Sustained Response with Dose-reduced Selpercatinib in a Pediatric Patient with Metastatic NCOA4-RET Fusion Papillary Thyroid Carcinoma.

Understanding the molecular landscape of papillary thyroid carcinoma (PTC), the most common thyroid cancer in children, creates additional therapeutic approaches. RET gene rearrangements are observed in pediatric PTC, and selective inhibition of RET is now possible with specific tyrosine kinase inhibitors designed to target diverse RET -activating alterations. We present a 13-year-old female with metastatic PTC, clinically resistant to radioactive iodine, and found to harbor a NCOA4-RET fusion. She responded to selpercatinib treatment with the elimination of supplemental oxygen need, marked reduction in pulmonary nodules and mediastinal lymphadenopathy, and biomarker decline. The response was maintained despite 2 dose reductions for possibly related weight gain.

Impact of the peripartum period on the longitudinal course of obsessive-compulsive disorder.

Some women are vulnerable to developing new onset obsessive-compulsive disorder (OCD) or having an exacerbation of pre-existing OCD during reproductive cycle events. Reports on the impact of the peripartum period on pre-existing OCD are inconsistent, with both worsening and improving symptom severity described. Studies have primarily been retrospective or have collected few data points, which limits the investigators' ability to capture the range of OCD symptoms during this time period, systematically and prospectively. The objective of this investigation was to add to the existing literature on the impact of the peripartum period on the course of pre-existing OCD. We conducted a secondary analysis of a subset data from the Brown Longitudinal Obsessive Compulsive Study, a prospective, observational study of OCD course. Nineteen women who experienced a pregnancy during the course of the study (9.5% of overall sample of women) were followed on average for 486 ± 133 weeks. Weekly psychiatric status ratings (PSRs) of OCD severity were compared between peripartum and non-peripartum periods. We found that the peripartum period did not significantly impact the course of OCD severity in the majority of women (N = 13, 69%). Of the minority of women with measurable variability in OCD symptoms, no statistically significant difference in PSR scores was observed between peripartum and non-peripartum periods. In this novel yet small dataset, the severity of OCD does not appear to worsen for most women during the peripartum period.

Predictors of response to insulin therapy in youth with poorly-controlled type 2 diabetes in the TODAY trial.

OBJECTIVE: To understand the factors associated with glycemic control after starting insulin in youth with type 2 diabetes following glycemic failure (persistent HbA1c ≥8%) with metformin alone, metformin + rosiglitazone or metformin + lifestyle in the TODAY study. METHODS: Change in HbA1c after add-on insulin therapy and the factors predictive of glycemic response were evaluated. At 1-year postinsulin initiation, 253 youth had a mean of 3.9 ± 1.0 visits since the time of insulin initiation. Participants were divided into three groups according to glycemic control: consistent decrease in HbA1c by ≥0.5%, change <0.5%, or consistent increase in HbA1c ≥0.5%, at 75% or more of the visits. RESULTS: Within 1-year postinsulin initiation, 33.2% of participants had a consistent HbA1c decrease of ≥0.5%, 46.2% changed HbA1c <0.5%, and 20.6% had an increase ≥0.5%. At randomization into TODAY and at time of insulin initiation, the three glycemia groups were similar in age, sex, race-ethnicity, pubertal stage, BMI z-score, diabetes duration, and insulin secretion indices. Consistent HbA1c improvement was associated with higher insulin sensitivity (1/fasting insulin) at randomization and at time of failure, higher adiponectin at randomization, and was not associated with indices of ß-cell function. CONCLUSIONS: Response to add-on insulin was highly variable among youth in TODAY. Greater insulin sensitivity and higher adiponectin concentrations at randomization were associated with improved glycemic control after initiation of insulin. Due to limited information on adherence to insulin injections, the roles of adherence to the prescribed insulin regimen or psychosocial factors are unknown.

The Veterans Affairs Continuous Positive Airway Pressure Use and Diabetic Retinopathy Study.

