Low-intensity transcranial ultrasound stimulation improves memory in vascular dementia by enhancing neuronal activity and promoting spine formation.

Memory is closely associated with neuronal activity and dendritic spine formation. Low-intensity transcranial ultrasound stimulation (TUS) improves the memory of individuals with vascular dementia (VD). However, it is unclear whether neuronal activity and dendritic spine formation under ultrasound stimulation are involved in memory improvement in VD. In this study, we found that seven days of TUS improved memory in VD model while simultaneously increasing pyramidal neuron activity, promoting dendritic spine formation, and reducing dendritic spine elimination. These effects lasted for 7 days but disappeared on 14 d after TUS. Neuronal activity and dendritic spine formation strongly corresponded to improvements in memory behavior over time. In addition, we also found that the memory, neuronal activity and dendritic spine of VD mice cannot be restored again by TUS of 7 days after 28 d. Collectively, these findings suggest that TUS increases neuronal activity and promotes dendritic spine formation and is thus important for improving memory in patients with VD.

Low-intensity transcranial ultrasound stimulation improves memory behavior in an ADHD rat model by modulating cortical functional network connectivity.

Working memory in attention deficit hyperactivity disorder (ADHD) is closely related to cortical functional network connectivity (CFNC), such as abnormal connections between the frontal, temporal, occipital cortices and with other brain regions. Low-intensity transcranial ultrasound stimulation (TUS) has the advantages of non-invasiveness, high spatial resolution, and high penetration depth and can improve ADHD memory behavior. However, how it modulates CFNC in ADHD and the CFNC mechanism that improves working memory behavior in ADHD remain unclear. In this study, we observed working memory impairment in ADHD rats, establishing a corresponding relationship between changes in CFNCs and the behavioral state during the working memory task. Specifically, we noted abnormalities in the information transmission and processing capabilities of CFNC in ADHD rats while performing working memory tasks. These abnormalities manifested in the network integration ability of specific areas, as well as the information flow and functional differentiation of CFNC. Furthermore, our findings indicate that TUS effectively enhances the working memory ability of ADHD rats by modulating information transmission, processing, and integration capabilities, along with adjusting the information flow and functional differentiation of CFNC. Additionally, we explain the CFNC mechanism through which TUS improves working memory in ADHD. In summary, these findings suggest that CFNCs are important in working memory behaviors in ADHD.

Neuroprotective Effects of Melittin Against Cerebral Ischemia and Inflammatory Injury via Upregulation of MCPIP1 to Suppress NF-κB Activation In Vivo and In Vitro.

Melittin, a principal constituent of honeybee venom, exhibits diverse biological effects, encompassing anti-inflammatory capabilities and neuroprotective actions against an array of neurological diseases. In this study, we probed the prospective protective influence of melittin on cerebral ischemia, focusing on its anti-inflammatory activity. Mechanistically, we explored whether monocyte chemotactic protein-induced protein 1 (MCPIP1, also known as ZC3H12A), a recently identified zinc-finger protein, played a role in melittin-mediated anti-inflammation and neuroprotection. Male C57/BL6 mice were subjected to distal middle cerebral artery occlusion to create a focal cerebral cortical ischemia model, with melittin administered intraperitoneally. We evaluated motor functions, brain infarct volume, cerebral blood flow, and inflammatory marker levels within brain tissue, employing quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assays, and western blotting. In vitro, an immortalized BV-2 microglia culture was stimulated with lipopolysaccharide (LPS) to establish an inflammatory cell model. Post-melittin exposure, cell viability, and cytokine expression were examined. MCPIP1 was silenced using siRNA in LPS-induced BV-2 cells, with the ensuing nuclear translocation of nuclear factor-κB assessed through cellular immunofluorescence. In vivo, melittin enhanced motor functions, diminished infarction, fostered blood flow restoration in ischemic brain regions, and markedly inhibited the expression of inflammatory cytokines (interleukin-1ß, interleukin-6, tumor necrosis factor-α, and nuclear factor-κB). In vitro, melittin augmented MCPIP1 expression in LPS-induced BV-2 cells and ameliorated inflammation-induced cell death. The neuroprotective effect conferred by melittin was attenuated upon MCPIP1 knockdown. Our findings establish that melittin-induced tolerance to ischemic injury is intrinsically linked with its anti-inflammatory capacity. Moreover, MCPIP1 is, at the very least, partially implicated in this process.

