Knowledge, attitudes, and practice of physicians and pharmacists regarding the prevention and treatment of cardiovascular toxicity associated with cancer treatment.

This study aimed to explore physicians' and pharmacists' knowledge, attitudes, and practice (KAP) regarding the prevention and treatment of cardiovascular toxicity associated with cancer treatment. A multicenter cross-sectional study included physicians and pharmacists between April 2023 and June 2023. The study included 918 participants (514 physicians and 404 pharmacists). The average scores of knowledge, attitudes, and practice were 11.6 ± 3.39, 24.7 ± 2.6, and 26.3 ± 6.8 points. Sufficient knowledge was significantly associated with age ≥ 41 years (odds ratio (OR) = 2.745, 95% confidence interval (CI) 1.086-6.941, P = 0.033), male (OR = 2.745, 95% CI 1.150-2.223, P = 0.005), bachelor's degree (OR = 0.084, 95% CI 0.013-0.533, P = 0.009), master's degree and above (OR = 0.096, 95% CI 0.015-0.609, P = 0.013), physician occupation (OR = 7.601, 95% CI 1.337-43.207, P = 0.022), pharmacy department (OR = 18.858, 95% CI 3.245-109.57, P = 0.001), oncology department (OR = 4.304, 95% CI 2.426-7.634, P < 0.001), cardiology department (OR = 3.001, 95% CI 1.387-6.492, P = 0.005), hospitals located in Eastern China (OR = 1.957, 95% CI 1.120-3.418, P = 0.018), and hospitals located in Western China (OR = 3.137, 95% CI 1.783-5.518, P < 0.001). Positive attitudes were significantly associated with a senior professional title (OR = 2.989, 95% CI 1.124-7.954, P = 0.028) and hospitals located in Eastern China (OR = 0.424, 95% CI 0.257-0.698, P = 0.001), Western China (OR = 0.231, 95% CI 0.136-0.394, P < 0.001), and Southern China (OR = 0.341, 95% CI 0.198-0.587, P < 0.001). Proactive practice was significantly associated with male (OR = 1.414, 95% CI 1.029-1.943, P = 0.033), senior professional title (OR = 3.838, 95% CI 1.176-12.524, P = 0.026), oncology department (OR = 3.827, 95% CI 2.336-6.272, P < 0.001), and cardiology department (OR = 2.428, 95% CI 1.263-4.669, P = 0.008). Both physicians and pharmacists had positive attitudes toward the prevention and treatment of cardiovascular toxicity associated with cancer treatment, while their knowledge and practice were not as proactive.

iGlarLixi for type 2 diabetes: a systematic review and meta-analysis.

OBJECTIVES: To assess the efficacy and tolerability of iGlarLixi-a novel, fixed-ratio, soluble combination of insulin glargine and lixisenatide-for the treatment of type 2 diabetes (T2D). METHODS: The PubMed, Embase, Cochrane Library and ClinicalTrials.gov databases were searched from inception to November 15, 2023 to identify randomized controlled trials (RCTs) comparing iGlarLixi with a placebo or any other antidiabetic agent in adults with T2D. Risk ratios (RRs) and mean differences (MDs) with 95% confidence intervals (CIs) were calculated to evaluate the outcomes. RESULTS: A total of 10 trials enrolling 6071 T2D patients were included. Compared with placebos or other antidiabetic agents, iGlarLixi exerted beneficial effects on changes in HbA1c, the percentage of patients who achieved an HbA1c < 7%, the percentage of patients who achieved an HbA1c < 6.5%, the percentage of patients who achieved an HbA1c < 7.0% without weight gain and/or without severe or blood glucose-confirmed hypoglycemic episodes, changes in fasting plasma glucose, and changes in self-measured plasma glucose. Regarding safety, iGlarLixi did not increase the incidence of severe hypoglycemia or serious adverse events but did increase the incidence of gastrointestinal adverse events, symptomatic hypoglycemia, and adverse events (e.g., nausea, vomiting, diarrhea). CONCLUSIONS: iGlarLixi showed improved efficacy and safety in patients with T2D. Additional large, multicenter RCTs are warranted to obtain deeper insights into the efficacy and safety of iGlarLixi, thereby providing guidance for clinical treatment decisions.

