Tyrosine hydroxylase plays crucial roles in larval cuticle formation and larval-pupal tanning in the rice stem borer, Chilo suppressalis.

The striped stem borer, Chilo suppressalis (Walker), a notorious pest infesting rice, has evolved a high level of resistance to many commonly used insecticides. In this study, we investigate whether tyrosine hydroxylase (TH), which is required for larval development and cuticle tanning in many insects, could be a potential target for the control of C. suppressalis. We identified and characterized the full-length cDNA (CsTH) of C. suppressalis. The complete open reading frame of CsTH (MW690914) was 1683 bp in length, encoding a protein of 560 amino acids. Within the first to the sixth larval instars, CsTH was high in the first day just after molting, and lower in the ensuing days. From the wandering stage to the adult stage, levels of CSTH began to rise and reached a peak at the pupal stage. These patterns suggested a role for the gene in larval development and larval-pupal cuticle tanning. When we injected dsCsTH or 3-iodotyrosine (3-IT) as a TH inhibitor or fed a larva diet supplemented with 3-IT, there were significant impairments in larval development and larval-pupal cuticle tanning. Adult emergence was severely impaired, and most adults died. These results suggest that CsTH might play a critical role in larval development as well as larval-pupal tanning and immunity in C. suppressalis, and this gene could form a potential novel target for pest control.

[Improvement effect of cinnamaldehyde on reserpine-induced Parkinson's disease rat model].

In order to study the neuroprotective mechanism of cinnamaldehyde on reserpine-induced Parkinson's disease(PD) rat models, 72 male Wistar rats were randomly divided into blank group, model group, Madopar group, and cinnamaldehyde high-, medium-, and low-dose groups. Except for the blank group, the other groups were intraperitoneally injected with reserpine of 0.1 mg·kg~(-1) once every other morning, and cinnamaldehyde and Madopar solutions were gavaged every afternoon. Open field test, rotarod test, and oral chewing movement evaluation were carried out in the experiment. The brain was taken and fixed. The positive expression of dopamine receptor D1(DRD1) was detected by TSA, and the changes in neurotransmitters such as dopamine(DA) and 3,4-dihydroxyphenylacetic acid(DOPAC) in the brain were detected by enzyme-linked immunosorbent assay(ELISA). The protein and mRNA expression levels of tyrosine hydroxylase(TH) and α-synuclein(α-Syn) in substantia nigra(SN) were detected by RT-PCR and Western blot. The results showed that after the injection of reserpine, the hair color of the model group became yellow and dirty; the arrest behavior was weakened, and the body weight was reduced. The spontaneous movement and exploration behavior were reduced, and the coordination exercise ability was decreased. The number of oral chewing was increased, but the cognitive ability was decreased, and the proportion of DRD1 positive expression area in SN was decreased. The expression of TH protein and mRNA was down-regulated, and that of α-Syn protein and mRNA was up-regulated. After cinnamaldehyde intervention, it had an obvious curative effect on PD model animals. The spontaneous movement behavior, the time of staying in the rod, the time of movement, the distance of movement, and the number of standing times increased, and the number of oral chewing decreased. The proportion of DRD1 positive expression area in SN increased, and the protein and mRNA expression levels of α-Syn were down-regulated. The protein and mRNA expression levels of TH were up-regulated. In addition, the levels of DA, DOPAC, and homovanillic acid(HVA) neurotransmitters in the brain were up-regulated. This study can provide a new experimental basis for clinical treatment and prevention of PD.

(Pro)renin receptor signaling in hypothalamic tyrosine hydroxylase neurons is required for obesity-associated glucose metabolic impairment.

Glucose homeostasis is achieved via complex interactions between the endocrine pancreas and other peripheral tissues and glucoregulatory neurocircuits in the brain that remain incompletely defined. Within the brain, neurons in the hypothalamus appear to play a particularly important role. Consistent with this notion, we report evidence that (pro)renin receptor (PRR) signaling within a subset of tyrosine hydroxylase (TH) neurons located in the hypothalamic paraventricular nucleus (PVNTH neurons) is a physiological determinant of the defended blood glucose level. Specifically, we demonstrate that PRR deletion from PVNTH neurons restores normal glucose homeostasis in mice with diet-induced obesity (DIO). Conversely, chemogenetic inhibition of PVNTH neurons mimics the deleterious effect of DIO on glucose. Combined with our finding that PRR activation inhibits PVNTH neurons, these findings suggest that, in mice, (a) PVNTH neurons play a physiological role in glucose homeostasis, (b) PRR activation impairs glucose homeostasis by inhibiting these neurons, and (c) this mechanism plays a causal role in obesity-associated metabolic impairment.

Corydaline alleviates Parkinson's disease by regulating autophagy and GSK-3ß phosphorylation.