Time-frequency cross-coupling between cortical low-frequency neuronal calcium oscillations and blood oxygen metabolism evoked by ultrasound stimulation.

Low-intensity transcranial ultrasound stimulation (TUS) can modulate the coupling of high-frequency (160-200 Hz) neural oscillations and cerebral blood oxygen metabolism (BOM); however, the correlation of low-frequency (0-2 Hz) neural oscillations with BOM in temporal and frequency domains under TUS remains unclear. To address this, we monitored the TUS-evoked neuronal calcium oscillations and BOM simultaneously in the mouse visual cortex by using multimodal optical imaging with a high spatiotemporal resolution. We demonstrated that TUS can significantly increase the intensity of the neuronal calcium oscillations and BOM; the peak value, peak time, and duration of calcium oscillations are functionally related to stimulation duration; TUS does not significantly increase the neurovascular coupling strength between calcium oscillations and BOM in the temporal domain; the time differences of the energy peaks between TUS-induced calcium oscillations and BOM depend on their spectral ranges; the frequency differences of the energy peaks between TUS-induced calcium oscillations and BOM depend on their time ranges; and TUS can significantly change the phase of calcium oscillations and BOM from uniform distribution to a more concentrated region. In conclusion, ultrasound stimulation can evoke the time-frequency cross-coupling between the cortical low-frequency neuronal calcium oscillations and BOM in mouse.

Protective effects of low-intensity pulsed ultrasound (LIPUS) against cerebral ischemic stroke in mice by promoting brain vascular remodeling via the inhibition of ROCK1/p-MLC2 signaling pathway.

Vascular remodeling is essential for patients with cerebral ischemic stroke (CIS). Our previous study proved that low-intensity pulsed ultrasound (LIPUS) could increase cortical hemodynamics. However, the effects and mechanisms of LIPUS on cerebral vascular remodeling after CIS are still unknown. In this study, we applied LIPUS to the mouse brain at 0.5 h after distal middle cerebral artery occlusion (dMCAO) and subsequently daily for a stimulation time of 30 min. Results showed that compared with the dMCAO group, LIPUS markedly increased cerebral blood flow (CBF), reduced brain swelling, and improved functional recovery at day 3 after CIS. LIPUS promoted leptomeningeal vasculature remodeling, enlarged vascular diameter, and increased the average vessel length and density at day 3 after CIS. Proteomic analysis highlighted that LIPUS mainly participated in the regulation of actin cytoskeleton pathway. Rho kinase 1 (ROCK1) was downregulated by LIPUS and participated in regulation of actin cytoskeleton. Subsequently, we verified that ROCK1 was mainly expressed in pericytes. Furthermore, we demonstrated that LIPUS inhibited ROCK1/p-MLC2 signaling pathway after CIS, which had positive effects on vascular remodeling and cerebral blood circulation. In conclusion, our preliminary study revealed the vascular remodeling effects and mechanism of LIPUS in CIS, provided evidence for potential clinical application of LIPUS.

Proprotein convertase subtilisin/kexin type 9 inhibitor ameliorates cerebral ischemia in mice by inhibiting inflammation.

OBJECTIVES: To investigate the potential protective effects of evolocumab, a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor, on ischemic stroke and its underlying mechanisms. MATERIALS AND METHODS: We established a mouse model with distal middle cerebral artery occlusion. We evaluated the therapeutic effects through neurological function and infarct size, while the underlying mechanisms were elucidated using western blotting and real-time polymerase chain reaction. RESULTS: Evolocumab improved neurological recovery, reduced the infarct volume, suppressed the activation of Toll-like receptor (TLR) 4 and nuclear factor-kappa B (NF-κB), and attenuated the increased levels of IL-1ß and TNF-α after cerebral ischemia. CONCLUSION: Evolocumab protects against cerebral ischemic injury by inhibiting inflammation. Therefore, the TLR4/NF-кB pathway may represent a major mechanism in ischemic stroke.

