Ash1L ameliorates psoriasis via limiting neuronal activity-dependent release of miR-let-7b

BACKGROUND AND PURPOSE

Psoriasis is a common autoimmune skin disease that significantly diminishes patients' quality of life. Interactions between primary afferents of the somatosensory system and the cutaneous immune system mediate the pathogenesis of psoriasis. This study aims to elucidate the molecular mechanisms of how primary sensory neurons regulate psoriasis formation.

EXPERIMENTAL APPROACH

Skin and total RNA were extracted from wild-type (WT) and ASH1-like histone lysine methyltransferase (Ash1l+/- ) mice in both naive and imiquimod (IMQ)-induced psoriasis models. Immunohistochemistry, quantitative real-time polymerase chain reaction (qRT-PCR) and fluorescence-activated cell sorting (FACS) were then performed. Microfluidic chamber coculture was used to investigate the interaction between somatosensory neurons and bone marrow dendritic cells (BMDCs) ex vivo. Whole-cell patch clamp recordings were used to evaluate neuronal excitability after Ash1L haploinsufficiency in primary sensory neurons.

KEY RESULTS

The haploinsufficiency of ASH1L, a histone methyltransferase, in primary sensory neurons causes both neurite hyperinnervation and increased neuronal excitability, which promote miR-let-7b release from primary afferents in the skin in a neuronal activity-dependent manner. With a 'GUUGUGU' core sequence, miR-let-7b functions as an endogenous ligand of toll-like receptor 7 (TLR7) and stimulates the activation of dermal dendritic cells (DCs) and interleukin (IL)-23/IL-17 axis, ultimately exacerbating the symptoms of psoriasis. Thus, by limiting miR-let-7b release from primary afferents, ASH1L prevents dermal DC activation and ameliorates psoriasis.

CONCLUSION AND IMPLICATIONS

Somatosensory neuron ASH1L modulates the cutaneous immune system by limiting neuronal activity-dependent release of miR-let-7b, which can directly activate dermal DCs via TLR7 and ultimately lead to aggravated psoriatic lesion.

[The risk prediction value of paraquat poisoning dose, urine protein and myocardial enzymes]

Objective: To explore the value of paraquat (PQ) intake, urine protein and myocardial enzyme indexes in judging the prognosis of patients with acute PQ poisoning. Methods: From September to December 2021, all 201 patients with acute PQ poisoning admitted to Guangzhou Twelfth People's Hospital from January 2010 to December 2019 were selected as the research objects. Based on follow-up results 60 days after poisoning, the research objects were divided into survival group (n=78) and death group (n=123) . The differences in information about poisoning, treatment plan, PQ intake, urine protein, creatine kinase, creatine kinase isoenzyme, lactate dehydrogenase, and α-hydroxybutyrate dehydrogenase between the two groups of patients were compared and analyzed. Logistic regression and Cox regression were used to analyze the correlation between poisoning outcome and PQ intake, urine protein and myocardial enzymes. ROC curve and principal component analysis were used to explore high-efficiency indicators for predicting the outcome of acute PQ poisoning. Results: The PQ intake[50 (20, 100) ml], urine protein (total rank 15570.50) , creatine kinase[ (336.36±261.96) U/L], creatine kinase isoenzyme[ (43.91±43.74) U/L], lactate dehydrogenase [ (346.01±196.50) U/L], α-hydroxybutyrate dehydrogenase content[ (271.23±11.92) U/L] of patients in the death group were all higher than the survival group[15 (10, 20) ml, 4730.50, (187.78±178.06) U/L, (18.88±15.50) U/L, (190.92±60.50) U/L, (152.60±48.34) U/L, respectively] (P<0.05) . The outcome of acute PQ poisoning was positively correlated with PQ intake, urine protein, creatine kinase, creatine kinase isoenzyme, lactate dehydrogenase, and α-hydroxybutyrate dehydrogenase (P<0.05) . Multivariate logistic regression and multivariate Cox regression analysis showed that creatine kinase, creatine kinase isoenzyme, lactate dehydrogenase and α-hydroxybutyrate dehydrogenase was positively correlated with the prognosis of patients with acute PQ poisoning (P<0.05) . ROC curve analysis and principal component analysis showed that the combined indexes of PQ intake, urine protein and myocardial enzymes had the highest efficacy and weight in judging the prognosis of patients (AUC=0.91, weight coefficient=0.19, sensitivity=0.76, specificity=0.89) . When the combined score was ≥4, the probability of accurately predicting the death of patients was as high as 91% (positive predictive value=0.91) . Conclusion: PQ intake, urine protein combined with creatine kinase, creatine kinase isoenzyme, lactate dehydrogenase, and α-hydroxybutyrate dehydrogenase has high value in predicting the prognosis of patients with acute PQ poisoning.

