MrgprA3+ Primary Sensory Neurons Mediate Acute Allergic Itch Responses in Atopic Dermatitis Model Mice.

Itch is a prominent symptom of atopic dermatitis (AD). However, the underlying mechanism remains complex and has not yet been fully elucidated. Mas-related G protein-coupled receptor A3 (MrgprA3) has emerged attention as a marker of primary sensory neurons that specifically transmit itch signals; however, its involvement in AD-related itch has not been extensively explored. In this study, we developed an AD itch mouse model by repeatedly applying house dust mite (HDM) extract to barrier-impaired skin via a special diet. To clarify the role of MrgprA3+ neurons in itch behavior in our AD model, we adopted a toxin receptor-mediated cell knockout strategy using transgenic mice in which the diphtheria toxin receptor (DTR) gene was placed under the control of the Mrgpra3 promoter. When the HDM extract was repeatedly applied to the face and back skin of special diet-fed mice, the mice exhibited AD-like dry and eczematous skin lesions accompanied by three types of itch-related behaviors:1) spontaneous scratching, 2) acute scratching after antigen challenge, and 3) light touch-evoked scratching. Upon diphtheria toxin administration, substantial depletion of DTR+/MrgprA3+ neurons was observed in the dorsal root ganglion. Ablation of MrgprA3+ neurons suppressed acute itch responses after HDM application, whereas spontaneous and touch-evoked itch behaviors remained unaffected. Our findings unequivocally demonstrate that in our AD model, MrgprA3+ primary sensory neurons mediate acute allergic itch responses, whereas these neurons are not involved in spontaneous itch or alloknesis.

[RECOMMENDATION FOR ITCH ASSESSMENT FROM THE ATOPIC ITCH CONSENSUS MEETING (AICOM)].

BACKGROUND: Itch is the most troublesome symptom of atopic dermatitis, and it is important to assess it appropriately for optimal treatment. We discussed issues regarding itch and the most appropriate methods of assessment at the Atopic Itch Consensus Meeting (AICOM), attended by physicians and researchers with expertise in itch treatment and research. METHODS: The AICOM participants prepared a draft consensus statement that addressed the most appropriate itch assessment methods for age groups <2 years, 2-6 years, 7-14 years, and ≥15 years. Consensus was defined as agreement by ≥80% of the participants. RESULTS: Votes were cast by 20 participants (8 dermatologists, 7 pediatricians, and 5 researchers), and a consensus on the best current methods of itch assessment was reached with 95% agreement. For infants and preschool children, because subjective evaluation is difficult, a checklist for itch assessment was developed for caregivers. CONCLUSION: For itch assessment, we recommend subjective evaluation by the patient using a rating scale. For infants and preschoolers, evaluation should be done by the caregiver using a checklist, combined with objective evaluation (of skin lesions, for example) by a physician. We anticipate that more objective itch assessment indices will be established in the future.

Astrocytic STAT3 activation and chronic itch require IP3R1/TRPC-dependent Ca2+ signals in mice.

BACKGROUND: Chronic itch is a debilitating symptom of inflammatory skin diseases, but the underlying mechanism is poorly understood. We have recently demonstrated that astrocytes in the spinal dorsal horn become reactive in models of atopic and contact dermatitis via activation of the transcription factor signal transducer and activator of transcription 3 (STAT3) and critically contribute to chronic itch. In general, STAT3 is transiently activated; however, STAT3 activation in reactive astrocytes of chronic itch model mice persistently occurs via an unknown mechanism. OBJECTIVE: We aimed to determine the mechanisms of persistent activation of astrocytic STAT3 in chronic itch conditions. METHODS: To determine the factors that are required for persistent activation of astrocytic STAT3, Western blotting and calcium imaging with cultured astrocytes or spinal cord slices were performed. Thereafter, chronic itch model mice were used for genetic and behavioral experiments to confirm the role of the factors determined to mediate persistent STAT3 activation from in vitro and ex vivo experiments in chronic itch. RESULTS: IP3 receptor type 1 (IP3R1) knockdown in astrocytes suppressed IL-6-induced persistent STAT3 activation and expression of lipocalin-2 (LCN2), an astrocytic STAT3-dependent inflammatory factor that is required for chronic itch. IP3R1-dependent astrocytic Ca2+ responses involved Ca2+ influx through the cation channel transient receptor potential canonical (TRPC), which was required for persistent STAT3 activation evoked by IL-6. IL-6 expression was upregulated in dorsal root ganglion neurons in a mouse model of chronic itch. Dorsal root ganglion neuron-specific IL-6 knockdown, spinal astrocyte-specific IP3R1 knockdown, and pharmacologic spinal TRPC inhibition attenuated LCN2 expression and chronic itch. CONCLUSION: Our findings suggest that IP3R1/TRPC channel-mediated Ca2+ signals elicited by IL-6 in astrocytes are necessary for persistent STAT3 activation, LCN2 expression, and chronic itch, and they may also provide new targets for therapeutic intervention.

