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1.
Mol Cell Biochem ; 477(12): 2787-2799, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35639235

RESUMO

Mitotic catastrophe (MC) is a suppressive mechanism that mediates the elimination of mitosis-deficient cells through apoptosis, necrosis or senescence after M phase block. SIRT1 is involved in the regulation of several cellular processes, including autophagy. However, the relationship between SIRT1 and MC has been largely obscure. Our study highlights that SIRT1 might be involved in the regulation of MC. We have shown that degradation of the SIRT1 protein via proteasome and lysosomal pathway was accompanied by MC induced via BMH-21. Overexpression of SIRT1 alleviated MC by decreasing the proportion of apoptotic and multinuclear cells induced by G2/M block and triggered autophagy whereas knockdown of SIRT1 aggravated MC and repressed autophagy. Furthermore, we found that serum starvation triggered autophagy evidently generated lower MC whereas siRNA of ATG5/7 suppressed autophagy leading to higher MC. ChIP analysis revealed that SIRT1 could bind to the promoter of BubR1, a component of spindle assembly checkpoint (SAC), to upregulate its expression. Overexpression of BubR1 decreased MC whereas knockdown of BubR1 increased it. These results reveal that SIRT1 regulates MC through autophagy and BubR1 signaling, and provide evidence for SIRT1, autophagy and BubR1 being the potential cancer therapeutic targets.


Assuntos
Proteínas Serina-Treonina Quinases , Sirtuína 1 , Sirtuína 1/genética , Sirtuína 1/metabolismo , Proteínas Serina-Treonina Quinases/genética , Morte Celular , Autofagia , Transdução de Sinais , Mitose
2.
Molecules ; 27(7)2022 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-35408707

RESUMO

In the current study, Bismuth molybdate was synthesized using simple co-precipitation procedure, and their characterization was carried out by various methods such as FT-IR, SEM, and P-XRD. Furthermore, the photocatalytic degradation of Orange G (ORG) dye using synthesized catalyst under visible light irradiation was studied. Response surface Method was used for the optimization of process variables and degradation kinetics evaluated by modeling of experimental data. Based on the experimental design outcomes, the first-order model was proven as a practical correlation between selected factors and response. Further ANOVA analysis has revealed that only two out of six factors have a significant effect on ORG degradation, however ORG concentration and irradiation time indicated the significant effects sequentially. Maximum ORG degradation of approximately 96% was achieved by keeping process parameters in range, such as 1 g L-1 loading of catalyst, 50 mg L-1 concentration of ORG, 1.4 mol L-1 concentration of H2O2 at pH 7 and a temperature of 30 °C. Kinetics of ORG degradation followed the pseudo first order, and almost complete degradation was achieved within 8 h. The effectiveness of the Bi2MoO6/H2O2 photo-Fenton system in degradation reactions is due to the higher number of photo-generated e- available on the catalyst surface as a result of their ability to inhibit recombination of e- and h+ pair.


Assuntos
Bismuto , Peróxido de Hidrogênio , Compostos Azo , Bismuto/química , Catálise , Luz , Molibdênio , Espectroscopia de Infravermelho com Transformada de Fourier
3.
J Cell Biochem ; 122(10): 1517-1533, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34224593

RESUMO

The ribosomal gene DNA (rDNA) often forms secondary constrictions in the chromosome; however, the molecular mechanism involved remains poorly understood. Here, we report that occurrence of rDNA constriction was increased in the chromosomes in human cancer cell lines compared with normal cells and that decondensed rDNA was significantly enhanced after partial inhibition of rDNA transcription. rDNA transcription was found during the S phase when replication occurred, and thus, DNA replication inhibitors caused constriction formation through hindering rDNA transcription. Inhibition of ataxia ATR (telangiectasia-mutated and RAD3-related) induced rDNA constriction formation. Replication stress or transcription inhibition increased R-loop formation. Topoisomerase I and RNase H1 suppressed secondary constriction formation. These data demonstrate that transcription stress causes the accumulation of stable R-loops (RNA-DNA hybrid) and subsequent constriction formation in the chromosomes.


