An update on the development of a bottlenose dolphin, Tursiops truncatus, immune reagent toolkit

There are extensive immunological reagents available for laboratory rodents and humans. However, for veterinary species there is a need for expansion of immunological toolkits, with this especially evident for marine mammals, such as cetaceans. In addition to their use in a research setting, immune assays could be employed to monitor the health status of cetaceans and serve as an adjunct to available diagnostic tests. Such development of specific and sensitive immune assays will enhance the proper care and stewardship of wild and managed cetacean populations. Our goal is to provide immune reagents and immune assays for the research community, clinicians, and others involved in care of bottlenose dolphins. This review will provide an update on our development of a bottlenose dolphin immunological toolkit. The future availability and continued development of these reagents is critical for improving wild and managed bottlenose dolphin population health through enhanced assessment of their responses to alterations in the marine environment, including pathogens, and improve our ability to monitor their status following vaccination.

Pre-anal gland abscess in a male Atlantic bottlenose dolphin (Tursiops truncatus)

OBJECTIVE

Anal glands have been identified in a variety of terrestrial and aquatic mammalian species, but there are few accounts describing their presence in cetaceans. To our knowledge, this report describes the first documented case of a pre-anal gland abscess in an Atlantic bottlenose dolphin (Tursiops truncatus).

ANIMAL

A 9-year-old male bottlenose dolphin (T truncatus) part of the US Navy Marine Mammal Program in San Diego Bay, California.

CLINICAL PRESENTATION, PROGRESSION, AND PROCEDURES

The patient presented for a 3-day history of lethargy, failure to perform voluntary behaviors, and an elevated respiratory rate. Complete blood count and serum biochemistry results showed an inflammatory hemogram. Physical examination revealed a 4-cm circular swelling at the right pre-anal gland pore. The swelling was warm and erythematous, with multifocal pinpoint ulcerations. An abscess of the pre-anal gland was diagnosed using cytology, culture, and ultrasound.

TREATMENT AND OUTCOME

Treatment included systemic oral antibiotic and antifungal therapy, along with daily lavage and warm compress of the gland. Treatment was successful, and the abscess resolved.

CLINICAL RELEVANCE

This case provides insight into a previously unreported disease process in bottlenose dolphins and encourages veterinarians to evaluate the pre-anal gland during routine physical examinations and complete further work-up if swelling or clinical signs associated with this region are present.

Evaluation of the safety and efficacy of fecal microbiota transplantations in bottlenose dolphins (Tursiops truncatus) using metagenomic sequencing

AIMS

Gastrointestinal disease is a leading cause of morbidity in bottlenose dolphins (Tursiops truncatus) under managed care. Fecal microbiota transplantation (FMT) holds promise as a therapeutic tool to restore gut microbiota without antibiotic use. This prospective clinical study aimed to develop a screening protocol for FMT donors to ensure safety, determine an effective FMT administration protocol for managed dolphins, and evaluate the efficacy of FMTs in four recipient dolphins.

METHODS AND RESULTS

Comprehensive health monitoring was performed on donor and recipient dolphins. Fecal samples were collected before, during, and after FMT therapy. Screening of donor and recipient fecal samples was accomplished by in-house and reference lab diagnostic tests. Shotgun metagenomics was used for sequencing. Following FMT treatment, all four recipient communities experienced engraftment of novel microbial species from donor communities. Engraftment coincided with resolution of clinical signs and a sustained increase in alpha diversity.

CONCLUSION

The donor screening protocol proved to be safe in this study and no adverse effects were observed in four recipient dolphins. Treatment coincided with improvement in clinical signs.

The dynamics of persistent organic pollutant (POP) transfer from female bottlenose dolphins (Tursiops truncatus) to their calves during lactation

Persistent organic pollutants (POPs) are lipophilic compounds that can accumulate in high concentrations in the blubber of marine mammals, which are long-lived, top-level predators in their ecosystems. These compounds, which include DDTs, PCBs, PBDEs, HCHs, and CHLDs, impact mammalian health, including neurological effects, reduced immune system efficiency, and reproductive failure. POPs are transferred from females to their offspring during gestation and lactation, which have implications for the health of newborn marine mammals, particularly first-born offspring who receive higher concentrations. The dynamics of POP transfer during lactation have been studied in a few pinniped species, but there are no comparable studies on living cetaceans. Because life history strategies and behavior of lactating phocids differ from dolphins, a study on delphinid maternal transfer is warranted. To accomplish this, placenta and longitudinally collected blood and milk samples were taken concurrently from trained bottlenose dolphin, Tursiops truncatus, mother/calf pairs to assess the dynamics of maternal contaminant transfer. Initial POP levels in placenta, blood serum, and milk varied by individual and were related to the age and reproductive history of the females. Regardless of initial POP levels, maternal serum and milk concentrations decreased while calf serum POP levels increased over time. Pollutant transfer varied by POP class and by congener. Contaminant transfer efficiency to calves was most apparent for 4- to 6‑chlorine PCBs, DDT isomers p,p'-DDD, p,p'-DDT, o,p'-DDD, and o,p'-DDE, trans-nonachlor, cis-nonachlor, heptachlor epoxide, nonachlor III, and oxychlordane. By the end of the lactation period, calf serum POP levels were considerably greater than those of their mothers, particularly for compounds with fewer chlorines. POP levels were most biomagnified in the calf born to the primiparous female. These results provide critical information on one component of contaminant transfer in the marine ecosystem and for understanding potential risks of POP exposure to developing odontocete calves.

Phlpp1 Expression in Osteoblasts Plays a Modest Role in Bone Homeostasis

Prior work demonstrated that Phlpp1 deficiency alters limb length and bone mass, but the cell types involved and requirement of Phlpp1 for this effect were unclear. To understand the function of Phlpp1 within bone-forming osteoblasts, we crossed Phlpp1 floxed mice with mice harboring type 1 collagen (Col1a12.3kb)-Cre. Mineralization of bone marrow stromal cell cultures derived from Phlpp1 cKOCol1a1 was unchanged, but levels of inflammatory genes (eg, Ifng, Il6, Ccl8) and receptor activator of NF-κB ligand/osteoprotegerin (RANKL/OPG) ratios were enhanced by either Phlpp1 ablation or chemical inhibition. Micro-computed tomography of the distal femur and L5 vertebral body of 12-week-old mice revealed no alteration in bone volume per total volume, but compromised femoral bone microarchitecture within Phlpp1 cKOCol1a1 conditional knockout females. Bone histomorphometry of the proximal tibia documented no changes in osteoblast or osteoclast number per bone surface but slight reductions in osteoclast surface per bone surface. Overall, our data show that deletion of Phlpp1 in type 1 collagen-expressing cells does not significantly alter attainment of peak bone mass of either males or females, but may enhance inflammatory gene expression and the ratio of RANKL/OPG. Future studies examining the role of Phlpp1 within models of advanced age, inflammation, or osteocytes, as well as functional redundancy with the related Phlpp2 isoform are warranted. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

The role of hyperbaric oxygen in osteoradionecrosis-a prophylactic insight

BACKGROUND

Osteoradionecrosis (ORN) is an uncommon and debilitating consequence of head and neck radiotherapy and hyperbaric oxygen therapy (HBOT) has been advocated for prophylaxis prior to performing dentoalveolar procedures. The aim of this study was to evaluate a prophylactic HBOT protocol and describe the outcomes of susceptible individuals.

METHODS

A retrospective audit of adults who attended the Oral and Maxillofacial Surgery department at the Royal Adelaide Hospital (South Australia) who received dental extractions with a history of radiotherapy to the jaws from 2008 to 2020. Data including demographic information and outcomes of osteoradionecrosis and delayed healing was recorded.

RESULTS

A total of 121 individuals were eligible for case note review; 68.6% of individuals were male and 55.4% were aged over 67 years. Osteoradionecrosis occurred in 9.1% of individuals and delayed healing for 3.3%; fifteen individuals (12.4%) were unable to complete the HBOT protocol. The individuals who were diagnosed with ORN had a significant association with age (P = 0.006) and binary analysis showed alcohol consumption to be a significant predictor.

CONCLUSIONS

Prophylactic HBOT protocol had a lower proportion of individuals diagnosed with ORN and those who were diagnosed were more likely to be younger males and have current alcohol consumption.

