Bio-inspired peptide-conjugated liposomes for enhanced planktonic bacteria killing and biofilm eradication.

Developing new antimicrobial agents has become an urgent task to address the increasing prevalence of multidrug-resistant pathogens and the emergence of biofilms. Cationic antimicrobial peptides (AMPs) have been regarded as promising candidates due to their unique non-specific membrane rupture mechanism. However, a series of problems with the peptides hindered their practical application due to their high toxicity and low bioactivity and stability. Here, inspired by broadening the application of cell-penetrating peptides (CPPs), we selected five different sequences of cationic peptides which are considered as both CPPs and AMPs, and developed a biomimetic strategy to construct cationic peptide-conjugated liposomes with the virus-like structure for both enhancements of antibacterial efficacy and biosafety. The correlation between available peptide density/peptide variety and antimicrobial capabilities was evaluated from quantitative perspectives. Computational simulation and experimental investigations assisted to identify the optimal peptide-conjugated liposomes and revealed that the designed system provides high charge density for enhanced anionic bacterial membrane binding capability without compromised cytotoxicity, being capable of enhanced antibacterial efficacy of bacteria/biofilm of clinically important pathogens. The bio-inspired design has shown enhanced therapeutic efficiency of peptides and may promote the development of next-generation antimicrobials.

Advances in In Vitro Models of Neuromuscular Junction: Focusing on Organ-on-a-Chip, Organoids, and Biohybrid Robotics.

The neuromuscular junction (NMJ) is a peripheral synaptic connection between presynaptic motor neurons and postsynaptic skeletal muscle fibers that enables muscle contraction and voluntary motor movement. Many traumatic, neurodegenerative, and neuroimmunological diseases are classically believed to mainly affect either the neuronal or the muscle side of the NMJ, and treatment options are lacking. Recent advances in novel techniques have helped develop in vitro physiological and pathophysiological models of the NMJ as well as enable precise control and evaluation of its functions. This paper reviews the recent developments in in vitro NMJ models with 2D or 3D cultures, from organ-on-a-chip and organoids to biohybrid robotics. Related derivative techniques are introduced for functional analysis of the NMJ, such as the patch-clamp technique, microelectrode arrays, calcium imaging, and stimulus methods, particularly optogenetic-mediated light stimulation, microelectrode-mediated electrical stimulation, and biochemical stimulation. Finally, the applications of the in vitro NMJ models as disease models or for drug screening related to suitable neuromuscular diseases are summarized and their future development trends and challenges are discussed.

Piezo1 channel-mediated Ca2+ signaling inhibits lipopolysaccharide-induced activation of the NF-κB inflammatory signaling pathway and generation of TNF-α and IL-6 in microglial cells.

Microglial cells are crucial in maintaining central nervous system (CNS) homeostasis and mediating CNS disease pathogenesis. Increasing evidence supports that alterations in the mechanical properties of CNS microenvironments influence glial cell phenotypes, but the mechanisms regulating microglial cell function remain elusive. Here, we examined the mechanosensitive Piezo1 channel in microglial cells, particularly, how Piezo1 channel activation regulates pro-inflammatory activation and production of pro-inflammatory cytokines, using BV2 and primary microglial cells. Piezo1 expression in microglial cells was detected both at mRNA and protein levels. Application of Piezo1 channel activator Yoda1 induced Ca2+ flux to increase intracellular Ca2+ concentration that was reduced by treatment with ruthenium red, a Piezo1 inhibitor, or Piezo1-specific siRNA, supporting that Piezo1 functions as a cell surface Ca2+ -permeable channel. Priming with lipopolysaccharide (LPS) induced microglial cell activation and production of TNF-α and IL-6, which were inhibited by treatment with Yoda1. Furthermore, LPS priming induced the activation of ERK, p38 MAPKs, and NF-κB. LPS-induced activation of NF-κB, but not ERK and p38, was inhibited by treatment with Yoda1. Yoda1-induced inhibition was blunted by siRNA-mediated depletion of Piezo1 expression and, furthermore, treatment with BAPTA-AM to prevent intracellular Ca2+ increase. Collectively, our results support that Piezo1 channel activation downregulates the pro-inflammatory function of microglial cells, especially production of TNF-α and IL-6, by initiating intracellular Ca2+ signaling to inhibit the NF-κB inflammatory signaling pathway. These findings reveal Piezo1 channel activation as a previously unrecognized mechanism regulating microglial cell function, raising an interesting perspective on targeting this molecular mechanism to alleviate neuroinflammation and associated CNS pathologies.