The safety and efficacy of NOACs versus LMWH for thromboprophylaxis after THA or TKA: A systemic review and meta-analysis.

The differences in the safety and efficacy of anticoagulation between different types of new oral anticoagulants(NOACs) and low molecular weight heparin(LMWH) are still controversial. The main purposes of this study were to analyze safety and efficacy of NOACs versus LMWH for thromboprophylaxis, and perform subgroup analyses stratified by individual NOACs and different populations after total hip arthroplasty (THA) or total knee arthroplasty (TKA). Literature search was performed in PubMed, EMBASE, Cochrane Library, CNKI and Wanfang databases until June 31, 2022. This systematic review and meta-analysis included 46 randomized controlled trials (RCT) with 39, 924 patients. We evaluated the safety and efficacy of thromboprophylaxis between LMWH and NOACs. NOACs were more effective in reducing deep vein thrombosis (DVT) (RR0.59; 95%CI 0.49-0.71) and adverse events (RR: 0.96; 95%CI: 0.93-0.99) than LMWH. The subgroup analyses for different anticoagulants revealed that rivaroxaban (RR:0.49; 95%CI:0.36-0.66), apixaban (RR: 0.54; 95%CI: 0.36-0.81) and edoxaban (RR:0.49; 95%CI: 0.32-0.75) have the lower risk of DVT than LMWH. Apixaban (RR:0.89; 95%CI: 0.80-1.00) had superior prevention of bleeding to LMWH. Edoxaban exhibited a lower risk of VTE (RR: 0.46; 95%CI: 0.33-0.65), advantage events (RR: 0.87; 95%CI: 0.82-0.93), and drug-related adverse events (DRAEs) (RR: 0.64; 95%CI: 0.53-0.76) than LMWH. East Asian population was superior to western population for preventing DVT, advantage events, and DRAE using NOACs. In conclusion, NOACs are more effective than LMWH at preventing DVT and adverse events after arthroplasty. Apixaban has lower bleeding than LMWH, and East Asian populations may benefit more than western population from NOACs.

The Different Therapeutic Effects of Traditional Chinese Medicine Shensong Yangxin Capsule and Salubrinal in High-intensity Exercise-induced Heart Failure in Rats with Acute Myocardial Infarction.