SIGNIFICANCE: Obstructive sleep apnea has been linked to the development and progression of diabetic retinopathy. In this study, diabetic patients compliant with continuous positive airway pressure therapy (CPAP) for sleep apnea were less likely to have retinopathy, emphasizing the benefits and potential therapeutic role of CPAP in individuals with both conditions. PURPOSE: The aim of this study was to compare the prevalence of diabetic retinopathy in type 2 diabetic patients with obstructive sleep apnea who were compliant with CPAP therapy with those who were not compliant with CPAP therapy. METHODS: A retrospective cross-sectional review of type 2 diabetic patients using CPAP for obstructive sleep apnea was conducted. The prevalence of retinopathy was identified, and groups with and without retinopathy were compared using univariate analyses and multivariate logistic regression. RESULTS: The prevalence of retinopathy was 19.6% (n = 321). Retinopathy was significantly less prevalent in those compliant with CPAP (odds ratio, 0.54; 95% confidence interval, 0.31 to 0.94; P = .04). The relationship remained statistically significant when adjusting for other factors known to impact the course of diabetic eye disease. CONCLUSIONS: Increased CPAP compliance may mitigate the risk of developing diabetic retinopathy in type 2 diabetic patients with obstructive sleep apnea.

Factors Associated with Non-Completion of a Pediatric Metabolic and Bariatric Surgery Program.

BACKGROUND: Childhood obesity is a devastating disease process disproportionately affecting minority and low-income populations. Though bariatric surgery leads to durable weight loss and reversal of multiple obesity-related comorbidities, only a small fraction of pediatric patients undergoes the procedure. We sought to identify factors associated with non-completion in a pediatric bariatric surgery program. METHODS: Retrospective review of consecutive patients ≤18-years-old referred to an academic adolescent bariatric surgery program between 2017 and 2022 (n = 20 completers, 40 non-completers) was completed. Demographics and medical and psychosocial histories were summarized by completion status. RESULTS: Of the 33% (20/60; 85% female, 30% racial minorities) who successfully completed the program, the median age was 16 years [IQR 16, 17]. The median age of non-completers was 16 years [IQR 15, 17] (55% female, 56% racial minorities). Non-completion was associated with male gender (15% of completers vs 45% of non-completers, p = 0.022), neighborhood income <150% poverty level (0 completers vs 17.5% of non-completers, p = 0.047), and presence of environmental or family stressors (22% of completers vs 65% of non-completers, p = 0.008). Though not statistically significant, non-completers tended to be racial minorities (p = 0.054). CONCLUSIONS: Non-completion of the bariatric surgery pathway was more prevalent among male patients from lower-income neighborhoods with significant environmental or family stressors. These patients also tended to be racial and ethnic minorities. The findings underscore the need for further investigation into barriers to pediatric bariatric surgery. LEVEL OF EVIDENCE: Level III.

Vitamin D suppression of endoplasmic reticulum stress promotes an antiatherogenic monocyte/macrophage phenotype in type 2 diabetic patients.

Cardiovascular disease is the leading cause of morbidity/mortality in patients with type 2 diabetes mellitus (T2DM), but there is a lack of knowledge about the mechanism(s) of increased atherosclerosis in these patients. In patients with T2DM, the prevalence of 25-hydroxy vitamin D (25(OH)D) deficiency is almost twice that for nondiabetics and doubles the relative risk of developing cardiovascular disease compared with diabetic patients with normal 25(OH)D. We tested the hypothesis that monocytes from vitamin D-deficient subjects will have a proatherogenic phenotype compared with vitamin D-sufficient subjects in 43 patients with T2DM. Serum 25(OH)D level inversely correlated with monocyte adhesion to endothelial cells even after adjustment for demographic and comorbidity characteristics. Vitamin D-sufficient patients (≥30 ng/ml 25(OH)D) had lower monocyte endoplasmic reticulum (ER) stress, a predominance of M1 over M2 macrophage membrane receptors, and decreased mRNA expression of monocyte adhesion molecules PSGL-1, ß(1)-integrin, and ß(2)-integrin compared with patients with 25(OH)D levels of <30 ng/ml. In vitamin D-deficient macrophages, activation of ER stress increased adhesion and adhesion molecule expression and induced an M2-predominant phenotype. Moreover, adding 1,25(OH)(2)D(3) to vitamin D-deficient macrophages shifted their phenotype toward an M1-predominant phenotype with suppressed adhesion. Conversely, deletion of the vitamin D receptor in macrophages from diabetic patients activated ER stress, accelerated adhesion, and increased adhesion molecule expression. The absence of ER stress protein CCAAT enhancer-binding protein homologous protein suppressed monocyte adhesion, adhesion molecule expression, and the M2-predominant phenotype induced by vitamin D deficiency. Thus, vitamin D is a natural ER stress reliever that induced an antiatherogenic monocyte/macrophage phenotype.