Protein kinase D3 conditional knockout impairs osteoclast formation and increases trabecular bone volume in male mice

Studies using kinase inhibitors have shown that the protein kinase D (PRKD) family of serine/threonine kinases are required for formation and function of osteoclasts in culture. However, the involvement of individual protein kinase D genes and their in vivo significance to skeletal dynamics remains unclear. In the current study we present data indicating that protein kinase D3 is the primary form of PRKD expressed in osteoclasts. We hypothesized that loss of PRKD3 would impair osteoclast formation, thereby decreasing bone resorption and increasing bone mass. Conditional knockout (cKO) of Prkd3 using a murine Cre/Lox system driven by cFms-Cre revealed that its loss in osteoclast-lineage cells reduced osteoclast differentiation and resorptive function in culture. Examination of the Prkd3 cKO mice showed that bone parameters were unaffected in the femur at 4 weeks of age, but consistent with our hypothesis, Prkd3 conditional knockout resulted in 18 % increased trabecular bone mass in male mice at 12 weeks and a similar increase at 6 months. These effects were not observed in female mice. As a further test of our hypothesis, we asked if Prkd3 cKO could protect against bone loss in a ligature-induced periodontal disease model but did not see any reduction in bone destruction in this system. Together, our data indicate that PRKD3 promotes osteoclastogenesis both in vitro and in vivo.

The impact of enzyme replacement therapy on the oral health manifestations of hypophosphatasia among children: a scoping review

PURPOSE

A scoping review to describe the use of enzyme replacement therapy (ERT) in the form of asfotase alfa to decrease the severity of oral manifestations in children with hypophosphatasia (HPP).

METHODS

Six databases were searched using keywords and index terms related to "hypophosphatasia," "children," and "enzyme replacement therapy." Duplicates were removed and two independent reviewers screened the titles and abstracts to identify articles for full-text review. Extracted data was summarised narratively.

RESULTS

The systematic search identified 3548 articles, with 171 suitable for full-text review and a final 22 that met inclusion criteria. Enzyme replacement therapy generally resulted in a reduction in the presence and severity of oral manifestations of HPP. However, numerous studies failed to report specific details regarding the nature of oral health outcomes and there were reported cases of further loss of primary teeth.

CONCLUSIONS

The available evidence suggests that that ERT in the form of asfotase alfa for HPP in infants and young children leads to improved oral health outcomes. It is recommended that the outcomes are improved with earlier initiation of ERT. Further, well-designed clinical research is required to assess oral health improvements and decreased morbidity associated with the early loss of teeth.

Advertising and general dental practice: how compliant are practice websites in Australia with legal requirements?

BACKGROUND

The Australian Health Practitioner Regulation Agency (AHPRA) requires general dental practitioners (GDPs) to agree to regulatory advertising guidelines on initial registration and annual renewal. The aim of this study was to determine the compliance of GDPs websites to these requirements.

METHODS

A representative sample of GDPs websites from each state and territory in Australia was based on the total AHPRA registrant distribution. Assessment of compliance was used across five domains consisting of 17 criteria related to AHPRA's advertising of regulated health services guidelines, as well as section 133 of the National Law. Inter-rater reliability was estimated using Fleiss's Kappa.

RESULTS

One hundred and ninety-two GDPs websites were reviewed with 85% non-compliant with at least one of the legal and regulatory requirements relating to advertising. Of these websites, 52% displayed false and misleading information, 12.8% had offers and inducement without clear terms and conditions, 11.5% used written testimonials, 33.9% created unrealistic expectation of benefit and 39.6% encouraged indiscriminate and unnecessary use of health services.

CONCLUSIONS

More than 85% of GDP websites in Australia did not comply with legal and regulatory requirements related to advertising. A multi-stakeholder approach involving AHPRA, professional dental bodies and dental registrants is necessary to improve compliance.

A time-series analysis of blood-based biomarkers within a 25-year longitudinal dolphin cohort

Causal interactions and correlations between clinically-relevant biomarkers are important to understand, both for informing potential medical interventions as well as predicting the likely health trajectory of any individual as they age. These interactions and correlations can be hard to establish in humans, due to the difficulties of routine sampling and controlling for individual differences (e.g., diet, socio-economic status, medication). Because bottlenose dolphins are long-lived mammals that exhibit several age-related phenomena similar to humans, we analyzed data from a well controlled 25-year longitudinal cohort of 144 dolphins. The data from this study has been reported on earlier, and consists of 44 clinically relevant biomarkers. This time-series data exhibits three starkly different influences: (A) directed interactions between biomarkers, (B) sources of biological variation that can either correlate or decorrelate different biomarkers, and (C) random observation-noise which combines measurement error and very rapid fluctuations in the dolphin's biomarkers. Importantly, the sources of biological variation (type-B) are large in magnitude, often comparable to the observation errors (type-C) and larger than the effect of the directed interactions (type-A). Attempting to recover the type-A interactions without accounting for the type-B and type-C variation can result in an abundance of false-positives and false-negatives. Using a generalized regression which fits the longitudinal data with a linear model accounting for all three influences, we demonstrate that the dolphins exhibit many significant directed interactions (type-A), as well as strong correlated variation (type-B), between several pairs of biomarkers. Moreover, many of these interactions are associated with advanced age, suggesting that these interactions can be monitored and/or targeted to predict and potentially affect aging.

Molar-incisor hypomineralisation prevalence in a cohort of Australian children with type 1 diabetes

PURPOSE

Systemic diseases or drugs administered early in life may cause a disruption in amelogenesis and contribute to the qualitative defect of enamel described as molar-incisor hypomineralisation (MIH). Therefore, an increase in prevalence of MIH in children with type 1 diabetes (T1D) may be expected as this systemic disorder is commonly diagnosed in early childhood. The aim of this study was to determine the prevalence of MIH in a cohort of children with T1D and investigate diagnosis of MIH with T1D factors.

METHODS

Cross-sectional study of children with T1D recruited from paediatric diabetes clinics at the Women's and Children's Hospital (South Australia). A detailed medical history, comprehensive dental and MIH examination according to the European Academy of Paediatric Dentistry (EAPD) long form classification was collected for each child. All upper and lower first permanent molars and central incisors were scored.

RESULTS

A total number of 73 participants; 35 (47.95%) males were examined including 584 teeth. The mean age of the participants was 13.25 ± 2.58 years, with a mean age of diagnosis 7.75 ± 3.58 years, and a mean HbA1c of 8.5 ± 1.6%. 42 out of 73 children (54.8%) had enamel defects on at least one of the teeth examined. However, 19.2% met the criteria for MIH. Univariate and bivariate analyses were conducted but no significant associations were noted between MIH and risk factors including diabetes control (p > 0.1).

CONCLUSION

There was a high prevalence of enamel defects and MIH amongst children with T1D. More research is required to establish association between T1D and MIH.

Pentadecanoylcarnitine is a newly discovered endocannabinoid with pleiotropic activities relevant to supporting physical and mental health

As an emerging dietary essential fatty acid, pentadecanoic acid (C15:0) is expected to have bioactive metabolites with broad health benefits. Here, we evaluated pentadecanoylcarnitine, an endogenous C15:0 metabolite, for dose dependent cell-based activities, including measurement of its effects on 148 clinically relevant biomarkers across twelve primary human cell systems mimicking various disease states. Mechanisms of action for pentadecanoylcarnitine were also assessed across 78 cell-based target assays. Pentadecanoylcarnitine had dose-dependent anti-inflammatory activities, including lower IL-1α, ITAC, MCP-1, and IP-10, across five cell systems relevant to treating cardiovascular, immune, neoplastic, pulmonary, and skin diseases. Targeted assays showed pentadecanoylcarnitine as a full-acting cannabinoid 1 and 2 receptor agonist (EC50 3.7 and 3.2 µM, 111% and 106% maximum activity compared to the positive control, respectively). Pentadecanoylcarnitine also had 5-HT1A and 5-HT1B receptor agonist and histamine H1 and H2 receptor antagonist activities. In summary, pentadecanoylcarnitine, a second discovered full-acting endocannabinoid, had broad pleiotropic activities relevant to regulating inflammation, pain, mood, and sleep. This study's findings further the need to evaluate the potential health impacts of C15:0 nutritional deficiencies caused by population-wide avoidance of all dietary saturated fats, including C15:0.

Histone deacetylase 5 is a phosphorylation substrate of protein kinase D in osteoclasts

Protein kinase D (PRKD) family kinases are required for formation and function of osteoclasts. However, the substrates of PRKD in osteoclasts are unknown. To identify PRKD-dependent protein phosphorylation in osteoclasts, we performed a quantitative LC-MS/MS phosphoproteomics screen for proteins showing differential phosphorylation in osteoclasts after treatment with the PRKD inhibitor CRT0066101. We identified 757 phosphopeptides showing significant changes following PRKD inhibition. Among the changes, we found a group of 13 proteins showing decreased phosphorylation at PRKD consensus phosphorylation motifs. This group includes histone deacetylase 5 (HDAC5), which is a previously validated PRKD target. Considering this known interaction, work suggesting HDACs may be important regulators of osteoclasts, and studies suggesting potential functional redundancy between HDACs, we further investigated the relationship between PRKD and class IIa HDACs in osteoclasts. We confirmed that CRT0066101 inhibits phosphorylation of endogenous HDAC5 and to a lesser extent HDAC4, whereas HDAC7 phosphorylation was not affected. Osteoclast cultures from Hdac5 global knockout mice displayed impaired differentiation and reduced ability to resorb bone, while conditional knockout of Hdac4 in osteoclasts showed no phenotype in vitro or in vivo. The inhibitory effect of CRT0066101 was reduced in Hdac5 KO osteoclasts. Together these data indicate that the PRKD/HDAC5 axis contributes to osteoclast formation in vitro and suggest that this pathway may contribute to regulation of skeletal dynamics in vivo.

