Phenyl-2-aminoethyl selenide ameliorates hippocampal long-term potentiation and cognitive deficits following doxorubicin treatment.

Chemotherapy-induced memory loss ("chemobrain") can occur following treatment with the widely used chemotherapeutic agent doxorubicin (DOX). However, the mechanisms through which DOX induces cognitive dysfunction are not clear, and there are no commercially available therapies for its treatment or prevention. Therefore, the aim of this study was to determine the therapeutic potential of phenyl-2-aminoethyl selenide (PAESe), an antioxidant drug previously demonstrated to reduce cardiotoxicity associated with DOX treatment, against DOX-induced chemobrain. Four groups of male athymic NCr nude (nu/nu) mice received five weekly tail-vein injections of saline (Control group), 5 mg/kg of DOX (DOX group), 10 mg/kg PAESe (PAESe group), or 5 mg/kg DOX and 10 mg/kg PAESe (DOX+PAESe group). Spatial memory was evaluated using Y-maze and novel object location tasks, while synaptic plasticity was assessed through the measurement of field excitatory postsynaptic potentials from the Schaffer collateral circuit. Western blot analyses were performed to assess hippocampal protein and phosphorylation levels. In this model, DOX impaired synaptic plasticity and memory, and increased phosphorylation of protein kinase B (Akt) and extracellular-regulated kinase (ERK). Co-administration of PAESe reduced Akt and ERK phosphorylation and ameliorated the synaptic and memory deficits associated with DOX treatment.

Intrafollicular injection of nanomolecules for advancing knowledge on folliculogenesis in livestock.

Despite the progress in assisted reproductive techniques, there is still a lack of rapid and minimally invasive in situ approaches for further enhancements of female fertility. Therefore, we synthesized clinically relevant liposome nanoparticles for ovarian intrafollicular injection to allow in vivo cellular imaging for future drug delivery, using the mare as an animal model. Ovarian follicles of living mares were injected in vivo with fluorescently labeled liposomes. Samples of the follicular wall (mural granulosa, theca interna, and theca externa), granulosa cells, and follicular fluid were harvested 24 h post-injection through the follicle wall biopsy (FWB), flushing, and aspiration techniques, respectively, using a transvaginal ultrasound-guided approach. In parallel, post-mortem dissected, and cultured porcine antral follicles were microinjected with doxorubicin-encapsulated liposomes to assess intracellular delivery potential. All injected mare and pig follicles were macroscopically healthy, and fluorescence imaging revealed successful intrafollicular binding to mural granulosa cells and progressive migration of liposomes to other follicle cell layers (theca interna, and theca externa), regardless of the follicle size. Intracellular delivery of doxorubicin was confirmed in all porcine follicle wall cell types. We conclude that the intrafollicular injection of nanomolecules is a promising approach for real-time monitoring of intrafollicular processes and potential utilization of in vivo cellular drug delivery to assist in follicle disease treatments and fertility improvement.

Tunable three-dimensional engineered prostate cancer tissues for in vitro recapitulation of heterogeneous in vivo prostate tumor stiffness.

In this manuscript we report the establishment and characterization of a three-dimensional in vitro, coculture engineered prostate cancer tissue (EPCaT) disease model based upon and informed by our characterization of in vivo prostate cancer (PCa) xenograft tumor stiffness. In prostate cancer, tissue stiffness is known to impact changes in gene and protein expression, alter therapeutic response, and be positively correlated with an aggressive clinical presentation. To inform an appropriate stiffness range for our in vitro model, PC-3 prostate tumor xenografts were established. Tissue stiffness ranged from 95 to 6,750 Pa. Notably, xenograft cell seeding density significantly impacted tumor stiffness; a two-fold increase in the number of seeded cells not only widened the tissue stiffness range throughout the tumor but also resulted in significant spatial heterogeneity. To fabricate our in vitro EPCaT model, PC-3 castration-resistant prostate cancer cells were co-encapsulated with BJ-5ta fibroblasts within a poly(ethylene glycol)-fibrinogen matrix augmented with excess poly(ethylene glycol)-diacrylate to modulate the matrix mechanical properties. Encapsulated cells temporally remodeled their in vitro microenvironment and enrichment of gene sets associated with tumorigenic progression was observed in response to increased matrix stiffness. Through variation of matrix composition and culture duration, EPCaTs were tuned to mimic the wide range of biomechanical cues provided to PCa cells in vivo; collectively, a range of 50 to 10,000 Pa was achievable. Markedly, this also encompasses published clinical PCa stiffness data. Overall, this study serves to introduce our bioinspired, tunable EPCaT model and provide the foundation for future PCa progression and drug development studies. STATEMENT OF SIGNIFICANCE: The development of cancer models that mimic the native tumor microenvironment (TME) complexities is critical to not only develop effective drugs but also enhance our understanding of disease progression. Here we establish and characterize our 3D in vitro engineered prostate cancer tissue model with tunable matrix stiffness, that is inspired by this study's spatial characterization of in vivo prostate tumor xenograft stiffness. Notably, our model's mimicry of the TME is further augmented by the inclusion of matrix remodeling fibroblasts to introduce cancer-stromal cell-cell interactions. This study addresses a critical unmet need in the field by elucidating the prostate tumor xenograft stiffness range and establishing a foundation for recapitulating the biomechanics of site-of-origin and soft tissue metastatic prostate tumors in vitro.

