Search

Background: Angiogenesis is a promising strategy for those with peripheral artery disease. Macrophage-centered inflammation is intended to govern the deficiency of the angiogenic response after hindlimb ischemia. However, little is known about the mechanism of macrophage activation beyond signals from cytokines and chemokines. We sought to identify a novel mechanical signal from the ischemic microenvironment that provokes macrophages and the subsequent inflammatory cascade and to investigate the potential role of Piezo-type mechanosensitive ion channels (Piezo) on macrophages during this process. Methods: Myeloid cell-specific Piezo1 (Piezo-type mechanosensitive ion channel component 1) knockout ( Piezo1 ΔMΦ ) mice were generated by crossing Piezo1 fl/fl ( LysM-Cre −/− ; Piezo1 flox/flox ) mice with LysM-Cre transgenic mice to assess the roles of Piezo1 in macrophages after hindlimb ischemia. Furthermore, in vitro studies were carried out in bone marrow–derived macrophages to decipher the underlying mechanism. Results: We found that tissue stiffness gradually increased after hindlimb ischemia, as indicated by Young’s modulus. Compared to Piezo2, Piezo1 expression and activation were markedly upregulated in macrophages from ischemic tissues in concurrence with increased tissue stiffness. Piezo1 ΔMΦ mice exhibited improved perfusion recovery by enhancing angiogenesis. Matrigel tube formation assays revealed that Piezo1 deletion promoted angiogenesis by enhancing FGF2 (fibroblast growth factor-2) paracrine signaling in macrophages. Conversely, activation of Piezo1 by increased stiffness or the agonist Yoda1 led to reduced FGF2 production in bone marrow–derived macrophages, which could be blocked by Piezo1 silencing. Mechanistically, Piezo1 mediated extracellular Ca 2+ influx and activated Ca 2+ -dependent CaMKII (calcium/calmodulin-dependent protein kinase II)/ETS1 (ETS proto-oncogene 1) signaling, leading to transcriptional inactivation of FGF2. Conclusions: This study uncovers a crucial role of microenvironmental stiffness in exacerbating the macrophage-dependent deficient angiogenic response. Deletion of macrophage Piezo1 promotes perfusion recovery after hindlimb ischemia through CaMKII/ETS1-mediated transcriptional activation of FGF2. This provides a promising therapeutic strategy to enhance angiogenesis in ischemic diseases.

Adipose derived stem cells (ADSCs) can differentiate into vascular lineages and participate in vascular remodeling. Perivascular ADSCs (PV-ADSCs) draw attention due to their unique location. The heterogeneity of subcutaneous (SUB-) and abdominal ADSCs were well addressed, but PV-ADSCs' heterogeneity hasn't been investigated. In the present study, we applied single-cell analysis to compare SUB-ADSCs and PV-ADSCs respectively regarding their subpopulations, functions, and cell fates. We uncovered 4 subpopulations of PV-ADSCs including Dpp4+, Col4a2+/Icam1+, Clec11a+/Cpe+ and Sult1e1+ cells, among which Clec11a+ subpopulation potentially participated in and regulated the PV-ADSCs differentiation towards a smooth muscle cell (SMC) phenotype. The present study revealed the distinct characteristics between PV-ADSCs and SUB-ADSCs.

Hemodynamic overload induces pathological cardiac hypertrophy, which is an independent risk factor for intractable heart failure in long run. Beyond neurohumoral regulation, mechanotransduction has been recently recognized as a major regulator of cardiac hypertrophy under a myriad of conditions. However, the identification and molecular features of mechanotransducer on cardiomyocytes are largely sparse. For the first time, we identified Piezo1 (Piezo type mechanosensitive ion channel component 1), a novel mechanosensitive ion channel with preference to Ca 2+ was remarkably upregulated under pressure overload and enriched near T-tubule and intercalated disc of cardiomyocyte. By applying cardiac conditional Piezo1 knockout mice (Piezo1 fl/fl Myh6Cre+, Piezo1 Cko ) undergoing transverse aortic constriction, we demonstrated that Piezo1 was required for the development of cardiac hypertrophy and subsequent adverse remodeling. Activation of Piezo1 by external mechanical stretch or agonist Yoda1 lead to the enlargement of cardiomyocytes in vitro, which was blocked by Piezo1 silencing or Yoda1 analog Dooku1 or Piezo1 inhibitor GsMTx4. Mechanistically, Piezo1 perturbed calcium homeostasis, mediating extracellular Ca 2+ influx and intracellular Ca 2+ overload, thereby increased the activation of Ca 2+ -dependent signaling, calcineurin, and calpain. Inhibition of calcineurin or calpain could abolished Yoda1 induced upregulation of hypertrophy markers and the hypertrophic growth of cardiomyocytes in vitro. From a comprehensive view of the cardiac transcriptome, most of Piezo1 affected genes were highly enriched in muscle cell physiology, tight junction, and corresponding signaling. This study characterizes an undefined role of Piezo1 in pressure overload induced cardiac hypertrophy. It may partially decipher the differential role of calcium under pathophysiological condition, implying a promising therapeutic target for cardiac dysfunction.

