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1.  Validation of power Doppler Versus Contrast Enhanced Magnetic Resonance Imaging Quantification of Joint Inflammation in Murine Inflammatory Arthritis 
Contrast enhancement magnetic resonance imaging (CE-MRI) of synovial volume is the radiographic gold standard to quantify joint inflammation but cost limits use. Therefore, we examined if power Doppler-ultrasound (PD-US) outcomes of synovitis in tumor necrosis factor transgenic (TNF-Tg) mice correlate with CE-MRI. TNF-Tg mice underwent PD-US of their knees to measure the joint space volume (JSV) and PD volume (PDV), and the results were correlated with synovial volume determined by CE-MRI. Immunohistochemistry for CD31 was performed to corroborate the PD signal. Synovial volume strongly correlated with both JSV and PDV (p<0.01). CD31+ blood vessels were observed in inflamed synovium proximal to the joint surface, which corresponded to areas of intense PD signals. JSV and PDV are valid measures of joint inflammation that correlate with synovial volume determined by CE-MRI and are associated with vascularity. Given the emergence of PD-US as a non-quantitative outcome of joint inflammation, we find JSV and PDV to be feasible and highly cost-effective for longitudinal studies in animal models. Furthermore, given the increasing utilization of PD-US in standard clinical practice, JSV and PDV could be translated to better quantify joint flare and response to therapy in RA patients.
PMCID: PMC4376603  PMID: 25359523
Bone ultrasound; Rheumatoid Arthritis (RA); Magnetic Resonance Imaging (MRI)
2.  Estrogen receptor-alpha is a key mediator and therapeutic target for bladder complications of benign prostatic hyperplasia 
The Journal of urology  2014;193(2):722-729.
While estrogens are important in prostate growth and play a role in benign prostatic hyperplasia (BPH), no current therapies directly target estrogen action. Estrogens act primarily via estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ). Using a mouse model, we evaluated the relative contribution of these receptors to bladder complications of BPH. We also evaluated prevention of these bladder complications by selective estrogen receptor modulators (SERMs), raloxifene and tamoxifen (ERα selective antagonists) and (R,R)-5,11-Diethyl-5,6,11,12-tetrahydro-2,8-chrysenediol (R,R-THC, ERβ selective antagonist).
Materials and Methods
Adult male C57bl/6 mice received implants of 25 mg testosterone (T) and 2.5 mg 17β-estradiol (E2) slow release pellets and untreated controls underwent sham surgery. We used ERα and ERβ knockout (KO) mice compared to their respective wild type (WT) littermates to probe contributions of ER subtypes. WT mice treated with T+E2 were compared to mice treated with T+E2 and 25 mg SERM to evaluate prevention of BPH complications with SERMs.
While ERαWT and ERβWT littermates treated with T+E2 developed large bladders with urinary retention, ERαKO mice treated with T+E2 did not. ERβKO mice treated with T+E2 developed large bladders with urinary retention and increased bladder mass. Co-treatment with the ERα antagonist raloxifene resulted in decreased bladder mass compared to WT mice treated with T+E2, while bladders from mice treated with the ERβ antagonist R,R-THC were similar to T+E2-treated mice.
ERα, but not ERβ, is a key mediator of bladder complications of BPH, and is a potential target for future therapies.
PMCID: PMC4305478  PMID: 25167991
mice; testosterone; 17β-estradiol; BPH; LUTS
3.  Distribution and Alteration of Lymphatic Vessels in Knee Joints of Normal and Osteoarthritic Mice 
To investigate the distribution and alteration of lymphatic vessels and draining function in knee joints of normal and osteoarthritic mice.
For the mouse models of osteoarthritis (OA), we used mice with meniscal-ligamentous injury or mice with conditional knockout of the gene for cartilage transforming growth factor β (TGF β) type II receptor. The severity of cartilage loss and joint destruction was assessed histologically. Capillary and mature lymphatic vessels were identified and analyzed using double immunofluorescence staining and a whole-slide digital imaging system. Lymphatic drainage of knee joints was examined using near-infrared lymphatic imaging. Patient joint specimens obtained during total knee or hip arthroplasty were evaluated to verify the content validity of the mouse findings.