Modulation effects of low-intensity transcranial ultrasound stimulation on the neuronal firing activity and synaptic plasticity of mice.

Low-intensity transcranial ultrasound stimulation (TUS) has been effective in modulating several neurological and psychiatric disorders. However, how TUS modulates neuronal firing activity and synaptic plasticity remains unclear. Thus, we behaviorally tested the whisker-dependent novel object discrimination ability in mice after ultrasound stimulation and examined the cortical neuronal firing activity and synaptic plasticity in awake mice after ultrasound stimulation by two-photon fluorescence imaging. The current study presented the following results: (1) TUS could significantly improve the whisker-dependent new object discrimination ability of mice, suggesting that their learning and memory abilities were significantly enhanced; (2) TUS significantly enhanced neuronal firing activity; and (3) TUS increased the growth rate of dendritic spines in the barrel cortex, but did not promote the extinction of dendritic spines, resulting in enhanced synaptic plasticity. The above results indicate that TUS can improve the learning and memory ability of mice and enhance the neuronal firing activity and synaptic plasticity that are closely related to it. This study provides a research basis for the application of ultrasound stimulation in the treatment of learning- and memory-related diseases.

Low-intensity pulsed ultrasound triggers a beneficial neuromodulation in dementia mice with chronic cerebral hypoperfusion via activation of hippocampal Fndc5/irisin signaling.

BACKGROUND: Exercise-related signaling Fndc5/irisin expresses in brain and acts as a crucial regulator of cognitive function, but its detailed roles in vascular dementia (VaD) are still unclear. Low intensity pulsed ultrasound (LIPUS), a novel brain stimulation approach, has been suggested as a promising treatment for dementia. Here, we investigated the activity and efficacy of Fndc5/irisin in experimental VaD, further explored whether the potential effects of LIPUS on VaD is related to Fndc5/irisin. METHODS: Mouse model of VaD was established with chronic cerebral hypoperfusion (CCH) using bilateral common carotid arteries stenosis (BCAS). Transcranial LIPUS was applied 24 h after BCAS and subsequently daily with a stimulation time of 5 min at an ultrasound pressure of 0.51 MPa for a period of 28 days. The levels of Fndc5/irisin in different brain regions, the hippocampal long-term potentiation and anti-inflammatory cytokines were investigated at day 28 after cognitive evaluation. Global Fndc5 knock-out (F5KO), forced expression or knockdown of Fndc5, and recombinant irisin application were respectively employed for mechanism exploration. The neuron dendritic spine density and astrocyte phenotype were detected in vitro. RESULTS: Fndc5/irisin was reduced in hippocampus of BCAS mice, forced expression hippocampal Fndc5 or bilateral intrahippocampal injection of recombinant irisin respectively improved hippocampal synaptic plasticity or inflammatory microenvironment, and then alleviated the cognitive impairments. LIPUS existed a positive efficacy in enhancing hippocampal Fndc5/irisin in BCAS mice, thus triggering a beneficial neuromodulation for VaD protection. Importantly, the neurorestorative effects of LIPUS on CCH-induced damages were totally reversed by knockdown the expression of hippocampal Fndc5 in WT mice, or in F5KO mice. Moreover, Fndc5 mediated the upregulated effects of LIPUS on spine density as well as irisin secretion of hippocampal neurons. The neuron-secreted irisin further drove reactive astrocytes to a neuroprotective phenotype. CONCLUSION: LIPUS induced a neurorestorative stimulation against VaD may be through upregulation of the hippocampal Fndc5/irisin levels. Hippocampal Fndc5/irisin signaling might be a promising strategic target for VaD.