Assuntos
DNA Ribossômico/química , DNA Ribossômico/genética , Leucócitos Mononucleares/metabolismo , Neoplasias/genética , Neoplasias/patologia , Estruturas R-Loop , Transcrição Gênica , Células A549 , Dano ao DNA , Replicação do DNA , DNA Topoisomerases Tipo I/genética , DNA Topoisomerases Tipo I/metabolismo , Células HeLa , Humanos , Ribonuclease H/genética , Ribonuclease H/metabolismo , Fase S/genética
4.
Physiol Plant ; 172(4): 2079-2089, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33887068

RESUMO

The role of the nucleolus in plant response to heat stress remains largely obscure. Our current efforts focused on exploring the underlying mechanism by which nucleolar disorganization is regulated in heat stressed-maize lines. Here, two maize lines, a heat-sensitive line, ZD958, and a heat-tolerant line, ZDH, were submitted to heat stress for investigating their association with the nucleolar disruption. Immunofluorescence staining showed that nucleolar disruption increased with prolonged treatment time. After heat treatment, a significant change in nucleolus organization was observed in the ZD958 line, but the ZDH line showed mild alteration. Moreover, actinomycin D (ActD)-induced nucleolus fission led to inhibition of maize growth under the normal condition. The ZD958 line exhibited a significant increase in the level of H3K9ac and H4K5ac of the 45S rDNA accompanied by a higher transcription of the 5'-external transcribed spacer (ETS) region, while the line ZDH showed a slight increase in histone acetylation levels and the transcriptional initiation at this site after heat treatment. To our knowledge, this is the first report providing a comparative insight between heat stress, rDNA histone modifications, and nucleolus disintegration in a heat-tolerant ZDH compared with a heat-sensitive line ZD958. Our investigation might assist maize breeders in obtaining heat-tolerant lines by targeting nucleoli using epigenetics.


Assuntos
Histonas , Zea mays , Acetilação , Nucléolo Celular/metabolismo , DNA Ribossômico/genética , Resposta ao Choque Térmico/genética , Histonas/metabolismo , Zea mays/genética , Zea mays/metabolismo
5.
Eur J Anaesthesiol ; 35(12): 955-965, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29762151

RESUMO

BACKGROUND AND OBJECTIVES: Infiltration of surgical wound with local anaesthetics attenuate postoperative pain. However, side effects can also occur. Somatostatin (SST) and its analogues like octreotide reportedly reduce peripheral sensitisation. The current study evaluates peripherally mediated antinociceptive effect of SST in a rat model of postoperative pain. This was compared with bupivacaine and morphine under identical experimental conditions. DESIGN: Randomised vehicle-controlled blind study. SETTING: Pain research laboratory, All India Institute of Medical Sciences, New Delhi from February 2014 to July 2017. EXPERIMENTAL SUBJECT: Rodent hind paw incision model. INTERVENTIONS: Sprague-Dawley rats were subjected to incision and one of the following drugs administered into the open wound once by a micropipette: SST (10, 30 or 100 µg), bupivacaine (3, 10, 30, 50 or 100 µg) or morphine (100 µg). Antinociceptive effect of SST was further evaluated for its reversibility, site of action, effect on spinal c-fos expression and blood glucose level. The site of action of morphine was also investigated. MAIN OUTCOME MEASURE: Nociception was estimated by nonevoked (guarding behaviour) and evoked (mechanical allodynia and thermal hyperalgesia) pain behaviours between 2 h and days 4 to 7. RESULTS: Nociception was maximum 2 h after incision. SST (10 to 100 µg) significantly attenuated guarding behaviour between 2 h and day 2. A delayed inhibitory effect was observed on allodynia. Bupivacaine (10 to 100 µg doses) similarly decreased guarding score up to day 2 though evoked pain behaviours were relatively unaffected. In contrast, morphine produced a potent but transient inhibitory effect on guarding score at 2 h, which was mediated by both peripheral and central opioid receptors. The antinociceptive effect of SST was peripherally mediated by type 2 receptors and was associated with decreased c-fos staining. Blood glucose level was unaltered. CONCLUSION: Guarding behaviour, which likely represents pain-at-rest following surgery, was attenuated by both bupivacaine and SST to comparable extents. This novel peripherally mediated antinociceptive effect of SST needs further evaluation.