Lymphatic vessels were distributed in soft tissues (mainly around the joint capsule, ligaments, fat pads, and muscles of normal knees). The number of lymphatic vessels, particularly the number of capillaries, was significantly increased in joints of mice with mild OA, while the number of mature lymphatic vessels was markedly decreased in joints of mice with severe OA. OA knees exhibited significantly decreased lymph clearance. The number of both capillary and mature lymphatic vessels was significantly decreased in the joints of patients with OA.
The whole-slide digital imaging system is a powerful tool, enabling the identification and assessment of lymphatic microvasculature in the entire mouse knee. Lymphatic capillaries and mature vessels are present in various soft tissues around articular spaces. Abnormalities of lymphatic vessels and draining function, including significantly reduced numbers of mature vessels and impaired clearance, are present in OA joints.
PMCID: PMC4074307  PMID: 24574226
4.  A pole and leash handling system for primates1 
PMCID: PMC1338677  PMID: 16811398
5.  Efficacy of B cell Depletion Therapy on Joint Flare is Associated with Increased Lymphatic Flow 
Arthritis and rheumatism  2013;65(1):130-138.
B cell depletion therapy (BCDT) ameliorates rheumatoid arthritis by mechanisms that are incompletely understood. Arthritic flare in tumor necrosis factor transgenic (TNF-Tg) mice is associated with efferent lymph node (LN) “collapse,” triggered by B cell translocation into lymphatic spaces and decreased lymphatic drainage. We examined whether BCDT efficacy is associated with restoration of lymphatic drainage due to removal of obstructing nodal B cells.
We developed contrast-enhancement (CE) MRI imaging, near-infrared indocyanine green (NIR-ICG) imaging, and intravital immunofluorescent imaging to longitudinally assess synovitis, lymphatic flow, and cell migration in lymphatic vessels in TNF-Tg mice. We tested to see if BCDT efficacy is associated with restoration of lymphatic draining and cell egress from arthritic joints.
Unlike active lymphatics to normal and pre-arthritic knees, afferent lymphatic vessels to collapsed LNs in inflamed knees do not pulse. Intravital immunofluorescent imaging demonstrated that CD11b+ monocytes/macrophages in lymphatic vessels afferent to expanding LN travel at high velocity (186 ± 37 micrometer/sec), while these cells are stationary in lymphatic vessels afferent to collapsed PLN. BCDT of flaring TNF-Tg mice significantly decreased knee synovial volume by 50% from the baseline level, and significantly increased lymphatic clearance versus placebo (p<0.05). This increased lymphatic drainage restored macrophages egress from inflamed joints without recovery of the lymphatic pulse.
These results support a novel mechanism in which BCDT of flaring joints lessens inflammation by increasing lymphatic drainage and subsequent migration of cells and cytokines from the synovial space.
PMCID: PMC3535508  PMID: 23002006
Rheumatoid Arthritis (RA); Flare; Tumor Necrosis Factor (TNF); B cells in Inflamed Lymph Nodes (B-in); Lymphatic Pulse
6.  Inherited pelvic organ prolapse in the mouse: preliminary evaluation of a new murine model 
To report the initial anatomic, radiographic, and genetic evaluations of a novel form of spontaneous pelvic organ prolapse (S-POP) in mice.
We observed S-POP in a colony of UPII-SV40T transgenic mice developed for studies on bladder cancer. We utilized magnetic resonance imaging and necropsy to characterize this finding. We have established a breeding colony to identify inheritance patterns and for future studies.
