Pharmacological profiles of animal- and nonanimal-derived sulfated polysaccharides – comparison of unfractionated heparin, the semisynthetic glucan sulfate PS3, and the sulfated polysaccharide fraction isolated from Delesseria sanguinea

Sulfated polysaccharides (SP) such as heparin are known to exhibit a wide range of biological activities, e.g., anticoagulant, anti-inflammatory, and antimetastastic effects. However, since the anticoagulant activity of heparin is dominating, its therapeutic use for other medical indications is limited due to an associated risk of bleeding. Further disadvantages of heparin are its animal origin, the shortage of resources, and its complex and variable composition. However, SP without these limitations may represent a substance class with good prospects for applications other than anticoagulation. In this study, the in vitro pharmacological profiles of two nonanimal-derived SP were investigated in comparison with unfractionated heparin. One is the natural SP fraction from the red algae Delesseria sanguinea (D.s.-SP). The other one is the chemically defined PS3, a semisynthetic β-1,3-glucan sulfate with proven in vivo anti-inflammatory and antimetastatic activities. All three polysaccharides were examined in vitro for their inhibitory effects on the coagulation and complement system, polymorphonuclear neutrophil elastase, hyaluronidase, matrix metalloproteinase-1, heparanase, and p-selectin-mediated cell adhesion. Compared with heparin, the nonanimal-derived polysaccharides have a four times weaker anticoagulant activity, but mostly exhibit stronger (1.4–224 times) effects on test systems investigating targets of inflammation or metastasis. According to their different structures, PS3 and D.s.-SP differ in their pharmacological profile with PS3 being the strongest inhibitor of heparanase and cell adhesion and D.s.-SP being the strongest inhibitor of hyaluronidase and complement activation. Considering both pharmacological profile and pharmaceutical quality parameters, PS3 represents a candidate for further development as an anti-inflammatory or antimetastatic drug whereas D.s.-SP might have perspectives for cosmetic applications

Delivery-corrected imaging of fluorescently-labeled glucose reveals distinct metabolic phenotypes in murine breast cancer.

When monitoring response to cancer therapy, it is important to differentiate changes in glucose tracer uptake caused by altered delivery versus a true metabolic shift. Here, we propose an optical imaging method to quantify glucose uptake and correct for in vivo delivery effects. Glucose uptake was measured using a fluorescent D-glucose derivative 2-(N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)Amino)-2-deoxy-D-glucose (2-NBDG) in mice implanted with dorsal skin flap window chambers. Additionally, vascular oxygenation (SO2) was calculated using only endogenous hemoglobin contrast. Results showed that the delivery factor proposed for correction, "RD", reported on red blood cell velocity and injected 2-NBDG dose. Delivery-corrected 2-NBDG uptake (2-NBDG60/RD) inversely correlated with blood glucose in normal tissue, indicating sensitivity to glucose demand. We further applied our method in metastatic 4T1 and nonmetastatic 4T07 murine mammary adenocarcinomas. The ratio 2-NBDG60/RD was increased in 4T1 tumors relative to 4T07 tumors yet average SO2 was comparable, suggesting a shift toward a "Warburgian" (aerobic glycolysis) metabolism in the metastatic 4T1 line. In heterogeneous regions of both 4T1 and 4T07, 2-NBDG60/RD increased slightly but significantly as vascular oxygenation decreased, indicative of the Pasteur effect in both tumors. These data demonstrate the utility of delivery-corrected 2-NBDG and vascular oxygenation imaging for differentiating metabolic phenotypes in vivo

Miniature spectral imaging device for wide-field quantitative functional imaging of the morphological landscape of breast tumor margins

general view, cana

The ratio 2-NBDG/R_D facilitates assessment of glucose demand in heterogeneous regions of metastatic mammary tumors.

<p>(A) Representative images of vascular oxygenation (SO₂) and delivery-corrected 2-NBDG (2-NBDG₆₀/R_D) for a 4T1 tumor with low mean SO₂, a 4T1 tumor with intermediate mean SO₂, and a 4T07 with high mean SO₂. Adapted from Rajaram, et al. 2013. (B) Survival curves (1-cumulative distributions) show 2-NBDG₆₀, R_D, and 2-NBDG₆₀/R_D for regions of distinct SO₂ (%) in 4T07 and 4T1 tumors. For 4T1, 2-NBDG₆₀ is lower for 02,4T1<10 regions than for any other SO_2,4T1 (p = N.S.). Significantly lower rates of R_D are seen for the 02,4T1<10 group than for well-oxygenated 4T1 regions (p<0.05 or p<0.01 for 02,4T1<10 vs. 202,4T1<40 or 402,4T1<60, respectively). After correction for low R_D, 2-NBDG₆₀/R_D increased slightly but significantly in hypoxic regions (p<0.01 for 02,4T1<10 vs. 402,4T1<60). For 4T07, 2-NBDG uptake for the highest SO_2,4T07 regions decreased compared to the lowest SO_2,4T07 (p<0.01 for all 202,4T07<40 vs. 602,4T1<80). R_D is indistinguishable between SO_2,4T07 levels. After correction by R_D, 2-NBDG₆₀/R_D is lowest for 602,4T07<80 (p<0.01). Comparison between 4T1 and 4T07 shows that 2-NBDG₆₀ is higher for all SO_2,4T1 than all SO_2,4T07 (p<0.01). On the other hand, R_D for the best oxygenated 4T07 groups (402,4T07<60 and 602,4T07<80) is greater than for all 4T1 groups (p<0.01 for all groups except 402,4T1<60 vs. 602,4T07<80 where p<0.06). After correction by R_D, 2-NBDG₆₀/R_D is higher for all SO_2,4T1 than all SO_2,4T07 (p<0.01 for all SO_2,4T1 compared to all SO_2,4T07). Number of mice per group indicated by group name in legend.</p

Delivery-corrected 2-NBDG uptake inversely correlates with blood glucose concentration.