BACKGROUND: Jitai tablet, a traditional Chinese medicine, has a neuroprotective effect on 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-induced Parkinson's disease (PD) mice. As one of the main active ingredients in the Jitai tablet, corydaline (Cory) has analgesic and anti-allergic effects, but it has not been studied in PD. Here, we investigated the role and mechanism of Cory in PD. METHODS: The PD model was induced by MPTP. Cell viability was measured by 3-(4, 5)-dimethylthiahiazo (-z-y1)-3, 5-di-phenytetrazoliumromide assay. The Pole test and traction test were performed to detect the behaviors of mice. The expression of tyrosine hydroxylase (Th) was detected by immunohistochemistry and Western blot. Immunofluorescence staining, monodansylcadaverine staining, and Western blot were conducted to assess autophagy. A lactic dehydrogenase release assay was used to detect cytotoxicity. Network pharmacology was used to screen the targets. RESULTS: There existed cytotoxicity when the concentration of Cory reached 40 µg/mL. Cory (not exceeding 20 µg/mL) could alleviate MPTP-induced cell damage. In vivo experiments indicated that Cory could improve the motor coordination of mice with PD. Besides, Cory could increase LC3-II/LC3-I levels both in vivo and in vitro. In addition, the Th levels reduced in the striatum and middle brain tissues of Parkinson's mice were recovered by Cory injection. We also found that Cory decreased the phosphorylation of glucogen synthase kinase-3 beta (GSK-3ß) at Tyr216 and increased the phosphorylation of GSK-3ß at Ser9 not only in primary neurons and SH-SY5Y cells but also in the striatum and middle brain tissues. Furthermore, Cory increased LC3-II/LC3-I levels and decreased p62 levels by regulating GSK-3ß. CONCLUSION: Cory enhanced autophagy, attenuated MPTP-induced cytotoxicity, and alleviated PD partly through the regulation of GSK-3ß phosphorylation.

Aqueous leaf extract of Phyllanthus amarus protects against oxidative stress and misfiring of dopaminergic neurons in Paraquat-induced Parkinson's disease-like model of adult Wistar rats.

BACKGROUND OF THE STUDY: Phyllanthus amarus has high nutritional value and is beneficial in managing and treating diverse ailments. This study assessed the role of aqueous leaf extract of Phyllanthus amarus on Paraquat (PQ) induced neurotoxicity in the substantia nigra of Wistar rats. MATERIALS AND METHODS: The role of aqueous leaves extract of Phyllanthus amarus was assessed using an open field test (OFT) for motor activity, oxidative stress biomarkers [Catalase (CAT), and Superoxide Dismutase (SOD)], histological examination (H and E stained) for cytoarchitectural changes and immunohistochemical studies using tyrosine hydroxylase (TH) as a marker for dopaminergic neurons. Forty-two (42) rats were categorized into six groups (n = 7); group 1: control was administered 0.5 ml/kg distilled water, group 2: received 10 mg/kg PQ + 10 mg/kg L-dopa as reference drug, group 3; received 10 mg/kg PQ, while group 4: received 10 mg/kg PQ + 200 mg/kg P. amarus, group 5: received 10 mg/kg PQ + 300 mg/kg P. amarus, and group 6: received 10 mg/kg PQ + 400 mg/kg P. amarus respectively, for 14 days. All administrations were done orally; a significant difference was set at p < 0.05. RESULTS AND DISCUSSION: The study's open field test (OFT) revealed no motor activity deficit with Paraquat (PQ) exposure. Also, cytoarchitectural distortions were not observed with Paraquat (PQ) only treatment group compared to the control and other groups pretreated with P. amarus and L-dopa. Moreover, the Paraquat (PQ) only treatment group showed oxidative stress by significantly decreasing the antioxidant enzyme (SOD) compared to the control and L-dopa pretreated group. A significant decrease in tyrosine hydroxylase (TH) expressing dopaminergic neurons was also observed in Paraquat (PQ) only treatment. However, P. amarus treatment showed therapeutic properties by significantly increasing tyrosine hydroxylase (TH) expressing dopaminergic neuron levels relative to control. CONCLUSION: Aqueous leaf extract of Phyllanthus amarus possesses therapeutic properties against Paraquat (PQ) induced changes in the substantia nigra of Wistar rats.

Locus coeruleus tyrosine hydroxylase positive neurons mediated the peripheral and central therapeutic effects of transcutaneous auricular vagus nerve stimulation (taVNS) in MRL/lpr mice.