Selective breeding isolated the S-POP phenotype from the transgene. In contrast to other animal models, the S-POP mouse does not require an obligatory antecedent event to manifest pelvic organ prolapse. Necropsy and imaging demonstrate significant displacement of the pelvic organs distal to the pelvic floor in both sexes. The appearance of the POP is similar to that seen in the human female phenotype. Preliminary breeding studies indicate an autosomal dominant inheritance pattern.
This mouse may be an effective animal model for the study of POP in humans.
PMCID: PMC3796144  PMID: 18802654
genetic; magnetic resonance imaging; mouse; pelvic organ prolapse
7.  Power Doppler Ultrasound Phenotyping of Expanding versus Collapsed Popliteal Lymph Nodes in Murine Inflammatory Arthritis 
PLoS ONE  2013;8(9):e73766.
Rheumatoid arthritis is a chronic inflammatory disease manifested by episodic flares in affected joints that are challenging to predict and treat. Longitudinal contrast enhanced-MRI (CE-MRI) of inflammatory arthritis in tumor necrosis factor-transgenic (TNF-Tg) mice has demonstrated that popliteal lymph nodes (PLN) increase in volume and contrast enhancement during the pre-arthritic “expanding” phase of the disease, and then suddenly “collapse” during knee flare. Given the potential of this biomarker of arthritic flare, we aimed to develop a more cost-effective means of phenotyping PLN using ultrasound (US) imaging. Initially we attempted to recapitulate CE-MRI of PLN with subcutaneous footpad injection of US microbubbles (DEFINITY®). While this approach allowed for phenotyping via quantification of lymphatic sinuses in PLN, which showed a dramatic decrease in collapsed PLN versus expanding or wild-type (WT) PLN, electron microscopy demonstrated that DEFINITY® injection also resulted in destruction of the lymphatic vessels afferent to the PLN. In contrast, Power Doppler (PD) US is innocuous to and efficiently quantifies blood flow within PLN of WT and TNF-Tg mice. PD-US demonstrated that expanding PLN have a significantly higher normalized PD volume (NPDV) versus collapsed PLN (0.553±0.007 vs. 0.008±0.003; p<0.05). Moreover, we define the upper (>0.030) and lower (<0.016) quartile NPDVs in this cohort of mice, which serve as conservative thresholds to phenotype PLN as expanding and collapsed, respectively. Interestingly, of the 12 PLN phenotyped by the two methods, there was disagreement in 4 cases in which they were determined to be expanding by CE-MRI and collapsed by PD-US. Since the adjacent knee had evidence of synovitis in all 4 cases, we concluded that the PD-US phenotyping was correct, and that this approach is currently the safest and most cost-effective in vivo approach to phenotype murine PLN as a biomarker of arthritic flare.
PMCID: PMC3767819  PMID: 24040061
9.  Measuring intranodal pressure and lymph viscosity to elucidate mechanisms of arthritic flare and therapeutic outcomes 
Rheumatoid arthritis (RA) is a chronic autoimmune disease with episodic flares in affected joints, whose etiology is largely unknown. Recent studies in mice demonstrated alterations in lymphatics from affected joints precede flares. Thus, we aimed to develop novel methods for measuring lymph node pressure and lymph viscosity in limbs of mice. Pressure measurements were performed by inserting a glass micropipette connected to a pressure transducer into popliteal lymph nodes (PLN) or axillary lymph nodes (ALN) of mice and determined that the lymphatic pressures were 9 and 12 cm of water, respectively. We are also developing methods for measuring lymph viscosity in lymphatic vessels afferent to PLN, which can be measured by multi-photon fluorescence recovery after photobleaching (MP-FRAP) of FITC-BSA injected into the hind footpad. These results demonstrate the potential of lymph node pressure and lymph viscosity measurements, and warrant future studies to test these outcomes as biomarkers of arthritic flare.
PMCID: PMC3334848  PMID: 22172039
Rheumatoid Arthritis; Lymph Node; Flare; Lymphatic Pressure; Lymph Viscosity
10.  Valproic acid decreases urothelial cancer cell proliferation and induces thrombospondin-1 expression 
BMC Urology  2012;12:21.