Cardiac assessments of bottlenose dolphins (Tursiops truncatus) in the Northern Gulf of Mexico following exposure to Deepwater Horizon oil

The Deepwater Horizon (DWH) oil spill profoundly impacted the health of bottlenose dolphins (Tursiops truncatus) in Barataria Bay, LA (BB). To comprehensively assess the cardiac health of dolphins living within the DWH oil spill footprint, techniques for in-water cardiac evaluation were refined with dolphins cared for by the U.S. Navy Marine Mammal Program in 2018 and applied to free-ranging bottlenose dolphins in BB (n = 34) and Sarasota Bay, Florida (SB) (n = 19), a non-oiled reference population. Cardiac auscultation detected systolic murmurs in the majority of dolphins from both sites (88% BB, 89% SB) and echocardiography showed most of the murmurs were innocent flow murmurs attributed to elevated blood flow velocity [1]. Telemetric six-lead electrocardiography detected arrhythmias in BB dolphins (43%) and SB dolphins (31%), all of which were considered low to moderate risk for adverse cardiac events. Echocardiography showed BB dolphins had thinner left ventricular walls, with significant differences in intraventricular septum thickness at the end of diastole (p = 0.002), and left ventricular posterior wall thickness at the end of diastole (p = 0.033). BB dolphins also had smaller left atrial size (p = 0.004), higher prevalence of tricuspid valve prolapse (p = 0.003), higher prevalence of tricuspid valve thickening (p = 0.033), and higher prevalence of aortic valve thickening (p = 0.008). Two dolphins in BB were diagnosed with pulmonary arterial hypertension based on Doppler echocardiography-derived estimates and supporting echocardiographic findings. Histopathology of dolphins who stranded within the DWH oil spill footprint showed a significantly higher prevalence of myocardial fibrosis (p = 0.003), regardless of age, compared to dolphins outside the oil spill footprint. In conclusion, there were substantial cardiac abnormalities identified in BB dolphins which may be related to DWH oil exposure, however, future work is needed to rule out other hypotheses and further elucidate the connection between oil exposure, pulmonary disease, and the observed cardiac abnormalities.

Dietary effects on urinary physicochemistry in Navy bottlenose dolphins (Tursiops truncatus) for the prevention of ammonium urate kidney stones

Bottlenose dolphins are susceptible to developing ammonium urate (NH₄U) kidney stones. The current study was designed to test the hypothesis that diet influences the urinary physicochemistry risk factors associated with nephrolithiasis in dolphins. A comprehensive nutrient analysis was performed revealing that the baseline diet (BD) commonly fed to dolphins under professional care had a greater purine content and a more negative dietary cation-anion difference (DCAD) when compared with a model diet consumed by free-ranging dolphins. A modified diet (MD) was formulated to include free-ranging diet fish species and achieve a more positive DCAD. The BD had a more negative DCAD (-52 mEq/Mcal metabolizable energy) when compared with the MD (+51 mEq/Mcal ME), which more closely approximated the DCAD of the free-ranging model diet (+152 mEq/Mcal ME). Six dolphins (with stones) were fed the BD followed by the MD for a minimum of 4 wk. At the end of each feeding trial, a 6-h continuous urine collection was performed to compare urine parameters of dolphins fed the BD versus MD. Dolphins consuming the MD demonstrated a significant decrease in urinary ammonium, net acid excretion, saturation index of ammonium urate, and phosphorous, and a significant increase in urinary citrate and net gastrointestinal (GI) alkali absorption, as compared with urine parameters assessed when fed the BD. Increasing the proportion of free-ranging diet fish species and optimizing the DCAD positively influenced some of the risk factors believed to be associated with NH₄U kidney stone development in bottlenose dolphins under professional care.

Biochemical and hematological biomarkers of reproductive failure in bottlenose dolphins Tursiops truncatus

The physiological demands of pregnancy inevitably result in alterations in both biochemical and hematological parameters as fetal development occurs. The shifts observed in successful pregnancy in bottlenose dolphins Tursiops truncatus to support both fetal physiological needs and maternal basal requirements have been established according to each trimester. Detecting aberrations in blood-based biomarkers could help facilitate diagnosis of gestational abnormalities, improve our understanding of factors influencing reproductive outcomes and aid in prediction of reproductive failure. This study retrospectively analyzed 263 blood samples from 15 bottlenose dolphins in 21 failed pregnancies over 28 yr (1989-2017). Most samples remained within normal pregnancy reference ranges; however, significant shifts were observed between trimesters. Hematological alterations, compared to successful pregnancy reference ranges from previously published data, were consistent across failed pregnancies and included an increased prevalence of elevated 2nd and 3rd trimester neutrophils, elevated 2nd trimester monocytes and decreased 3rd trimester eosinophils. In addition, low hematocrit and low red blood cells were more prevalent in the 2nd trimester. Biochemical shifts included an increased prevalence of elevated creatine phosphokinase in the 3rd trimester outside of the normal reference ranges. Across failed pregnancies, calcium and iron were decreased in the 3rd trimester. Significantly decreased progesterone in the 3rd trimester was a negative prognostic indicator of pregnancy outcome with decreasing 3rd trimester progesterone associated with failed pregnancy. This study demonstrates the use of blood-based biomarkers as possible predictors of pregnancy outcome in bottlenose dolphins.

Standardization of Dolphin Cardiac Auscultation and Characterization of Heart Murmurs in Managed and Free-Ranging Bottlenose Dolphins (Tursiops truncatus)

Cardiac auscultation is an important, albeit underutilized tool in aquatic animal medicine due to the many challenges associated with in-water examinations. The aims of this prospective study were to (1) establish an efficient and repeatable in-water cardiac auscultation technique in bottlenose dolphins (Tursiops truncatus), (2) describe the presence and characterization of heart murmurs detected in free-ranging and managed dolphins, and (3) characterize heart murmur etiology through echocardiography in free-ranging dolphins. For technique development, 65 dolphins cared for by the Navy Marine Mammal Program (Navy) were auscultated. The techniques were then applied to two free-ranging dolphin populations during capture-release health assessments: Sarasota Bay, Florida (SB), a reference population, and Barataria Bay, LA (BB), a well-studied population of dolphins impacted by the Deepwater Horizon oil spill. Systolic heart murmurs were detected at a frequent and similar prevalence in all dolphin populations examined (Navy 92%, SB 89%, and BB 88%), and characterized as fixed or dynamic. In all three populations, sternal cranial and left cranial were the most common locations for murmur point of maximal intensity (PMI). An in-water transthoracic echocardiogram technique was refined on a subset of Navy dolphins, and full echocardiographic exams were performed on 17 SB dolphins and 29 BB dolphins, of which, 40 had murmurs. Spectral Doppler was used to measure flow velocities across the outflow tracts, and almost all dolphins with audible murmurs had peak outflow velocities ≥1.6 m/s (95%, 38/40); three dolphins also had medium mitral regurgitation which could be the source of their murmurs. The presence of audible murmurs in most of the free-ranging dolphins (88%) was attributed to high velocity blood flow as seen on echocardiography, similar to a phenomenon described in other athletic species. These innocent murmurs were generally characterized as Grade I-III systolic murmurs with PMI in the left or sternal cranial region. This study is the first to describe an efficient technique for in-water dolphin cardiac auscultation, and to present evidence that heart murmurs are common in bottlenose dolphins.

Loss of myocyte enhancer factor 2 expression in osteoclasts leads to opposing skeletal phenotypes

Osteoclasts are multinuclear cells that resorb bone. Osteoclast differentiation is regulated by multiple transcription factors which may be acting in a single or multiple factor complex to regulate gene expression. Myocyte enhancer factor 2 (MEF2) is a family of transcription factors whose role during osteoclast differentiation has not been well characterized. Because MEF2A and MEF2D are the family members most highly expressed during osteoclast differentiation, we created conditional knockout mice models for MEF2A and/or MEF2D. In vitro cultures of A- and D-KO osteoclasts were smaller and less numerous than wild type cultures, while AD-KO osteoclasts were almost completely devoid of TRAP positive mononuclear cells. Female A-KO mice are osteopetrotic while male A- and D-KO mice of either sex had no significant in vivo skeletal phenotype, suggesting a sex-specific regulation of osteoclasts by MEF2A. Lastly, in vivo male AD-KO mice are osteopenic, indicating while MEF2 is required for M-CSF and RANKL-stimulated osteoclastogenesis in vitro, osteoclasts can form in the absence of MEF2 in vivo via a RANKL-alternative pathway.