Functional cooperation between IKCa and TRPC1 channels regulates serum-induced vascular smooth muscle cell proliferation via mediating Ca2+ influx and ERK1/2 activation.

The increased proliferation of vascular smooth muscle cells (VSMCs) contributes to the pathogenesis of vascular diseases. The intermediate conductance calcium-activated potassium (IKCa ) channel plays a critical role in VSMC proliferation by raising the intracellular calcium concentration ([Ca2+ ]i ), but the underlying mechanism is still not unclear. Here we investigated the cooperation between IKCa and transient receptor potential canonical 1 (TRPC1) channels in mediating extracellular Ca2+ entry, which in turn activates downstream Ca2+ signalling in the regulation of VSMC proliferation using serum-induced cell proliferation model. Serum-induced cell proliferation was accompanied with up-regulation of IKCa expression and an increase in [Ca2+ ]i . Serum-induced cell proliferation and increase in [Ca2+ ]i were suppressed by IKCa inhibition with TRAM-34 or IKCa knockdown. Serum-induced cell proliferation was strongly reduced by the removal of extracellular Ca2+ with EGTA or intracellular Ca2+ with BAPTA-AM and, additionally, by TRPC1 knockdown. Moreover, the increase in [Ca2+ ]i induced by serum or by IKCa activation with 1-EBIO was attenuated by TRPC1 knockdown. Finally, serum induced ERK1/2 activation, which was attenuated by treatment with TRAM-34 or BAPTA-AM, as well as TRPC1 knockdown. Consistently, serum-induced cell proliferation was suppressed by ERK1/2 inhibition with PD98059. Taken together, these results suggest that the IKCa and TRPC1 channels cooperate in mediating Ca2+ influx that activates the ERK1/2 pathway to promote cell proliferation, thus providing new mechanistic insights into VSMC proliferation.

Risk factors of cardiovascular and cerebrovascular diseases in young and middle-aged adults: A meta-analysis.

BACKGROUND: The risk factors for cardiovascular and cerebrovascular diseases in young and middle-aged people have not yet been determined. We conducted a meta-analysis to find the risk factors for cardiovascular and cerebrovascular diseases, in order to provide guidance for the prevention of diseases in the young and middle-aged population. METHODS: We searched PubMed, Embase, Cochrane Library from the establishment of the database to Mar 2022. We included case-control or cohort studies reporting risk factors for cardiovascular and cerebrovascular disease in young and middle-aged adults. We excluded repeated publication, research without full text, incomplete information or inability to conduct data extraction and animal experiments, reviews and systematic reviews. STATA 15.1 was used to analyze the data. RESULTS: The pooled results indicated that increased systolic blood pressure was significantly associated with increased risk of any stroke, ischemic stroke and hemorrhagic stroke. Body Mass Index (BMI), current smoking, hypertension, and diabetes were significantly associated with increased risk of any stroke and ischemic stroke. Atrial fibrillation was only significantly associated with increased risk of any stroke. Increased total cholesterol was significantly associated with an increased risk of ischemic stroke, whereas increased triglycerides were significantly associated with a decreased risk of ischemic stroke. In addition, increased hypertension was also significantly associated with an increased risk of acute coronary syndrome. CONCLUSION: Our pooled results show that BMI, current smoking, atrial fibrillation, hypertension, systolic blood pressure, and total cholesterol can be used as risk factors for cardiovascular and cerebrovascular diseases in young people, while triglycerides can be used as protective factors for cardiovascular and cerebrovascular diseases in young and middle-aged adults.

NEDD4L inhibits cell viability, cell cycle progression, and glutamine metabolism in esophageal squamous cell carcinoma via ubiquitination of c-Myc.