Prevention of bladder cancer recurrence is a central challenge in the management of this highly prevalent disease. The histone deacetylase inhibitor valproic acid (sodium valproate) has anti-angiogenic properties and has been shown to decrease bladder cancer growth in model systems. We have previously shown reduced expression of thrombospondin-1 in a mouse model and in human bladder cancer relative to normal urothelium. We speculated that inhibition of angiogenesis by valproate might be mediated by this anti-angiogenic protein.
Bladder cancer cell lines UMUC3 and T24 were treated with valproate or another histone deacetylase inhibitor, vorinostat, in culture for a period of three days. Proliferation was assessed by alamar blue reduction. Gene expression was evaluated by reverse transcription of RNA and quantitative PCR.
Proliferation assays showed treatment with valproate or vorinostat decreased proliferation in both cell lines. Histone deacetylase inhibition also increased relative expression of thrombospondin-1 up to 8 fold at 5 mM valproate.
Histone deacetylase inhibitors warrant further study for the prevention or treatment of bladder cancer.
PMCID: PMC3487994  PMID: 22898175
Bladder cancer; Valproic acid; Thrombospondin-1, Urothelial carcinoma; Gene expression
11.  CD23+/CD21hi B-cell translocation and ipsilateral lymph node collapse is associated with asymmetric arthritic flare in TNF-Tg mice 
Arthritis Research & Therapy  2011;13(4):R138.
Rheumatoid arthritis (RA) is a chronic autoimmune disease with episodic flares in affected joints. However, how arthritic flare occurs only in select joints during a systemic autoimmune disease remains an enigma. To better understand these observations, we developed longitudinal imaging outcomes of synovitis and lymphatic flow in mouse models of RA, and identified that asymmetric knee flare is associated with ipsilateral popliteal lymph node (PLN) collapse and the translocation of CD23+/CD21hi B-cells (B-in) into the paracortical sinus space of the node. In order to understand the relationship between this B-in translocation and lymph drainage from flaring joints, we tested the hypothesis that asymmetric tumor necrosis factor (TNF)-induced knee arthritis is associated with ipsilateral PLN and iliac lymph node (ILN) collapse, B-in translocation, and decreased afferent lymphatic flow.
TNF transgenic (Tg) mice with asymmetric knee arthritis were identified by contrast-enhanced (CE) magnetic resonance imaging (MRI), and PLN were phenotyped as "expanding" or "collapsed" using LNcap threshold = 30 (Arbitrary Unit (AU)). Inflammatory-erosive arthritis was confirmed by histology. Afferent lymphatic flow to PLN and ILN was quantified by near infrared imaging of injected indocyanine green (NIR-ICG). The B-in population in PLN and ILN was assessed by immunohistochemistry (IHC) and flow cytometry. Linear regression analyses of ipsilateral knee synovial volume and afferent lymphatic flow to PLN and ILN were performed.
Afferent lymph flow to collapsed nodes was significantly lower (P < 0.05) than flow to expanding nodes by NIR-ICG imaging, and this occurred ipsilaterally. While both collapsed and expanding PLN and ILN had a significant increase (P < 0.05) of B-in compared to wild type (WT) and pre-arthritic TNF-Tg nodes, B-in of expanding lymph nodes (LN) resided in follicular areas while B-in of collapsed LN were present within LYVE-1+ lymphatic vessels. A significant correlation (P < 0.002) was noted in afferent lymphatic flow between ipsilateral PLN and ILN during knee synovitis.
Asymmetric knee arthritis in TNF-Tg mice occurs simultaneously with ipsilateral PLN and ILN collapse. This is likely due to translocation of the expanded B-in population to the lumen of the lymphatic vessels, resulting in a dramatic decrease in afferent lymphatic flow. PLN collapse phenotype can serve as a new biomarker of knee flare.
PMCID: PMC3239381  PMID: 21884592

Results 1-11 (11)