Linking longitudinal and cross-sectional biomarker data to understand host-pathogen dynamics: Leptospira in California sea lions (Zalophus californianus) as a case study

Confronted with the challenge of understanding population-level processes, disease ecologists and epidemiologists often simplify quantitative data into distinct physiological states (e.g. susceptible, exposed, infected, recovered). However, data defining these states often fall along a spectrum rather than into clear categories. Hence, the host-pathogen relationship is more accurately defined using quantitative data, often integrating multiple diagnostic measures, just as clinicians do to assess their patients. We use quantitative data on a major neglected tropical disease (Leptospira interrogans) in California sea lions (Zalophus californianus) to improve individual-level and population-level understanding of this Leptospira reservoir system. We create a "host-pathogen space" by mapping multiple biomarkers of infection (e.g. serum antibodies, pathogen DNA) and disease state (e.g. serum chemistry values) from 13 longitudinally sampled, severely ill individuals to characterize changes in these values through time. Data from these individuals describe a clear, unidirectional trajectory of disease and recovery within this host-pathogen space. Remarkably, this trajectory also captures the broad patterns in larger cross-sectional datasets of 1456 wild sea lions in all states of health but sampled only once. Our framework enables us to determine an individual's location in their time-course since initial infection, and to visualize the full range of clinical states and antibody responses induced by pathogen exposure. We identify predictive relationships between biomarkers and outcomes such as survival and pathogen shedding, and use these to impute values for missing data, thus increasing the size of the useable dataset. Mapping the host-pathogen space using quantitative biomarker data enables more nuanced understanding of an individual's time course of infection, duration of immunity, and probability of being infectious. Such maps also make efficient use of limited data for rare or poorly understood diseases, by providing a means to rapidly assess the range and extent of potential clinical and immunological profiles. These approaches yield benefits for clinicians needing to triage patients, prevent transmission, and assess immunity, and for disease ecologists or epidemiologists working to develop appropriate risk management strategies to reduce transmission risk on a population scale (e.g. model parameterization using more accurate estimates of duration of immunity and infectiousness) and to assess health impacts on a population scale.

Modified fish diet shifted serum metabolome and alleviated chronic anemia in bottlenose dolphins (Tursiops truncatus): Potential role of odd-chain saturated fatty acids

Bottlenose dolphins (Tursiops truncatus) are long-lived mammals that can develop chronic aging-associated conditions similar to humans, including metabolic syndrome. Initial studies suggest that these conditions may be attenuated in dolphins using a modified fish diet. Serum metabolomics, fatty acid panels, and blood-based health indices were compared between 20 dolphins on a modified, 50% wild-type diet (50% mullet, 25% capelin, and 25% squid and/or herring) and 10 dolphins on a baseline diet (75% capelin and 25% squid and/or herring). Blood samples were collected at Months 0, 1, 3 and 6. Dolphins on the modified diet had lower insulin (7.5 ± 4.0 and 14.8 ± 14.0 μIU/ml, P = 0.039), lower cholesterol (160 ± 26 and 186 ± 24 mg/dl, P = 0.015) and higher hematocrit (46 ± 3 and 44 ± 3%, P = 0.043) by Month 1 compared to controls. Dolphins with anemia (hemoglobin ≤ 12.5 g/dl, n = 6) or low-normal hemoglobin (12.5-13.5 g/dl, n = 3) before placed on the modified diet had normal hemoglobin concentrations (> 13.5 g/dl) by Month 3. The modified diet caused a significant shift in the metabolome, which included 664 known metabolites. Thirty prioritized metabolites at Months 1 and 3 were 100% predictive of dolphins on the modified diet. Among 25 prioritized lipids, 10 (40%) contained odd-chain saturated fatty acids (OCFAs); C15:0 was the highest-prioritized OCFA. Increased dietary intake of C15:0 (from 1.3 ± 0.4 to 4.5 ± 1.1 g/day) resulted in increased erythrocyte C15:0 concentrations (from 1.5 ± 0.3 to 5.8 ± 0.8 μg/ml, P < 0.0001), which independently predicted raised hemoglobin. Further, increasing age was associated with declining serum C15:0 (R2 = 0.14, P = 0.04). While higher circulating OCFAs have been previously associated with lower risks of cardiometabolic diseases in humans, further studies are warranted to assess potential active roles of OCFAs, including C15:0, in attenuating anemia.

Regulation of Osteoclast Differentiation at Multiple Stages by Protein Kinase D Family Kinases

Balanced osteoclast and osteoblast activity is necessary for skeletal health, whereas unbalanced osteoclast activity causes bone loss in many skeletal conditions. A better understanding of pathways that regulate osteoclast differentiation and activity is necessary for the development of new therapies to better manage bone resorption. The roles of Protein Kinase D (PKD) family of serine/threonine kinases in osteoclasts have not been well characterized. In this study we use immunofluorescence analysis to reveal that PKD2 and PKD3, the isoforms expressed in osteoclasts, are found in the nucleus and cytoplasm, the mitotic spindle and midbody, and in association with the actin belt. We show that PKD inhibitors CRT0066101 and CID755673 inhibit several distinct aspects of osteoclast formation. Treating bone marrow macrophages with lower doses of the PKD inhibitors had little effect on M-CSF + RANKL-dependent induction into committed osteoclast precursors, but inhibited their motility and subsequent differentiation into multinucleated mature osteoclasts, whereas higher doses of the PKD inhibitors induced apoptosis of the preosteoclasts. Treating post-fusion multinucleated osteoclasts with the inhibitors disrupted the osteoclast actin belts and impaired their resorptive activity. In conclusion, these data implicate PKD kinases as positive regulators of osteoclasts, which are essential for multiple distinct processes throughout their formation and function.

Ultrasonographic findings associated with normal pregnancy and fetal well-being in the bottlenose dolphin (Tursiops truncatus)

Reproductive success is vital in sustaining free‐ranging and managed bottlenose dolphin (Tursiops truncatus) populations. Ultrasonography is an invaluable, non‐invasive tool in assessing the fetomaternal unit in humans and animals, including dolphins and horses. The purpose of this prospective longitudinal cohort study was to develop a protocol for fetomaternal ultrasonographic monitoring in dolphins and to report normal measurements and descriptive findings correlated with a positive outcome. From 2010 to 2017, serial ultrasonographic evaluations of 12 healthy dolphins were performed over the course of 16 pregnancies. A total of 203 ultrasound examinations were included in the study. Several metrics were accurate in predicting fetal age. Fetal biparietal diameter (BPD), thoracic width in dorsal and transverse planes, thoracic height in a sagittal plane, aortic diameter, and blubber thickness all demonstrated high correlation with gestational age (r > 0.94, P < .00001). Regional uteroplacental thickness significantly increased with each trimester (range 0.22–0.40 cm; P < .00011 cranial uterus, P < .00057 mid, and P < .000011 caudal). Lung:liver mean pixel intensity was 2.57 ± 0.46 (95% confidence interval 2.47‐2.67). Ultrasonographic characteristics of normal pregnancy in dolphins are described and an equation for prediction of parturition date in Tursiops is reported: days to parturition = 348.16 − (26.03 × BPD(cm)) (R² = 0.99). Future applications of these normal data will help identify in utero abnormalities indicative of fetal morbidity, and improve understanding of reproductive failure in wild and managed populations.

Pregnancy profiles in the common bottlenose dolphin (Tursiops truncatus): Clinical biochemical and hematological variations during healthy gestation and a successful outcome

The physiological demands of pregnancy inevitably result in changes of both biochemical and hematological parameters as the fetus develops. Alterations in blood parameters have been observed to shift according to both trimester and species, to support fetal physiological needs and maternal basal requirements. Establishing normal reference ranges for each stage in gestation is important to facilitate diagnosis of underlying health concerns and prevent over-diagnosing abnormalities. Despite bottlenose dolphins (Tursiops truncatus) being one of the most highly studied cetaceans, the blood profile changes occurring as a result of pregnancy have not been previously described. A retrospective analysis was performed from blood samples obtained from 42 successful pregnancies from 20 bottlenose dolphins in a managed population over 30 years. Samples were compared to non-pregnant states and among trimesters of pregnancy. Blood profile fluctuations occurred throughout gestation, however significant alterations predominantly occurred between the 2nd and 3rd trimester. Hematological changes from the 2nd to the 3rd trimester included a decrease in lymphocytes, decrease in platelet count, and hemoconcentration with increased hematocrit and hemoglobin. Biochemical changes in the 3rd trimester included significant reductions in ALKP (alkaline phosphatase), ALT (alanine aminotransferase) and AST (aspartate aminotransferase) with significant increases observed in albumin, globulins, total protein, cholesterol, triglycerides and CO₂. It's important to note that despite significant shifts occurring between the 2nd and 3rd trimester, there was no significant change in platelets, hematocrit, hemoglobin, lymphocytes or CO₂ between non-pregnant and 3rd trimester blood samples. The normal reference ranges for each trimester established herein, will enable future identification of abnormalities occurring during pregnancy and help improve our understanding of factors potentially influencing a failed or successful pregnancy outcome.