Sensitization of spinal itch transmission neurons in a mouse model of chronic itch requires an astrocytic factor.

BACKGROUND: Chronic itch is a highly debilitating symptom among patients with inflammatory skin diseases. Recent studies have revealed that gastrin-releasing peptide (GRP) and its receptor (gastrin-releasing peptide receptor [GRPR]) in the spinal dorsal horn (SDH) play a central role in itch transmission. OBJECTIVE: We aimed to investigate whether GRP-GRPR signaling is altered in SDH neurons in a mouse model of chronic itch and to determine the potential mechanisms underlying these alterations. METHODS: Patch-clamp recordings from enhanced green fluorescent protein (EGFP)-expressing (GRPR+) SDH neurons were used to examine GRP-GRPR signaling in spinal cord slices obtained from Grpr-EGFP mice. Immunohistochemical, genetic (gene expression and editing through adeno-associated virus vectors), and behavioral approaches were also used for in vivo experiments. RESULTS: We observed potentiation of GRP-evoked excitation in the GRPR+ SDH neurons of mice with contact dermatitis, without concomitant changes in GRPR expression. Interestingly, increases in excitation were attenuated by suppressing the reactive state of SDH astrocytes, which are known to be reactive in patients with chronic itch conditions. Furthermore, CRISPR-Cas9-mediated astrocyte-selective in vivo editing of a gene encoding lipocalin-2 (LCN2), an astrocytic factor implicated in chronic itch, suppressed increases in GRP-induced excitation of GRPR+ neurons, repetitive scratching, and skin damage in mice with contact dermatitis. Moreover, LCN2 potentiated GRP-induced excitation of GRPR+ neurons in normal mice. CONCLUSION: Our findings indicate that, under chronic itch conditions, the GRP-induced excitability of GRPR+ SDH neurons is enhanced through a non-cell-autonomous mechanism involving LCN2 derived from reactive astrocytes.

Role of reactive astrocytes in the spinal dorsal horn under chronic itch conditions.

Astrocytes are the most abundant glial cells in the central nervous system (CNS), including the spinal cord. Neuronal damage induces astrocytes to become reactive and contribute to various CNS pathologies. Recent studies have demonstrated that astrocytes in the spinal dorsal horn (SDH) become reactive in a transcription factor signal transducer and activator of transcription 3-dependent manner without neuronal damage under chronic itch conditions, causing release of the factor lipocalin-2, leading to induction of sensitization of gastrin releasing peptide-induced chemical itch signaling in the SDH. In this review, we describe recent advances in our understanding of SDH neuronal pathways for itch transmission, the mechanisms of SDH astrocytic activation and its contribution to abnormal itch processing and discuss the role of reactive astrocytes in the SDH in abnormal sensory processing under chronic itch conditions.

IP3R1-dependent astrocyte calcium signaling in chronic itch.

Astrocytes, the most abundant type of glial cell, are electrically non-excitable cells that use intracellular calcium (Ca2+) for functional regulation. Changes in intracellular Ca2+ concentration play important roles in the central nervous system (CNS), as they are involved in the release of gliotransmitters and the control of extracellular ion concentrations, thereby affecting the regulation of neuronal excitability, CNS homeostasis, and behavior. Intracellular calcium mobilization in astrocytes is known to be mediated via inositol 1,4,5-trisphosphate receptors (IP3Rs), particularly IP3R2, and its association with CNS pathogenesis has been widely reported. In addition, the existence of IP3R2-independent calcium signaling has recently been postulated; however, the detailed mechanisms and its role in astrocyte functions and CNS pathogenesis are still poorly understood. In this paper, we describe the putative mechanisms underlying IP3R1-dependent calcium signaling in astrocytes and its effects on the reactive state, compare this signaling with IP3R2-dependent calcium signaling, and discuss its contribution to chronic itch-like behavior.