Impact of youth onset type 2 diabetes during pregnancy on microvascular and cardiac outcomes.

AIMS: To examine the impact of pregnancy on microvascular and cardiovascular measures in women with youth-onset T2D. METHODS: Microvascular and cardiovascular measures were compared in in a cohort of 116 women who experienced a pregnancy of ≥ 20 weeks gestation and 291 women who did not among women in the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study. RESULTS: Cox regression models adjusted for participant characteristics at baseline including age, race/ethnicity, household income, diabetes duration, HbA1c (>6%), and BMI, demonstrated those who experienced pregnancy had 2.76 (1.38-5.49; p = 0.004) fold increased risk of hyperfiltration (eGFR ≥ 135 ml/min/1.73 m2), compared to those without a pregnancy. No differences were observed in rates of retinopathy (48.9% vs. 41.1%) or neuropathy (23.3% vs. 16.3%) in women who experienced pregnancy vs. women who did not, respectively. In fully adjusted models, pregnancy did not impact changes in echocardiographic or arterial stiffness compared to changes in women who were never pregnant. CONCLUSIONS: These results indicate that pregnancy increases the risk of hyperfiltration in women with youth-onset T2D, but not other micro or macrovascular complications. The rates of vascular complications are very high in youth-onset T2D potentially obscuring micro- and macrovascular changes attributable to pregnancy. CLINICAL TRIAL INFORMATION: ClinicalTrials.gov numbers,NCT01364350andNCT02310724.

Embryonic vitamin D deficiency programs hematopoietic stem cells to induce type 2 diabetes.

Environmental factors may alter the fetal genome to cause metabolic diseases. It is unknown whether embryonic immune cell programming impacts the risk of type 2 diabetes in later life. We demonstrate that transplantation of fetal hematopoietic stem cells (HSCs) made vitamin D deficient in utero induce diabetes in vitamin D-sufficient mice. Vitamin D deficiency epigenetically suppresses Jarid2 expression and activates the Mef2/PGC1a pathway in HSCs, which persists in recipient bone marrow, resulting in adipose macrophage infiltration. These macrophages secrete miR106-5p, which promotes adipose insulin resistance by repressing PIK3 catalytic and regulatory subunits and down-regulating AKT signaling. Vitamin D-deficient monocytes from human cord blood have comparable Jarid2/Mef2/PGC1a expression changes and secrete miR-106b-5p, causing adipocyte insulin resistance. These findings suggest that vitamin D deficiency during development has epigenetic consequences impacting the systemic metabolic milieu.

National Trends in Pediatric Metabolic and Bariatric Surgery: 2010-2017.

BACKGROUND: The childhood obesity epidemic has grown exponentially and is known to disproportionately affect minority groups. Successful treatment of this complex health issue requires a multidisciplinary approach including metabolic and bariatric surgery (MBS) for qualifying pediatric patients. This study examines current national trends in pediatric bariatric surgery from 2010 to 2017 using the National Inpatient Sample. METHODS: This study analyzed MBS among pediatric patients <19 years old using weighted discharge data from 2010 to 2017. The primary outcome was national procedure rates. Secondary analyses included procedure type, demographics, BMI, comorbidities, length of stay, and complication rates. RESULTS: From 2010 to 2017, annual bariatric procedure rates increased from 2.29 to 4.62 per 100 000 (P < .001). Laparoscopic sleeve gastrectomy outpaced Roux-en-Y gastric bypass and laparoscopic adjustable gastric band over time (0.31-3.99 per 100 000, P < .0001). The mean age was stable over time 18.10-17.96 (P = .78). The cohort was primarily female (76.5% to 75.4%), white (54.0% to 45.0%), and privately-insured (59.9% to 53.4%). Preoperative BMI increased from 2010 to 2017 (P < .001), whereas number of obesity-related comorbidities was stable (P > .05). Length of stay was <2 days (2.02-1.75, P = .04) and in-hospital complication rates were low (7.2% to 6.45%, P = .88). CONCLUSIONS: Pediatric MBS is underutilized nationally with disproportionately lower rates among minority groups. Despite incremental progress, further investigation into the racial and social determinants that limit access to pediatric weight loss surgery is critical.