BACKGROUND: Currently, endoplasmic reticulum stress is studied utilizing a dephosphorylation inhibitor (Sal). The traditional Chinese patent medicine and simple formulation Shensong Yangxin Capsule is a commonly used medication for the treatment of arrhythmia. However, the efficacy and underlying mechanism of the capsule in treating post-ischemic heart failure in myocardial tissue have not yet been investigated. OBJECTIVE: The therapeutic effects and the underlying mechanism of the Shensong Yangxin Capsule (SSYX) and the dephosphorylation inhibitor Salubrinal (Sal) on heart failure (HF) induced by high-intensity exercise in rats with acute myocardial infarction (AMI) were investigated. METHODS: Male infants of 8 weeks Spragge-Dawley (SD) rats were randomly assigned to one of four groups: sham surgery group, AMI+placebo group, AMI+Shensong Yangxin Capsule group (AMI+SSYX), and AMI+Sal administration group. Rats' myocardial infarction was induced by left coronary artery ligation. Rats were subjected to a 3-week high-intensity exercise program to simulate heart failure after 7 days of postoperative rest. After the fourth postoperative week, echocardiography was applied to determine the left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS), and left ventricular systolic volume (LVESV) in each group. HE and TUNEL labeling were employed to examine the morphology of cardiac cells and measure the percentage of apoptosis in each group; Western blotting was applied to detect the cardiomyocyte apoptosis-related proteins p-JNK, p-P38, and NOX2, while ELISA was used to detect glutathione(GSH), malondialdehyde (MDA), and superoxide dismutase (SOD) in serum. RESULTS: Following a 4-week drug intervention:(1)LVFS and LVEF in the AMI+placebo group were statistically significantly reduced, while LVESV were significantly higher, compared to those in the sham surgery group (P<0.05); The AMI+SSYX group performed statistically significantly better than the AMI+placebo group(P<0.05). (2) The myocardial cells in the AMI+placebo group exhibited significant swelling and inflammatory cell infiltration; the myocardial cells in the AMI+SSYX group and AMI+Sal group displayed mild swelling and minimal inflammatory cell infiltration; the AMI+SSYX group's myocardial cell morphology was superior to that of the AMI+Sal group; (3) The apoptosis rate of the AMI+placebo group was around 95%, greater than that of the sham surgery group (2.55%). The apoptosis rate of the AMI+SSYX group is approximately 21%, while the apoptosis rate of the AMI+Sal group is about 43%. (4) In the AMI+placebo group, p-JNK, p-P38, and NOX2 protein expression dramatically increased compared to the sham surgery group. The expression of p-P38, NOX2, and p-JNK/t-JNK was considerably reduced in the AMI+Shensong group and AMI+Sal group, compared to the AMI+placebo group. (P<0.01)The AMI+SSYX group's result is superior to that of the AMI+Sal group. (5) Compared to the sham surgery group, the serum levels of SOD and GSH were significantly lower, and MDA was significantly higher in the AMI+placebo group. Compared to the AMI+placebo group, the serum levels of SOD and GSH were significantly higher, and MDA was significantly lower in the AMI+SSYX group and the AMI+Sal group. (P<0.05) Conclusion: In rats with acute myocardial infarction in high-intensity exercise-induced heart failure, Shensong Yangxin Capsule dramatically reduces myocardial cell death and cardiac dysfunction. SSYX has a shorter course of treatment and a better therapeutic effect than Sal.

The role of Lactobacillus in inflammatory bowel disease: from actualities to prospects.

Inflammatory Bowel Disease (IBD), a chronic nonspecific intestinal inflammatory disease, is comprised of Ulcerative Colitis (UC) and Crohn's Disease (CD). IBD is closely related to a systemic inflammatory reaction and affects the progression of many intestinal and extraintestinal diseases. As one of the representative bacteria for probiotic-assisted therapy in IBD, multiple strains of Lactobacillus have been proven to alleviate intestinal damage and strengthen the intestinal immunological barrier, epithelial cell barrier, and mucus barrier. Lactobacillus also spares no effort in the alleviation of IBD-related diseases such as Colitis-associated Colorectal cancer (CAC), Alzheimer's Disease (AD), Depression, Anxiety, Autoimmune Hepatitis (AIH), and so on via gut-brain axis and gut-liver axis. This article aims to discuss the role of Lactobacillus in IBD and IBD-related diseases, including its underlying mechanisms and related curative strategies from the present to the future.

Fate mapping of hematopoietic stem cells reveals two pathways of native thrombopoiesis.

Hematopoietic stem cells (HSCs) produce highly diverse cell lineages. Here, we chart native lineage pathways emanating from HSCs and define their physiological regulation by computationally integrating experimental approaches for fate mapping, mitotic tracking, and single-cell RNA sequencing. We find that lineages begin to split when cells leave the tip HSC population, marked by high Sca-1 and CD201 expression. Downstream, HSCs either retain high Sca-1 expression and the ability to generate lymphocytes, or irreversibly reduce Sca-1 level and enter into erythro-myelopoiesis or thrombopoiesis. Thrombopoiesis is the sum of two pathways that make comparable contributions in steady state, a long route via multipotent progenitors and CD48hi megakaryocyte progenitors (MkPs), and a short route from HSCs to developmentally distinct CD48-/lo MkPs. Enhanced thrombopoietin signaling differentially accelerates the short pathway, enabling a rapid response to increasing demand. In sum, we provide a blueprint for mapping physiological differentiation fluxes from HSCs and decipher two functionally distinct pathways of native thrombopoiesis.