Adapting pediatric health care responses to the COVID-19 pandemic in Japan: A clinical perspective.

The COVID-19 pandemic required our pediatric health care staff to adjust to many irregularities and solve serious issues in our routine clinical practice. In outpatient clinics, many children exhibited common cold symptoms that mimic COVID-19, thus we initially screened patients via an interview form, then later via SARS-CoV-2 antigen test. Cluster infections were entirely avoided by following systematic, everyday precautions. Patientsquality of life has been difficult to maintain during the pandemic, due to social and staffing restrictions. Other unexpected repercussions - such as an unexpected lack of seasonal virus infections, then a respiratory syncytial (RS) virus outbreak - required agile management of hospital resources. While we must continue to adapt our treatment programs in response to the evolving COVID-19 crisis, it remains essential to support the well-being of children through regular health check-ups, mental health support, educational opportunities, proper socialization, and close communication with parents and families.

Neuronal pentraxin 2 is required for facilitating excitatory synaptic inputs onto spinal neurons involved in pruriceptive transmission in a model of chronic itch.

An excitatory neuron subset in the spinal dorsal horn (SDH) that expresses gastrin-releasing peptide receptors (GRPR) is critical for pruriceptive transmission. Here, we show that glutamatergic excitatory inputs onto GRPR+ neurons are facilitated in mouse models of chronic itch. In these models, neuronal pentraxin 2 (NPTX2), an activity-dependent immediate early gene product, is upregulated in the dorsal root ganglion (DRG) neurons. Electron microscopy reveals that NPTX2 is present at presynaptic terminals connected onto postsynaptic GRPR+ neurons. NPTX2-knockout prevents the facilitation of synaptic inputs to GRPR+ neurons, and repetitive scratching behavior. DRG-specific NPTX2 expression rescues the impaired behavioral phenotype in NPTX2-knockout mice. Moreover, ectopic expression of a dominant-negative form of NPTX2 in DRG neurons reduces chronic itch-like behavior in mice. Our findings indicate that the upregulation of NPTX2 expression in DRG neurons contributes to the facilitation of glutamatergic inputs onto GRPR+ neurons under chronic itch-like conditions, providing a potential therapeutic target.

Spinal glial cells in itch modulation.

Glial cells are non-neuronal cells in the nervous system that are electrically non-excitable and outnumber neurons in humans. Glial cells have attracted attention in recent years for their active involvement in the regulation of neuronal activity, suggesting their contribution to the pathogenesis and progression of neurological diseases. Studies have shown that astrocytes, a type of glial cell, are activated in the spinal cord in response to skin inflammation and contribute to the exacerbation of chronic itch. This review summarizes the current knowledge about the role of astrocytes and other glial cells in the modulation of itch processing and the mechanism of their activation under itch conditions.

Oral Management of a Haematopoietic Stem Cell Transplant Recipient with Chédiak-Higashi Syndrome.

Chédiak-Higashi syndrome (CHS), a rare autosomal recessive disorder associated with leukocyte dysfunction, is characterised by partial skin and hair albinism, immunodeficiency, and abnormal bleeding. Furthermore, it may be associated with cognitive and neurological impairments. The long-term prognosis of patients is generally poor, and haematopoietic stem cell transplantation is a radical immunodeficiency treatment. Here, we report a case of successful oral management of an 18-year-old woman with CHS accompanied by aggressive periodontitis who underwent haematopoietic stem cell transplantation.

α1A-adrenaline receptors in dorsal horn inhibitory neurons have an inhibitory role in the regulation of chloroquine-induced itch in mice.

Our previous study showed the intrinsic ability of descending noradrenergic neurons projecting from the locus coeruleus to the spinal dorsal horn (SDH) to suppress itch-related behaviors. Noradrenaline and α1A-adrenaline receptor (α1A-AR) agonist increase inhibitory synaptic inputs onto SDH interneurons expressing gastrin-releasing peptide receptors, which are essential for itch transmission. However, the contribution of α1A-ARs expressed in SDH inhibitory interneurons to itch-related behavior remains to be determined. In this study, RNAscope in situ hybridization revealed that Adra1a mRNA is expressed in SDH inhibitory interneurons that are positive for Slc32a1 mRNA (known as vesicular GABA transporter). Mice with conditional knock-out of α1A-ARs in inhibitory interneurons (Vgat-Cre;Adra1aflox/flox mice) exhibited an increase in scratching behavior when induced by an intradermal injection of chloroquine, but not compound 48/80, which are known as models of histamine-independent and dependent itch, respectively. Furthermore, knockout of inhibitory neuronal α1A-ARs in the SDH using the CRISPR-Cas9 system also increased the scratching behavior elicited by chloroquine but not compound 48/80. Our findings demonstrated for the first time that α1A-ARs in SDH inhibitory interneurons contribute to the regulation of itch signaling with preference for histamine-independent itch.