Sox17 protects human brain microvascular endothelial cells from AngII-induced injury by regulating autophagy and apoptosis.

Intracranial aneurysm (IA), is a localized dilation of the intracranial arteries, the rupture of which is catastrophic. Hypertension is major IA risk factor that mediates endothelial cell damage. Sox17 is highly expressed in intracranial vascular endothelial cells, and GWAS studies indicate that its genetic alteration is one of the major genetic risk factors for IA. Vascular endothelial cell injury plays a vital role in the pathogenesis of IA. The genetic ablation of Sox17 plus hypertension induced by AngII can lead to an increased incidence of intracranial aneurysms had tested in the previous animal experiments. In order to study the underlying molecular mechanisms, we established stable Sox17-overexpressing and knockdown cell lines in human brain microvascular endothelial cells (HBMECs) first. Then flow cytometry, western blotting, and immunofluorescence were employed. We found that the knockdown of Sox17 could worsen the apoptosis and autophagy of HBMECs caused by AngII, while overexpression of Sox17 had the opposite effect. Transmission electron microscopy displayed increased autophagosomes after the knockdown of Sox17 in HBMECs. The RNA-sequencing analysis shown that dysregulation of the Sox17 gene was closely associated with the autophagy-related pathways. Our study suggests that Sox17 could protect HBMECs from AngII-induced injury by regulating autophagy and apoptosis.

Hydrogen sulfide ameliorates senescence in vascular endothelial cells through ameliorating inflammation and activating PPARδ/SGLT2/STAT3 signaling pathway.

Mounting evidence demonstrates that hydrogen sulfide (H 2S) promotes anti-inflammatory molecules and inhibits pro-inflammatory cytokines in endothelial cells (ECs). This study aims to investigate the favorable action of H 2S on endothelial function in senescence by inhibiting the production of inflammatory molecules. Senescent ECs exhibit a reduction in H 2S, endothelial nitric oxide synthase (eNOS) and peroxisome proliferator-activated receptor δ (PPARδ), coupled with increased inflammatory molecules, sodium glucose transporter type 2 (SGLT2) and phosphorylation of STAT3, which could be reversed by the administration of a slow but sustained release agent of H 2S, GYY4137. Decreased production of eNOS and upregulated p-STAT3 and SGLT2 levels in senescent ECs are reversed by replenishment of the SGLT2 inhibitor EMPA and the PPARδ agonist GW501516. The PPARδ antagonist GSK0660 attenuates eNOS expression and increases the production of p-STAT3 and SGLT2. However, supplementation with GYY4137 has no beneficial effect on GSK0660-treated ECs. GYY4137, GW501516 and EMPA preserve endothelial-dependent relaxation (EDR) in D-gal-treated aortae, while GSK0660 destroys aortic relaxation even with GYY4137 supplementation. In summary, senescent ECs manifest aggravated the expressions of the inflammatory molecules SGLT2 and p-STAT3 and decreased the productions of PPARδ, eNOS and CSE. H 2S ameliorates endothelial dysfunction through the anti-inflammatory effect of the PPARδ/SGLT2/p-STAT3 signaling pathway in senescent ECs and may be a potential therapeutic target for anti-ageing treatment.

Indocyanine green combined with methylene blue versus methylene blue alone for sentinel lymph node biopsy in breast cancer: a retrospective study.