Downregulation of hERG channel expression by tyrosine kinase inhibitors nilotinib and vandetanib predominantly contributes to arrhythmogenesis.

Cardiotoxicity by tyrosine kinase inhibitors remains an important concern. Nilotinib and vandetanib clinically carry high proarrhythmic risk and the exact mechanism underlying arrhythmogenesis is not fully understood. In this study, we investigated the effects of nilotinib and vandetanib on the abundance of human ether-á-go-go-related gene (hERG) K+ channel and assessed the potential role of acute hERG blockage versus chronic effects in arrhythmogenesis. We found that both nilotinib and vandetanib prolonged the field potential duration reflecting the repolarisation process and induced cellrythmias of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) in a time-and concentration-dependent manner after, after chronic exposure. Patch-clamp recordings revealed significant reductions of hERG current densities by nilotinib or vandetanib after chronic incubation with hERG-HEK293 cells in addition to the acute inhibition. Western blot analysis showed that nilotinib and vandetanib decreased mature hERG protein (155-kDa) expression, in a greater extent than that of the immature form (135-kDa). A serum and glucocorticoid kinase 1 (SGK1) activator, C4-ceramide, prevented the nilotinib-and vandetanib-induced hERG protein downregulation and thus the incidence of cellrrhythmias. Taken together, our data demonstrated that the downregulation of hERG channel abundance on the cellular membrane predominantly contributed to the proarrhythmic effect of nilotinib and vandetanib.

T-box transcription factor 19 promotes hepatocellular carcinoma metastasis through upregulating EGFR and RAC1.

The effect of targeted therapy for metastatic hepatocellular carcinoma (HCC) is still unsatisfactory. Exploring the underlying mechanism of HCC metastasis is favorable to provide new therapeutic strategies. T-box (TBX) transcription factor family genes, which are crucial regulators in embryo and organ development, are vital for regulating tumor initiation, growth and metastasis. Here we explored the role of TBX19 in HCC metastasis, which is one of the most upregulated TBX family genes in human HCC tissues. TBX19 expression was markedly upregulated in HCC tissues and elevated TBX19 expression predicted poor prognosis. Overexpression of TBX19 enhanced HCC metastasis through upregulating epidermal growth factor receptor (EGFR) and Rac family small GTPase 1 (RAC1) expression. Downregulation of EGFR and RAC1 inhibited TBX19-mediated HCC metastasis, while upregulation of EGFR and RAC1 restored inhibition of HCC metastasis mediated by TBX19 knockdown. Furthermore, epidermal growth factor (EGF)/EGFR signaling upregulated TBX19 expression via the extracellular signal-regulated kinase (ERK)/nuclear factor (NF)-kB axis. Besides, the combined application of EGFR inhibitor Erlotinib and RAC1 inhibitor NSC23766 markedly inhibited TBX19-mediated HCC metastasis. In HCC cohorts, TBX19 expression was positively associated with EGFR and RAC1 expression. Patients with positive coexpression of TBX19/EGFR or TBX19/RAC1 displayed the poorest prognosis. In conclusion, EGF/EGFR signaling upregulated TBX19 expression via ERK/NF-kB pathway and TBX19 fostered HCC metastasis by enhancing EGFR and RAC1 expression, which formed an EGF-TBX19-EGFR positive feedback loop. Targeting this signaling pathway may offer a potential therapeutic strategy to efficiently restrain TBX19-mediated HCC metastasis.

Upregulation of phosphoinositide 3-kinase prevents sunitinib-induced cardiotoxicity in vitro and in vivo.