Assuntos
Analgésicos Opioides/administração & dosagem , Anestésicos Locais/administração & dosagem , Bupivacaína/administração & dosagem , Morfina/administração & dosagem , Dor Pós-Operatória/tratamento farmacológico , Somatostatina/administração & dosagem , Analgésicos/administração & dosagem , Animais , Relação Dose-Resposta a Droga , Masculino , Modelos Animais , Medição da Dor/efeitos dos fármacos , Medição da Dor/métodos , Dor Pós-Operatória/metabolismo , Dor Pós-Operatória/patologia , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Roedores , Resultado do Tratamento
6.
Trop Anim Health Prod ; 49(8): 1637-1644, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28785907

RESUMO

Fifteen close up pregnant Murrah buffaloes of mean body weight (668.3 ± 24.03) kg, lactation number (2.8 ± 0.17) and expected producing ability (EPA) (2125.7 ± 46.34) were randomly distributed into three groups each of five animals to investigate the performance at different levels of metabolizable energy and protein. Control group was fed as per ICAR Nutrient requirements of animals (2013) recommendation whereas treatment group (1) high metabolizable energy and high metabolizable protein (HMEMP) and group (2) low metabolizable energy and low metabolizable protein (LMEMP) were offered with ration containing 15% more and 15% less ME and MP, respectively. The feeding trial was carried out for the period of 40 days before parturition and continued for 120 days after parturition. Intake of dry matter (DM) (%BW) was similar among experimental groups. Metabolizable energy (ME) (MJ/100 kg BW) and metabolizable protein (MP) (g/100 kg BW) intake was highest in HMEMP followed by control and LMEMP group, respectively. Digestibility trial of 7 days was conducted at 60 days post-partum and it was observed that apparent digestibility coefficients (%) of DM, organic matter (OM), crude protein (CP), ether extracts (EE), neutral detergent fiber (NDF) and acid detergent fiber (ADF) were similar among the experimental groups. Milk yield (kg/kg DMI) was similar among treatment groups whereas 6% fat corrected milk (FCM) was lower in LMEMP group as compared to HMEMP and control. No significant effect of dietary MP and ME levels on milk composition was observed among experimental groups. There were no significant difference in non esterified fatty acid (NEFA), blood urea nitrogen(BUN), growth hormone (GH) and insulin like growth factor-1(IGF-1) concentration among different experimental groups whereas concentration of immunoglobulin G (IgG) (µg/ml) was found to be lower in LMEMP. The study results indicate that nutrient digestibility and lactation performance was not affected with 15% variation in intakes of ME and MP in lactating Murrah buffaloes.


Assuntos
Ração Animal/análise , Búfalos/fisiologia , Proteínas Alimentares/administração & dosagem , Ingestão de Energia , Lactação/fisiologia , Animais , Nitrogênio da Ureia Sanguínea , Peso Corporal , Búfalos/sangue , Dieta , Fibras na Dieta/administração & dosagem , Suplementos Nutricionais , Metabolismo Energético , Feminino , Leite/metabolismo , Necessidades Nutricionais , Gravidez , Ureia
7.
Indian J Med Res ; 144(5): 730-740, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28361827