Labeled quantitative mass spectrometry to study the host response during aspergillosis in the common bottlenose dolphin (Tursiops truncatus)

Aspergillosis is a fungal infection caused by Aspergillus molds that can affect both humans and animals. Despite advances in diagnostics and therapy, medical management of this disease remains difficult. Expansion of the basic knowledge regarding its pathophysiology in animals is critical to aid in the identification of new biomarkers of infection for diagnosis and therapeutic targets. For such a purpose, proteomics can be used by addressing protein changes during various disease processes. In the present study, a mass spectrometry analysis based on isobaric tagging for relative and absolute quantitation (iTRAQ^®) was applied for direct identification and relative quantitation of proteins in blood collected from 32 Aspergillus-diseased common bottlenose dolphins (Tursiops truncatus, 32 samples) in comparison with blood from 55 other dolphins (55 samples from 41 clinically-normal controls and from 14 cetaceans with miscellaneous non-Aspergillus inflammation diseases) and ten convalescent dolphins (28 samples). Sixty-six and 40 proteins were found to be ≥2.0-fold over- and underrepresented versus miscellaneous non-Aspergillus inflammatory dolphins, respectively, and most were confirmed vs. clinically-normal controls and convalescents. Many proteins which play a role in the adaptive immune response were identified, including MHC proteins and others involved in catalytic activity like the NADPH-ubiquinone oxido-reductases. Overall, iTRAQ^® appears to be a convenient proteomic tool greatly suited for exploratory ex vivo studies focusing on pathophysiology. This technique should be considered as a preliminary step before validation of new diagnostic markers.

Surgical Management of a Chronic Neck Abscess in a U.S. Navy Bottlenose Dolphin

Surgical intervention on cetaceans is rarely performed due to challenges including general anesthesia and post-operative wound healing. This report describes the evaluation and treatment of an adult female bottlenose dolphin (Tursiops truncatus) with the US Navy Marine Mammal Program, with a chronic ventral cervical abscess caused by Candida glabrata. Despite aspiration and lavage along with multiple antifungal drugs, the patient developed inspiratory stridor with decreased performance level and surgical treatment was pursued. Under general anesthesia with the dolphin in dorsal recumbency position a 12-cm longitudinal ventral midline neck incision was used for exploration. Intraoperative ultrasound aided the identification of surgical landmarks and the abscess cavity. After adequate drainage and curettage, a closed-suction drain was placed in the surgical site. Retention sutures were used to close the incision and the external drain bulb was secured to a pectoral fin strap. One-year post-op, the dolphin was clinically normal and follow-up imaging showed no significant recurrence of the abscess. This case demonstrates a novel surgical approach of managing abscesses in dolphins, including placement and management of a negative suction drain in a submerged patient. The successful collaboration between veterinary anesthesiology, veterinary medicine, radiology, and general surgery allowed the patient to continue her normal activities as a full-duty service member.

Evaluation of a genus-specific ELISA and a commercial Aspergillus Western blot IgG® immunoblot kit for the diagnosis of aspergillosis in common bottlenose dolphins (Tursiops truncatus)

Aspergillosis is a fungal infection with high mortality and morbidity rates. As in humans, its definitive diagnosis is difficult in animals, and thus new laboratory tools are required to overcome the diagnostic limitations due to low specificity and lack of standardization. In this study of common bottlenose dolphins (Tursiops truncatus), we evaluated the diagnostic performance of a new commercial immunoblot kit that had been initially developed for the serologic diagnosis of chronic aspergillosis in humans. Using this in a quantitative approach, we first established its positive cutoff within an observation cohort of 32 serum samples from dolphins with "proven" or "probable" diagnosis of aspergillosis and 55 negative controls. A novel enzyme-linked immunosorbent assay (ELISA) test was also developed for detecting anti-Aspergillus antibodies, and results were compared between the two assays. Overall, the diagnostic performance of immunoblot and ELISA were strongly correlated (P < .0001). The former showed lower sensitivity (65.6% versus 90.6%), but higher specificity (92.7% vs. 69.1%), with no cross-reaction with other fungal infections caused by miscellaneous non-Aspergillus genera. When assessing their use in a validation cohort, the immunoblot kit and the ELISA enabled positive diagnosis before mycological cultures in 42.9% and 33.3% subjects addressed for suspicion of aspergillosis, respectively. There was also significant impact of antifungal treatment on the results of the two tests (P < .05). In all, these new serological methods show promise in aiding in the diagnosis of aspergillosis in dolphins, and illustrate the opportunity to adapt commercial reagents directed for human diagnostics to detect similar changes in other animals.

SMAD1/5 signaling in osteoclasts regulates bone formation via coupling factors

Bone remodeling occurs via coupling between bone resorption by osteoclasts and bone formation by osteoblasts. The mechanisms that regulate osteoclast signals to osteoblasts are not well understood. Published studies have reported that BMP signaling in osteoclasts regulate osteoclast coupling targets. To investigate the necessity of canonical BMP signaling on osteoclast differentiation and coupling, we mated Smad1^fl/fl; Smad5^fl/fl mice to c-Fms-Cre mice. We analyzed male mice at 3 months of age to determine the skeletal phenotype of the Smad1^fl/fl; Smad5^fl/fl;c-Fms-Cre (SMAD1/5 cKO) mice. There was a 1.2-fold decrease in trabecular BV/TV in SMAD1/5 cKO. Analyses of osteoclast serum markers in SMAD1/5 cKO mice, showed a significant increase in CTX-1 (1.5 fold) and TRAP ELISA (3 fold) compared to control mice. In these same mice, there was a 1.3-fold increase in cortical thickness. Consistent with the increase in cortical thickness, we found a 3-fold increase in osteoblast activity as measured by P1NIP ELISA assay from SMAD1/5 cKO mice. To explain the changes in cortical thickness and P1NP activity, we determined conditioned media from SMAD1/5 cKO osteoclast cultures enhanced mineralization of an osteoblast cell line and coupling factors expressed by osteoclasts that regulate osteoblast activity Wnt1 (4.5-fold increase), Gja1 (3-fold increase) and Sphk1 (1.5-fold increase) were all upregulated in osteoclasts from SMAD1/5 cKO compared to control osteoclasts. Lastly osteoclasts treated with dorsomorphin, a chemical inhibitor of SMAD1/5 signaling, demonstrates an increase in Wnt1 and Gja1 expression similar to the SMAD1/5 cKO mice. Previous studies demonstrated that TGF-β signaling in osteoclasts leads to increases in WNT1 expression by osteoclasts. Therefore, our data suggest that TGF-β and BMP signaling pathways in osteoclasts could act in an antagonistic fashion to regulate osteoblast activity through WNT1 and other coupling factors.

Comparison of potential dietary and urinary risk factors for ammonium urate nephrolithiasis in two bottlenose dolphin ( Tursiops truncatus) populations

Dietary and urinary risk factors have been implicated in conditions favoring ammonium urate nephrolithiasis in managed dolphins compared with free-ranging dolphins. In this study, urine samples were collected from 16 dolphins (8 cases, 8 controls) from the U.S. Navy Marine Mammal Program for the purposes of assessing changes in urinary biomarkers after a large meal. Urinary biomarkers and nephrolithiasis presence were assessed opportunistically in 15 long-term resident free-ranging dolphins living in Sarasota Bay, Florida. Additionally, the total purine contents of fish commonly consumed by each dolphin population were measured to evaluate potential dietary risk factors. Populations were compared for total dietary purine composition, recently fed status, nephrolithiasis presence, and differences in urinary biochemical, acid-base, and physicochemical parameters via Wilcoxon rank sum analysis and least square means. Managed dolphins had higher urinary pH and ammonium ([Formula: see text]) in both pre- and postprandial conditions and higher urinary uric acid and saturation indices of NH₄U in the postprandial condition compared with free-ranging dolphins ( P < 0.05). The purine content was greater ( P < 0.0001) in the diet consumed by managed dolphins [7 mmol/Mcal metabolizable energy (ME)] than in the free-ranging dolphin diet (4 mmol/Mcal ME). Free-ranging dolphins did not show evidence of nephrolithiasis. Observed differences in urinary biomarkers and dietary purine content in these two dolphin populations suggest a pathophysiologic basis for the role of fish types on the risk of NH₄U stone formation. Future research should investigate fish type and feeding frequency, inhibitors and promoters, and alkalinizing therapy for reducing NH₄U nephrolithiasis in dolphins.