Esophageal squamous cell carcinoma (ESCC) is a common subtype of esophageal cancer with high incidence. Surgery remains the main strategy for treatment of ESCC at early stage. However, the treatment outcome is unsatisfactory. Therefore, finding new therapeutics is of great importance. In the present study, we measured the level of NEDD4L, an ubiquitin protein ligase, in clinical samples and investigated the effects of NEDD4L on cell viability, cell cycle progression, and glutamine metabolism in TE14 cells determined by CCK-8 assay, flow cytometry and biochemical analysis, respectively. The results show that NEDD4L is significantly decreased in ESCC specimens, and its decreased expression is associated with a poor clinical outcome. Overexpression of NEDD4L significantly inhibits cell viability, cell cycle progression, and glutamine metabolism in TE14 cells. Mechanistic study indicates that NEDD4L regulates tumor progression through ubiquitination of c-Myc and modulation of glutamine metabolism. NEDD4L inhibits cell viability, cell cycle progression, and glutamine metabolism in ESCC by ubiquitination of c-Myc to decrease the expressions of GLS1 and SLC1A5. Our findings highlight the importance of NEDD4L/c-Myc signaling in ESCC.

Differential Regulation by Mechanical Stretch of the Expressions of Large-Conductance Ca2+-Activated K+ Channel and L-Type Voltage-Dependent Ca2+ Channel in Rat Uterine Smooth Muscle Cells.

Large-conductance Ca2+-activated K+ (BKCa) channel and L-type voltage-dependent Ca2+ channel (L-VDCC) play important roles in regulating uterine contractility. The uterus stretch, occurring during pregnancy, is a critical factor to trigger uterine contraction. However, how mechanical stimuli impact the two channels remains unknown. Here we investigated the effects of exposure to mechanical stretches with varying magnitudes and durations on expressions of the two channels in rat uterine smooth muscle cells. Our results show that stretch down-regulates the BKCa channel expression but upregulates the L-VDCC expression. These findings are helpful to better understand the roles of L-VDCC and BKCa channel in stretch-triggered uterine contraction.

Role of endoplasmic reticulum stress in apoptosis induced by HK2 inhibitor and its potential as a new drug combination strategy.

Compared with normal cells, tumor cells mainly obtain energy through aerobic glycolysis. Hexokinase 2 (HK2) plays a key role in the regulation of tumor cell aerobic glycolysis, and targeting HK2 has become a new strategy for cancer treatment. However, little is known about the role of HK2 in colon cancer and the regulation of its targeted inhibitors. In this study, we found that the expression of HK2 in colorectal cancer tissues was significantly higher than that in adjacent tissues, and the expression level of HK2 in metastatic colorectal cancer was further increased. Meanwhile, the expression level of HK2 was closely related to clinical TNM stage and outcome of colorectal cancer patients. We provide here evidence that HK2 inhibitor 3-Bromopyruvate acid (3-BP) can significantly inhibit the survival and proliferation of colon cancer cells, and induce apoptosis through mitochondrial apoptosis signaling pathway. In addition, we found that 3-BP can also induce endoplasmic reticulum stress in colon cancer cells, the mechanism may be through the increase of intracellular calcium concentration. In vitro and in vivo experiments showed that inhibition of endoplasmic reticulum stress could further increase the proliferation inhibition and apoptosis induced by 3-BP. Collectively, our results show that HK2 is highly expressed in colorectal cancer. 3-BP, an inhibitor of HK2, can induce apoptosis and endoplasmic reticulum stress in colon cancer cells. Endoplasmic reticulum stress plays a protective role in cell death induced by 3-BP. This result suggested that targeting HK2 and endoplasmic reticulum stress may be a valuable strategy in targeted and combination therapy of colon cancer.

Stimulation of vascular smooth muscle cell proliferation by stiff matrix via the IKCa channel-dependent Ca2+ signaling.

Vascular stiffening, an early and common characteristic of cardiovascular diseases (CVDs), stimulates vascular smooth muscle cell (VSMC) proliferation which reciprocally accelerates the progression of CVDs. However, the mechanisms by which extracellular matrix stiffness accompanying vascular stiffening regulates VSMC proliferation remain largely unknown. In the present study, we examined the role of the intermediate-conductance Ca2+ -activated K+  (IKCa ) channel in the matrix stiffness regulation of VSMC proliferation by growing A7r5 cells on soft and stiff polydimethylsiloxane substrates with stiffness close to these of arteries under physiological and pathological conditions, respectively. Stiff substrates stimulated cell proliferation and upregulated the expression of the IKCa channel. Stiff substrate-induced cell proliferation was suppressed by pharmacological inhibition using TRAM34, an IKCa channel blocker, or genetic depletion of the IKCa channel. In addition, stiff substrate-induced cell proliferation was also suppressed by reducing extracellular Ca2+ concentration using EGTA or intracellular Ca2+ concentration using BAPTA-AM. Moreover, stiff substrate induced activation of extracellular signal-regulated kinases (ERKs), which was inhibited by treatment with TRAM34 or BAPTA-AM. Stiff substrate-induced cell proliferation was suppressed by treatment with PD98059, an ERK inhibitor. Taken together, these results show that substrates with pathologically relevant stiffness upregulate the IKCa channel expression to enhance intracellular Ca2+ signaling and subsequent activation of the ERK signal pathway to drive cell proliferation. These findings provide a novel mechanism by which vascular stiffening regulates VSMC function.