OBJECTIVE: This study aims to investigate the effects of transcutaneous auricular vagus nerve stimulation (taVNS) on the development of systemic lupus erythematosus (SLE) in MRL/lpr mice. METHODS: MRL/lpr mice were treated with taVNS for ten weeks. Locus coeruleus (LC) tyrosine hydroxylase positive (TH+) neurons were selectively lesioned by stereotactic injection of 6-hydroxydopamine (6-OHDA) or selectively activated by chemogenetic methods. Sympathetic denervation was conducted by intraperitoneal injection of 6-OHDA. RESULTS: TaVNS activated the TH + neurons in LC. TaVNS produced central therapeutic effects by reducing the number of hippocampal microglia, and increasing the number of surviving LC TH+ neurons in MRL/lpr mice. TaVNS also retarded the development of lymphadenectasis and splenomegaly, decreased the proportion of double-negative T (DNT) cells, and alleviated nephritis in MRL/lpr mice. The lesion of LC TH+ neurons eliminated both these central and peripheral therapeutic effects of taVNS, while chemogenetic activation of LC TH+ neurons mimicked most central and peripheral protective effects of taVNS in MRL/lpr mice. Furthermore, taVNS regulated the autonomic nervous system in MRL/lpr mice. CONCLUSION: This study provides direct evidence that taVNS can retard the development of peripheral and central symptoms of SLE, which is mediated by the LC TH+ neurons.

Effect of electroacupuncture on oxidative stress and cell apoptosis induced by ferroptosis in mice with Parkinson's disease. / ç”µé’ˆå¯¹å¸•é‡‘æ£®ç— å°é¼ é“æ­»äº¡è¯±å¯¼çš„æ°§åŒ–åº”æ¿€åŠç»†èƒžå‡‹äº¡çš„å½±å“.

OBJECTIVES: To observe the effect of electroacupuncture (EA) on ferroptosis and apoptosis-related proteins in the substantia nigra of midbrain in mice with Parkinson's disease (PD), so as to explore its possible mechanisms in the treatment of PD. METHODS: Twenty-four C57BL/6 mice were randomly divided into blank, model and EA groups, with 8 mice in each group. The PD model was established by continuous gavage of rotenone for 4 weeks. EA was applied at "Baihui" (GV20), "Quchi" (LI11) and "Zusanli" (ST36) for 20 min, once a day for 14 days, with 2-day rest after every 5-day treatment. The open field test was used to evaluate the residence time in the central area, ave-rage movement speed, and total distance of the open field. Western blot was used to detect the protein expression le-vels of divalent metal ion transporter 1 (DMT1), membrane ferroportin 1 (FPN1), glutathione peroxidase 4 (GPX4), proapoptotic protein Bax, and anti apoptotic protein Bcl-2 in the substantia nigra. Immunohistochemical method was used to detect the morphological changes of neurons and the positive expression of tyrosine hydroxylase (TH) in the substantia nigra of mice. RESULTS: After 4 weeks of modeling, compared with the blank group, the residence time in the central area, average speed and total distance of open field were significantly lower (P<0.000 1, P<0.01, P<0.001)；the protein expression levels of DMT1 and Bax in the substantia nigra were increased (P<0.001, P<0.000 1), while the protein expression levels of FPN1, GPX4 and Bcl-2, and the optical density of TH+ cells in the substantia nigra were decreased (P<0.000 1, P<0.001) in the model group. In comparison with the model group, the residence time in the central area, average speed, and total distance of the EA group were increased (P<0.01, P<0.05)；the protein expression levels of DMT1 and Bax in the substantia nigra were decreased (P<0.01, P<0.001), while the protein expression levels of FPN1, GPX4, and Bcl-2, and the optical density of TH+ cells in the substantia nigra were increased (P<0.000 1, P<0.01, P<0.001, P<0.05). CONCLUSIONS: EA has a protective effect on dopaminergic neurons in the substantia nigra of midbrain in PD model mice, which may be related with its effect in regulating oxidative stress and cell apoptosis induced by ferroptosis.

Vitamin D (VD3) Intensifies the Effects of Exercise and Prevents Alterations of Behavior, Brain Oxidative Stress, and Neuroinflammation, in Hemiparkinsonian Rats.

In the present study, we investigated the effects of physical exercise in the presence of Vitamin D3 (VD3), on 6-hydroxydopamine (6-OHDA)-lesioned hemiparkinsonian rats. The animals were divided into sham-operated (SO), 6-OHDA-lesioned, and 6-OHDA-lesioned plus VD3 (1 µg/kg, 21 days), in the absence (no exercise, NE) and presence (with exercise, WE) of physical exercise on a treadmill (30 min, speed of 20 cm/s, once a day/21 days). This procedure started, 24 h after the stereotaxic surgery (injections of 6-OHDA into the right striatum). The animals were then subjected to behavioral (rotarod, open field, and apomorphine tests) and their brain areas were dissected for neurochemical, dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC) determinations, and immunohistochemical studies for tyrosine hydroxylase (TH), dopamine transporter (DAT), and vitamin D receptor (VD3R). The effects on the brain oxidative stress: nitrite/nitrate, glutathione (GSH), and malondialdehyde (MDA) measurements were also evaluated. Behavioral changes of the 6-OHDA lesioned group were improved by exercise plus VD3. Similar results were observed in dopamine (DA) and 3,4-dihydroxyphenylacetic acid (DOPAC) concentrations increased by exercise and VD3, compared with SO groups. Additionally, tyrosine hydroxylase (TH) and dopamine transporter (DAT) immunoexpressions were decreased in the 6-OHDA-lesioned groups, with values normalized after exercise and VD3. The VD3 receptor immunoexpression decreased in the 6-OHDA (NE) group, and this was attenuated by exercise, especially after VD3. While 6-OHDA lesions increased, VD3 supplementation decreased the oxidative stress, which was intensified by exercise. VD3 showed neuroprotective properties that were intensified by physical exercise. These VD3 actions on hemiparkinsonian rats are possibly related to its antioxidant and anti-inflammatory effects.