RESUMO

BACKGROUND & OBJECTIVES: Treatment of inflammatory pain with opioids is accompanied by unpleasant and, at times, life-threatening side effects.Cannabis produces antinociception as well as psychotropic effects. It was hypothesized that peripheral cannabinoid receptors outside the central nervous system could be selectively activated for relief of pain. This study was undertaken to measure the antinociceptive effect of type 1 cannabinoid receptor (CB1r) agonist arachidonylcyclopropylamide (ACPA) in a rat model of inflammatory pain after intrawound administration and the effects were compared with lignocaine. METHODS: Wounds were produced under controlled conditions by an incision in the right hind paw in rats. ACPA (10, 30 or 100 µg/10 µl) was administered directly into the wound. Antinociception was evaluated by guarding, allodynia and thermal hyperalgesia. This was compared to lignocaine (30 µg/10 µl). Reversal of ACPA (30 µg)-mediated antinociceptive effect was attempted by intrawound AM251 (100 µg), a CB1r antagonist. Antinociception was also evaluated after contralateral administration of ACPA (30 µg). Primary afferent nociceptive input to the spinal cord was investigated by c-Fos expression after ACPA treatment (100 µg). RESULTS: ACPA, but not lignocaine, inhibited guarding behaviour, which was locally mediated. Conversely, lignocaine, but not ACPA, inhibited thermal hyperalgesia and mechanical allodynia. ACPA-mediated inhibitory effect was reversible and dose dependent. It was associated with a decreased c-Fos expression. Locomotor activity was unaffected following ACPA (100 µg) treatment. INTERPRETATION & CONCLUSIONS: Lignocaine attenuated evoked pain behaviour whereas ACPA decreased guarding score. This difference was likely due to blockade of sodium ion channels and the activation of peripheral CB1r, respectively. Central side effects were absent after ACPA treatment. Further studies need to be done to assess the effect of ACPA treatment in clinical conditions.


Assuntos
Analgésicos/administração & dosagem , Ácidos Araquidônicos/administração & dosagem , Dor/tratamento farmacológico , Medula Espinal/fisiopatologia , Animais , Humanos , Lidocaína/administração & dosagem , Masculino , Dor/fisiopatologia , Medição da Dor , Ratos , Receptor CB1 de Canabinoide/agonistas , Medula Espinal/efeitos dos fármacos , Medula Espinal/patologia , Cicatrização/efeitos dos fármacos
8.
Int Wound J ; 13(2): 252-6, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24750992

RESUMO

Wounds associated with injuries such as burns can produce moderate to severe pain. Besides causing distress to the patient, unrelieved pain could delay healing owing to stress-related problems. Thus, pain needs to be treated as early as possible after injury. It was hypothesised that local treatment of wounds with appropriate analgesic drugs could attenuate pain. HOE 140, a bradykinin receptor antagonist, reduced acute inflammatory pain in rats after intrawound administration. In this study, the analgesic effect of dimethylsulphoxide (DMSO) was investigated in a similar hind-paw incision model in rats. An extremely small quantity (10 µl) of 100% DMSO was administered into the incision site just before closure of the wound. It persistently attenuated guarding behaviour in rats over a period of 3 days without affecting thermal hyperalgesia or allodynia. Accumulated evidence indicates that guarding is equivalent to pain at rest in humans. The possible mechanisms of the analgesic effect could be inhibition of C group of peripheral nerve fibres or even free radical scavenging. Healing of the wound was found to be normal at the end of the study period. In conclusion, DMSO could be useful in the treatment of acute pain resulting from tissue injuries such as burns.


Assuntos
Dor Aguda/tratamento farmacológico , Dimetil Sulfóxido/administração & dosagem , Irrigação Terapêutica/métodos , Cicatrização/efeitos dos fármacos , Ferimentos e Lesões/complicações , Dor Aguda/etiologia , Animais , Modelos Animais de Doenças , Sequestradores de Radicais Livres/administração & dosagem , Masculino , Ratos , Ratos Sprague-Dawley , Ferimentos e Lesões/tratamento farmacológico
9.
Nitric Oxide ; 50: 98-104, 2015 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-26362773