Sunitinib (SNT) is a multi-targeted receptor tyrosine kinase inhibitor that has been approved by the FDA for cancer therapy. However, its cardiotoxicity has limited the clinical applicability with no effective therapeutic approach available. As a broadband kinase inhibitor, the function of several kinases that are essential to cardiac function might also be affected by SNT, such as calmodulin-dependent protein kinase (CaMKII), cyclic-AMP-dependent protein kinases (PKA), AMP-activated protein kinase (AMPK), and phosphoinositide 3 kinase (PI3K). In this study, we investigated whether SNT-induced cardiotoxicity could be prevented by blocking SNT-induced alteration in the corresponding signaling pathways. In human induced pluripotent stem cell-derived cardiomyocytes, SNT (0.5-20 µmol/L) inhibited contractility of cardiomyocytes in a concentration-dependent manner, and the inhibitory effect was prevented either by PIP3 (1 µmol/L) application or PI3K overexpression. On the contrary, the CaMKII inhibitor KN-93 (50 nmol/L), PKA inhibitor H89 (1 µmol/L), and AMPK activators metformin (2 mmol/L) and 5-aminoimidazole-4-carboxamide 1-b-D-ribofuranoside (2 mmol/L) presented negligible effects. Oral SNT administration (40 mg/kg/day) in mice progressively decreased the PI3K activity and cardiac function in 2 weeks with a significant decrease in the expression and activity of Cav1.2 and SERCA. Cardiac-specific PI3K overexpression through adeno-associated virus 9-mediated gene delivery in mice prevented SNT-induced reduction in cardiac function, calcium transient, calcium current, and Cav1.2 expression. In summary, our data indicate that increased PI3K activity is protective against SNT-induced calcium mishandling and contractile dysfunction. Cardiac-specific PI3K activation could be an effective therapeutic approach to treat SNT cardiotoxicity in patients with cancer.

Stem cell homeostasis by integral feedback through the niche.

Hematopoiesis is a paradigm for tissue development and renewal from stem cells. Experiments show that the maintenance of hematopoietic stem cells (HSCs) relies on signals from niche cells. However, it is not known how the size of the HSC compartment is set. Competition by HSCs for niche access has been suggested, yet niche cells in the bone marrow outnumber HSCs. Here we propose a cooperative model of HSC homeostasis in which stem and niche cells mutually interact such that niche cells function as negative feedback regulators of HSC proliferation. This model explains puzzling experimental findings, including homeostatic recovery of the HSC compartment after irradiation versus apparent lack of recovery after HSC ablation. We show that bidirectional niche-stem cell regulation has properties of a proportional-integral feedback controller. Moreover, we predict that the outflux of differentiated cells from HSCs can be regulated by the affinity of HSCs for niche cells. Much effort has been devoted to elucidating niche cell signaling to stem cells; our theoretical insights indicate that studying the effect of stem cells on the niche may be equally important for understanding stem cell homeostasis.

Serial Thyroglobulin Variation Trend Shortly after Radioiodine Therapy in Poorly to Moderately Differentiated Recurrent Thyroid Cancer.

Objective To dynamically observe the early change of thyroglobulin(Tg) levels after (131)I therapy in differentiated thyroid cancer(DTC) patients. Methods The study enrolled 22 post-total-thyroidectomy DTC patients and they were stratified as low to intermediate recurrence according to the 2009 American Thyroid Association Guidelines. The clinical data including pre-ablation stimulated Tg (ps-Tg),corresponding thyroid stimulating hormone(TSH),anti-thyroglobulin (TgAb) values,and the afterwards parameters were dynamically measured each week in the first month after (131)I therapy. Values collected at the first time were defined as Tg 0 and TSH0,while Tg1 and TSH1 were collected at the first week after (131)I therapy respectively. Then the variation trend curves of Tg were drawn,and factors influencing the variation of Tg were analyzed. Two groups were divided according to Tg levels:G1 (Tg≤0.1 ng/ml,n=9) and G2(Tg>0.1 ng/ml,n=13). Results The rates of negative Tg were 4.5%,18.0%,27.0%,36.0%,and 41.0%,respectively,exactly before (131)I therapy and the 1(st),2(nd),3(rd),and 4(th) week after the therapy. One-way analysis of variance showed that the two groups statistically differed in age (F=3.182,P=0.04) and remnant thyroid (U=4.849,P=0.026). Multivariate logistic regression analysis showed that early negative Tg was related to remnant thyroid tissue (OR:2.132;95%Cl:1.418- 6.532,P=0.009). Conclusions Negative Tg can be achieved in nearly half of DTC patients by the end of first month after (131)I therapy. The negative conversion is closely related with the volume of remnant thyroid tissue.