[Effect of electroacupuncture regulating NLRP3/Caspase-1 pathway on pyroptosis of dopaminergic neurons in rats with Parkinson's disease].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on the pyrolysis of dopaminergic neurons in rats with Parkinson's disease (PD), so as to explore its underlying molecular mechanism. METHODS: Male SD rats were randomly divided into the sham operation, model, EA, MCC950 and EA+MCC950 groups, with 12 rats in each group. The PD rat model was established by two-point injection of 6-OHDA. Rats in the MCC950 group were injected with MCC950 at the dose of 10 mg/kg, once a day; for rats of EA group, EA was applied to "Taichong" (LR3) and "Fengfu"(GV16) for 30 min, once a day; rats in the EA+ MCC950 group were given MCC950 injection and EA once a day. All above interventions were performed for 2 weeks. After the intervention, the behavioral changes of rats were observed using rotating induction experiment, rotating rod experiment and open field experiment; the positive expressions of dopaminergic neuronal markers tyrosine hydroxylase (TH) and α-Synuclein (α-Syn) in substantia nigra striatum were detected by immunohistochemistry; the damage of dopaminergic neurons in substantia nigra striatum was observed after HE staining; immunopositive coexpression of brain nucleotide-binding oligomerization domain like receptor protein 3 (NLRP3), Caspase-1 and ionized calcium binding adapter1 (Iba-1) were detected by immunofluorescence double staining; the levels of interleukin (IL)-1ß and IL-18 in brain tissues were detected by ELISA; the protein expression levels of NLRP3, Cleaved Caspase-1 and apoptosis-associated speck-like protein containing a CARD (ASC) in the substantia nigra striatum were detected by Western blot. RESULTS: Compared with the sham operation group, the number of rotations of rotating induction experiment, the residence time in the central area of open field experiment, the positive expression of α-Syn, the positive co-expressions of NLRP3/Iba-1 and Caspase-1/Iba-1, the contents of IL-1ß and IL-18 in brain tissues, and the protein expression levels of NLRP3, ASC and Cleaved Caspase-1 in substantia nigra striatum were significantly increased (P<0.05), while the drop latency of rotating rod experiment, the rearing times and the total distance of open field experiment, and the positive expression of TH in substantia nigra striatum were significantly decreased (P<0.05) in the model group. Compared with the model group, the above mentioned markers were reversed in EA, MCC950 and EA+MCC950 groups (P<0.05), and the improvement of the EA+MCC950 group was more obvious than those of the MCC950 and EA groups. In the model group, the neurons were disorderly arranged, the number of neurons was reduced, the cytoplasm was swollen, and some of them were vacuolar degeneration; while the degree of neuronal arrangement disorder, cytoplasmic swelling and the vacuolar degeneration were reduced in varying degrees in the MCC950, EA and EA+MCC950 groups. CONCLUSION: The ameliorative effect of EA on dopaminergic neuron damage in PD rats may be related to its effects in inhibiting NLRP3/Caspase-1 mediated neuronal pyrosis.

[Effects of early electroacupuncture on the expression of Iba-1 and TNF-α in Parkinson's disease mice].

OBJECTIVE: To observe the effect of early electroacupuncture(EA) intervention on ionized calcium binding adapter molecule 1 (Iba-1), tyrosine hydroxylase (TH) and tumor necrosis factor-α (TNF-α) in Parkinson's disease (PD) mice, so as to explore its neuroinflammation mechanism in treating PD. METHODS: A total of 24 male C57BL/6J mice (9 weeks old) were randomly divided into control, model and EA groups, with 8 mice in each group. The PD model was established by long-term low dose subcutaneous injection of rotenone. Started at the same time with modeling, EA (2 Hz/100 Hz, 1 mA) was applied to "Shenting"(GV24), bilateral "Tianshu"(LI11), "Quchi"(ST25), and "Shangjuxu"(ST37) for 15 min, once a day for 8 weeks. The motor function was assessed by rotorod test and step length test. The expression levels of Iba-1 and TH proteins in substantia nigra pars compacta (SNpc) was detected by Western blot and immunohistochemistry. The expression level of TNF-α protein in colon tissue was examined by Western blot and immunofluorescence staining. RESULTS: Compared with the control group, the fall latency shortened at 4, 6, and 8 weeks after modeling (P<0.01) and the step length of hind limbs shortened at 5 and 7 weeks after modeling (P<0.01), the expression levels of Iba-1 in SNpc and TNF-α in colon tissue were increased (P<0.01), and the expression level of TH in SNpc was decreased (P<0.01) in the model group. Compared with the model group, the fall latency prolonged at 6 and 8 weeks after modeling (P<0.01) and the step length of hind limbs prolonged at 5 and 7 weeks after modeling (P<0.01), the expression levels of Iba-1 in SNpc and TNF-α in colon tissue were decreased (P<0.01, P<0.05), and the expression level of TH in SNpc was increased (P<0.05, P<0.01) in the EA group. CONCLUSION: Early EA intervention can delay the occurring time of motor disfunction, alleviated the loss of substantia nigra dopaminergic neurons, and exerted a good neuroprotective effect on the degenerative changes in rotenone-induced PD mice, which may be related to its effects in alleviating the intestinal inflammation, inhibiting the activation of microglia, thereby reducing the neuroinflammation.

