| 1. |
- Niemi, MEK, et al.
(författare)
-
- 2021
-
swepub:Mat__t
|
|
| 2. |
- Rikard, S. Michaela, et al.
(författare)
-
Mathematical Model Predicts that Acceleration of Diabetic Wound Healing is Dependent on Spatial Distribution of VEGF-A mRNA (AZD8601)
- 2021
-
Ingår i: Cellular and Molecular Bioengineering. - : Springer. - 1865-5025 .- 1865-5033. ; 14:4, s. 321-338
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction Pharmacologic approaches for promoting angiogenesis have been utilized to accelerate healing of chronic wounds in diabetic patients with varying degrees of success. We hypothesize that the distribution of proangiogenic drugs in the wound area critically impacts the rate of closure of diabetic wounds. To evaluate this hypothesis, we developed a mathematical model that predicts how spatial distribution of VEGF-A produced by delivery of a modified mRNA (AZD8601) accelerates diabetic wound healing. Methods We modified a previously published model of cutaneous wound healing based on coupled partial differential equations that describe the density of sprouting capillary tips, chemoattractant concentration, and density of blood vessels in a circular wound. Key model parameters identified by a sensitivity analysis were fit to data obtained from an in vivo wound healing study performed in the dorsum of diabetic mice, and a pharmacokinetic model was used to simulate mRNA and VEGF-A distribution following injections with AZD8601. Due to the limited availability of data regarding the spatial distribution of AZD8601 in the wound bed, we performed simulations with perturbations to the location of injections and diffusion coefficient of mRNA to understand the impact of these spatial parameters on wound healing. Results When simulating injections delivered at the wound border, the model predicted that injections delivered on day 0 were more effective in accelerating wound healing than injections delivered at later time points. When the location of the injection was varied throughout the wound space, the model predicted that healing could be accelerated by delivering injections a distance of 1-2 mm inside the wound bed when compared to injections delivered on the same day at the wound border. Perturbations to the diffusivity of mRNA predicted that restricting diffusion of mRNA delayed wound healing by creating an accumulation of VEGF-A at the wound border. Alternatively, a high mRNA diffusivity had no effect on wound healing compared to a simulation with vehicle injection due to the rapid loss of mRNA at the wound border to surrounding tissue. Conclusions These findings highlight the critical need to consider the location of drug delivery and diffusivity of the drug, parameters not typically explored in pre-clinical experiments, when designing and testing drugs for treating diabetic wounds.
|
|
| 3. |
- Almquist, Joachim, et al.
(författare)
-
Model-Based Analysis Reveals a Sustained and Dose-Dependent Acceleration of Wound Healing by VEGF-A mRNA (AZD8601)
- 2020
-
Ingår i: CPT. - : WILEY. - 2163-8306. ; 9:7, s. 384-394
-
Tidskriftsartikel (refereegranskat)abstract
- Intradermal delivery of AZD8601, an mRNA designed to produce vascular endothelial growth factor A (VEGF-A), has previously been shown to accelerate cutaneous wound healing in a murine diabetic model. Here, we develop population pharmacokinetic and pharmacodynamic models aiming to quantify the effect of AZD8601 injections on the dynamics of wound healing. A dataset of 584 open wound area measurements from 131 mice was integrated from 3 independent studies encompassing different doses, dosing timepoints, and number of doses. Evaluation of several candidate models showed that wound healing acceleration is not likely driven directly by time-dependent VEGF-A concentration. Instead, we found that administration of AZD8601 induced a sustained acceleration of wound healing depending on the accumulated dose, with a dose producing 50% of the maximal effect of 92 mu g. Simulations with this model showed that a single dose of 200 mu g AZD8601 can reduce the time to reach 50% wound healing by up to 5 days.
|
|
| 4. |
- Beverborg, Niels Grote, et al.
(författare)
-
Phospholamban antisense oligonucleotides improve cardiac function in murine cardiomyopathy
- 2021
-
Ingår i: Nature Communications. - Stockholm : Karolinska Institutet, Dept of Cell and Molecular Biology. - 2041-1723.