Doxorubicin induces dysregulation of AMPA receptor and impairs hippocampal synaptic plasticity leading to learning and memory deficits.

Doxorubicin (Dox) is a chemotherapeutic agent used widely to treat a variety of malignant cancers. However, Dox chemotherapy is associated with several adverse effects, including "chemobrain," the observation that cancer patients exhibit through learning and memory difficulties extending even beyond treatment. This study investigated the effect of Dox treatment on learning and memory as well as hippocampal synaptic plasticity. Dox-treated mice (5 mg/kg weekly x 5) demonstrated impaired performance in the Y-maze spatial memory task and a significant reduction in hippocampal long-term potentiation. The deficit in synaptic plasticity was mirrored by deficits in the functionality of synaptic `α-amino-3- hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) channels, including reduced probability of opening, decreased dwell open time, and increased closed times. Furthermore, a reduction in the AMPAR subunit GluA1 level, its downstream signaling molecule Ca2+/calmodulin-dependent protein kinase (CaMKII), and brain-derived neurotrophic factor (BDNF) were observed. This was also accompanied by an increase in extracellular signal regulated kinase (ERK) and protein kinase B (AKT) activation. Together these data suggest that Dox-induced cognitive impairments are at least partially due to alterations in the expression and functionality of the glutamatergic AMPAR system.

Paradoxical Role of Glypican-1 in Prostate Cancer Cell and Tumor Growth.

Recent studies suggest that glypican-1 (GPC-1) is a biomarker for prostate cancer, but there are few studies elucidating the role of GPC-1 in prostate cancer progression. We observed high expression of GPC-1 in more aggressive prostate cancer cell lines such as PC-3 and DU-145. While inhibition of GPC-1 expression in PC-3 cells decreased cell growth and migration in vitro, it surprisingly increased cell proliferation and migration in DU-145 cells, suggesting that the role of GPC-1 is cell type-dependent. Further, GPC-1 inhibition increased PC-3 tumor size in NCr nude mice xenografts. We hypothesized that the discrepancy between the in vitro and in vivo data is mediated by stromal cells in the tumor microenvironment. Thus, we tested the effect of tumor conditioned media (TCM) on gene expression in human mesenchymal stem cells and fibroblasts. Treatment of stromal cells with TCM from PC-3 cells transfected with GPC-1 shRNA increased the expression of migration markers, endocrine/paracrine biomolecules, and extracellular matrix components. Additionally, the decreased cell growth in GPC-1 knockdown PC-3 cells was rescued by coculturing with stromal cells. These data demonstrate the paradoxical role that GPC-1 plays in prostate cancer cell growth by interacting with stromal cells and through ECM remodeling and endocrine/paracrine signaling.

Doxorubicin-induced neurotoxicity is associated with acute alterations in synaptic plasticity, apoptosis, and lipid peroxidation.

Cognitive deficits are commonly reported by patients following treatment with chemotherapeutic agents. Anthracycline-containing chemotherapy regimens are associated with cognitive impairment and reductions in neuronal connectivity in cancer survivors, and doxorubicin (Dox) is a commonly used anthracycline. Although it has been reported that Dox distribution to the central nervous system (CNS) is limited, considerable Dox concentrations are observed in the brain with co-administration of certain medications. Additionally, pro-inflammatory cytokines, which are overproduced in cancer or in response to chemotherapy, can reduce the integrity of the blood-brain barrier (BBB). Therefore, the aim of this study was to evaluate the acute neurotoxic effects of Dox on hippocampal neurons. In this study, we utilized a hippocampal cell line (H19-7/IGF-IR) along with rodent hippocampal slices to evaluate the acute neurotoxic effects of Dox. Hippocampal slices were used to measure long-term potentiation (LTP), and expression of proteins was determined by immunoblotting. Cellular assays for mitochondrial complex activity and lipid peroxidation were also utilized. We observed reduction in LTP in hippocampal slices with Dox. In addition, lipid peroxidation was increased as measured by thiobarbituric acid reactive substances content indicating oxidative stress. Caspase-3 expression was increased indicating an increased propensity for cell death. Finally, the phosphorylation of signaling molecules which modulate LTP including extracellular signal-regulated kinase 1/2 (ERK1/2), p38 mitogen-activated protein kinase, and Akt were increased. This data indicates that acute Dox exposure dose-dependently impairs synaptic processes associated with hippocampal neurotransmission, induces apoptosis, and increases lipid peroxidation leading to neurotoxicity.

Correlation of 360-degree Surface Mapping In Vivo Bioluminescence with Multi-Spectral Optoacoustic Tomography in Human Xenograft Tumor Models.

