖,可将50℃酶活保留率提高3.1倍,达到(99.3±1.2)%。10%甘油和复合保护剂均能显著提高PAH在4、20、37℃的储存稳定性,其中添加10%甘油或复合保护剂使得PAH在37℃下储存半衰期分别延长到129.9 h和237.5 h,比未添加保护剂的分别提高了1.9倍和4.3倍。该结果为PAH在医药领域的应用奠定了基础。

非典型21-羟化酶缺陷症研究进展

先天性肾上腺皮质增生症（congennital adrenal hyperplasia,CAH）是由于肾上腺皮质激素合成过程中所需的酶缺乏所致的一组常染色体隐性遗传性疾病。21-羟化酶缺乏症（21-hydroxylase deficiency,21-OHD）是CAH最常见的一种,约占90%~95%。根据临床表现的严重程度分为典型类型和非典型类型两种。

21-羟化酶缺乏症患儿的生长发育及治疗

先天性肾上腺皮质增生症（congenital adrenal hyperplasia,CAH）是一组常染色体隐性遗传疾病,由肾上腺皮质激素合成途径中酶的缺陷所引起。最常见的酶缺陷类型为21-羟化酶缺乏（21-hydroxylase deficiency,21-OHD）,占酶缺陷类型的90%,根据酶的缺陷程度又分为经典型及非经典型两种临床类型,儿童中主要为经典型。

Ginsenoside Rb1 protects dopaminergic neurons from inflammatory injury induced by intranigral lipopolysaccharide injection

Accumulating studies suggest that neuroinflammation characterized by microglial overactivation plays a pivotal role in the pathogenesis of Parkinson’s disease.As such,inhibition of microglial overactivation might be a promising treatment strategy to delay the onset or slow the progression of Parkinson’s disease.Ginsenoside Rbl,the most active ingredient of ginseng,reportedly exerts neuroprotective effects by suppressing inflammation in vitro.The present study aimed to evaluate the neuroprotective and anti-inflammatory effects of ginsenoside Rbl in a lipopolysaccharide-induced rat Parkinson’s disease model.Rats were divided into four groups.In the control group,sham-operated rats were intraperitoneally administered normal saline for 14 consecutive days.In the ginsenoside Rbl group,ginsenoside Rb1(20 mg/kg)was intraperitoneally injected for 14 consecutive days after sham surgery.In the lipopolysaccharide group,a single dose of lipopolysaccharide was unilaterally microinjected into the rat substantial nigra to establish the Parkinson’s disease model.Lipopolysaccharide-injected rats were treated with normal saline for 14 consecutive days.In the ginsenoside Rbl +lipopolysaccharide group,lipopolysaccharide was unilaterally microinjected into the rat substantial nigra.Subsequently,ginsenoside Rbl was intraperitoneally injected for 14 consecutive days.To investigate the therapeutic effects of ginsenoside Rbl,behavioral tests were performed on day 15 after lipopolysaccharide injection.We found that ginsenoside Rbl treatment remarkably reduced apomorphine-induced rotations in lipopolysaccharide-treated rats compared with the lipopolysaccharide group.To investigate the neurotoxicity of lipopolysaccharide and potential protective effect of ginsenoside Rbl,contents of dopamine and its metabolites in the striatum were measured by high-performance liquid chromatography.Compared with the lipopolysaccharide group,ginsenoside Rbl obviously attenuated the lipopolysaccharide-induced depletion of dopamine and its metabolites in the striatum.To further explore the neuroprotective effect of ginsenoside Rbl against lipopolysaccharide-induced neurotoxicity,immunohistochemistry and western blot assay of tyrosine hydroxylase were performed to evaluate dopaminergic neuron degeneration in the substantial nigra par compacta.The results showed that lipopolysaccharide injection caused a large loss of tyrosine hydroxylase-immunoreactive neurons in the substantia nigra and a significant decrease in overall tyrosine hydroxylase expression.However,ginsenoside Rb1 noticeably reversed these changes.To investigate whether the neuroprotective effect of ginsenoside Rbl was associated with inhibition of lipopolysaccharide-induced microglial activation,we examined expression of the microglia marker Iba-1.Our results confirmed that lipopolysaccharide injection induced a significant increase in Iba-1 expression in the substantia nigra;however,ginsenoside Rbl effectively suppressed lipopolysaccharide-induced microglial overactivation.To elucidate the inhibitory mechanism of ginsenoside Rb1,we examined expression levels of inflammatory mediators(tumor necrosis factor-a,interleukin-1β,inducible nitric oxide synthase,and cyclooxygenase 2)and phosphorylation of nuclear factor kappa B signaling-related proteins(IκB,IKK)in the substantia nigra with enzyme-linked immunosorbent and western blot assays.Our results revealed that compared with the control group,phosphorylation and expression of inflammatory mediators IκB and IKK in the substantia nigra of lipopolysaccharide group rats were significantly increased;whereas,ginsenoside Rbl obviously reduced lipopolysaccharide-induced changes on the lesioned side of the substantial nigra par compacta.These findings confirm that ginsenoside Rbl can inhibit inflammation induced by lipopolysaccharide injection into the substantia nigra and protect dopaminergic neurons,which may be related to its inhibition of the nuclear factor kappa B signaling pathway.This study was approved by the Experimental Animal Ethics Committee of Shandong University of China in April 2016(approval No.KYLL-2016-0148).