-
Tidskriftsartikel (refereegranskat)abstract
- Heart failure (HF) is a major cause of morbidity and mortality worldwide, highlighting an urgent need for novel treatment options, despite recent improvements. Aberrant Ca2+ handling is a key feature of HF pathophysiology. Restoring the Ca2+ regulating machinery is an attractive therapeutic strategy supported by genetic and pharmacological proof of concept studies. Here, we study antisense oligonucleotides (ASOs) as a therapeutic modality, interfering with the PLN/SERCA2a interaction by targeting Pln mRNA for downregulation in the heart of murine HF models. Mice harboring the PLN R14del pathogenic variant recapitulate the human dilated cardiomyopathy (DCM) phenotype; subcutaneous administration of PLN-ASO prevents PLN protein aggregation, cardiac dysfunction, and leads to a 3-fold increase in survival rate. In another genetic DCM mouse model, unrelated to PLN (Cspr3/Mlp−/−), PLN-ASO also reverses the HF phenotype. Finally, in rats with myocardial infarction, PLN-ASO treatment prevents progression of left ventricular dilatation and improves left ventricular contractility. Thus, our data establish that antisense inhibition of PLN is an effective strategy in preclinical models of genetic cardiomyopathy as well as ischemia driven HF.
|
|
| 5. |
- De Genst, Erwin, et al.
(författare)
-
Blocking phospholamban with VHH intrabodies enhances contractility and relaxation in heart failure
- 2022
-
Ingår i: Nature Communications. - Stockholm : Karolinska Institutet, Dept of Cell and Molecular Biology. - 2041-1723.
-
Tidskriftsartikel (refereegranskat)abstract
- The dysregulated physical interaction between two intracellular membrane proteins, the sarco/endoplasmic reticulum Ca2+ ATPase and its reversible inhibitor phospholamban, induces heart failure by inhibiting calcium cycling. While phospholamban is a bona-fide therapeutic target, approaches to selectively inhibit this protein remain elusive. Here, we report the in vivo application of intracellular acting antibodies (intrabodies), derived from the variable domain of camelid heavy-chain antibodies, to modulate the function of phospholamban. Using a synthetic VHH phage-display library, we identify intrabodies with high affinity and specificity for different conformational states of phospholamban. Rapid phenotypic screening, via modified mRNA transfection of primary cells and tissue, efficiently identifies the intrabody with most desirable features. Adeno-associated virus mediated delivery of this intrabody results in improvement of cardiac performance in a murine heart failure model. Our strategy for generating intrabodies to investigate cardiac disease combined with modified mRNA and adeno-associated virus screening could reveal unique future therapeutic opportunities.
|
|
| 6. |
- Hansson, Kenny M., et al.
(författare)
-
Abnormalities in coagulum lysis and structure are associated with deep venous thrombosis
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The present study aimed to investigate the relationship between deep venous thrombosis (DVT) and fibrinolytic susceptibility of plasma coagulum, including the possible role of this property in laboratory diagnosis. From 276 patients consecutively admitted to hospital for suspected deep venous thrombosis (DVT), 75 patients and 47 controls were selected. With certainty, the patients and controls either had or did not have DVT. Fibrinolytic susceptibility was assayed by reacting plasma with thromboplastin and tissue plasminogen activator and recording a nephelometric signal. Coagulation time (CT), coagulum lysis time (CLT) and maximal increase in coagulum light scatter (CLS) were determined. Increase in D-dimer levels caused by coagulum lysis was also determined. This was viewed as a fibrinogen measure. CL T and CLS were interpreted as measures of fibrinolytic susceptibility and coagulum structure, respectively. CL T and CLS for patients and controls differed, p<0.025 and p<0.001, respectively. Compared to 5% for controls, 24% and 43% of the patients showed CL T and CLS outside the reference range. High fibrinogen levels could not explain the findings, since these were normal in most patients with abnormal CL T and CLS. Abnormal coagulum lysis and abnormal coagulum structure were thus found to be associated with DVT. Possible laboratory diagnostic role of CL T and CLS was investigated with bivariate reference ranges that excluded 5% and 0.3%. These ranges excluded significantly (p<0.0001) more patients, 47% and 27%, respectively. Tests for abnormal fibrinolytic susceptibility and coagulum structure may thus have a role in laboratory diagnosis of thrombotic disorders.
|
|
| 7. |
|
|
| 8. |
- Hansson, Kenny M., et al.
