In vivo UTE-MRI reveals positive effects of raloxifene on skeletal bound water in skeletally mature beagle dogs

Raloxifene positively affects mechanical properties of the bone matrix in part through modification of skeletal bound water. The goal of this study was to determine if raloxifene induced alterations in skeletal hydration could be measured in vivo using ultra-short echotime magnetic resonance imaging (UTE-MRI). Twelve skeletally mature female beagle dogs (n=6/group) were treated for 6 months with oral doses of saline vehicle (VEH, 1 ml/kg/day) or raloxifene (RAL, 0.5 mg/kg/day). Following six months of treatment, all animals underwent in vivo UTE-MRI of the proximal tibial cortical bone. UTE-MRI signal intensity versus echotime curves were analyzed by fitting a double exponential to determine the short and long relaxation times of water with the bone (dependent estimations of bound and free water, respectively). Raloxifene-treated animals had significantly higher bound water (+14%; p = 0.05) and lower free water (-20%) compared to vehicle-treated animals. These data provide the first evidence that drug-induced changes in skeletal hydration can be non-invasively assessed using UTE-MRI.Funding for this study was provided by NIH (AR 62002 and a BIRT supplement). Raloxifene was provided by through an MTA with Eli Lilly

Longitudinal Bioluminescence Imaging of Primary Versus Abdominal Metastatic Tumor Growth in Orthotopic Pancreatic Tumor Models in NSG Mice

Objectives: The purpose of the present study was to develop and validate noninvasive bioluminescence imaging methods for differentially monitoring primary and abdominal metastatic tumor growth in mouse orthotopic models of pancreatic cancer. Methods: A semiautomated maximum entropy segmentation method was implemented for the primary tumor region of interest, and a rule-based method for manually drawing a region of interest for the abdominal metastatic region was developed for monitoring tumor growth in orthotopic models of pancreatic cancer. The 2 region-of-interest methods were validated by having 2 observers independently segment Panc-1 tumors, and the results were compared with the number of mesenteric lymph node nodules and histopathologic assessment of liver metastases. The findings were extended to orthotopic tumors of the more metastatic MIA PaCa-2 and AsPC-1 cells where separate groups of animals were implanted with different numbers of cells. Results: The results demonstrated that the segmentation methods were highly reliable, reproducible, and robust and allowed statistically significant discrimination in the growth rates of primary and abdominal metastatic tumors of different cell lines implanted with different numbers of cells. Conclusions: The present results demonstrate that primary tumors and abdominal metastatic foci in orthotopic pancreatic cancer models can be reliably quantified separately and noninvasively over time with bioluminescence imaging

Human adipose derived stromal/stem cells (hASCs) protect against STZ-induced hyperglycemia; analysis of hASC-derived paracrine effectors

Adipose-derived stromal/stem cells (ASCs) ameliorate hyperglycemia in rodent models of islet transplantation and autoimmune diabetes, yet the precise human ASC (hASC)-derived factors responsible for these effects remain largely unexplored. Here, we show that systemic administration of hASCs improved glucose tolerance, preserved β cell mass, and increased β cell proliferation in streptozotocin-treated nonobese diabetic/severe combined immunodeficient mice. Coculture experiments combining mouse or human islets with hASCs demonstrated that islet viability and function were improved by hASCs following prolonged culture or treatment with proinflammatory cytokines. Analysis of hASC-derived factors revealed vascular endothelial growth factor and tissue inhibitor of metalloproteinase 1 (TIMP-1) to be highly abundant factors secreted by hASCs. Notably, TIMP-1 secretion increased in the presence of islet stress from cytokine treatment, while TIMP-1 blockade was able to abrogate in vitro prosurvival effects of hASCs. Following systemic administration by tail vein injection, hASCs were detected in the pancreas and human TIMP-1 was increased in the serum of injected mice, while recombinant TIMP-1 increased viability in INS-1 cells treated with interleukin-1beta, interferon-gamma, and tumor necrosis factor alpha. In aggregate, our data support a model whereby factors secreted by hASCs, such as TIMP-1, are able to mitigate against β cell death in rodent and in vitro models of type 1 diabetes through a combination of local paracrine as well as systemic effects

Potentiation of Carboplatin-Mediated DNA Damage by the Mdm2 Modulator Nutlin-3a in a Humanized Orthotopic Breast-to-Lung Metastatic Model