[Effects of miRNA-21 on paclitaxel-resistance in human breast cancer cells].

OBJECTIVE: To investigate the effects of miR-21 on paclitaxel-resistance in human breast cancer MCF-7/PR and SKBR-3/PR cells. METHODS: Paclitaxel-resistant human breast cancer cell lines MCF-7/PR and SKBR-3/PR were established by stepwise selection in increasing concentration of paclitaxel. Cellular morphology, mRNA and protein level of MDR1, BCRP and MRP1 in MCF-7/PR and SKBR-3/PR cells were determined. The expression of Bax, Bcl-2 and miR-21 in parental and paclitaxel-resistant cells was detected by RT-PCR and Western blotting. The synthetic miR-21 inhibitor or miR-21 mimic were transfected into MCF-7/PR, SKBR-3/PR and MCF-7, SKBR-3 cells with Lipofectamine 2000. The miR-21 levels were determined by RT-PCR, and P-gp, Bcl-2 and Bax protein levels were examined by Western blotting. MTT assay was used to measure the cell viability, and flow cytometry was performed to analyze the cell cycle and apoptosis. RESULTS: The levels of MDR1, BCRP, MRP1, Bcl-2/Bax and miR-21 in MCF-7/PR and SKBR-3/PR cells were significantly higher than those in MCF-7 and SKBR-3 cells. The protein levels of P-gp, Bcl-2 were up-regulated, and Bax was down-regulated compared with parental cells. MiR-21 was significantly down-regulated after miR-21 inhibitor was transfected; and the levels of MDR1, BCRP, MRP1 and Bcl-2/Bax (P <0.05) were also down-regulated. MiR-21 inhibitors significantly suppressed G0/G1 transition of the cell cycle, and induced cell apoptosis in MCF-7/PR and SKBR-3/PR cells. MTT results showed that miR-21 inhibitors induced sensitivity of MCF-7/PR and SKBR-3/PR cells to paclitaxel. And miR-21 mimic can increase the expression of MDR1, Bcl-2/Bax and change cell morphology from parental cells to resistant cells. RESULTS: The established MCF-7/PR and SKBR-3/PR breast cancer cells show typical multidrug resistance characteristics, which can be used as the model for drug resistance study. Down-regulated miR-21 expression in MCF-7/PR and SKBR-3/PR breast cancer cells can enhance cell sensitivity to paclitaxel.

Relationship between Variation of Pre-ablation Stimulated Thyroglobulin and Distant Metastasis in Patients with Differentiated Thyroid Cancer.