(författare)
-
Surface plasmon resonance and free oscillation rheometry in combination : A new approach forstudies on haemostasis and biomaterials
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In haemostasis and biomaterial research it is important to be able to study biological processes at surfaces and in the bulk. Surface plasmon resonance (SPR) is sensitive to changes at surface and free oscillation rheometry (FOR) probes the bulk. The present work demonstrates the usefulness of the combination of the techniques for simultaneous real-time measurements on coagulation and fibrinolysis of blood plasma, as well as coagulation of whole blood. SFLLRN stimulated coagulation of native whole blood presented a higher SPR signal with a different appearance than for plasma coagulation, while the FOR signals corresponding to plasma and whole blood coagulation were similar. This result indicated that the SPR technique was more sensitive to cell-surface interactions than to fibrin formation in whole blood, while the FOR technique were equally sensitive to coagulation in whole blood and plasma. Spontaneous coagulation of native whole blood in contact with methyland hydroxyl-terminated self-assembled monolayers on gold and gold surfaces regenerated after coagulation by degradation of adsorbed proteins with trypsin and SOS were also studied. The regenerated gold surfaces displayed the shortest coagulation times, although the contact-activation of blood coagulation was found to be low. The methylated and hydroxylated surfaces were comparable in terms of coagulation activation, while the hydroxylated surfaces presented FOR signals that indicated difficulties for the coagulum to attach to the surface. The combination of SPR and FOR may be suited for studies of cell-surface interactions, and may find applications in studies of blood cell defects in patients and testing of medical substances.
|
|
| 9. |
- Hansson, Kenny, 1972-, et al.
(författare)
-
Surface plasmon resonance (SPR) analysis of coagulation in whole blood with application in prothrombin time assay
- 1999
-
Ingår i: Biosensors & bioelectronics. - 0956-5663 .- 1873-4235. ; 14:8-9, s. 671-682
-
Tidskriftsartikel (refereegranskat)abstract
- It is previously shown that surface plasmon resonance (SPR) can be used to study blood plasma coagulation. This work explores the use of this technique for the analysis of tissue factor induced coagulation, i.e. prothrombin time (PT) analysis, of whole blood and plasma. The reference method was nephelometry. The prothrombin time analysis by SPR was performed by mixing two volumes of blood/plasma, one volume of thromboplastin, and one volume of CaCl2 solution directly on a sensor surface. The measurements show good agreement between nephelometry and SPR plasma analysis and also between SPR plasma and whole blood analysis. The effect of anticoagulant treatment on the clotting times was significant both quantitatively and qualitatively. The impact on the SPR signal of different physiological events in the coagulation process is discussed, and tentative interpretations of the sensorgram features are given. The major advantage of the SPR method compared to nephelometry is the possibility to perform analysis on whole blood instead of plasma. In conclusion, SPR is a promising method for whole blood coagulation analysis.
|
|
| 10. |
- Radulovic, Vladimir, 1969, et al.
(författare)
-
Sustained heparin effect contributes to reduced plasma thrombin generation capacity early after cardiac surgery.
- 2012
-
Ingår i: Thrombosis research. - : Elsevier BV. - 1879-2472 .- 0049-3848. ; 130:5, s. 769-774
-
Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Thrombin is a key component in the coagulation cascade, and impaired thrombin generation has been linked to increased bleeding after surgical procedures. The aim was to evaluate postoperative thrombin generation capacity in plasma after cardiac surgery, and its potential associations to activity of individual coagulation factors and heparin. MATERIAL AND METHODS: Forty-eight coronary artery bypass grafting patients were included in a prospective observational cohort study. Thrombin generation capacity was analysed in plasma with calibrated automated thrombogram with tissue factor as activator before (baseline), and 2h and 24h after surgery. In addition, plasma activity of coagulation factors II, V, VII, VIII, IX, X, XI, XIII, were determined. Heparin effect was assessed by anti-Xa activity, APTT and thrombin time. RESULTS: Thrombin generation was markedly reduced 2h after surgery compared to baseline. Peak levels decreased with median 74% (interquartile range 52-90), p<0.001, and endogenous thrombin generation potential decreased with 65% (43-86), p<0.001. Postoperative changes in endogenous thrombin generation potential correlated inversely to changes in anti-Xa activity (r=-0.51, p=0.010) and to changes in thrombin time (r=-0.51, p=0.009), but there were no correlations to changes in individual coagulation factor activity. CONCLUSIONS: A marked reduction in thrombin generation potential was observed in the early postoperative phase after cardiac surgery. The decrease was independent of reductions in individual coagulation factor activity but correlated to heparin effects. The results indicate that a sustained heparin effect contributes to the postoperative reduction in thrombin generation capacity.
|
|