RESUMO

Acute tissue damage is accompanied by synthesis of nitric oxide (NO) in the inflamed tissue as well as in the spinal cord. NO release at the spinal level is likely involved in the neuroplastic changes contributing to pain. Also, previous studies indicate that this could be due to the inducible isoform of the nitric oxide synthase (iNOS) enzyme. Though, the role of NO has been investigated in several animal models of nociception, the precise contribution of NO to nociception arising from hind paw incision is unknown, which is a rodent model of postoperative pain. In the present work, we have estimated the formation of NO in Sprague-Dawley rats, both at the site of incision and the corresponding spinal cord levels by Griess assay. Subsequently, naive rats were implanted with chronic indwelling intrathecal (i.t.) catheters. Fixed quantity (30 µg) of 1400 W, an iNOS inhibitor, was either administered locally into the wound at the time of incision or into the i.t. space, 15 min before hind paw incision. In a different set, i.t. 1400 W was administered, 20 h after incision. Control group received i.t. saline. Nociception was evaluated by guarding score, mechanical allodynia and thermal hyperalgesia. NO level was significantly increased between 4 h - day 1 locally and at 4 h at the spinal level after incision. Local inhibition of iNOS produced transient decrease of guarding (4-12 h) whereas pronounced decrease of guarding and allodynia was evident after spinal inhibition of iNOS. Also, spinal NO level decreased after i.t. drug administration. Post-incision drug treatment resulted in greater antinociceptive effect at day 1 though not on day 2. These results indicate involvement of NO in postincisional nociception in rats.

10.
Nat Commun ; 15(1): 2911, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38575590

RESUMO

The roles of Aß low-threshold mechanoreceptors (LTMRs) in transmitting mechanical hyperalgesia and in alleviating chronic pain have been of great interest but remain contentious. Here we utilized intersectional genetic tools, optogenetics, and high-speed imaging to specifically examine functions of SplitCre labeled mouse Aß-LTMRs in this regard. Genetic ablation of SplitCre-Aß-LTMRs increased mechanical nociception but not thermosensation in both acute and chronic inflammatory pain conditions, indicating a modality-specific role in gating mechanical nociception. Local optogenetic activation of SplitCre-Aß-LTMRs triggered nociception after tissue inflammation, whereas their broad activation at the dorsal column still alleviated mechanical hypersensitivity of chronic inflammation. Taking all data into consideration, we propose a model, in which Aß-LTMRs play distinctive local and global roles in transmitting or alleviating mechanical hyperalgesia of chronic pain, respectively. Our model suggests a strategy of global activation plus local inhibition of Aß-LTMRs for treating mechanical hyperalgesia.


Assuntos
Dor Crônica , Hiperalgesia , Camundongos , Animais , Hiperalgesia/genética , Nociceptividade , Mecanorreceptores/fisiologia , Inflamação/genética
11.
Indian J Exp Biol ; 51(12): 1130-6, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24579380

RESUMO

The genomic and cDNA sequences of BnSUT1C were isolated from B. napus. Combination of cDNA and genomic DNA sequences revealed that the BnSUT1C gene contained three exons and two introns. The cDNA encodes a protein of 513 amino acids with a calculated molecular mass of 54.7 kDa and an isoelectric point of 9.12. It exhibits typical features of sucrose transporter with 12 trans-membranes spanning domains. BnSUT1C showed highly homologous with AtSUC1 and AtSUC5. A histidine residue, which is conserved across all functional sucrose transporter proteins in higher plants, is located at position 66 of the BnSUT1C. Two putative pollen-specific cis-elements, AGAAA and GTGA motifs, are located in 5'-upstream of BnSUT1C. The spatial and temporal expression patterns carried out by semi-quantitative RT-PCR and Real-Time PCR, which indicated that BnSUT1C predominantly expressed in later developmental stages of anther, as tapetal cells began to shrink and collapse. BnSUT1C could mediate the uptake of sucrose in the pollen and retrieval of tapetal degenerated products during pollen maturation.


Assuntos
Brassica napus/genética , Clonagem Molecular , DNA/genética , Proteínas de Membrana Transportadoras/isolamento & purificação , Proteínas de Plantas/isolamento & purificação , Sequência de Aminoácidos , Arabidopsis/genética , Sequência de Bases , DNA Complementar/genética , Proteínas de Membrana Transportadoras/genética , Proteínas de Plantas/genética , RNA Mensageiro/genética , Homologia de Sequência de Aminoácidos , Transcriptoma
12.
Res Sq ; 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37398333