Intrinsic braking role of descending locus coeruleus noradrenergic neurons in acute and chronic itch in mice.

Itch is defined as an unpleasant sensation that provokes a desire to scratch. Our understanding of neuronal circuits for itch information transmission and processing in the spinal dorsal horn (SDH) has progressively advanced following the identification of SDH neuron subsets that are crucial for scratching behavior in models of itch. However, little is known about the control of acute and chronic itch by descending signals from the brain to the SDH. In this study, using genetic approaches that enable cell-type and circuit-specific functional manipulation, we reveal an intrinsic potential of locus coeruleus (LC)-noradrenergic (NAergic) neurons that project to the SDH to control acute and chronic itch. Activation and silencing of SDH-projecting LC-NAergic neurons reduced and enhanced scratching behavior, respectively, in models of histamine-dependent and -independent acute itch. Furthermore, in a model of chronic itch associated with contact dermatitis, repetitive scratching behavior was suppressed by the activation of the descending LC-NAergic pathway and by knocking out NA transporters specific to descending LC-NAergic neurons using a CRISPR-Cas9 system. Moreover, patch-clamp recording using spinal slices showed that noradrenaline facilitated inhibitory synaptic inputs onto gastrin-releasing peptide receptor-expressing SDH neurons, a neuronal subset known to be essential for itch transmission. Our findings suggest that descending LC-NAergic signaling intrinsically controls acute and chronic itch and provide potential therapeutic strategies for the treatment of acute and chronic itch.

(-)(545)-fac-Δ-Tris(l-prolinato)cobalt(III) trihydrate.

The absolute configuration of the octa-hedral fac-CoN(3)O(3) title complex, [Co(C(5)H(8)NO(2))(3)]·3H(2)O, has been determined by single-crystal X-ray analysis. A three-dimensional network of hydrogen bonds is observed between the proline carboxyl-ate groups and the three uncoordinated water mol-ecules.

Evaluation of the effects of combination therapy with branched-chain amino acid and zinc supplements on nitrogen metabolism in liver cirrhosis.

AIM: Disorders of protein metabolism in liver cirrhosis can affect prognosis or cause complications. Treatment with branched-chain amino acid (BCAA) and zinc supplements has been shown to be effective against abnormal nitrogen metabolism in liver cirrhosis. There are, however, few studies on the effects of combining these supplements. In this study, the effect of combining BCAA and zinc treatment in cirrhosis was investigated. METHODS: Forty patients with liver cirrhosis who had blood albumin levels of 3.5 g/dL or less and blood zinc levels of 70 mug/dL or less were randomized to receive either BCAA alone or a combination of BCAA and zinc supplements. Blood albumin, the Fischer ratio, and ammonia levels were compared over 5-6 months of treatment. RESULTS: In the combination group, the post/pre treatment change ratio in blood ammonia levels decreased significantly (0.87 +/- 0.26 vs. 1.22 +/- 0.38, P = 0.0033), and the change ratio in the Fischer ratio increased significantly (1.22 +/- 0.29 vs. 1.08 +/- 0.16, P = 0.0165) in comparison with the BCAA monotherapy group. The change ratio in blood albumin levels showed no significant difference between the groups (1.01 +/- 0.07 vs. 1.03 +/- 0.08, P = 0.4646). CONCLUSIONS: More improvement in disorders of nitrogen metabolism in liver cirrhosis occurred after administration of BCAA with zinc than after BCAA alone over 5-6 months of treatment. Further investigation is necessary to determine mechanisms of the action and longer-term clinical efficacy.

[Familial occurrence of bronchiolitis obliterans associated with pulmonary aspergillosis].