A critical role of the KCa 3.1 channel in mechanical stretch-induced proliferation of rat bone marrow-derived mesenchymal stem cells.

Mechanical stimulation is an important factor regulating mesenchymal stem cell (MSC) functions such as proliferation. The Ca2+ -activated K+ channel, KCa 3.1, is critically engaged in MSC proliferation but its role in mechanical regulation of MSC proliferation remains unknown. Here, we examined the KCa 3.1 channel expression and its role in rat bone marrow-derived MSC (BMSC) proliferation in response to mechanical stretch. Application of mechanical stretch stimulated BMSC proliferation via promoting cell cycle progression. Such mechanical stimulation up-regulated the KCa 3.1 channel expression and pharmacological or genetic inhibition of the KCa 3.1 channel strongly suppressed stretch-induced increase in cell proliferation and cell cycle progression. These results support that the KCa 3.1 channel plays an important role in transducing mechanical forces to MSC proliferation. Our finding provides new mechanistic insights into how mechanical stimuli regulate MSC proliferation and also a viable bioengineering approach to improve MSC proliferation.

Design, synthesis and biological evaluation of bromophenol-thiazolylhydrazone hybrids inhibiting the interaction of translation initiation factors eIF4E/eIF4G as multifunctional agents for cancer treatment.

The eukaryotic initiation factor 4E (eIF4E) is an emerging anticancer drug target for specific anticancer therapy as a promising approach to overcome drug resistance and promote chemotherapy antitumor efficacy. A series of bromophenol-thiazolylhydrazone hybrids were designed, synthesized and evaluated for their antitumor activities. Among of them, the most potent compound 3e (EGPI-1) could inhibit the eIF4E/eIF4G interaction. Further mechanism study demonstrated EGPI-1 played an antitumor role in multiple modes of action including regulating the activity of eIF4E by inhibiting the phosphorylation of eIF4E and 4EBP1, disrupting mitochondrial function through the mTOR/4EBP1 signaling pathway, and inducing autophagy, apoptosis and ROS generation. Moreover, EGPI-1 showed good safety and favorable pharmacokinetic properties in vivo. These observations demonstrate that EGPI-1 may serve as an excellent lead compound for the development of new anticancer drugs that target the eIF4E/eIF4G interface and as a chemical genetic probe to investigate the role of the eIF4E in biological processes and human diseases.

Highly Selective Protein Tyrosine Phosphatase Inhibitor, 2,2',3,3'-Tetrabromo-4,4',5,5'-tetrahydroxydiphenylmethane, Ameliorates Type 2 Diabetes Mellitus in BKS db Mice.

Protein tyrosine phosphatase 1B (PTP1B) is a widely confirmed target of the type 2 diabetes mellitus (T2DM) treatment. Herein, we reported a highly specific PTP1B inhibitor 2,2',3,3'-tetrabromo-4,4',5,5'-tetrahydroxydiphenylmethane (compound 1), which showed promising hypoglycemic activity in diabetic BKS db mice. With the IC50 value of 2.4 µM, compound 1 could directly bind to the catalytic pocket of PTP1B through a series of hydrogen bonds. Surface plasmon resonance analysis revealed that the target affinity [KD (equilibrium dissociation constant) value] of compound 1 binding to PTP1B was 2.90 µM. Moreover, compound 1 could activate the insulin signaling pathway in C2C12 skeletal muscle cells. We further evaluated the long-term effects of compound 1 in diabetic BKS db mice. Notably, oral administration of compound 1 significantly reduced the blood glucose levels of diabetic mice with increasing insulin sensitivity. In addition, the dyslipidemia of diabetic mice was also significantly improved by compound 1 gavage. The histological experiments showed that compound 1 treatment significantly ameliorated the disordered hepatic and pancreatic architecture and increased the glycogen content in the liver tissues as well as improved the insulin secretion function of pancreas. Taken together, our results manifested that the natural product compound 1 was a highly specific PTP1B inhibitor, which could activate insulin signaling pathway and ameliorate hyperglycemia and dyslipidemia in diabetic BKS db mice.