RESUMO

The roles of Aß low-threshold mechanoreceptors (LTMRs) in transmitting mechanical hyperalgesia and in alleviating chronic pain have been of great interest but remain contentious. Here we utilized intersectional genetic tools, optogenetics, and high-speed imaging to specifically examine functions of SplitCre labeled Aß-LTMRs in this regard. Genetic ablation of SplitCre-Aß-LTMRs increased mechanical pain but not thermosensation in both acute and chronic inflammatory pain conditions, indicating their modality-specific role in gating mechanical pain transmission. Local optogenetic activation of SplitCre-Aß-LTMRs triggered nociception after tissue inflammation, whereas their broad activation at the dorsal column still alleviated mechanical hypersensitivity of chronic inflammation. Taking all data into consideration, we propose a new model, in which Aß-LTMRs play distinctive local and global roles in transmitting and alleviating mechanical hyperalgesia of chronic pain, respectively. Our model suggests a new strategy of global activation plus local inhibition of Aß-LTMRs for treating mechanical hyperalgesia.

13.
bioRxiv ; 2023 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-37293085

RESUMO

The roles of Aß low-threshold mechanoreceptors (LTMRs) in transmitting mechanical hyperalgesia and in alleviating chronic pain have been of great interest but remain contentious. Here we utilized intersectional genetic tools, optogenetics, and high-speed imaging to specifically examine functions of Split Cre labeled Aß-LTMRs in this regard. Genetic ablation of Split Cre -Aß-LTMRs increased mechanical pain but not thermosensation in both acute and chronic inflammatory pain conditions, indicating their modality-specific role in gating mechanical pain transmission. Local optogenetic activation of Split Cre -Aß-LTMRs triggered nociception after tissue inflammation, whereas their broad activation at the dorsal column still alleviated mechanical hypersensitivity of chronic inflammation. Taking all data into consideration, we propose a new model, in which Aß-LTMRs play distinctive local and global roles in transmitting and alleviating mechanical hyperalgesia of chronic pain, respectively. Our model suggests a new strategy of global activation plus local inhibition of Aß-LTMRs for treating mechanical hyperalgesia.

14.
bioRxiv ; 2023 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-36993480

RESUMO

The versatility of somatosensation arises from heterogeneous dorsal root ganglion (DRG) neurons. However, soma transcriptomes of individual human DRG (hDRG) neurons-critical in-formation to decipher their functions-are lacking due to technical difficulties. Here, we developed a novel approach to isolate individual hDRG neuron somas for deep RNA sequencing (RNA-seq). On average, >9,000 unique genes per neuron were detected, and 16 neuronal types were identified. Cross-species analyses revealed remarkable divergence among pain-sensing neurons and the existence of human-specific nociceptor types. Our deep RNA-seq dataset was especially powerful for providing insight into the molecular mechanisms underlying human somatosensation and identifying high potential novel drug targets. Our dataset also guided the selection of molecular markers to visualize different types of human afferents and the discovery of novel functional properties using single-cell in vivo electrophysiological recordings. In summary, by employing a novel soma sequencing method, we generated an unprecedented hDRG neuron atlas, providing new insights into human somatosensation, establishing a critical foundation for translational work, and clarifying human species-species properties.

15.
J Invest Dermatol ; 142(4): 1136-1144, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34570999

RESUMO

Contact dermatitis (CD), including allergic and irritant CD, are common dermatological diseases and are characterized by an erythematous rash and severe itch. In this study, we investigated the function of TRPC3, a canonical transient receptor potential channel highly expressed in type 1 nonpeptidergic (NP1) nociceptive primary afferents and other cell types, in a mouse CD model. Although TrpC3 null mice had little deficits in acute somatosensation, they showed significantly increased scratching with CD. In addition, TrpC3 null mice displayed no differences in mechanical and thermal hypersensitivity in an inflammatory pain model, suggesting that this channel preferentially functions to antagonize CD-induced itch. Using dorsal root ganglia and panimmune-specific TrpC3 conditional knockout mice, we determined that TrpC3 in dorsal root ganglia neurons but not in immune cells is required for this phenotype. Furthermore, the number of MRGPRD+ NP1 afferents in CD-affected dorsal root ganglia is significantly reduced in TrpC3-mutant mice. Taken together, our results suggest that TrpC3 plays a critical role in NP1 afferents to cope with CD-induced excitotoxicity and that the degeneration of NP1 fibers may lead to an increased itch of CD. Our study identified a role of TrpC3 and NP1 afferents in CD pathology.