Monitoring bottlenose dolphin leukocyte cytokine mRNA responsiveness by qPCR

Both veterinarians caring for dolphins in managed populations and researchers monitoring wild populations use blood-based diagnostics to monitor bottlenose dolphin (Tursiops truncatus) health. Quantitative PCR (qPCR) can be used to assess cytokine transcription patterns of peripheral blood mononuclear cells (PBMC). This can supplement currently available blood tests with information on immune status. Full realization of this potential requires establishment of normal ranges of cytokine gene transcription levels in bottlenose dolphins. We surveyed four dolphins over the span of seven months by serial bleeds. PBMC were stimulated with phytohaemagglutinin (1, 5, and 10 μg/mL) and concanavalin A (1 μg/mL) for 48 H in vitro. RNA from these cultures was probed by qPCR using Tursiops truncatus-specific primers (IL-1α, IL-1β, IL-1RA, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p40, IL-13, IL-18, IFN-γ and TNF-α). Two blood samples from an additional bottlenose dolphin diagnosed with acute pulmonary disease add further perspective to the data. We observed that mitogen choice made a significant difference in the magnitude of gene transcription observed. On the other hand, most cytokines tested exhibited limited intra-animal variation. However, IL-6 and IL-12p40 differed between older and younger dolphins. Furthermore, the magnitude of mitogenic response clusters the tested cytokines into three groups. The data provide a reference for the selection of target cytokine mRNAs and their expected range of mitogen-stimulated cytokine gene transcription for future studies.

Dietary cation-anion difference may explain why ammonium urate nephrolithiasis occurs more frequently in common bottlenose dolphins () under human care than in free-ranging common bottlenose dolphins

Ammonium urate nephrolithiasis frequently develops in common bottlenose dolphins () managed under human care but is rare in free-ranging common bottlenose dolphins. In other species, the dietary cation-anion difference (DCAD) can affect ammonium urate urolith formation by increasing proton excretion as ammonium ions. Therefore, differences in diet between the 2 dolphin populations could affect urolith formation, but the DCAD of most species consumed by free-ranging and managed dolphins is unknown. To compare the nutrient composition of diets consumed by free-ranging and managed bottlenose dolphins, samples ( = 5) of the 8 species of fish commonly consumed by free-ranging bottlenose dolphins in Sarasota Bay, FL, and the 7 species of fish and squid commonly fed to managed bottlenose dolphins were analyzed for nutrient content. Metabolizable energy was calculated using Atwater factors; the DCAD was calculated using 4 equations commonly used in people and animals that use different absorption coefficients. The nutrient composition of individual species was used to predict the DCAD of 2 model diets typically fed to managed common bottlenose dolphins and a model diet typically consumed by common bottlenose dolphins in Sarasota Bay. To mimic differences in postmortem handling of fish for the 2 populations of bottlenose dolphins, "free-ranging" samples were immediately frozen at -80°C and minimally thawed before analysis, whereas "managed" samples were frozen for 6 to 9 mo at -18°C and completely thawed. "Free-ranging" species contained more Ca and P and less Na and Cl than "managed" fish and squid species. As a consequence, the DCAD of both model managed dolphin diets obtained using 3 of the 4 equations was much more negative than the DCAD of the model free-ranging bottlenose dolphin diet ( < 0.05). The results imply that managed bottlenose dolphins must excrete more protons in urine than free-ranging bottlenose dolphins, which will promote nephrolith formation. The nutrient composition of the free-ranging bottlenose dolphin diet, determined for the first time here, can be used as a guide for feeding managed bottlenose dolphins, but research in vivo is warranted to determine whether adding more cations to the diet will prevent urolith formation in managed dolphins.

Breast cancer cell-derived fibroblast growth factors enhance osteoclast activity and contribute to the formation of metastatic lesions

Fibroblast growth factors (FGFs) and their receptors (FGFRs) have been implicated in promoting breast cancer growth and progression. While the autocrine effects of FGFR activation in tumor cells have been extensively studied, little is known about the effects of tumor cell-derived FGFs on cells in the microenvironment. Because FGF signaling has been implicated in the regulation of bone formation and osteoclast differentiation, we hypothesized that tumor cell-derived FGFs are capable of modulating osteoclast function and contributing to growth of metastatic lesions in the bone. Initial studies examining FGFR expression during osteoclast differentiation revealed increased expression of FGFR1 in osteoclasts during differentiation. Therefore, studies were performed to determine whether tumor cell-derived FGFs are capable of promoting osteoclast differentiation and activity. Using both non-transformed and transformed cell lines, we demonstrate that breast cancer cells express a number of FGF ligands that are known to activate FGFR1. Furthermore our results demonstrate that inhibition of FGFR activity using the clinically relevant inhibitor BGJ398 leads to reduced osteoclast differentiation and activity in vitro. Treatment of mice injected with tumor cells into the femurs with BGJ398 leads to reduced osteoclast activity and bone destruction. Together, these studies demonstrate that tumor cell-derived FGFs enhance osteoclast function and contribute to the formation of metastatic lesions in breast cancer.

Class II and IV HDACs function as inhibitors of osteoclast differentiation

Histone deacetylases (HDACs) are negative regulators of transcription and have been shown to regulate specific changes in gene expression. In vertebrates, eighteen HDACs have thus far been identified and subdivided into four classes (I-IV). Key roles for several HDACs in bone development and biology have been elucidated through in vitro and in vivo models. By comparison, there is a paucity of data on the roles of individual HDACs in osteoclast formation and function. In this study, we investigated the gene expression patterns and the effects of suppressing individual class II (Hdac4, 5, 6, 9, and 10) and class IV (Hdac11) HDACs during osteoclast differentiation. We demonstrated that HDAC class II and IV members are differentially expressed during osteoclast differentiation. Additionally, individual shRNA-mediated suppression of Hdac4, 5, 9, 10 and 11 expression resulted in increased multinucleated osteoclast size and demineralization activity, with little to no change in the overall number of multinucleated osteoclasts formed compared with control shRNA-treated cells. We also detected increased expression of genes highly expressed in osteoclasts, including c-Fos, Nfatc1, Dc-stamp and Cathepsin K. These observations indicate that HDACs cooperatively regulate shared targets in a non-redundant manner.

Clinical management of Candida albicans keratomycosis in a bottlenose dolphin (Tursiops truncatus)

OBJECTIVE

Corneal ulceration secondary to trauma commonly affects marine mammals, often with opportunistic secondary bacterial or fungal infections. This report characterizes the combined use of auriculopalpebral and ophthalmic nerve blocks, adipose-derived stem cells, and subconjunctival injections for successful treatment of corneal trauma and infection in dolphins.

ANIMAL STUDIED

An 11-year-old, female bottlenose dolphin (Tursiops truncatus) presented with bilateral diffuse corneal opacities, which progressed to keratomycosis caused by Candida albicans.

PROCEDURE

Aggressive medical management was employed, including the use of subconjunctival injections of adipose-derived stem cells, plasma, topical and oral antifungals and antibiotics, and anti-inflammatory and pain medications. Anesthetic block of the auriculopalpebral and ophthalmic nerves was employed to evaluate the corneas.

CONCLUSION

Subconjunctival injections were employed over 52 days, followed by topical drops for 5 months. At last evaluation, there was no evidence of blepharospasm bilaterally. Only a faint superficial gray corneal opacity remained OS. A temporal paraxial corneal opacity was present OD, with receding inactive vascularization and a small amount of melanosis temporally.

The Function of Twisted Gastrulation in Regulating Osteoclast Differentiation is Dependent on BMP Binding

Proper regulation of osteoclast (OCL) function is critical for normal bone homeostasis. Bone morphogenetic protein (BMP) signaling and its regulation have been shown to have direct effects on OCL differentiation and activity. One of the major modulators of BMP signaling in the extracellular space is the secreted protein twisted gastrulation (TWSG1), which can inhibit BMP signaling and OCL differentiation. In this study we examine specific N-terminal regions of TWSG1 protein that have been previously proposed as BMP binding sites to determine whether TWSG1 binding to BMPs is required for its inhibitory effects on OCLs. We demonstrate that overexpression of wild type TWSG1 suppresses osteoclastogenesis, while overexpression of mutant TWSG1 proteins (W66A and N80Q/N146Q mutants), which cannot bind BMPs, leads to increased BMP signaling, enhanced osteoclastogenesis, increased resorptive activity, and expression of OCL-specific genes. Our results show that BMP binding is required for TWSG1-mediated inhibition of OCL formation and function, and validate the critical functional regions within the TWSG1 protein for these interactions.