Triple-negative breast cancers (TNBC) are typically resistant to treatment, and strategies that build upon frontline therapy are needed. Targeting the murine double minute 2 (Mdm2) protein is an attractive approach, as Mdm2 levels are elevated in many therapy-refractive breast cancers. The Mdm2 protein-protein interaction inhibitor Nutlin-3a blocks the binding of Mdm2 to key signaling molecules such as p53 and p73α and can result in activation of cell death signaling pathways. In the present study, the therapeutic potential of carboplatin and Nutlin-3a to treat TNBC was investigated, as carboplatin is under evaluation in clinical trials for TNBC. In mutant p53 TMD231 TNBC cells, carboplatin and Nutlin-3a led to increased Mdm2 and was strongly synergistic in promoting cell death in vitro. Furthermore, sensitivity of TNBC cells to combination treatment was dependent on p73α. Following combination treatment, γH2AX increased and Mdm2 localized to a larger degree to chromatin compared with single-agent treatment, consistent with previous observations that Mdm2 binds to the Mre11/Rad50/Nbs1 complex associated with DNA and inhibits the DNA damage response. In vivo efficacy studies were conducted in the TMD231 orthotopic mammary fat pad model in NOD.Cg-Prkdc(scid)Il2rg(tm1Wjl)/SzJ (NSG) mice. Using an intermittent dosing schedule of combined carboplatin and Nutlin-3a, there was a significant reduction in primary tumor growth and lung metastases compared with vehicle and single-agent treatments. In addition, there was minimal toxicity to the bone marrow and normal tissues. These studies demonstrate that Mdm2 holds promise as a therapeutic target in combination with conventional therapy and may lead to new clinical therapies for TNBC

Beta Cell Imaging—From Pre-Clinical Validation to First in Man Testing

There are presently no reliable ways to quantify human pancreatic beta cell mass (BCM) in vivo, which prevents an accurate understanding of the progressive beta cell loss in diabetes or following islet transplantation. Furthermore, the lack of beta cell imaging hampers the evaluation of the impact of new drugs aiming to prevent beta cell loss or to restore BCM in diabetes. We presently discuss the potential value of BCM determination as a cornerstone for individualized therapies in diabetes, describe the presently available probes for human BCM evaluation, and discuss our approach for the discovery of novel beta cell biomarkers, based on the determination of specific splice variants present in human beta cells. This has already led to the identification of DPP6 and FXYD2γa as two promising targets for human BCM imaging, and is followed by a discussion of potential safety issues, the role for radiochemistry in the improvement of BCM imaging, and concludes with an overview of the different steps from pre-clinical validation to a first-in-man trial for novel tracers

A Clinically Suitable Approach to Whole-Body Imaging for Quantification of Regional Perfusion: Validation of Positron Emission Tomography (PET) with 62Cu-ETS and Image-based Tracer Kinetic Modeling

Background & Hypothesis: We hypothesize that whole-body PET imaging with 62Cu-ETS and readily implemented tracer kinetic models, can enable absolute quantification of regional perfusion (mL•min-1•g-1) in a fashion that is reproducible; readily standardized across institutions; and logistically suitable for clinical implementation.  Experimental Design: Thirty-five paired 62Cu-ETS and H215O studies were performed in six Göttingen minipigs to validate the use of image-derived input functions. H215O estimates of tissue perfusion served as a reference standard for comparison with 62Cu-ETS. To demonstrate quantitative whole-body perfusion imaging in humans, paired 62Cu-ETS and H215O studies were performed in 14 renal cell carcinoma patients both prior to and following sunitinib therapy.  Results: The pig studies showed a strong correlation between regional blood flow estimates made with 62Cu-ETS and H215O, using image-derived input functions with tracer kinetic model-based corrections for 62Cu-ETS decomposition in blood (slope=0.932, R2=0.746). High quality voxel-wise 62Cu-ETS perfusion and blood volume parametric images demonstrated a strong correlation with H215O across all tissues within the imaging field-of-view. Using a same-day test-retest design, which was then repeated across two weeks, the animal study demonstrated good test-retest variability (TRV) for 62Cu-ETS and H215O with TRV of 6.3% ± 5.40% and 5.0% ± 4.77%, respectively. These findings strongly support application of the modeling methods to the human data, which is currently in progress.  Conclusion & Potential Impact: Whole-body imaging to non-invasively quantify regional perfusion holds promising potential for clinical implementation, using 62Cu-ETS PET coupled with tracer kinetic models that rely solely on the acquired imaging data

Bladder Pain Syndrome (BPS): A Comprehensive Review of Treatment Strategies and Management Approaches