Mechanosensitive Ion Channel TMEM63A Gangs Up with Local Macrophages to Modulate Chronic Post-amputation Pain

Post-amputation pain causes great suffering to amputees, but still no effective drugs are available due to its elusive mechanisms. Our previous clinical studies found that surgical removal or radiofrequency treatment of the neuroma at the axotomized nerve stump effectively relieves the phantom pain afflicting patients after amputation. This indicated an essential role of the residual nerve stump in the formation of chronic post-amputation pain (CPAP). However, the molecular mechanism by which the residual nerve stump or neuroma is involved and regulates CPAP is still a mystery. In this study, we found that nociceptors expressed the mechanosensitive ion channel TMEM63A and macrophages infiltrated into the dorsal root ganglion (DRG) neurons worked synergistically to promote CPAP. Histology and qRT-PCR showed that TMEM63A was mainly expressed in mechanical pain-producing non-peptidergic nociceptors in the DRG, and the expression of TMEM63A increased significantly both in the neuroma from amputated patients and the DRG in a mouse model of tibial nerve transfer (TNT). Behavioral tests showed that the mechanical, heat, and cold sensitivity were not affected in the Tmem63a^-/- mice in the naïve state, suggesting the basal pain was not affected. In the inflammatory and post-amputation state, the mechanical allodynia but not the heat hyperalgesia or cold allodynia was significantly decreased in Tmem63a^-/- mice. Further study showed that there was severe neuronal injury and macrophage infiltration in the DRG, tibial nerve, residual stump, and the neuroma-like structure of the TNT mouse model, Consistent with this, expression of the pro-inflammatory cytokines TNF-α, IL-6, and IL-1β all increased dramatically in the DRG. Interestingly, the deletion of Tmem63a significantly reduced the macrophage infiltration in the DRG but not in the tibial nerve stump. Furthermore, the ablation of macrophages significantly reduced both the expression of Tmem63a and the mechanical allodynia in the TNT mouse model, indicating an interaction between nociceptors and macrophages, and that these two factors gang up together to regulate the formation of CPAP. This provides a new insight into the mechanisms underlying CPAP and potential drug targets its treatment.

[An investigation of an accident of acute mixed gas poisoning]

An accident of mixed acute gas poisoning accident happened in a place in GuangDong in March 2018. To investigates three poisoning workers and related clinical data were summarized., we tested the field air and analyzed the accident reasons. This event due to the staff lack of occupational protection awareness and illegal operation. The working environment must be ventilated before limited space operation, and must be sure that the limited space is safe by toxic gas monitoring. In case of occupational acute gas poisoning, rescuers should help the persons who are poisoned reasonably and meanwhile their own safety.

Neonatal Maternal Deprivation Followed by Adult Stress Enhances Adrenergic Signaling to Advance Visceral Hypersensitivity

The pathophysiology of visceral pain in patients with irritable bowel syndrome remains largely unknown. Our previous study showed that neonatal maternal deprivation (NMD) does not induce visceral hypersensitivity at the age of 6 weeks in rats. The aim of this study was to determine whether NMD followed by adult stress at the age of 6 weeks induces visceral pain in rats and to investigate the roles of adrenergic signaling in visceral pain. Here we showed that NMD rats exhibited visceral hypersensitivity 6 h and 24 h after the termination of adult multiple stressors (AMSs). The plasma level of norepinephrine was significantly increased in NMD rats after AMSs. Whole-cell patch-clamp recording showed that the excitability of dorsal root ganglion (DRG) neurons from NMD rats with AMSs was remarkably increased. The expression of β₂ adrenergic receptors at the protein and mRNA levels was markedly higher in NMD rats with AMSs than in rats with NMD alone. Inhibition of β₂ adrenergic receptors with propranolol or butoxamine enhanced the colorectal distention threshold and application of butoxamine also reversed the enhanced hypersensitivity of DRG neurons. Overall, our data demonstrate that AMS induces visceral hypersensitivity in NMD rats, in part due to enhanced NE-β₂ adrenergic signaling in DRGs.

Sensitization of P2X3 receptors in insular cortex contributes to visceral pain of adult rats with neonatal maternal deprivation

Aims

Insular cortex is a brain region critical for processing of the sensation. Purinergic receptors are involved in the formation of chronic pain. The aim of the present study was to explore the role and mechanism of P2X3 receptors (P2X3Rs) in insular cortex in chronic visceral pain.