Objective: Macrophage-mediated inflammatory response is closely associated with the neovascularization process following hindlimb ischemia. We previously demonstrated that HO-1 (heme oxygenase-1) in macrophages evoked proinflammatory reactions and tissue damage. Here, we evaluated the role played by macrophage-derived HO-1 and elucidated its underlying molecular mechanisms in perfusion recovery after hindlimb ischemia. Approach and Results: We found significant upregulation of HO-1 in mouse ischemic muscles after hindlimb ischemia surgery and with most of this expression occurring in infiltrated macrophages. Myeloid conditional HO-1-deficient mice exhibited higher perfusion recovery, evidenced by restored blood flow, motor function and attenuated tissue damage as well as increased capillary density in the gastrocnemius muscles after hindlimb ischemia, relative to littermate controls. This protective effect was accompanied by reduced NLRP3 (Nod-like receptor family pyrin domain containing 3) inflammasome activation in the infiltrated macrophages without the alteration of macrophage infiltration and polarization. Moreover, suppressing inflammasome activation with NLRP3 inhibitor MCC950 improved blood flow and capillary density in wild-type mice compared with untreated mice. Mechanistically, suppressing HO-1 abolished TNF (tumor necrosis factor)-α-induced NLRP3 protein rather than mRNA expression in bone marrow–derived macrophages, indicating that HO-1 mediated post-transcriptional regulation of NLRP3. Furthermore, HO-1 inhibition promoted autolysosome-dependent degradation of NLRP3 in bone marrow–derived macrophages. Matrigel tube formation assay revealed that HO-1 deletion abrogated the antiangiogenic effect of inflammasome-activated macrophages. Conclusions: Taken together, these findings indicate that macrophage HO-1 deficiency promotes perfusion recovery after hindlimb ischemia by accelerating autolysosomal degradation of NLRP3. The underlying mechanism of action is a potential target for therapeutic angiogenesis in ischemic diseases.

Traditional network intrusion detection algorithm is based on pattern matching, which has made great progress in network intrusion detection system, but the efficiency of this algorithm for data packet matching is quite low. With the rapid increase of Internet scale and capacity, the general information security problem appears, and it brought hidden danger for an open network security. In this paper, the author analyse the intrusion detection and performance simulation based on improved sequential pattern mining algorithm. We integrate the data mining algorithms to implement the IDS, and the simulation result reflects the effectiveness of the methodology. The simulation shows that when minimum support is very small, PrefixSpan running time running a lot less time than other algorithm, and the difference between the two is obvious. Due to the mining algorithm of the relative independence of intrusion detection system, algorithm does not depend on the specific data and specific system, so the intrusion detection system based on data mining to data source requirement is very low.

Water breakthrough in horizontal wells is now the main factor restricting the stable production of the Tainan Gas Field in the Qaidam Basin. In view of this problem, the distribution characteristics of irreducible water saturation were investigated by using the nuclear magnetic resonance logging interpretation technology. And combined with the production situations of the horizontal wells in Tainan Gas Field in the initial stage of their production, the characteristic parameters of the reservoir which produced the intrastratal water as soon as it was put into production were determined. Then, the factors influencing the production of irreducible water were studied by means of gas drive water core experiments, and the factors influencing the sealing ability of the interbeds were researched by conducting mudstone breakdown tests. What's more, the effects on the bottomhole pressure by the length of horizontal section at different daily gas productions were investigated through numerical simulation. Finally, the prevention & control countermeasures for water breakthrough in horizontal wells were proposed. And the following research results were obtained. First, the horizontal well which drills into the reservoir with mobile water saturation higher than 7.2% and gas saturation lower than 63.5% produces formation water in its initial stage of production. Second, the lower the shale content is and the greater the production pressure difference is, the more favorable it is for the production of irreducible water. The production of irreducible water in the reservoirs with stronger areal heterogeneity is a continuous process. Third, the sealing capacity of the interbed increases with the decrease of its vertical permeability and water saturation and with the increase of its shale content and thickness. Fourth, the breakthrough pressure of type I mudstone (shale content > 90%) is about 4 MPa, that of type II mudstone (80%

Adipose derived stem cells (ADSCs) can differentiate into vascular lineages and participate in vascular remodeling. Perivascular ADSCs (PV-ADSCs) draw attention due to their unique location. The heterogeneity of subcutaneous (SUB-) and abdominal ADSCs were well addressed, but PV-ADSCs’ heterogeneity hasn’t been investigated. In the present study, we applied single-cell analysis to compare SUB-ADSCs and PV-ADSCs respectively regarding their subpopulations, functions, and cell fates. We uncovered 4 subpopulations of PV-ADSCs including Dpp4+, Col4a2+/Icam1+, Clec11a+/Cpe+ and Sult1e1+ cells, among which Clec11a+ subpopulation potentially participated in and regulated the PV-ADSCs differentiation towards a smooth muscle cell (SMC) phenotype. The present study revealed the distinct characteristics between PV-ADSCs and SUB-ADSCs.