Glucose counterregulatory responses to hypoglycemia.

The brain relies almost exclusively on glucose for fuel. Therefore, adequate uptake of glucose from the plasma is key for normal brain function and survival. Despite wide variations in glucose flux (i.e., fed state, fasting state, etc), blood glucose is maintained in a very narrow range. This is accomplished by a series of hormonal and physiologic responses. As a result, hypoglycemia is a rare occurrence in normal individuals. However, glucose counterregulatory responses are altered in patients with diabetes treated with insulin especially after repeated hypoglycemia or antecedent exercise.

Pharmacotherapy for depression and bipolar disorder during lactation: A framework to aid decision making.

OBJECTIVE: Breastmilk is recommended as the exclusive source of nutrition for infants younger than 6 months due to the numerous health benefits for both infants and mothers. Although many women are prescribed medications during pregnancy and postpartum, limited data are available to assist women in weighing the benefits compared to the risks of peripartum medication use. The goals of this paper are to discuss the importance of breastmilk for the health of both the mother and infant, evaluate the impact of medication use on women's infant feeding choice, describe the transfer of drugs to breastmilk and infants, and provide a framework for clinicians to support evidence-based counseling for women treated for mood disorders. RECOMMENDATIONS: We recommend early pregnancy counseling to discuss the benefits and risks of medications during breastfeeding. The Surgeon General's Call to Action (2011) highlights the short and long-term negative health effects of not providing breastmilk. Integrating recommendations from the pediatric and obstetric teams allows patients to make decisions based on evidence and reach their infant feeding goals. Databases containing summaries of research findings and pharmacologic properties of the drug of interest are an essential resource for clinicians.

Menstrual Dysfunction in Girls From the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) Study.

Context: Little is known about reproductive function in girls with youth-onset type 2 diabetes. Objectives: To characterize girls with irregular menses and effects of glycemic treatments on menses and sex steroids in the Treatment Options for Type 2 Diabetes in Youth (TODAY) study. Design: Differences in demographic, metabolic, and hormonal characteristics between regular- vs irregular-menses groups were tested; treatment group (metformin with or without rosiglitazone, metformin plus lifestyle) effect on menses and sex steroids over time in the study was assessed. This is a secondary analysis of TODAY data. Setting: Multicenter study in an academic setting. Patients: TODAY girls not receiving hormonal contraception and those at least 1-year postmenarche were included. Irregular menses was defined as three or fewer periods in the prior 6 months. Results: Of eligible participants with serum measurement of sex steroids (n = 190; mean age, 14 years), 21% had irregular menses. Those with irregular vs regular menses had higher body mass index (BMI) (P = 0.001), aspartate aminotransferase (AST) (P = 0.001), free androgen index (P = 0.0003), and total testosterone (P = 0.01) and lower sex hormone-binding globulin (SHBG) (P = 0.004) and estradiol (P = 0.01). Differences remained after adjustment for BMI. There was no treatment group effect on menses or sex steroids at 12 or 24 months, and no association of sex steroids was seen with measures of insulin sensitivity or secretion. Conclusions: Menstrual dysfunction is common in girls with recently diagnosed type 2 diabetes and associated with alterations in sex steroids, SHBG, and AST but not with alteration in insulin sensitivity or ß-cell function and did not improve with 2 years of antihyperglycemic treatment.

Synthesis, characterization and in vivo studies of Cu(II)-64-labeled cross-bridged tetraazamacrocycle-amide complexes as models of peptide conjugate imaging agents.

Copper-64, a positron emitter suitable for positron emission tomography (PET), demonstrates improved in vivo clearance when chelated by the cross-bridged tetraazamacrocycle CB-TE2A compared to TETA. Good in vivo clearance was also observed for 64Cu-CB-TE2A conjugated to a peptide, which converts one coordinating carboxylate pendant arm to an amide. To better understand the in vivo stability of peptide- conjugated CB-TE2A, cross-bridged monoamides were synthesized. Crystal structures of natCu(II)-CB-TEAMA and natCu(II)-CB-PhTEAMA revealed hexadentate, distorted octahedral coordination geometry. In vivo biodistribution showed clearance of all 64Cu-radiolabeled cross-bridged monoamides from liver and bone marrow such that uptake at 24 h was <10% of uptake at 30 min. In contrast, >60% of 30 min uptake from 64Cu-TETA was retained in these tissues at 24 h. Clearance of 64Cu-cross-bridged monoamides from nontarget organs suggests good in vivo stability, thus supporting the use of CB-TE2A as a bifunctional chelator without modifications to the macrocycle backbone.