Lycium barbarum polysaccharide improves dopamine metabolism and symptoms in an MPTP-induced model of Parkinson's disease.

BACKGROUND: Parkinson's disease (PD) is the second most common neurodegenerative disease in middle-aged and elderly populations, whereas there is no cure for PD so far. Novel animal models and medications await development to elucidate the aetiology of PD and attenuate the symptoms, respectively. METHODS: A neurotoxin, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), was used in the current study to establish a PD pathologic model in silkworms. The time required to complete specific behaviours was recorded. Dopamine content was detected by ultra-performance liquid chromatography (UPLC). The activity of insect tyrosine hydroxylase (TH) was determined using a double-antibody sandwich method. Oxidative stress was assessed by changes in antioxidant enzyme activity and the content of oxidative products. RESULTS: MPTP-treated silkworms were characterized by impaired motor ability, reduced dopamine content, and elevated oxidative stress level. The expression of TH, a dopamine biosynthetic enzyme within dopaminergic neurons in the brain, was significantly reduced, indicating that dopaminergic neurons were damaged. Moreover, MPTP-induced motility impairment and reduced dopamine level in the silkworm PD model could be rescued after feeding a combination of levodopa (L-dopa [LD]) and carbidopa (CD). MPTP-induced oxidative damage was also alleviated, in ways consistent with other PD animal models. Interestingly, administration of Lycium barbarum polysaccharide (LBP) improved the motor ability, dopamine level, and TH activity, and the oxidative damage was concomitantly reduced in the silkworm PD model. CONCLUSIONS: This study provides a promising animal model for elucidating the pathogenesis of PD, as well as a relevant preliminary drug screening (e.g., LBP) and evaluation.

Integrated Metabolomics and Network Pharmacology to Reveal the Mechanisms of Guizhi-Fuling Treatment for Myocardial Ischemia.

Myocardial ischemia is a cardio-physiological condition due to a decrease in blood perfusion to the heart, leading to reduced oxygen supply and abnormal myocardial energy metabolism. Guizhi-Fuling (GZFL) is effective in treating Myocardial ischemia. However, its mechanism of action is unclear and requires further exploration. We attempt to decipher the mechanisms behind GZFL treating Myocardial ischemia by integrating metabolomics and network pharmacology. In this study, myocardial metabolomic analysis was performed using GC/MS to identify the potential mechanism of action of GZFL during myocardial ischemia. Then, network pharmacology was utilized to analyze key pathways and construct a pathway-core target network. Molecular docking was incorporated to validate core targets within network pharmacological signaling pathways. Finally, western blots were utilized to verify core targets of metabolomics, network pharmacology integrated pathways, and key signaling targets. Thus, 22 critical biomarkers of GZFL for treating myocardial ischemia were identified. Most of these metabolites were restored using modulation after GZFL treatment. Based on the network pharmacology, 297 targets of GZFL in treating myocardial ischemia were identified. The further comprehensive analysis focused on three key targets, such as Tyrosine hydroxylase (TH), myeloperoxidase (MPO), and phosphatidylinositol 3-kinases (PIK3CA), and their related metabolites and pathways. Compared with the model group, the protein expression levels of TH, MPO and PIK3CA were reduced in GZFL. Therefore, the mechanism of GZFL for treating myocardial ischemia could inhibit myocardial inflammatory factors, reduce myocardial inflammation, and restore endothelial function while controlling norepinephrine release and uric acid concentration.

Vasopressin acts as a synapse organizer in limbic regions by boosting PSD95 and GluA1 expression.