CYC27 Synthetic Derivative of Bromophenol from Red Alga Rhodomela confervoides: Anti-Diabetic Effects of Sensitizing Insulin Signaling Pathways and Modulating RNA Splicing-Associated RBPs.

RNA-binding proteins (RBPs) lie at the center of posttranscriptional regulation and the dysregulation of RBPs contributes to diabetes. Therefore, the modulation of RBPs is anticipated to become a potential therapeutic approach to diabetes. CYC27 is a synthetic derivative of marine bromophenol BDB, which is isolated from red alga Rhodomela confervoides. In this study, we found that CYC27 significantly lowered the blood glucose levels of diabetic BKS db mice. Moreover, CYC27 effectively ameliorated dyslipidemia in BKS db mice by reducing their total serum cholesterol (TC) and triglyceride (TG) levels. Furthermore, CYC27 was an insulin-sensitizing agent with increased insulin-stimulated phosphorylation of insulin receptors and relevant downstream factors. Finally, to systemically study the mechanisms of CYC27, label-free quantitative phosphoproteomic analysis was performed to investigate global changes in phosphorylation. Enriched GO annotation showed that most regulated phosphoproteins were related to RNA splicing and RNA processing. Enriched KEGG analysis showed that a spliceosome-associated pathway was the predominant pathway after CYC27 treatment. Protein-protein interaction (PPI) analysis showed that CYC27 modulated the process of mRNA splicing via phosphorylation of the relevant RBPs, including upregulated Cstf3 and Srrt. Our results suggested that CYC27 treatment exerted promising anti-diabetic effects by sensitizing the insulin signaling pathways and modulating RNA splicing-associated RBPs.

Bone marrow derived endothelial progenitor cells retain their phenotype and functions after a limited number of culture passages and cryopreservation.

A critical limitation for tissue engineering and autologous therapeutic applications of bone marrow derived EPCs is their low frequency, which is even lower in number and activity level in patients with cardiovascular risk factors and other diseases. New strategies for obtaining and reserving sufficient ready-to-use EPCs for clinical use have hit major obstacles, because effects of serial passage and cryopreservation on EPC phenotype and functions are still needed to be explored. The present study aims at investigating effects of a limited number of culture passages as well as cryopreservation on EPC phenotype and functions. We isolated EPCs from rat bone marrow and cultured them up to passage 12 (totaling achievements of 40 population doublings). The phenotype and functions of fresh cultured and post-cryopreserved EPCs at passages 7 and 12, respectively, were evaluated. EPCs at passage 12 maintained the morphological characteristics, marker phenotype, Dil-ac-LDL uptake and FITC-UEA-1 binding functions, enhanced EPCs proliferation, tube formation and migration, but decreased CD133 expression compared with EPCs at passage 7. Cryopreservation caused limited impairment in EPC phenotype and functions. In brief, our results demonstrated that a limited number of culture passages and cryopreservation did not change EPC phenotype and functions, and can be used for the development of robust strategies and quality control criterion for obtaining sufficient and high-quality ready-to-use EPCs for tissue engineering and therapeutic applications.

A case report of hemolytic streptococcal gangrene in the danger triangle of the face with thrombocytopenia and hepatitis.

BACKGROUND: Hemolytic streptococcus gangrene is a life threatening invasive bacterial infection. Hemolytic streptococcus gangrene in the danger triangle of the face is too lethal to operate. A case of the confirmed hemolytic streptococcus gangrene in the danger triangle of the face caused by Group A beta-hemolytic streptococcus (GAS) in 20-months old boy is presented to draw attention of clinicians to this uncommon but frequently fatal infection. CASE PRESENTATION: Previously healthy 20 months old boy suddenly developed paranasal gangrene on the left side of the danger triangle of the face, followed by rapidly progressive thrombocytopenia and hepatitis. The clinical features, liver function, and hematological and serological parameters resembled to a description of streptococcal toxic shock syndrome (STSS). Aggressive antibiotics, substitutional and supportive therapy were conducted without surgical debridement of facial tissues. Prompt diagnosis and aggressive timely treatment completely cured the disease in 28 days. CONCLUSIONS: The present case report demonstrates prompt diagnosis and timely treatment as a strategy to cure the fatal hemolytic streptococcus gangrene located in too risky body part to operate.