<p>(A) Representative images show the kinetics of 2-NBDG uptake <i>in vivo</i> in non-tumor window chambers. The same mouse was given 6 mM or 10 mM 2-NBDG on subsequent days and imaged for 60 minutes following injection. (B) Averaged 2-NBDG kinetics for a cohort of mice injected with 0.1 mL of either 6 mM or 10 mM 2-NBDG. At 5 minutes post-injection (2-NBDG₀₅), the fluorescence ratio of the dose groups (2-NBDG_{05,10 mM}/2-NBDG_{05,6 mM}) was proportional to molarity (p<0.01). The table shows the expected ratio of 10 mM/6 mM fluorescence, if all differences in fluorescence were due to dose. 2-NBDG_{05,10 mM}/2-NBDG_{05,6 mM} corresponds to the ratio of 10 mM and 6 mM fluorescence intensities at t = 5 min. The ratio R_{D,10 mM}/R_{D,6 mM} corresponds to the rate of 2-NBDG delivery for 10 mM and 6 mM. Each group in panel B contains the same n = 7 subjects. p values are from a student's paired t-test. Error bars show standard error. Values in table are mean ± standard error. (C) R_D was strongly correlated with 2-NBDG fluorescence at 5 minutes (p<0.001). R_D did not correlate with 2-NBDG₆₀ (not shown). (D) 2-NBDG₆₀/R_D was inversely correlated with baseline blood glucose in normal mice (R = −0.61, p = 0.02). 2-NBDG₆₀ was also correlated with blood glucose (R = −0.52, p = 0.05, not shown). For animals that received both 6 mM and 10 mM doses, the average values of the endpoints (2-NBDG₀₅, 2-NBDG₆₀, and 2-NBDG₆₀/R_D) for both doses were used in calculating the correlations. These subjects are denoted by “mean” in the legend. n = 15 mice for (C) and (D).</p

Delivery-corrected glucose uptake reveals distinct glycolytic phenotypes in metastatic (4T1) and non-metastatic (4T07) mammary tumors.

<p>(A) Representative images of vascular oxygen saturation (SO₂) and delivery-corrected 2-NBDG (2-NBDG₆₀/R_D) for a 4T1 tumor and a 4T07 tumor, <i>in vivo</i>. (B) 2-NBDG₆₀/R_D showed contrast in glucose uptake between metastatic 4T1 and non-metastatic 4T07 tumors <i>in vivo</i> (p<0.01). A Seahorse Glycolysis Stress Test also revealed that the glycolytic capacity, defined as extracellular acidification rate (ECAR) after blockade of respiration by oligomycin, was significantly greater for 4T1 than for 4T07 (p<0.01). (C) Mean vascular oxygen saturation (SO₂) was comparable for 4T07 and 4T1 tumors in window chambers (p = N.S.). Vascular density was indistinguishable between tumor lines (p = N.S.). A Seahorse Glycolysis Stress Test showed that oxygen consumption rate (OCR) is comparable for 4T1 and 4T07 tumors (p = N.S.). Number of mice per group indicated by group name on axis. For Seahorse results, n = 12 cell samples from 3 distinct assays. Midline of box plots show median, box edges correspond to 25^th and 75^th percentiles, and scatter points show all data values.</p

Outline of methods.

<p>(A) Timeline of imaging events. Mice that were imaged under two imaging conditions were imaged on subsequent days. The order of imaging was scrambled to minimize order effects. (B) A 6 mM injection of 2-NBDG was given and imaged for at least 60 minutes, and the mean of the tumor region for each image was used to construct a kinetic curve. Images for the endpoints 2-NBDG₆₀ (2-NBDG intensity at 60 minutes) and the rate of delivery of 2-NBDG (R_D = 2-NBDG₆₀/T_max) are shown. (C) Trans-illumination images were collected in 10 nm increments from 500–600 nm and used to calculate hemoglobin saturation (SO2). (D) The table shows the number of mice used in each perturbation group. Each mouse was used for up to two imaging sessions, with 24 hours between sessions. The groups were randomized to minimize bias from imaging order, and an analysis of variance (ANOVA) was performed to test for order effects. No significant imaging order effect was observed for any experiment.</p

The rate of 2-NBDG delivery, R_D, is strongly correlated with blood velocity.

<p>(A) Representative images of blood velocity and the rate of 2-NBDG delivery (R_D) in a normal mouse at baseline and during reoxygenation after 1 hour of hypoxia. (B) Paired data for a set of mice at baseline and after 1 hour of hypoxia. After hypoxia, flow velocity and R_D increased significantly (p<0.02 for both). N = 6 mice. (C) The rate of 2-NBDG delivery (R_D) is highly correlated with blood velocity (R = 0.87, p<0.05). The trendline corresponds to the trend for post-hypoxia data only.</p