BACKGROUND: Recent studies have shown that near-infrared (NIR) fluorescence imaging using Indocyanine green (ICG) may improve the efficiency of sentinel lymph node biopsy (SLNB). This study aimed to assess the effectiveness of the combination of ICG and methylene blue (MB) in breast cancer patients undergoing SLNB. PATIENTS AND METHOD: We evaluated ICG plus MB (ICG + MB) identification effectiveness with MB alone using retrospective analysis. From 2016 to 2020, we collected data on 300 eligible breast cancer patients who got SLNB treatment in our institution by ICG + MB or MB alone. By comparing the distribution of clinicopathological characteristics, the detection rate of sentinel lymph nodes (SLNs) and metastatic SLNs, as well as the total number of SLNs in the two groups, we were able to assess the imaging efficiency. RESULTS: Fluorescence imaging allowed 131 out of 136 patients in the ICG + MB group to find SLNs. ICG + MB group and MB group had detection rates of 98.5% and 91.5% (P = 0.007, χ2 = 7.352), respectively. Besides, the ICG + MB approach was able to produce improved recognition outcomes. What's more, compared with the MB group, the ICG + MB group can identify more lymph nodes (LNs) (3.1 to 2.6, P = 0.000, t = 4.447). Additionally, in the ICG + MB group, ICG could identify more LNs than MB (3.1 vs 2.6, P = 0.004, t = 2.884). CONCLUSION: ICG has high detection effectiveness for SLNs, and when paired with MB, the detection efficiency can be increased even further. Furthermore, the ICG + MB tracing mode does not involve radioisotopes, which has a lot of promise for clinical use and can take the place of conventional standard detection methods.

BLU-554, A selective inhibitor of FGFR4, exhibits anti-tumour activity against gastric cancer in vitro.

BACKGROUND: Fibroblast growth factor receptor 4 (FGFR4) plays a key role in cancer progression, including tumour proliferation, invasion, and metastasis. Recent studies have shown that the FGFR4 selective inhibitor BLU-554 has clinical benefits on tumour regression in hepatocellular carcinoma patients. However, the effect of BLU-554 on gastric cancer remains unknown. METHODS: Changes in cell proliferation, apoptosis and cell cycle, migration, and invasion capabilities of MKN-45 cells treated with FGFR4 selective inhibitors were detected by CCK-8 assay, flow cytometry, transwell assay, and wound healing assay, respectively. Western blotting was used to detect the effect of BLU-554 on the expression of FGFR4, FRS2α, and p-ERK1/2. RESULTS: As the concentration of the inhibitor increased, the survival rate of gastric cancer cells decreased, and the trend of BLU-554 was more obvious; a high dose of BLU-554 caused significant cell apoptosis and cell cycle arrest as well as reduced cell invasion ability. The expression levels of FGFR4, FRS2α, and p-ERK1/2 were also significantly reduced when cells were treated with medium and high doses of BLU-554. CONCLUSION: BLU-554 inhibited the mitogen-activated protein kinase (RAS-RAF-MEK-ERK) pathway by inhibiting FGFR4, ultimately impeding the proliferation and invasion of gastric cancer cells and promoting cell apoptosis and cell cycle arrest.

Liraglutide Ameliorates Cerebral Ischemia in Mice via Antipyroptotic Pathways.

It was recently shown that pyroptosis, an inflammatory form of programmed cell death, is critically involved in the pathogenesis of ischemic stroke. Liraglutide (Lg) is a novel long-acting analog of glucagon-like peptide-1 that has potential protective effects against stroke. However, the relationship between Lg and pyroptosis in the brain is not well defined. In this study, we found that injection of Lg significantly improved the recovery of motor function, increased cerebral blood flow and ameliorated cerebral damage in a mouse model of focal cerebral cortical ischemia. Our results revealed that Lg treatment significantly reduced the levels of NLRP3, Caspase1, IL-1ß and the pore-forming protein gasdermin D in microglial cells in vitro, suggesting that the neuroprotective effect of Lg may be achieved through the inhibition of pyroptosis. Furthermore, by using a specific inhibitor of NOD-like receptor protein 3 (NLRP3), we confirmed that the antipyroptotic mechanism of Lg may be mediated by NLRP3 in vivo. Our present study unveils a novel neuroprotective mechanism through which Lg alleviates ischemia by exerting NLRP3-dependent antipyroptotic effects.

Dl-3-n-butylphthalide promotes neurite outgrowth of primary cortical neurons by Sonic Hedgehog signaling via upregulating Gap43.