Electrospun membranes of PELCL/PCL-REDV loading with miRNA-126 for enhancement of vascular endothelial cell adhesion and proliferation.

Surface modification for rapid endothelialization of vascular biomaterials is known as an important way to prevent thrombosis and intimal hyperplasia. Moreover, therapeutical manipulation of microRNAs (miRNAs) expression via local delivery of miRNA mimics or inhibitors by electrospun ultrafine fibers has demonstrated the promise in tissue regeneration. In this work, a dual-functional electrospun membrane was developed by combining Arg-Glu-Asp-Val (REDV) peptide-modification of the fiber surface to enhance vascular endothelial cell (VEC) adhesion and encapsulation of miRNA-126 (miR-126) complexes in the electrospun fibers to accelerate VEC proliferation. The electrospun membranes were specially prepared by emulsion electrospinning of poly(ethylene glycol)-b-poly(l-lactide-co-ε-caprolactone) (PELCL) and REDV-terminated polycaprolactone (PCL) (50/50 mass ratio), in which miR-126 was encapsulated via REDV peptide-modified trimethyl chitosan-g-poly(ethylene glycol). By introduction of REDV-terminated PCL with lower molecular weight, the obtained electrospun fibers could be modified by REDV on their surface, and also achieve a relatively fast release profile of miR-126 in favor of VEC proliferation. Results of direct seeding VECs on the electrospun membranes indicated the enhanced cell adhesion and proliferation. The combination of REDV peptide-modification of the electrospun fibrous membranes and controllable miRNA release may provide a synergistic strategy of surface guidance and biochemical signals to support and modulate VECs for vascular tissue regeneration.

Selectivity, cell permeability and oral availability studies of novel bromophenol derivative HPN as protein tyrosine phosphatase 1B inhibitor.

BACKGROUND AND PURPOSE: Protein tyrosine phosphatase 1B (PTP1B) negatively regulates insulin signalling by tyrosine dephosphorylation of the insulin receptor. It is a highly validated target for type 2 diabetes therapeutics. Here, the anti-diabetic effects of HPN were evaluated in the diabetic BKS db mice. EXPERIMENTAL APPROACH: The mode of inhibition of PTP1B by HPN was determined according to the Lineweaver-Burk plot. A surface plasmon resonance assay and molecular docking were used to study the interaction between HPN and PTP1B. C2C12 skeletal muscle cells were used to investigate the cell permeability of HPN and the effect of HPN on insulin signalling pathways. Long-term effects of HPN on glycaemic control were investigated in diabetic BKS db mice. Glycogen contents in liver and muscle were determined. Furthermore, changes in the number of beta cells were evaluated by Gomori staining. KEY RESULTS: HPN was identified as a specific PTP1B inhibitor. HPN directly interacted with PTP1B by binding to the catalytic domain through hydrogen bonds in a competitive mode. Approximately 56.98% of HPN entered into the cultured C2C12 myotubes. HPN ameliorated the impaired insulin signalling in palmitate-treated C2C12 myocytes. Notably, oral administration of HPN significantly protected mice from hyperglycaemia, dyslipidemia and hyperinsulinaemia. HPN also enhanced the storage of glycogen in liver and muscle. Moreover, HPN obviously improved the beta cell numbers of the pancreatic islets. CONCLUSION AND IMPLICATIONS: Our results indicate that HPN is a specific PTP1B inhibitor, with anti-diabetic properties and good cell permeability and oral availability.

Quantitative Studies of Endothelial Cell Fibronectin and Filamentous Actin (F-Actin) Coalignment in Response to Shear Stress.

Both fibronectin (FN) and filamentous actin (F-actin) fibers play a critical role for endothelial cells (ECs) in responding to shear stress and modulating cell alignment and functions. FN is dynamically coupled to the F-actin cytoskeleton via focal adhesions. However, it is unclear how ECs cooperatively remodel their subcellular FN matrix and intracellular F-actin cytoskeleton in response to shear stress. Current studies are hampered by the lack of a reliable and sensitive quantification method of FN orientation. In this study, we developed a MATLAB-based feature enhancement method to quantify FN and F-actin orientation. The role of F-actin in FN remodeling was also studied by treating ECs with cytochalasin D. We have demonstrated that FN and F-actin codistributed and coaligned parallel to the flow direction, and that F-actin alignment played an essential role in regulating FN alignment in response to shear stress. Our findings offer insight into how ECs cooperatively remodel their subcellular ECM and intracellular F-actin cytoskeleton in response to mechanical stimuli, and are valuable for vascular tissue engineering.