Assuntos
Dermatite de Contato , Prurido , Animais , Dermatite de Contato/patologia , Modelos Animais de Doenças , Gânglios Espinais , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Prurido/patologia
16.
Neuron ; 110(5): 809-823.e5, 2022 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-34986325

RESUMO

Whether glutamate or itch-selective neurotransmitters are used to confer itch specificity is still under debate. We focused on an itch-selective population of primary afferents expressing MRGPRA3, which highly expresses Vglut2 and the neuropeptide neuromedin B (Nmb), to investigate this question. Optogenetic stimulation of MRGPRA3+ afferents triggers scratching and other itch-related avoidance behaviors. Using a combination of optogenetics, spinal cord slice recordings, Vglut2 conditional knockout mice, and behavior assays, we showed that glutamate is essential for MRGPRA3+ afferents to transmit itch. We further demonstrated that MRGPRA3+ afferents form monosynaptic connections with both NMBR+ and NMBR- neurons and that NMB and glutamate together can enhance the activity of NMBR+ spinal DH neurons. Moreover, Nmb in MRGPRA3+ afferents and NMBR+ DH neurons are required for chloroquine-induced scratching. Together, our results establish a new model in which glutamate is an essential neurotransmitter in primary afferents for itch transmission, whereas NMB signaling enhances its activities.


Assuntos
Ácido Glutâmico , Prurido , Animais , Camundongos , Camundongos Knockout , Neurônios , Prurido/induzido quimicamente , Medula Espinal
17.
Elife ; 112022 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-36476338

RESUMO

Mice are the most commonly used model animals for itch research and for development of anti-itch drugs. Most laboratories manually quantify mouse scratching behavior to assess itch intensity. This process is labor-intensive and limits large-scale genetic or drug screenings. In this study, we developed a new system, Scratch-AID (Automatic Itch Detection), which could automatically identify and quantify mouse scratching behavior with high accuracy. Our system included a custom-designed videotaping box to ensure high-quality and replicable mouse behavior recording and a convolutional recurrent neural network trained with frame-labeled mouse scratching behavior videos, induced by nape injection of chloroquine. The best trained network achieved 97.6% recall and 96.9% precision on previously unseen test videos. Remarkably, Scratch-AID could reliably identify scratching behavior in other major mouse itch models, including the acute cheek model, the histaminergic model, and a chronic itch model. Moreover, our system detected significant differences in scratching behavior between control and mice treated with an anti-itch drug. Taken together, we have established a novel deep learning-based system that could replace manual quantification for mouse scratching behavior in different itch models and for drug screening.


Assuntos
Aprendizado Profundo , Camundongos , Animais , Prurido/induzido quimicamente , Comportamento Animal , Injeções , Cloroquina/farmacologia , Modelos Animais de Doenças
18.
Ann Transl Med ; 9(6): 448, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33850845

RESUMO

BACKGROUND: Pain is a predominant symptom in rheumatoid arthritis (RA) patients that results from joint inflammation and is augmented by central sensitization. Regulator of G-protein signaling 12 (RGS12) is the largest protein in the RGS protein family and plays a key role in the development of inflammation. This study investigated the regulation of RGS12 in inflammatory pain and explored the underlying mechanisms and potential RA pain targets. METHODS: Macrophage-specific RGS12-deficient (LysM-Cre+;RGS12fl/fl) mice were generated by mating RGS12fl/fl mice with LysM-Cre+ transgenic mice. Collagen antibody-induced arthritis (CAIA) models were induced in LysM-Cre+;RGS12fl/fl mice by the administration of a cocktail of five monoclonal antibodies and LPS. Mouse nociception was examined using the von Frey and heat plate tests. Primary macrophages and RAW264.7 cells were used to analyze the regulatory function and mechanism of RGS12 in vitro. The expression and function of RGS12 and COX2 (cyclooxygenase 2) were determined by real-time PCR, ELISA, and luciferase assays. RESULTS: Ablation of RGS12 in macrophages decreased pain-related phenotypes, such as paw swelling, the clinical score, and the inflammatory score, in the CAIA model. LysM-Cre+;RGS12fl/fl mice displayed increased resistance to thermal and mechanical stimulation from day 3 to day 9 during CAIA, indicating the inhibition of inflammatory pain. Overexpression of COX2 and PGE2 in macrophages enhanced RGS12 expression, and PGE2 regulated RGS12 expression through the G-protein-coupled receptors EP2 and EP4. Furthermore, RGS12 or the RGS12 PTB domain strengthened the transcriptional regulation of COX2 by NF-κB, whereas inhibiting NF-κB suppressed RGS12-mediated regulation of COX2 in macrophages. CONCLUSIONS: Our results demonstrate that the deletion of RGS12 in macrophages attenuates inflammatory pain, which is likely due to impaired regulation of the COX2/PGE2 signaling pathway.