Neurite outgrowth is the basis for wiring during the development of the nervous system. Dl-3-n-butylphthalide (NBP) has been recognized as a promising treatment to improve behavioral, neurological and cognitive outcomes in ischemic stroke. However, little is known about the effect and mechanism of NBP on the neurite outgrowth. In this study, we used different methods to investigate the potential effects of NBP on the neurite extension and plasticity of immature and mature primary cortical neurons and explored the underlying mechanisms. Our results demonstrated that in immature and mature cortical neurons, NBP promoted the neurite length and intersections, increased neuritic arborization, elevated numbers of neurite branch and terminal points and improved neurite complexity and plasticity of neuronal development processes. Besides, our data revealed that NBP promoted neurite extension and branching partly by activating Shh signaling pathway via increasing Gap43 expression both in immature and mature primary cortical neurons. The present study provided new insights into the contribution of NBP in neuronal plasticity and unveiled a novel pathway to induce Gap43 expression in primary cortical neurons.

Edaravone Dexborneol Downregulates Neutrophil Extracellular Trap Expression and Ameliorates Blood-Brain Barrier Permeability in Acute Ischemic Stroke.

Background: Our previous work has shown that inflammatory processes play a detrimental role in the pathophysiology of acute ischemic stroke (AIS). Neutrophil extracellular traps (NETs) have been recognized as a key contributor to the proinflammatory response in AIS and could aggravate blood-brain barrier (BBB) damage. Recently, experimental and clinical researches showed that Edaravone Dexborneol (Eda.B), which is comprised of two active ingredients, Edaravone and (+)-Borneol, was effective in treatment of AIS. However, it is not clear whether the effects of Eda.B against AIS are related to NETs and BBB permeability. Methods: Experiment 1 was to detect the effects of Eda.B in AIS patients. Serum samples of volunteers and AIS patients were collected before and 3 days after Edaravone Dexborneol treatment. Markers of NETs and occludin were detected by ELISA kit. Experiment 2 was to explore the effects of Eda.B on experimental stroke mice. Male C57BL/6 mice were subjected to distal middle cerebral artery occlusion (MCAO) and treated with vehicle, Eda.B, or DeoxyribonueleaseI (DNase I). After stroke, the neurobehavioral tests, infarct volume, and cerebral blood flow evaluation were determined. Leakage of Evans blue was to assess the integrity of BBB. Western blot, real-time quantitative polymerase chain reaction (RT-qPCR), and immunofluorescence were used to examine the expression of NETs and tight junction- (TJ-) associated proteins. Results: Eda.B significantly improved neurological function and cerebral blood flow but reduced infarct volume after experimental stroke. Eda.B downregulated level of NETs in serum samples of AIS patients and tissue samples of MCAO mouse cortex. Eda.B and DNase I alleviated BBB permeability by upregulating TJ-associated proteins. Conclusion: NETs are related to the early stage of AIS. Eda.B exerted neuroprotective effects and ameliorated BBB permeability after AIS.

Adenosine mono-phosphate-activated protein kinase-mammalian target of rapamycin signaling participates in the protective effect of chronic intermittent hypobaric hypoxia on vascular endothelium of metabolic syndrome rats.

Our previous study demonstrated that chronic intermittent hypobaric hypoxia (CIHH) protects vascular endothelium function through ameliorating autophagy in mesenteric arteries of metabolic syndrome (MS) rats. This study aimed to investigate the role of adenosine mono-phosphate-activated protein kinase-mammalian target of rapamycin (AMPK-mTOR) signaling in CIHH effect. Six-week-old male Sprague-Dawley rats were divided into control (CON), MS model, CIHH treatment (CIHH), and MS + CIHH groups. Serum pro-inflammatory cytokines were measured. The endothelium dependent relaxation (EDR), endothelial ultrastructure and autophagosomes were observed in mesenteric arteries. The expression of phosphor (p)-AMPKα, p-mTOR, autophagy-related and endoplasmic reticulum stress-related proteins, p-endothelial nitric oxide synthase, and cathepsin D were assayed. In MS rats, pro-inflammatory cytokines were increased, EDR was attenuated, and endothelial integrity was impaired. In addition, the expression level of p-AMPKα and cathepsin D was down-regulated, but the level of p-mTOR was up-regulated. While in MS + CIHH rats, all aforementioned abnormalities were ameliorated, and the beneficial effect of CIHH was cancelled by AMPKα inhibitor. In conclusion, AMPK-mTOR signaling pathway participates in the protection of CIHH on vascular endothelium of MS rats.