Pre-clinical monitoring of tumor growth and identification of distal metastasis requires a balance between accuracy and expediency. Bioluminescence imaging (BLI) is often used to track tumor growth but is primarily limited to planar 2-dimensional (2D) imaging. Consistent subject placement within a standard top-mounted, single-detector small animal imager is vital to reducing variability in repeated same-animal measures over time. Here, we describe a method for tracking tumor development using a multi-angle BLI and photo-acoustic workflow. We correlate serial caliper measurements and 2D BLI to 360° BLI and photo-acoustic datasets for the same animals. Full 360° BLI showed improved correlations with both volumes obtained from caliper measurements and photo-acoustic segmentation, as compared to planar BLI. We also determined segmented tumor volumes from photo-acoustic datasets more accurately reflects true excised tumors' volumes compared to caliper measurements. Our results demonstrate the distinct advantages of both 360° surface mapping by BLI and photo-acoustic methodologies for non-invasive tracking of tumor growth in pre-clinical academic settings. Furthermore, our design is fully implementable in all top-mounted, single-detector imagers, thereby providing the opportunity to shift the paradigm away from planar BLI into rapid BLI tomography applications.

Kinetic involvement of acetaldehyde substrate inhibition on the rate equation of yeast aldehyde dehydrogenase.

In order to evaluate the effectiveness of aldehyde dehydrogenase (ALDH) from Saccharomyces cerevisiae as a catalyst for the conversion of acetaldehyde into its physiologically and biologically less toxic acetate, the kinetics over broad concentrations were studied to develop a suitable kinetic rate expression. Even with literature accounts of the binding complexations, the yeast ALDH currently lacks a quantitative kinetic rate expression accounting for simultaneous inhibition parameters under higher acetaldehyde concentrations. Both substrate acetaldehyde and product NADH were observed as individual sources of inhibition with the combined effect of a ternary complex of acetaldehyde and the coenzyme leading to experimental rates as little as an eighth of the expected activity. Furthermore, the onset and strength of inhibition from each component were directly affected by the concentration of the co-substrate NAD. While acetaldehyde inhibition of ALDH is initiated below concentrations of 0.05 mM in the presence of 0.5 mM NAD or less, the acetaldehyde inhibition onset shifts to 0.2 mM with as much as 1.6 mM NAD. The convenience of the statistical software package JMP allowed for effective determination of experimental kinetic constants and simplification to a suitable rate expression: v = Vmax(AB)/(K(ia)K(b) + K(b)A + K(a)B + AB + B(2)/K(I-Ald) + B(2)Q/K(I-Ald-NADH) + BQ/K(I-NADH)) where the last three terms represent the inhibition complex terms for acetaldehyde, acetaldehyde-NADH, and NADH, respectively. The corresponding values of K(I-Ald), K(I-Ald-NADH), and K(I-NADH) for yeast ALDH are 2.55, 0.0269, and 0.162 mM at 22 °C and pH 7.8.

Impact of high pyruvate concentration on kinetics of rabbit muscle lactate dehydrogenase.

In order to evaluate the effectiveness of L: -lactate dehydrogenase (LDH) from rabbit muscle as a regenerative catalyst of the biologically important cofactor nicotinamide adenine dinucleotide (NAD), the kinetics over broad concentrations were studied to develop a suitable kinetic rate expression. Despite robust literature describing the intricate complexations, the mammalian rabbit muscle LDH lacks a quantitative kinetic rate expression accounting for simultaneous inhibition parameters, specifically at high pyruvate concentrations. Product inhibition by L: -lactate was observed to reduce activity at concentrations greater than 25 mM, while expected substrate inhibition by pyruvate was significant above 4.3 mM concentration. The combined effect of ternary and binary complexes of pyruvate and the coenzymes led to experimental rates as little as a third of expected activity. The convenience of the statistical software package JMP allowed for effective determination of experimental kinetic constants and simplification to a suitable rate expression: [formula: see text] where the last three terms represent the inhibition complex terms for lactate, pyruvate, and pyruvate-NAD, respectively. The corresponding values of K (I-Lac), K (I-Pyr), and K (I-Pyr-NAD) for rabbit muscle LDH are 487.33 mM(-1) and 29.91 mM and 97.47 mM at 22 °C and pH 7.8.

Observations of instability, hysteresis, and oscillation in low-Reynolds-number flow past polymer gels.

We perform a set of experiments to study the nonlinear nature of an instability that arises in low-Reynolds-number flow past polymer gels. A layer of a viscous liquid is placed on a polydimethylsiloxane (PDMS) gel in a parallel-plate rheometer which is operated in stress-controlled mode. As the shear stress on the top plate increases, the apparent viscosity stays relatively constant until a transition stress where it sharply increases. If the stress is held at a level slightly above the transition stress, the apparent viscosity oscillates with time. If the stress is increased to a value above the transition stress and then decreased back to zero, the apparent viscosity shows hysteretic behavior. If the stress is instead decreased to a constant value and held there, the apparent viscosity is different from its pretransition value and exhibits sustained oscillations. This can happen even if the stress is held at values below the transition stress. Our observations suggest that the instability studied here is subcritical and leads to a flow that is oscillatory and far from viscometric. The phenomena reported here may be useful in applications such as microfluidics, membrane separations, and polymer processing. They may also provide insight into the rheological behavior of complex fluids that undergo flow-induced gelation.