Background: Arrhythmogenic cardiomyopathy (AC) is one of the leading causes for sudden cardiac death (SCD). Recent studies have identified mutations in cardiac desmosomes as key players in the pathogenesis of AC. However, the specific etiology in individual families remains largely unknown. Methods: A 4-generation family presenting with syncope, lethal ventricular arrhythmia and SCD was recruited. Targeted next generation sequencing (NGS) was performed and validated by Sanger sequencing. Plasmids containing the mutation and wild type (WT) were constructed, real-time PCR, western-blot and immunofluorescence were performed to detect the functional change due to the mutation. Results: The proband, a 56-year-old female, presented with recurrent palpitations and syncope. An ICD was implanted due to her family history of SCD/ aborted SCD. NGS revealed a novel heterozygous frame-shift variant ( c.832delG ) in Desmoplakin ( DSP ) among 5 family members. The variant led to frame-shift and premature termination, producing a truncated protein. Cardiac magnetic resonance (CMR) of the family members carrying the same variant shown myocardium thinning and fatty infiltration in the right ventricular, positive bi-ventricular late gadolinium enhancement and severe RV dysfunction, fulfilling the diagnostic criteria of AC. HEK293T cells transfected with mutant expressed truncated DSP mRNA and protein, upregulation of nuclear junction plakoglobin ( JUP ) and downregulation of β-catenin, when compared with WT. Conclusion: We infer that the novel c.832delG variant in DSP was associated with AC in this family, likely through Wnt/β-catenin signaling pathway.

Rationale: To date, our understanding of the role of HO-1 (heme oxygenase-1) in inflammatory diseases has mostly been limited to its catalytic function and the potential for its heme-related catabolic products to suppress inflammation and oxidative stress. Whether and how HO-1 in macrophages plays a role in the development of septic cardiac dysfunction has never been explored. Objective: Here, we investigated the role of macrophage-derived HO-1 in septic cardiac dysfunction. Methods and Results: Intraperitoneal injection of lipopolysaccharide significantly activated HO-1 expression in cardiac infiltrated macrophages. Surprisingly, we found that myeloid conditional HO-1 deletion in mice evoked resistance to lipopolysaccharide-triggered septic cardiac dysfunction and lethality in vivo, which was accompanied by reduced cardiomyocyte apoptosis in the septic hearts and decreased peroxynitrite production and iNOS (inducible NO synthase) in the cardiac infiltrated macrophages, whereas proinflammatory cytokine production and macrophage infiltration were unaltered. We further demonstrated that HO-1 suppression abolished the lipopolysaccharide-induced iNOS protein rather than mRNA expression in macrophages. Moreover, we confirmed that the inhibition of HO-1 promoted iNOS degradation through a lysosomal rather than proteasomal pathway in macrophages. Suppression of the lysosomal degradation of iNOS by bafilomycin A1 drove septic cardiac dysfunction in myeloid HO-1–deficient mice. Mechanistically, we demonstrated that HO-1 interacted with iNOS at the flavin mononucleotide domain, which further prevented iNOS conjugation with LC3 (light chain 3) and subsequent lysosomal degradation in macrophages. These effects were independent of HO-1’s catabolic products: ferrous ion, carbon monoxide, and bilirubin. Conclusions: Our results indicate that HO-1 in macrophages drives septic cardiac dysfunction. The mechanistic insights provide potential therapeutic targets to treat septic cardiac dysfunction.

With the rapid development of broadband wireless technology and the wide demand of multimedia mobile services, various broadband mobile multimedia services are coming into being. However, the limited radio resources do not adequately guarantee the quality of service requirements for these multimedia mobile services. In this paper, the improved chaotic neural network technology is applied to three typical broadband wireless communication systems. Through the theoretical analysis and the simulation, the proposed algorithm can make full use of the chaotic neural power to search the optimal solution, which can achieve the purpose of further optimizing the wireless resources. At the same time, it also make the positive attempt to promote cross-disciplinary integration.