OBJECTIVE: To investigate the relationship between the dynamic variation of pre-ablation stimulated thyroglobulin(sTg)and distant metastasis in patietns with differentiated thyroid cancer(DTC). METHODS: DTC patients after total or near total thyroidectomy were divided into two groups as M1 group(n=38)and M0 group(n=130)according to the presence of distant metastases or not. Clinical data including pre-ablation sTg and the corresponding thyrotropin(TSH)values were dynamically measured. The pre-ablation sTg and corresponding TSH collected at the first time were defined as Tg1 and TSH1,while as Tg2 and TSH2 at the last time. χ(2) test was used to compare the variation tendency of sTg between these two groups. Tg1,Tg2,pre-ablation sTg variation(∆Tg),and ∆Tg/∆TSH ratio between M0 and M1 were compared by Mann-Whitney rank-sum test. The receiver operating characteristic(ROC)curves and diagnostic critical point(DCP)were employed to evaluate the predictive values of the above indicators. RESULTS: Both Tg1 and Tg2 of M1 were significantly higher than those of M0(the Mann-Whitney rank-sum test:Tg1 P<0.001,Tg2 P<0.001). The corresponding areas under the ROC curve(AUC)to differentiate the two groups were 0.921 and 0.942,respectively. The cut-off value of Tg2,which was more accurate in predicting distant metastasis,was 24.3 ng/ml with a sensitivity of 92.11% and a specificity of 83.85%. Both ∆Tg and ∆Tg/∆TSH between these two groups were significantly different(the Mann-Whitney rank-sum test:∆Tg P=0.002,∆Tg/∆TSH P<0.001). ∆Tg/∆TSH worked better than Tg2 in predicting distant metastasis with both higher accuracy(87.50%)and higher specificity(86.92%). CONCLUSIONS: Dynamically tracing pre-ablation sTg may improve the accuracy and specificity of distant metastases prediction in DTC patients. ∆Tg/∆TSH,which means the ratio of sTg variation to TSH variation,may be a useful diagnostic marker for predicting distant metastases in DTC.

Gene delivery of PEI incorporating with functional block copolymer via non-covalent assembly strategy.

A novel functional diblock polymer P(PEGMA-b-MAH) is prepared and incorporated to improve the gene delivery efficiency of poly(ethyleneimine) PEI via non-covalent assembly strategy. First, P(PEGMA-b-MAH) is prepared from l-methacrylamidohistidine methyl ester (MAH) by reversible addition fragmentation chain transfer polymerization, with poly[poly(ethylene glycol) methyl ether methacrylate] (P(PEGMA)) as the macroinitiator. Then P(PEGMA-b-MAH) is assembled with plasmid DNA (pDNA) and PEI (M(w)=10kDa) to form PEI/P(PEGMA-b-MAH)/pDNA ternary complexes. The agarose gel retardation assay shows that the presence of P(PEGMA-b-MAH) does not interfere with DNA condensation by the PEI. Dynamic light scattering tests show that PEI/P(PEGMA-b-MAH)/pDNA ternary complexes have excellent serum stability. In vitro transfection indicates that, compared to the P(PEGMA-b-MAH) free PEI-25k/pDNA binary complexes, PEI-10k/P(PEGMA-b-MAH)/pDNA ternary complexes have lower cytotoxicity and higher gene transfection efficiency, especially under serum conditions. The ternary complexes proposed here can inspire a new strategy for the development of gene and drug delivery vectors.

Glycopolymer modification on physicochemical and biological properties of poly(L-lysine) for gene delivery.

Poly(L-lysine) (PLL) has excellent plasmid DNA (pDNA) condensation capacity. However, the relatively high cytotoxicity and low transfection efficiency limit its application as gene delivery vectors. Here, well-defined glycopolymers are synthesized by reversible addition fragmentation transfer polymerization and grafted onto PLL to improve the gene delivery performance. After glycopolymer modification, PLL shows reduced cytotoxicity. By regulating the glycopolymer length and amino group substitution degree, the glycopolymer modified PLL can condense pDNA with proper strength, protect the condensed pDNA from degradation and release them in time. Transfection with NIH3T3 and HepG2 cells shows that the glycopolymer modified PLL has improved transfection efficiencies. The low cytotoxicity, effective pDNA protection and enhanced transfection efficiencies indicate that glycopolymer modification would be an effective strategy to improve the polycation properties for gene delivery.

The target gene carrying validity to HePG2 cells with the brush-like glutathione modified chitosan compound.