Methods

Chronic visceral pain in adult rats was induced by neonatal maternal deprivation and measured by detecting the threshold of colorectal distension. Western blotting, immunofluorescence, and real-time quantitative polymerase chain reaction techniques were used to detect the expression and distribution of P2X3Rs. Synaptic transmission in insular cortex was recorded in brain slices by patch clamp techniques.

Results

Expression of P2X3Rs both at mRNA and protein levels in right hemisphere of insular cortex was significantly increased in neonatal maternal deprivation rats. In addition, P2X3Rs were expressed with NeuN or synaptophysin but not with glial fibrillary acidic protein and CD11b. The co-localization of P2X3Rs with NeuN or synaptophysin was greatly enhanced in right hemisphere of insular cortex in neonatal maternal deprivation rats. Furthermore, neonatal maternal deprivation markedly increased both the frequency and amplitude of miniature excitatory postsynaptic current in right hemisphere of insular cortex. Incubation of A347091 significantly decreased the frequency of spontaneous excitatory postsynaptic current and miniature excitatory postsynaptic current of insular cortex neurons of neonatal maternal deprivation rats. Incubation of P2X3Rs agonists α,β-mATP remarkably increased the frequency of spontaneous excitatory postsynaptic current and miniature excitatory postsynaptic current of the right hemisphere of insular cortex neurons of healthy control rats. Importantly, injection of A317491 significantly enhanced the colorectal distension threshold of neonatal maternal deprivation rats, while injection of α,β-mATP into right but not left insular cortex markedly decreased the colorectal distension threshold in healthy control rats.

Conclusions

Overall, our data provide integrated pharmacological, biochemical, and functional evidence demonstrating that P2X3Rs are physically and functionally interconnected at the presynaptic level to control synaptic activities in the right insular cortex, thus contributing to visceral pain of neonatal maternal deprivation rats.

New insights into the heterogeneity and functional diversity of human mesenchymal stem cells

Mesenchymal stem cells (MSCs) are being tested in several biological systems and clinical settings with the aim of exploring their therapeutic potentials for a variety of diseases. MSCs are also known to be heterogeneous populations with variable functions. In the context of this multidimensional complexity, a recurrent question is what source or population of MSCs is suitable for specific clinical indications. Here, we reported that the biological features of MSCs varied with the individual donor, the tissue source, the culture condition and the subpopulations. Placental chorionic villi (CV) derived MSCs exhibited superior activities of immunomodulation and pro-angiogenesis compared to MSCs derived from bone marrow (BM), adipose and umbilical cord (UC). We identified a subpopulation of CD106(VCAM-1)+MSCs, which are present richly in placental CV, moderately in BM, and lowly in adipose and UC. The CD106+MSCs possess significantly increased immunomodutory and pro-angiogenic activities compared to CD106-MSCs. Analysis of gene expression and cytokine secretion revealed that CD106+MSCs highly expressed several immnumodulatory and pro-angiogenic cytokines. Our data offer new insights on the identification and selection of suitable source or population of MSCs for clinical applications. Further efforts should be concentrated on standardizing methods which will ultimately allow the validation of MSC products with defined biomarkers as predictive of potency in suitable pre-clinical models and clinical settings.

Wnt1-overexpressing skeletal myoblasts as an improved cell therapy for cardiac repair following myocardial infarction

AIM

Recent findings highlight the critical role of the Wnt signaling pathway in cardiac repair and stem cell regulation. Our previous study shows that lithium chloride (LiCl) optimizes skeletal myoblast (SkM) for transplantation by mimicking the Wnt/β-catenin signaling activities. In this study, we evaluate the therapeutic potential of SkMs genetically modified with Wnt1gene (Wnt1 SkMs) in a rat model with myocardial infarction (MI).

METHODS

We harvested neonatal SkMs using Wistar rats (1-3-day old) transfected with p-EGFP-C3-Wnt1 plasmid. RT-PCR and immunofluorescence showed a higher expression of Wnt1 in the Wnt1 SkMs. We observed that Wnt1 SkMs increased connexin 43 (Cx43) expression, reduced apoptosis induced by hydrogen peroxide (H2O2) and decreased caspase-3 expression via the canonical Wnt signaling pathways compared to the empty vector transfected SkMs (control SkMs). For in vivo studies, the myocardial infarction model was developed in the Wistar rats. The rats were grouped to receive 100 μL basal DMEM without cells or containing 1.5×106SkMs and Wnt1 SkMs. Histological studies revealed improved survival of SkMs, reduced cardiomyocytes apoptosis, and upregulated expression of Cx43 in Wnt1 SkMs therapy group. Echocardiography monitored four weeks after therapy showed improvement of the left ventricular function in rats treated with Wnt1SkMs compared to other groups.