Contribution of retrotrapezoid nucleus neurons to CO2 -amplified cardiorespiratory activity in spontaneously hypertensive rats.

KEY POINTS: This study demonstrates that both CO2 -induced respiratory and cardiovascular responses are augmented in spontaneously hypertensive rats (SHRs). Genetic ablation of the retrotrapezoid nucleus (RTN) neurons depresses enhanced hypercapnic ventilatory response and eliminates CO2 -stimulated increase in arterial pressure and heart rate in SHRs. SHRs have a high protein level of pH-sensitive channels in the RTN, including the TASK-2 channel, Kv12.1 channel and acid-sensing ion channel 3. The inhibition of putative TASK-2 channel activity by clofilium diminishes amplified hypercapnic ventilatory and cardiovascular responses, and reduces the number of CO2 -activated RTN neurons in SHRs. These results indicate that RTN neurons contribute to enhanced CO2 -stimulated respiratory and cardiovascular responses in SHRs. ABSTRACT: The respiratory regulation of cardiovascular activity is essential for maintaining an efficient ventilation and perfusion ratio. Activation of central respiratory chemoreceptors not only elicits a ventilatory response but also regulates sympathetic nerve activity and arterial blood pressure (ABP). The retrotrapezoid nucleus (RTN) is the most completely characterized cluster of central respiratory chemoreceptors. We hypothesize that RTN neurons contribute to augmented CO2 -stimulated respiratory and cardiovascular responses in adult spontaneously hypertensive rats (SHRs). Our findings indicate that SHRs exhibit more enhanced hypercapnic cardiorespiratory responses than age-matched normotensive Wistar-Kyoto rats. Genetic ablation of RTN neurons notably depresses an enhanced hypercapnic ventilatory response (HCVR) and eliminates a CO2 -stimulated greater increase in ABP and heart rate in SHRs. In addition, SHRs have a higher protein level of pH-sensitive channels in the RTN, including TASK-2 channels, Kv12.1 channels and acid-sensing ion channel 3. Administration of clofilium (i.p.), an unselective inhibitor of TASK-2 channels, not only significantly reduces the enhanced HCVR but also inhibits CO2 -amplified increases in ABP and heart rate in SHRs. Moreover, clofilium significantly decreases the number of CO2 -activated RTN neurons in SHRs. Taken together, we suggest that RTN neurons play an important role in enhanced hypercapnic ventilatory and cardiovascular responses in SHRs and the putative mechanism involved is associated with TASK-2 channel activity in the RTN.

EGFR-mutant NSCLC presenting with stroke and massive systemic embolization as the first manifestation: case report.

BACKGROUND: Presentation with massive systemic embolization as the initial manifestation of occult malignancy is infrequent. The standard management of cancer-related arterial thromboembolism has not yet been established. CASE PRESENTATION: We described a case of Trousseau's syndrome resulting in acute ischemic stroke concomitant with multiple embolizations in the spleen and kidney during oral administration of dabigatran for pulmonary embolism preceding the diagnosis of a malignant tumor. A cancer-related hypercoagulable state was suspected because the patient was admitted to the neurology department due to acute ischemic stroke with three territory infarcts on diffusion-weighted imaging (DWI) in the absence of identifiable conventional risk factors and brain vessel narrowing. The patient was subsequently diagnosed with epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC) (stage IV) with pleural metastasis. Administration of low-molecular-weight heparin followed by long-term dabigatran under effective cancer therapy comprising gefitinib and subsequent chemotherapy did not cause stroke relapse during the 1-year follow-up. CONCLUSIONS: This case suggests that cancer-related hypercoagulability should be considered an important etiology for stroke patients who develop unexplained disseminated acute cerebral infarction without conventional stroke risk factors, especially concomitant with multiple organ embolization. Novel oral anticoagulants may be an alternative therapy for the long-term management of cancer-related arterial thromboembolism under effective cancer therapy.