Evaluation of annual survival and mortality rates and longevity of bottlenose dolphins (Tursiops truncatus) at the United States Navy Marine Mammal Program from 2004 through 2013

Objective-To evaluate annual survival and mortality rates and the longevity of a managed population of bottlenose dolphins (Tursiops truncatus). Design-Retrospective cohort study. Animals-103 bottlenose dolphins at the US Navy Marine Mammal Program (MMP). Procedures-Population age structures, annual survival and crude mortality rates, and median age at death for dolphins > 30 days old were determined from 2004 through 2013. Results-During 2004 through 2013, the annual survival rates for MMP dolphins ranged from 0.98 to 1.0, and the annual crude mortality rates ranged from 0% to 5%, with a mean of 2.7%. The median age at death was 30.1 years from 2004 through 2008 and increased to 32 years from 2009 through 2013. The maximum age for a dolphin in the study was 52 years. Conclusions and Clinical Relevance-Results indicated that the annual mortality rates were low and survival rates were high for dolphins in the MMP from 2004 through 2013 and that the median age at death for MMP dolphins during that time was over 10 years greater than that reported in free-ranging dolphins. These findings were likely attributable to the continually improving care and husbandry of managed dolphin populations.

Marine mammals harbor unique microbiotas shaped by and yet distinct from the sea

Marine mammals play crucial ecological roles in the oceans, but little is known about their microbiotas. Here we study the bacterial communities in 337 samples from 5 body sites in 48 healthy dolphins and 18 healthy sea lions, as well as those of adjacent seawater and other hosts. The bacterial taxonomic compositions are distinct from those of other mammals, dietary fish and seawater, are highly diverse and vary according to body site and host species. Dolphins harbour 30 bacterial phyla, with 25 of them in the mouth, several abundant but poorly characterized Tenericutes species in gastric fluid and a surprisingly paucity of Bacteroidetes in distal gut. About 70% of near-full length bacterial 16S ribosomal RNA sequences from dolphins are unique. Host habitat, diet and phylogeny all contribute to variation in marine mammal distal gut microbiota composition. Our findings help elucidate the factors structuring marine mammal microbiotas and may enhance monitoring of marine mammal health.

Smad1/5 and Smad4 expression are important for osteoclast differentiation

To investigate the necessity of the canonical BMP pathway during osteoclast differentiation, we created osteoclasts with a conditional gene deletion for Smad1 and Smad5 (SMAD1/5), or Smad4 using adenovirus expressing CRE recombinase (Ad-CRE). Reduction of either Smad4 or Smad1/5 expression resulted in fewer and smaller multinuclear cells compared to control cells. We also detected changes in osteoclast enriched genes, demonstrated by decreased Dc-stamp and cathepsin K expression in both Smad4 and Smad1/5 Ad-CRE osteoclasts, and changes in c-fos and Nfatc1 expression in only Smad4 Ad-CRE cells. Lastly we also detected a significant decrease in resorption pits and area resorbed in both the Smad4 and Smad1/5 Ad-CRE osteoclasts. Because we inhibited osteoclast differentiation with loss of either Smad4 or Smad1/5 expression, we assessed whether BMPs affected osteoclast activity in addition to BMP's effects on differentiation. Therefore, we treated mature osteoclasts with BMP2 or with dorsomorphin, a chemical inhibitor that selectively suppresses canonical BMP signaling. We demonstrated that BMP2 stimulated resorption in mature osteoclasts whereas treatment with dorsomorphin blocks osteoclast resorption. These results indicate that the BMP canonical signaling pathway is important for osteoclast differentiation and activity.

Increased Dietary Intake of Saturated Fatty Acid Heptadecanoic Acid (C17:0) Associated with Decreasing Ferritin and Alleviated Metabolic Syndrome in Dolphins

Similar to humans, bottlenose dolphins (Tursiops truncatus) can develop metabolic syndrome and associated high ferritin. While fish and fish-based fatty acids may protect against metabolic syndrome in humans, findings have been inconsistent. To assess potential protective factors against metabolic syndrome related to fish diets, fatty acids were compared between two dolphin populations with higher (n = 30, Group A) and lower (n = 19, Group B) mean insulin (11 ± 12 and 2 ± 5 μIU/ml, respectively; P < 0.0001) and their dietary fish. In addition to higher insulin, triglycerides, and ferritin, Group A had lower percent serum heptadecanoic acid (C17:0) compared to Group B (0.3 ± 0.1 and 1.3 ± 0.4%, respectively; P < 0.0001). Using multivariate stepwise regression, higher percent serum C17:0, a saturated fat found in dairy fat, rye, and some fish, was an independent predictor of lower insulin in dolphins. Capelin, a common dietary fish for Group A, had no detectable C17:0, while pinfish and mullet, common in Group B's diet, had C17:0 (41 and 67 mg/100g, respectively). When a modified diet adding 25% pinfish and/or mullet was fed to six Group A dolphins over 24 weeks (increasing the average daily dietary C17:0 intake from 400 to 1700 mg), C17:0 serum levels increased, high ferritin decreased, and blood-based metabolic syndrome indices normalized toward reference levels. These effects were not found in four reference dolphins. Further, higher total serum C17:0 was an independent and linear predictor of lower ferritin in dolphins in Group B dolphins. Among off the shelf dairy products tested, butter had the highest C17:0 (423mg/100g); nonfat dairy products had no detectable C17:0. We hypothesize that humans' movement away from diets with potentially beneficial saturated fatty acid C17:0, including whole fat dairy products, could be a contributor to widespread low C17:0 levels, higher ferritin, and metabolic syndrome.

Deletion of histone deacetylase 7 in osteoclasts decreases bone mass in mice by interactions with MITF

Molecular regulators of osteoclast formation and function are an important area of research due to the central role of osteoclasts in bone resorption. Transcription factors such as MITF are essential for osteoclast generation by regulating expression of the genes required for cellular differentiation and resorptive function. We recently reported that histone deacetylase 7 (HDAC7) binds to and represses the transcriptional activity of MITF in osteoclasts, and that loss of HDAC7 in vitro accelerated osteoclastogenesis. In the current study, we extend this initial observation by showing that conditional deletion of HDAC7 in osteoclasts of mice leads to an in vivo enhancement in osteoclast formation, associated with increased bone resorption and lower bone mass. Expression of multiple MITF target genes is increased in bone marrow derived osteoclast cultures from the HDAC7 knockout mice. Interestingly, multiple regions of the HDAC7 amino-terminus can bind to MITF or exert repressive activity. Moreover, mutation or deletion of the HDAC7 conserved deacetylase catalytic domain had little effect on repressive function. These observations identify HDAC7 in osteoclasts as an important molecular regulator of MITF activity and bone homeostasis, but also highlight a gap in our understanding of exactly how HDAC7 functions as a corepressor.

Hybrid nanotopographical surfaces obtained by biomimetic mineralization of statherin-inspired elastin-like recombinamers

Modification of surfaces mimicking unique chemical and physical features of mineralized tissues is of major interest for obtaining biomaterials for replacing and regenerating biological tissues. Here, human salivary statherin-inspired genetically engineered recombinamers (ELRs, HSS) on biomedical surfaces regulates mineralization to form an amorphous-calcium-phosphate (ACP) layer that reproduces the original substrate nanotopography. The HSS-ELRs carry a statherin-derived peptide with high affinity to tooth enamel. They are tethered to nanorough surfaces and mineralized using an enzyme-directed process. A homogeneous layer of ACP-minerals forms on HSS-coated surfaces retaining the original nanotopography of the substrate. In contrast, biomineralization of control surfaces results in uncontrolled growth of minerals. This suggest the statherin-inspired ELRs have ability to induce and control growth of the minerals on the biofunctional surfaces. Likely, the HSS-ELR coating have similar bioactivity to that of statherin in human saliva. The hybrid nanorough surfaces improve adhesion and differentiation of preosteoblasts and show potential for dental and orthopedic implants integration. This method enables the combination and tailoring of nanotopographical and biochemical cues to design functionalized surfaces to investigate and potentially direct the stem cell fate.

Pathophysiological and physicochemical basis of ammonium urate stone formation in dolphins

PURPOSE

Nephrolithiasis is increasingly reported in bottle-nosed dolphins. All cases to date have been ammonium urate nephrolithiasis.

MATERIALS AND METHODS

A case-control study was performed in dolphins with and without evidence of nephrolithiasis to identify biomarkers and risk factors associated with stone formation in a managed population. Dolphins were sampled in fasting and postprandial states to study the effect of dietary factors on serum and urinary biochemistry. Urine was continuously collected for 6 hours via catheter and divided into 3, 2-hour collections with a bolus fish meal given after completing the first collection. Blood was sampled at the beginning of the fasting period and the end of the postprandial period.

RESULTS

There were no significant differences in serum and urine chemistry or acid-base profiles between dolphins with vs without stones at baseline or postprandially. This suggests that cases and controls represent a continuum of stone risk. On analysis combining cases and controls in a single cohort we noted significant postprandial increases in urinary uric acid, sulfate and net acid excretion accompanied by increased urinary ammonium excretion and a commensurate increase in urine pH. The supersaturation index of ammonium urate increased more than twofold postprandially.

CONCLUSIONS

These findings suggest that dolphins are susceptible to ammonium urate nephrolithiasis at least in part because a high dietary load of acid and purines results in a transient but marked increase in the urinary supersaturation of the sparingly soluble ammonium urate salt.