Noninvasive imaging of osteoclasts in parathyroid hormone-induced osteolysis using a 64Cu-labeled RGD peptide.

UNLABELLED: Bone diseases are often a result of increased numbers of osteoclasts, or bone-resorbing cells. Bone metastases are a significant cause of morbidity in many types of cancer. An imaging agent targeting osteoclasts, which are upregulated in osteolytic lesions, may facilitate earlier follow-up in patients with osteolytic or mixed bone metastases. Osteoclasts express high levels of alpha(v)beta3 integrin, to which peptides containing the Arg-Gly-Asp (RGD) sequence are known to bind. We proposed that radiolabeled RGD peptides could be used to detect osteoclasts in lytic bone lesions. METHODS: The cross-bridged macrocyclic chelator 4,11-bis(carboxymethyl)-1,4,8,11-tetraazabicyclo[6.6.2]hexadecane (CB-TE2A) was conjugated to c(RGDyK) for radiolabeling with 64Cu (t(1/2), 12.7 h; beta+, 17.4%; E(beta+ max), 656 keV; beta-, 39%; E(beta- max), 573 keV). The in vitro affinity of Cu(II)-CB-TE2A-c(RGDyK) for alpha(v)beta3 and alpha(v)beta5 was evaluated in a heterologous competitive binding assay. Ex vivo uptake was examined in osteoclasts prepared from bone marrow macrophages. As a proof of principle, biodistribution and imaging studies were performed on parathyroid hormone (PTH)-induced osteolysis in the calvarium. RESULTS: Cu-CB-TE2A-c(RGDyK) was shown to have a 30-fold higher affinity for alpha(v)beta3 than for alpha(v)beta5. Osteoclasts were shown to specifically take up (64)Cu-CB-TE2A-c(RGDyK). However, bone marrow macrophages showed only nonspecific uptake. PTH treatment increased calvarial uptake of 64Cu-CB-TE2A-c(RGDyK), compared with uptake in mice receiving a sham treatment. In addition, calvarial uptake correlated linearly with the number of osteoclasts on the bone surface. CONCLUSION: These results suggest that 64Cu-CB-TE2A-c(RGDyK) selectively binds alpha(v)beta3 on osteoclasts and may potentially be used to identify increased numbers of osteoclasts in osteolytic bone diseases such as osteolytic bone metastasis and inflammatory osteolysis.

In vitro and in vivo investigation of matrix metalloproteinase expression in metastatic tumor models.

INTRODUCTION: Overexpression of matrix metalloproteinases (MMPs), particularly MMP-2 and MMP-9, has been correlated with poor prognosis in several cancer types including lung, colon and breast. Noninvasive detection of MMP expression might allow physicians to better determine when more aggressive cancer therapy is appropriate. The peptide CTT (CTTHWGFTLC) was identified as a selective inhibitor of MMP-2/9 that inhibits the growth of MDA-MB-435 human breast cancer xenografts. METHODS: CTT was conjugated with the bifunctional chelator DOTA (1,4,7,10-tetraazacyclotetradecane-N,N',N'',N'''-tetraacetic acid) for radiolabeling with (64)Cu (t(1/2)=12.7 h, 17.4% beta(+), 39% beta(-)), a radionuclide suitable for positron emission tomography (PET). In vitro affinity was determined in a fluorogenic substrate assay. Tumor gelatinase targeting was evaluated in both biodistribution and microPET imaging studies. RESULTS: Cu(II)-DOTA-CTT inhibited hMMP-2 (EC(50)=8.7 microM) and mMMP-9 (EC(50)=18.2 microM) with similar affinity to CTT (hMMP-2 EC(50)=13.2 microM; mMMP-9 EC(50)=11.0 microM). In biodistribution and microPET imaging studies, (64)Cu-DOTA-CTT was taken up by MMP-2/9-positive B16F10 murine melanoma tumors. Subsequently, imaging studies using (64)Cu-DOTA-CTT were performed on MDA-MB-435 tumor-bearing mice. With zymography, tumor MMP-2/9 expression in this model was shown to be inconsistent, resulting in microPET detection of the MDA-MB-435 tumor in only 1 of 24 imaged mice. Following limited imaging success, (64)Cu-DOTA-CTT was shown to have poor in vivo stability. CONCLUSIONS: Despite some evidence for selective uptake of (64)Cu-DOTA-CTT by gelatinase-expressing tumors, the low affinity for MMP-2 and MMP-9 and in vivo instability make this an inadequate radioligand for in vivo tumor evaluation.