The developing trends and driving factors of environmental information disclosure in China.

Environmental Information Disclosure (EID) is a new tool for environmental governance in the era of big data and information. Based on the Pollution Information Disclosure Index (PITI) of 120 cities in China from 2003 to 2019, spatial data exploratory analysis and dynamic spatial panel model were adopted to analyze the spatial-temporal evolution characteristics and influencing factors of EID in China. The results show that (1) great progress of China's EID has been made in legislation and practice and its ways and channels are gradually becoming diversified, while it is accompanied by the problem of inadequate and unbalanced development; (2) EID shows the "superposition effect" promoted by previous accumulation has the "peer effect" of mutual imitation and learning and presents "demonstration effect", which shows significant agglomeration distribution pattern of spatial "club", while the spillover effect within the region is significant while the radiation effect between regions is weak. (3) In a dynamic process, cities with better economic development, firm performance, environmental performance and regulation, disclosure more environmental information, while the role of government competition and public participation needs further discussion. (4) Negative factors have a great influence during the economic crisis, while positive factors play a significant role in promoting the disclosure of environmental information during the economic expansion after crises. Cities in the developed regions (coastal, east and large cities) disclosure more than developing regions (inland, west, and small cities), and the positive factors are more likely to take effect.

Activation of Phox2b-Expressing Neurons in the Nucleus Tractus Solitarii Drives Breathing in Mice.

The nucleus tractus solitarii (NTS) is implicated in the control of breathing, but the neuronal phenotype and circuit mechanism involved in such a physiological function remain incompletely understood. This study focused on the respiratory role of paired-like homeobox 2b gene (Phox2b)-expressing NTS neurons and sought to determine whether selective stimulation of this set of neurons activates breathing in male mice. A Cre-dependent vector encoding a Gq-coupled human M3 muscarinic receptor (hM3Dq) was microinjected into the NTS of Phox2b-Cre transgenic mice. The hM3Dq-transduced neurons were pharmacologically activated in conscious mice while respiratory effects were measured by plethysmography. We demonstrate that chemogenetic stimulation of Phox2b-expressing NTS neurons significantly increased baseline minute volume via an increase in respiratory frequency rather than tidal volume. Chemogenetic stimulation also synergized with moderate CO2 stimulation to enhance pulmonary ventilatory response. Selective ablation of Phox2b-expressing NTS neurons notably attenuated a hypercapnic ventilatory response. Moreover, histological evidence revealed that stimulation of Phox2b-expressing NTS neurons increased neuronal activity of the preBötzinger complex. Finally, we presented the neuroanatomical evidence of direct projection of Phox2b-expressing NTS neurons to putative respiratory central pattern generator. Overall, these findings suggest that selective activation of Phox2b-expressing NTS neurons potentiates baseline pulmonary ventilation via an excitatory drive to respiratory central pattern generator and this group of neurons is also required for the hypercapnic ventilatory response.SIGNIFICANCE STATEMENT The nucleus tractus solitarii (NTS) has been implicated in the control of breathing. The paired-like homeobox 2b gene (Phox2b) is the disease-defining gene for congenital central hypoventilation syndrome and is restrictively present in brainstem nucleus, including the NTS. Using a chemogenetic approach, we demonstrate herein that selective stimulation of Phox2b-expressing NTS neurons vigorously potentiates baseline pulmonary ventilation via an excitatory drive to respiratory central pattern generator in rodents. Genetic ablation of these neurons attenuates the hypercapnic ventilatory response. We also suggest that a fraction of Phox2b-expressing neurons exhibit CO2 sensitivity and presumably function as central respiratory chemoreceptors. The methodology is expected to provide a future applicability to the patients with sleep-related hypoventilation or apnea.