[Efficacy of Bortezomib for Maintenance therapy of Patients with Multiple Myeloma].

OBJECTIVE: To observe the efficacy of chemotherapy consisted of bortezomib as main druy in maintenance therapy for recurrence of newly diagnosed MM patients. METHODS: The clinical data and outcome of 37 MM patients during 2008-2013 were analyzed retrospectively, the 37 MM patients were divided into 2 group: 19 cases including 13 cases of newly diagnosed MM with symptoms and 6 cases of relapsed refractory MM were enrolled in group A; 17 cases of newly diagnosed MM with symptoms were enrolled in group B. The patients of group A received maintenance therapy consisted of bortezomib plus dexamethasone (VD group), while the patient group B received maintenance therapy consisted of melphalan plus prednisone(MP group), then the therapeutic efficacy of 2 group was compared. RESULTS: The overall response rate(ORR) in VD groupe was 84.2%(16/19), out of which CR rate reached 42%(8/19), PR rate reached 31.6%(6/19), MR rate reached 10.5%(3/19). During median follow-up for 21.8(5-51) months, death occurred, while the ORR in MP group was 52(9/17), out of which CR rate was 23.5%(4/17), PR rate reached 23.5%(4/17), MR rate reached 5.9%(1/17). Druing median follow-up for 16.4(4-39) months, the worteity reaced 64.7%(11/17). The differencr between 2 groups was significant(P<0.05). The median OS time of patients in VD group was 21.6 months, that in MP group was 17.9 months(P<0.05). The median PFS in VD group and MP group were 13.4 and 9.4 months respectively(P<0.001). CONCLUSION: The ORR and CR rates of bortezomib maintenance therapy for newly diagnosed and relapsed / refractory MM patients are very high, and its toxicity can be controlled, therefore, the patients need maintenance therapy after remission.

Nanofiber-mediated microRNA-126 delivery to vascular endothelial cells for blood vessel regeneration.

UNLABELLED: As manipulation of gene expression by virtue of microRNAs (miRNAs) is one of the emerging strategies for cardiovascular disease remedy, local delivery of miRNAs to a specific vascular tissue is challenging. In this work, we developed an efficient delivery system composed of electrospun fibrous membranes and target carriers for the intracellular delivery of miRNA-126 (miR-126) to vascular endothelial cells (VECs) in the local specific vascular environment. A bilayer vascular scaffold was specially prepared via emulsion electrospinning of poly(ethylene glycol)-b-poly(l-lactide-co-ε-caprolactone) (PELCL) and dual-power electrospinning of poly(ε-caprolactone) (PCL) and gelatin. The inner layer of PELCL, which was loaded with complexes of miR-126 in REDV peptide-modified trimethyl chitosan-g-poly(ethylene glycol), regulated the response of VECs, while the outer layer of PCL/gelatin contributed to the mechanical stability. Biological activities of the miR-126-loaded electrospun membranes were evaluated by cell proliferation and SPRED-1 expression of a miR-126 target gene. By encapsulating targeting complexes of miR-126 in the electrospun membranes, a sustained release profile of miRNA was obtained for 56days. Significant down-regulation of SPRED-1 gene expression in VECs was detected on day 3, and it was found that miR-126 released from the electrospun membranes accelerated VEC proliferation in the first 9days. The bilayer vascular scaffold loaded with miR-126 complexes could also improve endothelialization in vivo. These results demonstrated the potential of this approach towards a new and more effective delivering system for local delivery of miRNAs to facilitate blood vessel regeneration. STATEMENT OF SIGNIFICANCE: Tissue engineering of small-diameter blood vessels is still challenging because of thrombosis and low long-term patency. The manipulation of gene expression by miRNAs could be a novel strategy in vascular regeneration. Here, we report an efficient delivery system of electrospun fibrous scaffold combined with REDV peptide-modified trimethyl chitosan for targeted intracellular delivery of miR-126 to VECs in the local vascular environment. Results exhibited that miR-126 released from the electrospun membrane could modulate VEC proliferation via down-regulation of SPRED-1 gene expression. The electrospun scaffolds loaded with target-delivery carriers may serve as an ideal platform for local delivery of miRNAs in the vascular tissue engineering.