Laterodorsal Tegmentum and Pedunculopontine Tegmental Nucleus Circuits Regulate Renal Functions: Neuroanatomical Evidence in Mice Models

Neurons in the laterodorsal tegmentum (LDTg) and pedunculopontine tegmental nucleus (PPTg) play important roles in central autonomic circuits of the kidney. In this study, we used a combination of retrograde tracers pseudorabies virus (PRV)-614 and fluorescence immunohistochemistry to characterize the neuroanatomic substrate of PPTg and LDTg innervating the kidney in the mouse. PRV-614-infected neurons were retrogradely labeled in the rostral and middle parts of LDTg, and the middle and caudal parts of PPTg after tracer injection in the kidney. PRV-614/TPH double-labeled neurons were mainly localized in the rostral of LDTg, whereas PRV-614/TH neurons were scattered within the three parts of LDTg. PRV-614/TPH and PRV-614/TH neurons were located predominantly in the caudal of PPTg (cPPTg). These data provided direct neuroanatomical foundation for the identification of serotonergic and catecholaminergic projections from the mid-brain tegmentum to the kidney.

Changes of 5-hydroxytryptamine and tryptophan hydroxylase expression in the ventral horn of spinal cord

Objective To investigate changes of 5-hydroxytryptamine （5-HT） and its synthesis rate-limiting enzyme tryp-tophan hydroxylase （TPH） in the ventral horn of spinal cord after exercise-induced fatigue, and to further discuss the mecha- nism of exercise-induced central fatigue at spinal level. Methods Sixteen healthy adult Wistar rats were randomly divided into 2 groups： exercise-induced fatigue group and control group. Immunohistochemical staining for 5-HT and TPH in the ventral horn were performed and analysized quantitatively. The mean optic densities of 5-HT and TPH positive fibers or terminals were measured by computerized image analyzer. Results Both 5-HT and TPH positive fibers/terminals decreased in the exercise-induced fatigue group. The immunohistochemical staining was weaker and the mean optic densities decreased obviously in the fatigue group compared with those in the control group （P 〈 0.05）. Conclusion 5-HT and TPH in the ventral horn of spinal cord might be involved in exercise-induced fatigue.