19.
Vet Parasitol Reg Stud Reports ; 24: 100572, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-34024388

RESUMO

Theileriosis is an important tick borne disease of cattle caused by a haemoprotozoan of genus Theileria. Clinical bovine theileriosis is mainly caused by T. annulata or T. parva but the clinical disease due to T. orientalis is rare. T. orientalis mainly infect RBCs and causes "Oriental theileriosis" or Theileria-associated bovine anaemia in cattle and other livestock species. Two genotypes of T. orientalis (Chitose and Ikeda) are reported to cause severe disease in some countries. In this report, a spontaneous outbreak of Oriental theileriosis was studied in an organized Holstein-Friesian cattle breeding farm situated in the south-eastern Himalayan ranges of Himachal Pradesh State of India. Animal blood and tick samples were tested using cytological and PCR techniques. The disease episode occurred in a protracted manner spanning over 10 to 12 months and association of T. orientalis was confirmed in 93.3% of the blood and 21.7% of Rhipicephalus microplus (tick) samples. No other tick borne pathogen was detected except Anaplasma marginale in two blood samples. Haematological profiling of infected cattle showed characteristic indicators of anaemia like haemoblobin, RBC count, haematocrit value and mean corpuscular volume at either lower than normal or near the lower normal range. The prevailing persistent anaemic changes led to more severe clinical manifestations like abortion and joint inflammation. The detected T. orientalis strains and ticks species were further confirmed by nucleotide sequence analysis of 18S rRNA and 16S rRNA genes. Phylogenetically, T. orientalis strains showed clustering with other reported strains of T. orientalis from the surrounding regions. This first report of clinical Oriental theileriosis from India emphasises the importance of T. orientalis as an emerging tick borne pathogen and role of widely prevalent ticks species in disease transmission and their impact on livestock production.


Assuntos
Doenças dos Bovinos , Rhipicephalus , Theileria , Theileriose , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Surtos de Doenças/veterinária , Fazendas , RNA Ribossômico 16S , Rhipicephalus/genética , Theileria/genética , Theileriose/epidemiologia
20.
Front Genet ; 11: 43, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32117455

RESUMO

The nucleolar structure and integrity are important for a range of cellular functions of the nucleoli. It has been shown that cells lacking histone H3 Lysine 9 (H3K9) methylation form fragmented nucleoli. However, the molecular mechanism involved remains poorly understood. Here, we present evidence suggesting that loss of H3K9 dimethylation (H3K9me2) triggers R-loop accumulation at the rDNA locus, which further leads to the multilobed nucleoli. We reveal that suppression of H3K9 methyltransferase G9a by the inhibitor BIX 01294 causes R-loop accumulation at the rDNA region as well as inducing formation of multiple nucleoli. SiRNA-mediated knockdown of RNase H1 which can hydrolyze the RNA chain in R-loops causes an increase in R-loop formation, which in turn results in multiple nucleoli in one nucleus, whereas H3K9me2 levels are not affected by R-loop accumulation. Inhibition of RNA polymerase I transcription elongation by small molecule inhibitors induces a substantial decrease in H3K9me2 levels, accumulation of R-loops at rDNA sites, and nucleolus fragmentation. These results provide a mechanistic insight into the role of H3K9me2 in the structural integrity and organization of nucleoli via regulating R-loop accumulation.

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