Hypothalamic arginine vasopressin (AVP)-containing magnocellular neurosecretory neurons (AVPMNN) emit collaterals to synaptically innervate limbic regions influencing learning, motivational behaviour, and fear responses. Here, we characterize the dynamics of expression changes of two key determinants for synaptic strength, the postsynaptic density (PSD) proteins AMPAR subunit GluA1 and PSD scaffolding protein 95 (PSD95), in response to in vivo manipulations of AVPMNN neuronal activation state, or exposure to exogenous AVP ex vivo. Both long-term water deprivation in vivo, which powerfully upregulates AVPMNN metabolic activity, and exogenous AVP application ex vivo, in brain slices, significantly increased GluA1 and PSD95 expression as measured by western blotting, in brain regions reportedly receiving direct ascending innervations from AVPMNN (i.e., ventral hippocampus, amygdala and lateral habenula). By contrast, the visual cortex, a region not observed to receive AVPMNN projections, showed no such changes. Ex vivo application of V1a and V1b antagonists to ventral hippocampal slices ablated the AVP stimulated increase in postsynaptic protein expression measured by western blotting. Using a modified expansion microscopy technique, we were able to quantitatively assess the significant augmentation of PSD95 and GLUA1 densities in subcellular compartments in locus coeruleus tyrosine hydroxylase immunopositive fibres, adjacent to AVP axon terminals. Our data strongly suggest that the AVPMNN ascending system plays a role in the regulation of the excitability of targeted neuronal circuits through upregulation of key postsynaptic density proteins corresponding to excitatory synapses.

Calcium carbonate supplementation causes motor dysfunction.

We previously showed that a diet containing calcium carbonate causes impairments in spatial and recognition memory in mice. In this study, we investigated the effects of calcium carbonate supplementation on motor function. Motor function was determined using different tests that have been used to analyze different aspects of Parkinsonism. A catalepsy test for akinesia; a muscular strength assessment, pole test, beam-walking test, and gait analysis for motor coordination and balance assessment; and an open-field test for locomotor activity assessment were performed. The mice were fed diets containing 0.6% or 1.0% calcium carbonate for eight weeks, after which they were evaluated for motor functions. The diets containing calcium carbonate caused significant motor dysfunction, as revealed by the different tests, although the spontaneous locomotor activity did not change. Calcium carbonate supplementation decreased the dopamine content in the basal ganglia, including the striatum and substantia nigra, and the number of tyrosine hydroxylase-positive neurons in the substantia nigra. In addition, administration of L-dopa led to at least a partial recovery of motor dysfunction, suggesting that calcium carbonate supplementation causes motor dysfunction by decreasing the dopamine content in the basal ganglia. These results suggest that mice with calcium carbonate-induced motor dysfunction may be useful as a new animal model for Parkinson's disease and Huntington's disease.

Tyrosine hydroxylase involved in cuticle tanning and reproduction in the 28-spotted potato ladybeetle, Henosepilachna vigintioctopunctata.

BACKGROUND: Tyrosine hydroxylase (TH), a melanin synthesis pathway enzyme hydroxylating tyrosine into 3,4-dihydroxyphenylalanine, is involved in the pigmentation and sclerotization of insect cuticles. However, the role of TH in 28-spotted potato ladybeetle (Henosepilachna vigintioctopunctata), an emerging pest of the solanaceous crops has been explored to a limited extent. In this study, we integrated dietary RNA interference (RNAi) and hematoxylin and eosin (H&E) staining with various bioassays to analyze the role of tyrosine hydroxylase (HvTH) throughout the developmental processes of Henosepilachna vigintioctopunctata. RESULTS: The results revealed that ingestion of dsHvTH led to cuticle tanning impairment, arrested larval feeding in the first and second instars of Henosepilachna vigintioctopunctata, and subsequently resulted in 100% mortality. The H&E staining assays revealed that dsHvTH prevented new abdominal cuticle formation. A pharmacological study using 3-iodo-tyrosine (3-IT), a HvTH inhibitor, disrupted larval-larval-pupal cuticle tanning during the third-fourth instar larval development and eventually failed to pupate. Similarly, dsHvTH fed to fourth instars hindered larval-pupal-adult cuticle tanning, and the eclose adults were 100% malformed. Ingestion of dsHvTH or 3-IT significantly down-regulated HvTH, HvDDC, Hvebony, and Hvlaccase2 expression and reduced dopamine levels. Finally, HvTH silencing in adult females substantially reduced the offspring hatching rates. CONCLUSIONS: The collective results of the study suggested that HvTH plays conserved roles in larval-pupal-adult cuticle melanization and sclerotization while exhibiting a novel function in Henosepilachna vigintioctopunctata reproduction. © 2022 Society of Chemical Industry.

[Mechanism of electroacupuncture against intestinal inflammation in mice with Parkinson's di-sease by NF-κB/IL-6 pathway].