Treadmill step training promotes spinal cord neural plasticity after incomplete spinal cord injury

A large body of evidence shows that spinal circuits are significantly affected by training, and that intrinsic circuits that drive locomotor tasks are located in lumbosacral spinal segments in rats with complete spinal cord transection. However, after incomplete lesions, the effect of treadmil training has been debated, which is likely because of the difficulty of separating spontaneous stepping from specific training-induced effects. In this study, rats with moderate spinal cord contusion were sub-jected to either step training on a treadmil or used in the model （control） group. The treadmil training began at day 7 post-injury and lasted 20 ± 10 minutes per day, 5 days per week for 10 weeks. The speed of the treadmil was set to 3 m/min and was increased on a daily basis according to the tolerance of each rat. After 3 weeks of step training, the step training group exhibited a sig-nificantly greater improvement in the Basso, Beattie and Bresnahan score than the model group. The expression of growth-associated protein-43 in the spinal cord lesion site and the number of tyrosine hydroxylase-positive ventral neurons in the second lumbar spinal segment were greater in the step training group than in the model group at 11 weeks post-injury, while the levels of brain-derived neurotrophic factor protein in the spinal cord lesion site showed no difference between the two groups. These results suggest that treadmil training significantly improves functional re-covery and neural plasticity after incomplete spinal cord injury.

In vitro Effect of Dithiocarbamate Pesticides and of CaNa_2EDTA on Human Serum Dopamine-β-hydroxylase

Serum dopamine-β-hydroxylase (DBH) inhibition has been reported in lead workers treated with CaNa2EDTA and in alcoholic patients repeatedly treated with the alcohol aversive drug Disulfiram. The mechanism of inhibition involves Cu-chelation at the active site of DBH. The effect of CaNa2EDTA and Disulfiram on serum DBH has been compared to the effect of dithiocarbamate pesticides in vitro for the possible use of serum DBH determination for the biological monitoring of workers exposed to these pesticides.Most dithiocarbamates inhibit human serum DBH at micromoIar concentrations (range of I50, 0.027-1.6 μmol/L). The inhibitory potency increased from methyl- and dimethyl dithiocarbamates to diethyl dithiocarbamates up to the most potent ethylene bisdithiocarbamates. The I50 of CaNa.EDTA was 3.8 mol/L, higher than those of dithiocarbamates. Copper addition to the test system rcactivated at stoichiometric concentrations dithiocarbamaie-inhibited DBH indicating that both base line values and percent of inhibition can be calculated in a single blood sample. Results suggest that serum DBH determination couId be useful in case of acute poisoning involving high doses of dithiocarbamate pesticides

Bone marrow-derived mesenchymal stem cells increase dopamine synthesis in the injured striatum

Previous studies showed that tyrosine hydroxylase or neurturin gene-modified cells transplanted into rats with Parkinson＇s disease significantly improved behavior and increased striatal dopamine content. In the present study, we transplanted tyrosine hydroxylase and neurturin gene-modified bone marrow-derived mesenchymal stem cells into the damaged striatum of Parkinson＇s disease model rats. Several weeks after cell transplantation, in addition to an improvement of motor function tyrosine hydroxylase and neurturin proteins were up-regulated in the injured striatum, and importantly, levels of dopamine and its metabolite 3,4-dihydroxyphenylacetic acid increased significantly. Furthermore, the density of the D2 dopamine receptor in the postsynaptic membranes of dopaminergic neurons was decreased. These results indicate that transplantation of tyrosine hydroxylase and neurturin gene-modified bone marrow-derived mesenchymal stem cells increases dopamine synthesis and significantly improves the behavior of rats with Parkinson＇s disease.

Downregulation of thioredoxin reductase 1 expression in the substantia nigra pars compacta of Parkinson's disease mice

Because neurons are susceptible to oxidative damage and thioredoxin reductase 1 is extensively distributed in the central nervous system and has antioxidant properties, we speculated that the enzyme may be involved in the pathogenesis of Parkinson＇s disease. A Parkinson＇s disease model was produced by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine into C57BL/6 mice. Real-time reverse transcription-PCR, western blot analysis and colorimetric assay showed that the levels of thioredoxin reductase 1 mRNA and protein were decreased, along with a significant reduction in thioredoxin reductase activity, in the midbrain of Parkinson＇s disease mice compared with normal mice. Immunohistochemical staining revealed that the number of thioredoxin reductase 1-positive neurons in the substantia nigra pars compacta of Parkinson＇s disease mice was significantly decreased compared with normal mice. These experimental findings suggest that the expression of thioredoxin reductase 1 in the substantia nigra pars compacta of Parkinson＇s disease mice is significantly decreased, and that the enzyme may be associated with disease onset.