CONCLUSION

Transplantation of Wnt1 SkMs improves rat myocardial function and enhances anti apoptotic properties of both SkMs and cardiomyocytes and upregulation of tissue Cx43 after infarction via the canonical Wnt/β-catenin signaling activities.

Precision Measurement of the Proton Flux in Primary Cosmic Rays from Rigidity 1 GV to 1.8 TV with the Alpha Magnetic Spectrometer on the International Space Station

A precise measurement of the proton flux in primary cosmic rays with rigidity (momentum/charge) from 1 GV to 1.8 TV is presented based on 300 million events. Knowledge of the rigidity dependence of the proton flux is important in understanding the origin, acceleration, and propagation of cosmic rays. We present the detailed variation with rigidity of the flux spectral index for the first time. The spectral index progressively hardens at high rigidities.

Precision Measurement of the (e^{+}+e^{-}) Flux in Primary Cosmic Rays from 0.5 GeV to 1 TeV with the Alpha Magnetic Spectrometer on the International Space Station

We present a measurement of the cosmic ray (e^{+}+e^{-}) flux in the range 0.5 GeV to 1 TeV based on the analysis of 10.6 million (e^{+}+e^{-}) events collected by AMS. The statistics and the resolution of AMS provide a precision measurement of the flux. The flux is smooth and reveals new and distinct information. Above 30.2 GeV, the flux can be described by a single power law with a spectral index γ=-3.170±0.008(stat+syst)±0.008(energy scale).

Electron and positron fluxes in primary cosmic rays measured with the alpha magnetic spectrometer on the international space station

Precision measurements by the Alpha Magnetic Spectrometer on the International Space Station of the primary cosmic-ray electron flux in the range 0.5 to 700 GeV and the positron flux in the range 0.5 to 500 GeV are presented. The electron flux and the positron flux each require a description beyond a single power-law spectrum. Both the electron flux and the positron flux change their behavior at ∼30  GeV but the fluxes are significantly different in their magnitude and energy dependence. Between 20 and 200 GeV the positron spectral index is significantly harder than the electron spectral index. The determination of the differing behavior of the spectral indices versus energy is a new observation and provides important information on the origins of cosmic-ray electrons and positrons.

High statistics measurement of the positron fraction in primary cosmic rays of 0.5-500 GeV with the alpha magnetic spectrometer on the international space station

A precision measurement by AMS of the positron fraction in primary cosmic rays in the energy range from 0.5 to 500 GeV based on 10.9 million positron and electron events is presented. This measurement extends the energy range of our previous observation and increases its precision. The new results show, for the first time, that above ∼200  GeV the positron fraction no longer exhibits an increase with energy.

First result from the Alpha Magnetic Spectrometer on the International Space Station: precision measurement of the positron fraction in primary cosmic rays of 0.5-350 GeV

A precision measurement by the Alpha Magnetic Spectrometer on the International Space Station of the positron fraction in primary cosmic rays in the energy range from 0.5 to 350 GeV based on 6.8 × 10(6) positron and electron events is presented. The very accurate data show that the positron fraction is steadily increasing from 10 to ∼ 250  GeV, but, from 20 to 250 GeV, the slope decreases by an order of magnitude. The positron fraction spectrum shows no fine structure, and the positron to electron ratio shows no observable anisotropy. Together, these features show the existence of new physical phenomena.

Lithium chloride preconditioning optimizes skeletal myoblast functions for cellular cardiomyoplasty in vitro via glycogen synthase kinase-3beta/beta-catenin signaling

The benefits of skeletal myoblast (SkM) transplantation for cardiomyoplasty are limited due to their decreased functional integration with host cardiomyocytes and the poor survival of implanted cells in ischemic hearts. However, little success has been achieved with respect to the strategies aiming to improve the efficiency of SkM transplantation. In this study, we demonstrated that LiCl-preconditioned SkMs resulted in significantly increased connexin 43 (Cx43) expression and gap-junctional communication with cardiomyocytes. Vascular endothelial growth factor (VEGF) expression of SkMs was significantly upregulated in response to LiCl. Furthermore, hydrogen peroxide induced SkM apoptosis and increased caspase-3 expression, whereas LiCl inhibited SkM apoptosis, resulted in the decrease of caspase-3 expression and promoted SkM proliferation. These effects of LiCl were mediated by inactivating glycogen synthase kinase-3beta (GSK-3beta), stabilizing the effector protein beta-catenin and translocating it into the nucleus of SkMs, confirming that LiCl mimics canonical Wnt signaling. These findings suggest that LiCl preconditioning may be a novel strategy to optimize SkM function for cellular cardiomyoplasty in vitro.