The grafting modified chitosan with L-glutathione (GSH) end capped PEG brush-like poly [poly(ethylene glycol) methacrylate] (PMPEG), CS-PMPEG-GSH, as the pDNA condensed vector material could result in a much higher transfection efficiency and lower cytotoxity for NIH3T3 cells. In this work, we have further examined the morphology stabilities of CS-PMPEG-GSH/pDNA vectors at different medium pH values and in the presence of serum protein in detail. And then the targeted characters for HepG2 cells have been probed by tracing the cell uptake behavior and transfection efficiency.

A novel glutathione modified chitosan conjugate for efficient gene delivery.

A novel non-viral gene vector based on poly[poly(ethylene glycol) methacrylate] (PMPEG) and l-glutathione (GSH) grafted chitosan (CS) has been fabricated. First, well-defined brush-like PMPEG living polymers with dithioester residues were prepared by the reversible addition-fragmentation chain transfer (RAFT) polymerization and grafted onto the allylchitosan via radical coupling method. Then, the tripeptide GSH was introduced onto the end of PMPEG chain to give a CS-PMPEG-GSH conjugate. In comparison with pristine chitosan, CS-PMPEG-GSH conjugate could not only condense plasmid DNA (pDNA) and prevent the condensed CS-PMPEG-GSH/pDNA nanoparticle self-aggregation, but also increase the binding ability to cell membrane efficiently and improve decondensed ability of pDNA from the nanoparticles in cytoplasm which thus has resulted in the higher transfection efficiency in mouse embryonic fibroblast cells (NIH3T3). In addition, cytotoxicity assays showed that the conjugate is less cytotoxic than CS, and still retain the cationic polyelectrolyte characteristic as chitosan. These results indicate that the non-viral vector is a promising candidate for gene therapy in clinical application.

Circadian KaiC phosphorylation: a multi-layer network.

Circadian KaiC phosphorylation in cyanobacteria reconstituted in vitro recently initiates a series of studies experimentally and theoretically to explore its mechanism. In this paper, we report a dynamic diversity in hexameric KaiC phosphoforms using a multi-layer reaction network based on the nonequivalence of the dual phosphorylation sites (S431 and T432) in each KaiC subunit. These diverse oscillatory profiles can generate a kaleidoscopic phase modulation pattern probably responsible for the genome-wide transcription rhythms directly and/or indirectly in cyanobacteria. Particularly, our model reveals that a single KaiC hexamer is an energy-based, phosphorylation-dependent and self-regulated circadian oscillator modulated by KaiA and KaiB. We suggest that T432 is the main regulator for the oscillation amplitude, while S431 is the major phase regulator. S431 and T432 coordinately control the phosphorylation period. Robustness of the Kai network was examined by mixing samples in different phases, and varying protein concentrations and temperature. Similar results were obtained regardless of the deterministic or stochastic method employed. Therefore, the dynamic diversities and robustness of Kai oscillator make it a qualified core pacemaker that controls the cellular processes in cyanobacteria pervasively and accurately.

Dynamic simulation of the effect of calcium-release activated calcium channel on cytoplasmic Ca2+ oscillation.

A mathematical model is proposed to illustrate the activation of STIM1 (stromal interaction molecule 1) protein, the assembly and activation of calcium-release activated calcium (CRAC) channels in T cells. In combination with De Young-Keizer-Li-Rinzel model, we successfully reproduce a sustained Ca(2+) oscillation in cytoplasm. Our results reveal that Ca(2+) oscillation dynamics in cytoplasm can be significantly affected by the way how the Orai1 CRAC channel are assembled and activated. A low sustained Ca(2+) influx is observed through the CRAC channels across the plasma membrane. In particular, our model shows that a tetrameric channel complex can effectively regulate the total quantity of the channels and the ratio of the active channels to the total channels, and a period of Ca(2+) oscillation about 29 s is in agreement with published experimental data. The bifurcation analyses illustrate the different dynamic properties between our mixed Ca(2+) feedback model and the single positive or negative feedback models.