Preparation and biological evaluation of copper-64-labeled tyr3-octreotate using a cross-bridged macrocyclic chelator.

PURPOSE: Somatostatin receptors (SSTr) are expressed on many neuroendocrine tumors, and several radiotracers have been developed for imaging these types of tumors. For this reason, peptide analogues of somatostatin have been well characterized. Copper-64 (t(1/2) = 12.7 hours), a positron emitter suitable for positron emission tomography (PET) imaging, was shown recently to have improved in vivo clearance properties when chelated by the cross-bridged tetraazamacrocycle 4,11-bis(carboxymethyl)-1,4,8,11-tetraazabicyclo(6.6.2)hexadecane (CB-TE2A) compared with 1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetic acid (TETA). EXPERIMENTAL DESIGN: CB-TE2A and TETA were conjugated to the somatostatin analogue tyrosine-3-octreotate (Y3-TATE) for evaluation of CB-TE2A as a bifunctional chelator of 64Cu. The in vitro affinity of each compound for SSTr was determined using a homologous competitive binding assay. In vivo characteristics of both radiolabeled compounds were examined in biodistribution and microPET studies of AR42J tumor-bearing rats. RESULTS: Cu-CB-TE2A-Y3-TATE (Kd = 1.7 nmol/L) and Cu-TETA-Y3-TATE (Kd = 0.7 nmol/L) showed similar affinities for AR42J derived SSTr. In biodistribution studies, nonspecific uptake in blood and liver was lower for 64Cu-CB-TE2A-Y3-TATE. Differences increased with time such that, at 4 hours, blood uptake was 4.3-fold higher and liver uptake was 2.4-fold higher for 64Cu-TETA-Y3-TATE than for 64Cu-CB-TE2A-Y3-TATE. In addition, 4.4-times greater tumor uptake was detected with 64Cu-CB-TE2A-Y3-TATE than with 64Cu-TETA-Y3-TATE at 4 hours postinjection. MicroPET imaging yielded similar results. CONCLUSIONS: CB-TE2A appears to be a superior in vivo bifunctional chelator of 64Cu for use in molecular imaging by PET or targeted radiotherapy due to both improved nontarget organ clearance and higher target organ uptake of 64Cu-CB-TE2A-Y3-TATE compared with 64Cu-TETA-Y3-TATE.

Safety and Tolerability of Enteral Protein Supplementation for Infants With Brain Injury.

BACKGROUND: We hypothesized that enteral protein supplementation in infants with brain injury would be safe and well tolerated and improve growth. MATERIALS AND METHODS: Twenty-five infants with perinatal brain injury were randomized to a high-protein (4 g/kg/d) or standard-protein diet and followed for 12 months. RESULTS: The whey protein powder was well tolerated by 9 of the 13 infants in the high-protein group, and no adverse events related to the supplement were seen. The protein group had higher serum urea nitrogen at 10 and 30 days after study initiation but no difference in bicarbonate levels at either time point. Infants in the protein group maintained their weight z score from birth to 3 months of age, while infants in the standard group had a significant decrease in their weight z score over the same time period. CONCLUSION: These results suggest that enteral protein supplementation may reduce growth failure in infants with brain injury.

Vitamin D deficiency induces high blood pressure and accelerates atherosclerosis in mice.