We report the familial occurrence of bronchiolitis obliterans (BO) associated with pulmonary aspergillosis. A mother and daughter admitted for dyspnea after taking Sauropus androgynus both had overfiltration of both lungs in chest X-ray and severe obstructive impairment in lung function tests. They were initially diagnosed with severe asthma and treated with high-dose prednisolone (0.5mg/kg/day) for 1 month to no effects. They did not show reversibility in lung function test. They were difinitively diagnosed with BO associated with Sauropus androgynus. Six months later, the mother's symptoms worsened with productive sputum and severe dyspnea, and her chest X-ray showed patty shadow in both upper lung fields. Precipitating antibodies to aspergillus antigen were positive and aspergillus fumigatus was detected from her sputum culture. She was diagnosed with aspergillosis and treatment with Micafungin (MCFG) and Itraconazole (ITCZ) was started. The daughter's symptoms also worsened and her chest tomography showed multiple cavities in both lung fields. Precipitating antibodies to aspergillus were positive. She was diagnosed with Invasive aspergillosis. She was treated unsuccessfully with MCFG and Amphotericin B (AMPH) and ITCZ. Few reports cover BO with aspergillus infection without organ impairment. In these 2 cases, treatment with steroids' or immune suppression of the lung with BO may a trigger aspergillus infection.

[Familial occurrence of bronchiolitis obliterans associated with sauropus androgynus].

We experienced familial occurrence of bronchiolitis obliterans (BO) associated with Sauropus androgynus. The cases were a mother and daughter and both were admitted to our hospital because of dyspnea after taking Sauropus androgynus. Both cases had hyperinflation of both lungs in chest x-ray and lung function test showed severe obstructive impairment. At first, they were given a diagnosis of severe asthma and treated as such. However, neither their symptoms nor lung function improved. They did not show any reversibility on lung function tests. Although we did not perform histological examination of the lung, they were given a diagnosis of BO associated with Sauropus androgynus (SABO), because of the following reasons. Cases of SABO in Taiwan have already been demonstrated in the 1990's, and there were no other reasons to explain their severe airflow obstruction. Neither bronchodilators nor steroid treatment improved airflow obstruction. BO is rare and can mimic asthma and chronic obstructive pulmonary disease (COPD). We should inquire about the intake of food or medication in cases suspected BO.

The Imaging Diagnosis of Less Advanced Cases of Cardiac Amyloidosis: The Relative Apical Sparing Pattern.

An early diagnosis is important for improving the prognosis of cardiac amyloidosis (CA). We herein describe the utility of two-dimensional speckle tracking echocardiography (2-D STE) in diagnosing CA at a less advanced stage. A 63-year-old woman with exertional dyspnea was suspected of having CA based on her echocardiographic and electrocardiographic findings. A myocardial biopsy was negative for amyloid deposits, while the relative apical sparing pattern was detected on 2-D STE, which was highly suggestive of CA. Chemotherapy was initiated as a treatment for CA, and the patient's symptoms were immediately relieved. Thereafter, amyloid deposits were detected in a skin biopsy specimen.

Chemogenetic silencing of GABAergic dorsal horn interneurons induces morphine-resistant spontaneous nocifensive behaviours.

Inhibitory interneurons in the spinal dorsal horn (SDH) are crucial for processing somatosensory information originating in the periphery. However, the effects of the acute and selective inactivation of GABAergic SDH interneurons on pain processing are not fully understood. In this study, we used designer receptors exclusively activated by designer drugs (DREADD) technology and vesicular GABA transporter-Cre (Vgat-Cre) mice to selectively express a modified human muscarinic Gi protein-coupled receptor (hM4Di) in Vgat-Cre + GABAergic SDH interneurons in the fourth lumbar segment. We found that clozapine-N-oxide (CNO) treatment rapidly hyperpolarized these neurons and induced spontaneous nocifensive behaviours in these mice. In Vgat-Cre neg lamina II neurons, CNO produced facilitation of A fibre-mediated polysynaptic excitatory responses, an effect that required N-methyl-D-aspartate (NMDA) receptor activation. The CNO-induced nocifensive behaviours were also reduced by NMDA receptor antagonism. Moreover, these nocifensive behaviours were suppressed by pregabalin but resistant to morphine. Our findings indicate that Vgat-Cre + SDH interneurons play an important role in morphine-resistant nocifensive behaviours and suggest that this approach may provide a useful model for understanding the mechanisms of opioid-resistant pain signalling and for developing novel analgesics.