Background Arrhythmogenic right ventricular cardiomyopathy (ARVC) is one of the leading causes for sudden cardiac death (SCD). Recent studies have identified mutations in cardiac desmosomes as key players in the pathogenesis of ARVC. However, the specific etiology in individual families remains largely unknown. Methods A 4-generation family presenting with syncope, lethal ventricular arrhythmia and SCD was recruited. Targeted next generation sequencing (NGS) was performed and validated by Sanger sequencing. Plasmid containing the mutation and wild type (WT) was constructed, western-blot and immunofluorescence were performed to detect the functional change due to the mutation. Results The proband, a 56-year-old female, presented with recurrent palpitation and syncope. An ICD was implanted due to her family history of SCD/ aborted SCD. NGS revealed a novel heterozygous frame-shift variant ( c.832delG ) in Desmoplakin ( DSP ) among 5 family members. The variant led to a frame-shift and a premature termination codon, producing a truncated protein. Cardiac magnetic resonance (CMR) of the family members carrying the same variant shown myocardium thinning and fatty infiltration in the right ventricular, positive bi-ventricular late gadolinium enhancement and severe RV dysfunction, fulfilling the diagnostic criteria of ARVC. HEK293T cells transfected with mutant expressed truncated DSP protein, upregulation of nuclear junction plakoglobin ( PG ) and downregulation of β-catenin, when compared with WT. Conclusion We infer that the novel c.832delG variant in DSP was associated with ARVC in this family, likely through Wnt/β-catenin signaling pathway.

Background and aims Abdominal aortic aneurysm (AAA) is characterized by infiltration of inflammatory cells, extracellular matrix (ECM) degradation, and dysfunction of vascular smooth muscle cells (VSMCs). Recent studies reported that exosomes mediate intercellular communication and are involved in different diseases. Whether exosomes play a role in AAA is poorly understood. Hence, this study evaluated the function of exosomes in AAA development. Methods The presence of exosomes in human and calcium phosphate (CaPO4)-induced AAA tissues was determined by immunofluorescence staining of CD63 and Alix. GW4869, an inhibitor of exosome biogenesis, was intraperitoneally injected into CaPO4-induced AAA tissues to evaluate the effects of exosomal inhibition on AAA development. To explore the underlying mechanisms, the human monocytic cell line THP-1 was differentiated into macrophages, and exosomes were collected from macrophages. VSMCs were treated with macrophage-derived exosomes, and the expression of matrix metalloproteinase-2 (MMP-2) was evaluated. The activation of mitogen-activated protein kinases (MAPKs) pathways was also investigated in vitro and in vivo. Results Exosomes were detected in the adventitia of aneurysmal tissues obtained from humans and mice. They were mainly expressed in clusters of macrophages. Intraperitoneal injection of GW4869 for two weeks significantly attenuated the progression of CaPO4-induced AAA, preserved elastin integrity and decreased MMP-2 expression. Similarly, administration of GW4869 suppressed the systemic and aneurysmal exosome generation. In vitro, treatment with macrophage-derived exosomes elevated MMP-2 expression in human VSMCs, while pre-treatment with GW4869 abolished these effects. It was also found that JNK and p38 pathways mediated the production of MMP-2 in VSMCs following treatment with macrophage-derived exosomes. Conclusions This study suggests that exosomes derived from macrophages are involved in the pathogenesis of AAA. Macrophage-derived exosomes trigger MMP-2 expression in VSMC via JNK and p38 pathways. GW4869 supplementation attenuates CaPO4-induced AAA in mice.

Backgound and Importance Idiopathic hypertrophic cranial pachymeningitis (IHCP) is a rare fibrosing inflammatory process involving the dura mater. Currently, there is no consensus on the treatments for IHCP, and the usefulness of immunosuppressive agents as a first-line option remains controversial. Cerebral venous sinus occlusion (CVSO) and cerebral venous sinus thrombosis (CVST) secondary to IHCP, which may cause progressive intracranial hypertension and venous obstructive parenchymal lesions, make the diagnosis and treatment of IHCP more complicated. Methods We present a case of IHCP. We also review previous cases of IHCP with secondary CVSO/CVST and then summarize the clinical characteristics of these patients. Clinical Presentation A 52-year-old female patient with IHCP developed secondary CVST. She had a severe headache with a hyperintense lesion on computed tomography, which was considered as subarachnoid hemorrhage. Lumbar tapping with a cerebrospinal fluid test, in addition to gadolinium contrast-enhanced magnetic resonance imaging, suggested IHCP. Secondary CVST was identified by digital subtraction angiography and magnetic resonance venography. Fatal intracranial hypertension with severe neurologic deficits occurred, despite mannitol, furosemide, and corticoid therapy. After administration of intravenous pulse cyclophosphamide, she obtained complete remission. Conclusions We experienced a patient with CVST secondary to IHCP, who was successfully treated with cyclophosphamide pulse therapy. Because IHCP with secondary venous obstruction has various differential diagnoses, venography is necessary to avoid misdiagnosis. The use of immunosuppressive agents may be promising but needs further verification.