Multiple epidemiological studies link vitamin D deficiency to increased cardiovascular disease (CVD), but causality and possible mechanisms underlying these associations are not established. To clarify the role of vitamin D-deficiency in CVD in vivo, we generated mouse models of diet-induced vitamin D deficiency in two backgrounds (LDL receptor- and ApoE-null mice) that resemble humans with diet-induced hypertension and atherosclerosis. Mice were fed vitamin D-deficient or -sufficient chow for 6 weeks and then switched to high fat (HF) vitamin D-deficient or -sufficient diet for 8-10 weeks. Mice with diet-induced vitamin D deficiency showed increased systolic and diastolic blood pressure, high plasma renin, and decreased urinary sodium excretion. Hypertension was reversed and renin was suppressed by returning chow-fed vitamin D-deficient mice to vitamin D-sufficient chow diet for 6 weeks. On a HF diet, vitamin D-deficient mice had ~2-fold greater atherosclerosis in the aortic arch and ~2-8-fold greater atherosclerosis in the thoracic and abdominal aorta compared to vitamin D-sufficient mice. In the aortic root, HF-fed vitamin D-deficient mice had increased macrophage infiltration with increased fat accumulation and endoplasmic reticulum (ER) stress activation, but a lower prevalence of the M1 macrophage phenotype within atherosclerotic plaques. Similarly, peritoneal macrophages from vitamin D-deficient mice displayed an M2-predominant phenotype with increased foam cell formation and ER stress. Treatment of vitamin D-deficient mice with the ER stress reliever PBA during HF feeding suppressed atherosclerosis, decreased peritoneal macrophage foam cell formation, and downregulated ER stress proteins without changing blood pressure. Thus, we suggest that vitamin D deficiency activates both the renin angiotensin system and macrophage ER stress to contribute to the development of hypertension and accelerated atherosclerosis, highlighting vitamin D replacement as a potential therapy to reduce blood pressure and atherosclerosis.

Targeting the alphavbeta3 integrin for small-animal PET/CT of osteolytic bone metastases.

UNLABELLED: This article describes the evaluation of the radiopharmaceutical (64)Cu-CB-TE2A-c(RGDyK) ((64)Cu-RGD) as an imaging agent for osteolytic bone metastases and their associated inflammation by targeting of the alpha(v)beta(3) integrin on osteoclasts and the proinflammatory cells involved at the bone metastatic site. METHODS: The (64)Cu-RGD radiotracer was evaluated in the transgenic mouse expressing Tax (Tax(+)), which spontaneously develops osteolytic tumors throughout the vertebrae and hind limbs, using biodistribution studies and small-animal PET/CT. Histologic analysis was also performed on Tax(+) mouse tails, using hematoxylin and eosin and tartrate-resistant acid phosphatase to confirm the presence of osteolytic bone lesions and the presence of osteoclasts, respectively. Additionally, a proof-of-principle study was conducted with a small group of Tax(+) animals presenting with osteolytic lesions. These animals were treated with the bisphosphonate zoledronic acid and imaged with (64)Cu-RGD to determine whether this radiopharmaceutical was sensitive enough to detect a response to the bisphosphonate therapy. RESULTS: Biodistribution studies using (64)Cu-RGD demonstrated that Tax(+) mice between the ages of 6 and 12 mo had a greater accumulation of activity in their tail vertebrae than did the wild-type (WT) cohort (P = 0.013). Additionally, Tax(+) mice between the ages of 6 and 12 mo had significantly more tracer activity associated with their tail vertebrae than did Tax(+) mice older than 12 mo (P = 0.003), suggesting that earlier bone metastases cause an increased recruitment of alpha(v)beta(3)-expressing cells. Small-animal PET/CT with (64)Cu-RGD was conducted on Tax(+) and WT mice. On the basis of standardized uptake value analysis, Tax(+) mice had approximately 2-fold more tail-associated activity than did WT animals (P = 0.0157). Additionally, decreases in uptake were observed in the tails of Tax(+) mice after treatment with the osteoclast inhibitor zoledronic acid, and histologic analysis of Tax(+) mouse-tail vertebrae revealed the presence of Tax(+) tumor cells, osteoclasts, and proinflammatory cells within the bone microenvironment. CONCLUSION: Together, these data suggest that (64)Cu-RGD has the potential to effectively image osteolytic bone metastases and monitor the physiologic changes in the bone metastatic microenvironment after osteoclast-inhibiting bisphosphonate therapy.