OBJECTIVE: To observe the effects of electroacupuncture (EA) at "Fengfu"(GV16), "Taichong"(LR3), and "Zusanli"(ST36) on the tyrosine hydroxylase (TH), nuclear factor-kappa B (NF-κB), interleukin (IL)-6, and zonula occludens-1 (ZO-1) in mice with Parkinson's disease (PD), and to explore the underlying mechanism of EA in the treatment of PD. METHODS: C57BL/6 mice were randomly divided into control, model, and EA groups, with 10 mice in each group. The PD model was induced by rotenone (i.g.) in mice for 28 d. EA was applied to GV16, LR3 and ST36 of mice in the EA group for 30 min, once daily for 14 d. The behavioral changes of mice in each group before and after treatment were observed and scored. The total distance traveled autonomously of mice was detected in the open field test. TH expression in the substantia nigra (SN) was measured by immunohistochemistry, and the changes in colon tissue structure were observed by HE staining. The intestinal mRNA expression of ZO-1, NF-κB, and IL-6 was detected by quantitative real-time PCR, and the colon tissue protein expression of NF-κB was detected by Western blot. The colon tissue concentration of IL-6 was detected by ELISA. RESULTS: Compared with the control group, the pre- and post-treatment behavioral scores of the model group and the pre-treatment behavioral score of the EA group were increased (P<0.01). Compared with the model group, the EA group showed reduced behavioral score after treatment (P<0.01). Compared with the control group, the model group showed reduced goblet cells and crypts and thinner muscle layer in the intestinal specimens of mice. Compared with the model group, the EA group showed intact surface villi, increased goblet cells and crypts, and thickened muscle layer. Compared with the control group, the model group exhibited reduced total distance traveled in the open field test, TH expression in SN, and ZO-1 mRNA expression (P<0.01), and elevated mRNA and protein expression of NF-κB and IL-6, and the ratio of p-NF-κB/NF-κB in the intestinal tract (P<0.01). Compared with the model group, the EA group displayed increased total distance traveled, TH expression in SN, and ZO-1 mRNA expression (P<0.01), and declining mRNA and protein expression of NF-κB and IL-6, and the ratio of p-NF-κB/NF-κB in the colon tissue (P<0.01, P<0.05). CONCLUSION: EA at GV16, LR3, and ST36 can regulate the expression of NF-κB/IL-6, inhibit the transmission of the colon tissue inflammatory response, repair the intestinal barrier function, and potentiate the TH activity, thereby improving the behavioral performance of PD mice.

Sensory and autonomic innervation of the local tissues at traditional acupuncture point locations GB14, ST2 and ST6.

OBJECTIVE: To visualize and compare the sensory and autonomic innervation of the local tissues at the sites of different traditional acupuncture points in the rat forehead and face by histochemical examination. METHODS: GB14 (Yangbai), ST2 (Sibai) and ST6 (Jiache) were selected as the representative traditional acupuncture points in this study, and the local tissues at these sites were dissected in rats after perfusion followed by double or triple fluorescent histochemical staining. Here, calcitonin gene-related peptide (CGRP), tyrosine hydroxylase (TH) and vesicular acetylcholine transporter (VAChT) were used to label the sensory, sympathetic and parasympathetic nerve fibers, respectively. RESULTS: The CGRP+ sensory, TH+ sympathetic and VAChT+ parasympathetic nerve fibers were simultaneously demonstrated in the local tissues at GB14, ST2 and ST6. Although the three kinds of nerve fibers ran in parallel or intermingled with each other, by the analysis from the view of three-dimensional reconstruction, it was clear that each of them distributed in an independent pattern to their corresponding target tissues including the blood vessels, hair follicles, arrector pili and subcutaneous muscles, as well as sebaceous glands. CONCLUSION: Our study demonstrated the sensory and autonomic innervation of the local tissues at GB14, ST2 and ST6, providing neurochemical evidence indicating that the CGRP+ sensory, TH+ sympathetic and VAChT+ parasympathetic nerve fibers form a neural network at these point locations that may respond to acupuncture stimulation.

T-lymphocyte tyrosine hydroxylase regulates TH17 T-lymphocytes during repeated social defeat stress.

Posttraumatic stress disorder (PTSD) is a debilitating psychiatric disorder which results in deleterious changes to psychological and physical health. Patients with PTSD are especially susceptible to life-threatening co-morbid inflammation-driven pathologies, such as autoimmunity, while also demonstrating increased T-helper 17 (TH17) lymphocyte-driven inflammation. While the exact mechanism of this increased inflammation is unknown, overactivity of the sympathetic nervous system is a hallmark of PTSD. Neurotransmitters of the sympathetic nervous system (i.e., catecholamines) can alter T-lymphocyte function, which we have previously demonstrated to be partially mitochondrial redox-mediated. Furthermore, we have previously elucidated that T-lymphocytes generate their own catecholamines, and strong associations exist between tyrosine hydroxylase (TH; the rate-limiting enzyme in the synthesis of catecholamines) and pro-inflammatory interleukin 17A (IL-17A) expression within purified T-lymphocytes in a rodent model of psychological trauma. Therefore, we hypothesized that T-lymphocyte-generated catecholamines drive TH17 T-lymphocyte polarization through a mitochondrial superoxide-dependent mechanism during psychological trauma. To test this, T-lymphocyte-specific TH knockout mice (THT-KO) were subjected to psychological trauma utilizing repeated social defeat stress (RSDS). RSDS characteristically increased tumor necrosis factor-α (TNFα), IL-6, IL-17A, and IL-22, however, IL-17A and IL-22 (TH17 produced cytokines) were selectively attenuated in circulation and in T-lymphocytes of THT-KO animals. When activated ex vivo, secretion of IL-17A and IL-22 by THT-KO T-lymphocytes was also found to be reduced, but could be partially rescued with supplementation of norepinephrine specifically. Interestingly, THT-KO T-lymphocytes were still able to polarize to TH17 under exogenous polarizing conditions. Last, contrary to our hypothesis, we found RSDS-exposed THT-KO T-lymphocytes still displayed elevated mitochondrial superoxide, suggesting increased mitochondrial superoxide is upstream of T-lymphocyte TH induction, activity, and TH17 regulation. Overall, these data demonstrate TH in T-lymphocytes plays a critical role in RSDS-induced TH17 T-lymphocytes and offer a previously undescribed regulator of inflammation in RSDS.