Loris Cacciatore,1 Angelo Territo,2 Antonio Minore,1 Antonio Testa,1 Guglielmo Mantica,3 Francesco Esperto1 1Department of Urology, Fondazione Policlinico Universitario Campus Bio-Medico Di Roma, Rome, Italy; 2Department of Urology, Fundació Puigvert, Autonoma University of Barcelona, Barcelona, Spain; 3Department of Surgical and Diagnostic Integrated Sciences (DISC), University of Genova, Genoa, ItalyCorrespondence: Loris Cacciatore, Department of Urology, Fondazione Policlinico Universitario Campus Bio-Medico di Roma, Rome, Italy, Email [email protected]: Bladder pain Syndrome presents a multifaceted challenge in contemporary urological practice, marked by LUTS, negative behavioural, sexual, or emotional experiences, and the potential for sexual dysfunction. We meticulously explored the existing literature of conservative, non-invasive and invasive interventions, aiming to provide clinicians with a nuanced understanding of available options for comprehensive BPS management. We delve into the effectiveness and safety profiles from behavioural approaches through lifestyle changes and physical therapy, to oral or intravesical medications, until the definitive surgical treatment. The best option evaluated is the involvement of a multidisciplinary team, including urologists, urotherapists, gynaecologists, pain specialists, primary care physicians and psychologists, educating those patients regarding the condition and its chronic course and tailoring the perfect treatment for each person. Despite this, BPS remains a challenge for urologists. Indeed, our objective is to contribute to the evolving landscape of BPS management, fostering informed decision-making and personalized care for individuals grappling with this challenging condition.Keywords: bladder pain syndrome, interstitial cystitis, lower urinary tract symptoms, females, continence, therapy, conservative treatmen

Skeletal levels of bisphosphonate in the setting of chronic kidney disease are independent of remodeling rate and lower with fractionated dosing

Background Chronic kidney disease (CKD) results in a dramatic increase in skeletal fracture risk. Bisphosphates (BP) are an effective treatment for reducing fracture risk but they are not recommended in advanced CKD. We have recently shown higher acute skeletal accumulation of fluorescently-tagged zoledronate (ZOL) in the setting of CKD but how this accumulation is retained/lost over time is unclear. Furthermore, it is unknown if alternative dosing approaches can modulate accumulation in the setting of CKD. Methods To address these two questions normal (NL) and Cy/+ (CKD) rats were divided into control groups (no dosing), a single dose of a fluorescent-tagged ZOL (FAM-ZOL), a single dose of non-labelled zoledronate (ZOL) or ten weekly doses of FAM-ZOL each at 1/10th the dose of the single dose group. Half of the CKD animals in each group were provided water with 3% calcium in drinking water (CKD + Ca) to suppress PTH and remodeling. At 30 or 35 weeks of age, serum, tibia, ulna, radius, vertebra, femora, and mandible were collected and subjected to assessment methods including biochemistry, dynamic histomorphometry and multi-spectral fluorescence levels (using IVIS SpectrumCT). Results FAM-ZOL did not significantly reduce bone remodeling in either NL or CKD animals while Ca supplementation in CKD produced remodeling levels comparable to NL. At five- and ten-weeks post-dosing, both CKD and CKD + Ca groups had higher levels of FAM-ZOL in most, but not all, skeletal sites compared to NL with no difference between the two CKD groups suggesting that the rate of remodeling did not affect skeletal retention of FAM-ZOL. Fractionating the FAM-ZOL into ten weekly doses led to 20–32% less (p < 0.05) accumulation/retention of compound in the vertebra, radius, and ulna compared to administration as a single dose. Conclusions The rate of bone turnover does not have significant effects on levels of FAM-ZOL accumulation/retention in animals with CKD. A lower dose/more frequent administration paradigm results in lower levels of accumulation/retention over time. These data provide information that could better inform the use of bisphosphonates in the setting of CKD in order to combat the dramatic increase in fracture risk

Comprehensive Evaluation of the 5XFAD Mouse Model for Preclinical Testing Applications: A MODEL-AD Study.

The ability to investigate therapeutic interventions in animal models of neurodegenerative diseases depends on extensive characterization of the model(s) being used. There are numerous models that have been generated to study Alzheimer\u27s disease (AD) and the underlying pathogenesis of the disease. While transgenic models have been instrumental in understanding AD mechanisms and risk factors, they are limited in the degree of characteristics displayed in comparison with AD in humans, and the full spectrum of AD effects has yet to be recapitulated in a single mouse model. The Model Organism Development and Evaluation for Late-Onset Alzheimer\u27s Disease (MODEL-AD) consortium was assembled by the National Institute on Aging (NIA) to develop more robust animal models of AD with increased relevance to human disease, standardize the characterization of AD mouse models, improve preclinical testing in animals, and establish clinically relevant AD biomarkers, among other aims toward enhancing the translational value of AD models in clinical drug design and treatment development. Here we have conducted a detailed characterization of the 5XFAD mouse, including transcriptomics, electroencephalogram