Changes of microbial community structures and functional genes during biodegradation of phenolic compounds under high salt condition

The changes of microbial community structures and functional genes during the biodegradation of single phenol and phenol plus p-cresol under high salt condition were explored.It was found that the phenol-fed system（PFS） exhibited stronger degrading abilities and more stable biomass than that of the phenol plus p-cresol-fed system（PCFS）.The microbial community structures were revealed by a modern DNA fingerprint technique,ribosomal intergenic spacer analysis（RISA）.The results indicated that the microbial community of PFS changed obviously when gradually increased phenol concentration,while PCFS showed a little change.16S rRNA sequence analysis of the major bands showed that Alcanivorax sp.genus was predominant species during phenolic compounds degradation.Furthermore,amplified functional DNA restriction analysis（AFDRA） on phenol hydroxylase genes showed that the fingerprints were substantially different in the two systems,and the fingerprints were not the same during the different operational periods.

Role of calbindin-D28K in estrogen treatment for Parkinson’s disease

Studies have shown that estrogen has neuroprotective effects on the nigrostriatal system. The present study established a Parkinson＇s disease model in C57BL/6 mice by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrapyridine. The mice were subjected to 1713 estradiol injection into the lateral ventricle. Immunofluorescence double staining showed that estrogen increased tyrosine hydroxylase and calbindin-D28K expression and co-expression in dopaminergic neurons of midbrain substantia nigra pars compacta of model mice. Behavior experiments showed that estrogen improved swimming and hanging behaviors in this mouse model of Parkinson＇s disease.

Zhichan powder regulates nigrostriatal dopamine synthesis and metabolism in Parkinson's disease rats

In this study, rat models of Parkinson＇s disease induced by substantia nigra injection of 6-hydroxy-dopamine were intragastrically administered Zhichan powder daily for 50 days. Reverse transcription PCR results showed that tyrosine hydroxylase mRNA expression in the rat substantia nigra was significantly increased, while monoamine oxidase B mRNA expression was significantly decreased in the Zhichan powder group, compared with the model group. In addition, the levels of striatal dopamine and homovanillic acid, the ratio of dopamine to homovanillic acid, and the activity of blood superoxide dismutase were all higher in the Zhichan powder group than in the model group but the content of malondialdehyde in blood was lower. Our experimental findings indicate that Zhichan powder has an antioxidant effect, it can regulate the expression of monoamine oxidase B and tyrosine hydroxylase in the substantia nigra of Parkinson＇s disease rats, and it can facilitate the secretion of striatal dopamine and its metabolite homovanillic acid.

Verbascoside promotes the regeneration of tyrosine hydroxylase-immunoreactive neurons in the substantia nigra

Tyrosine hydroxylase is a key enzyme in dopamine biosynthesis. Change in tyrosine hydroxylase expression in the nigrostriatal system is closely related to the occurrence and development of Parkinson＇s disease. Verbascoside, an extract from Radix Rehmanniae Praeparata has been shown to be clinically effective in treating Parkinson＇s disease. However, the underlying mechanisms remain unclear. It is hypothesized that the effects of verbascoside on Parkinson＇s disease are related to tyrosine hydroxylase expression change in the nigrostriatal system. Rat models of Parkinson＇s disease were established and verbascoside（60 mg/kg） was administered intraperitoneally once a day. After 6 weeks of verbascoside treatment, rat rotational behavior was alleviated; tyrosine hydroxylase m RNA and protein expression and the number of tyrosine hydroxylase-immunoreactive neurons in the rat right substantia nigra were significantly higher than the Parkinson＇s model group. These findings suggest that the mechanism by which verbascoside treats Parkinson＇s disease is related to the regeneration of tyrosine hydroxylase-immunoreactive neurons in the substantia nigra.