Ameliorative role of Syzygium aromaticum aqueous extract on synaptosomal tyrosine hydroxylase activity, oxidative stress parameters, and behavioral changes in lead-induced neurotoxicity in mice.

This study reports the protective role of the aqueous extract of Syzygium aromaticum (ESA) against lead (Pb)-induced neurotoxicity in mice. Thirty male mice weighing between 18 g and 25 g were randomly divided into five groups. (1) Group 1 (control group), (2) group 2 (Pb-test group): was administered with a solution containing 0.1% (w/v) of lead acetate (PbAc), (3) group 3 (ESA + Pb100 group): was administered with 0.1% (w/v) of PbAc followed by 100 mg/kg of S. aromaticum extract by gavage, (4) group 4 (ESA + Pb200): was administered with 0.1% (w/v) of PbAc followed by 200 mg/kg of S. aromaticum extract, and (5) group 5 (ESA-group): was administered with 100 mg/kg of S. aromaticum. Level of lead was determined by atomic absorption spectroscopy. Cerebral cortex synaptosomes prepared from mice administered orally with lead-acetate shown a significantly increased (p < .05) in tyrosine hydroxylase and protein carbonyl level and significantly decreased (p < .05) superoxide dismutase, glutathione reductase, and glutathione transferase activities. Also, there was a significant increase in brain lead concentration level, however, it was observed that S. aromaticum significantly reduced (p < .05) the level of lead at all tested doses. S. aromaticum rescued cerebral cortex synaptosomes from lead-induced neurotoxicity by relieving oxidative stress and abating elevated tyrosine hydroxylase activity. Moreover, S. aromaticum at the different dose grade (100 mg and 200 mg) abrogated the loss of motor performance in mice groups induced with lead. Altogether, our findings showed that S. aromaticum possesses antioxidant and neuro-modulatory potential against lead-induced neuronal damage. PRACTICAL APPLICATIONS: Environmental pollution with heavy metals is a known public health concern and their incremental concentrations in soil and water have risen to an unprecedented degree. Lead is one of the top 10 contaminants on the WHO's list of substances of greatest public health concern that impact the brain. However, exogenous natural bioactive supplements molecules could be one of the remedies to reduce Pb-induced toxicity. Our findings indicate therefore that, S. aromaticum could be a good fit for lowering Pb neurotoxicity and could be suggested as a neuroprotective molecule against neurodegenerative diseases involving catecholaminergic dysfunction induced by metallic elements.

Exercise increases NPY/AgRP and TH neuron activity in the hypothalamus of female mice.

Recent evidence identifies a potent role for aerobic exercise to modulate the activity of hypothalamic neurons related to appetite; however, these studies have been primarily performed in male rodents. Since females have markedly different neuronal mechanisms regulating food intake, the current study aimed to determine the effects of acute treadmill exercise on hypothalamic neuron populations involved in regulating appetite in female mice. Mature, untrained female mice were exposed to acute sedentary, low- (10 m/min), moderate- (14 m/min), and high (18 m/min)-intensity treadmill exercise in a randomized crossover design. Mice were fasted 10 h before exercise, and food intake was monitored for 48 h after bouts. Immunohistochemical detection of cFOS was performed 3 h post-exercise to determine the changes in hypothalamic neuropeptide Y (NPY)/agouti-related peptide (AgRP), pro-opiomelanocortin (POMC), tyrosine hydroxylase (TH), and SIM1-expressing neuron activity concurrent with the changes in food intake. Additionally, stains for pSTAT3tyr705 and pERKthr202/tyr204 were performed to detect exercise-mediated changes in intracellular signaling. Briefly, moderate- and high-intensity exercises increased 24-h food intake by 5.9 and 19%, respectively, while low-intensity exercise had no effects. Furthermore, increases in NPY/AgRPARC, SIM1PVN, and TH neuron activity were observed 3 h after high-intensity exercise, with no effects on POMCARC neurons. While no effects of exercise on pERKthr202/tyr204 were observed, pSTAT3tyr705 was elevated specifically in NPY/AgRP neurons 3 h post-exercise. Overall, aerobic exercise increased the activity of several appetite-stimulating neuron populations in the hypothalamus of female mice, which may provide insight into previously reported sexual dimorphisms in post-exercise feeding.