Bone morphogenetic proteins signal via SMAD and mitogen-activated protein (MAP) kinase pathways at distinct times during osteoclastogenesis

To investigate the role of bone morphogenetic protein (BMP) signaling in osteoclastogenesis in vivo, we eliminated BMPRII in osteoclasts by creating a BMPRII(fl/fl);lysM-Cre mouse strain. Conditional knock-out (cKO) mice are osteopetrotic when compared with WT controls due to a decrease in osteoclast activity. Bone marrow macrophages (BMMs) isolated from cKO mice are severely inhibited in their capacity to differentiate into mature osteoclasts in the presence of M-CSF and receptor activator of NF-κB (RANK) ligand. We also show that BMP noncanonical (MAPK) and canonical (SMAD) pathways are utilized at different stages of osteoclast differentiation. BMP2 induces p38 phosphorylation in pre-fusion osteoclasts and increases SMAD phosphorylation around osteoclast precursor fusion. Phosphorylation of MAPKs was decreased in differentiated BMMs from cKO animals. Treating BMMs with the SMAD inhibitor dorsomorphin confirms the requirement for the canonical pathway around the time of fusion. These results demonstrate the requirement for BMP signaling in osteoclasts for proper bone homeostasis and also explore the complex signaling mechanisms employed by BMP signaling during osteoclast differentiation.

Identification of Lactobacillus strains with probiotic features from the bottlenose dolphin (Tursiops truncatus)

Aims

In order to develop complementary health management strategies for marine mammals, we used culture-based and culture-independent approaches to identify gastrointestinal lactobacilli of the common bottlenose dolphin, Tursiops truncatus.

Methods and Results

We screened 307 bacterial isolates from oral and rectal swabs, milk and gastric fluid, collected from 38 dolphins in the U.S. Navy Marine Mammal Program, for potentially beneficial features. We focused our search on lactobacilli and evaluated their ability to modulate TNF secretion by host cells and inhibit growth of pathogens. We recovered Lactobacillus salivarius strains which secreted factors that stimulated TNF production by human monocytoid cells. These Lact. salivarius isolates inhibited growth of selected marine mammal and human bacterial pathogens. In addition, we identified a novel Lactobacillus species by culture and direct sequencing with 96·3% 16S rDNA sequence similarity to Lactobacillus ceti.

Conclusions

Dolphin-derived Lact. salivarius isolates possess features making them candidate probiotics for clinical studies in marine mammals.

Significance and Impact of the Study

This is the first study to isolate lactobacilli from dolphins, including a novel Lactobacillus species and a new strain of Lact. salivarius, with potential for veterinary probiotic applications. The isolation and identification of novel Lactobacillus spp. and other indigenous microbes from bottlenose dolphins will enable the study of the biology of symbiotic members of the dolphin microbiota and facilitate the understanding of the microbiomes of these unique animals.

Protein kinase D promotes in vitro osteoclast differentiation and fusion

Although PKD is broadly expressed and involved in numerous cellular processes, its function in osteoclasts has not been previously reported. In this study, we found that PKD2 is the main PKD isoform expressed in osteoclastic cells. PKD phosphorylation, indicative of the activated state, increased after 2-3 days of treatment of bone marrow macrophages with M-CSF and RANKL, corresponding to the onset of preosteoclast fusion. RNAi against PKD2 and treatment with the PKD inhibitor CID755673 showed that PKD activity is dispensable for induction of bone marrow macrophages into tartrate-resistant acid phosphatase-positive preosteoclasts in culture but is required for the transition from mononucleated preosteoclasts to multinucleated osteoclasts. Loss of PKD activity reduced expression of DC-STAMP in RANKL-stimulated cultures. Overexpression of DC-STAMP was sufficient to rescue treatment with CID755673 and restore fusion into multinucleated osteoclasts. From these data, we conclude that PKD activity promotes differentiation of osteoclast progenitors through increased expression of DC-STAMP.

Comparison of Nephrolithiasis Prevalence in Two Bottlenose Dolphin (Tursiops truncatus) Populations

In humans, ammonium urate (AU) nephrolithiasis is rare in the Western hemisphere and more common in Japan and developing countries. Among a variety of risk factors, insulin resistance has been associated with urate nephrolithiasis in people. Bottlenose dolphins (Tursiops truncatus) are susceptible to AU nephrolithiasis, and it is believed that some populations are more likely to develop nephrolithiasis compared to others. In an effort to better understand population-based risk factors for AU nephrolithiasis in dolphins and their comparative value to humans, sonographic evaluation was performed on dolphins from a managed collection in San Diego Bay, CA (n = 40) and dolphins from a free-ranging, nearshore population in Sarasota Bay, FL (n = 39) to look for evidence of nephrolithiasis. While 14 (35%) of San Diego Bay dolphins evaluated for the study had sonographic evidence of nephrolithiasis, none of the Sarasota Bay dolphins had evidence of disease. Presence or absence of stones was confirmed by computed tomography in a subset of the San Diego collection (n = 10; four dolphins with stones, six without stones). Age was identified as a risk factor, as dolphins with stones in the San Diego collection were significantly older than dolphins without stones (25.4 vs. 19.1 years, respectively; P = 0.04). Additionally, San Diego dolphins included in the study were significantly older than Sarasota Bay dolphins (21.3 vs. 13.8 years, respectively; P = 0.008). In addition to the previously reported risk factors of hypocitraturia and hyperinsulinemia in bottlenose dolphins, other potential factors include geographic location, managed vs. free-ranging status, prey species, and feeding schedules.

Development and application of specific cytokine assays in tissue samples from a bottlenose dolphin with hyperinsulinemia

Chronic inflammation has been associated with insulin resistance and type 2 diabetes (T2D) in humans. Postmortem hepatic and splenic tissue from a 46-year-old geriatric male bottlenose dolphin (Tursiops truncatus) with insulin resistance (chronic hyperinsulinemia with hyperglycemia), chronic inflammation (white blood cell count greater than 12,000 cells/μL), and mild fatty liver disease was evaluated for elevated pro-inflammatory mediators. Cytokine mRNA expression in postmortem hepatic and splenic tissue, as determined by real-time PCR, included an array of cytokines: TGF-β, TNF-α, IFN-γ, IL-2, IL-4, IL-10, IL-12p40, IL-13, and IL-18. Values from this dolphin were compared to a younger reference dolphin with no known chronic metabolic perturbations or inflammation. Levels of TGF-β, TNF-α, and IL-4 were higher in the case dolphin's liver compared to that of the reference dolphin. In the case dolphin's spleen, IL-10 and IFN-γ mRNA was upregulated while IL-4 was less than the reference dolphin. IL-18 and IL-13 were upregulated in both tissues. Fluorescent immunohistochemistry (IHC) utilized the following antibodies: anti-porcine IL-6, anti-bovine IFN-γ, IL-4, and IL-10, anti-human TGF-β, anti-ovine IL-1β, and anti-dolphin IL-8. Fluorescent IHC in spleen from the case dolphin revealed staining of IL-4, IL-6, IL-8, and TGF-β throughout the tissue. IL-10 and IFN-γ were seen to predominate in areas surrounding the follicles of splenic tissue. This is the first characterization of cytokine levels in dolphin hepatic and splenic tissue. While there are limitations to a case study, this report of inflammatory biomarkers in tissues of a dolphin with insulin resistance and fatty liver disease are similar to those observed in human patients.

Iron indices in bottlenose dolphins (Tursiops truncatus)

Bottlenose dolphins can have iron overload (that is, hemochromatosis), and managed populations of dolphins may be more susceptible to this disease than are wild dolphins. Serum iron, total iron-binding capacity (TIBC), transferrin saturation, and ferritin were measured in 181 samples from 141 dolphins in 2 managed collections and 2 free-ranging populations. Although no iron indices increased with age among free-ranging dolphins, ferritin increased with age in managed collections. Dolphins from managed collections had higher iron, ferritin, and transferrin saturation values than did free-ranging dolphins. Dolphins with high serum iron (exceeding 300 μg/dL) were more likely to have elevated ferritin but not ceruloplasmin or haptoglobin, demonstrating that high serum levels of iron are due to a true increase in total body iron. A time-series study of 4 dolphins with hemochromatosis that were treated with phlebotomy demonstrated significant decreases in serum ferritin, iron, and TIBC between pre- and posttreatment samples; transferrin saturation initially fell but returned to prephlebotomy levels by 6 mo after treatment. Compared with those in managed collections, wild dolphins were 15 times more likely to have low serum iron (100 μg/dL or less), and this measure was associated with lower haptoglobin. In conclusion, bottlenose dolphins in managed collections are more likely to have greater iron stores than are free-ranging dolphins. Determining why this situation occurs among some dolphin populations and not others may improve the treatment of hemochromatosis in dolphins and provide clues to causes of nonhereditary hemochromatosis in humans.