Angelica gigas: Signature Compounds, In Vivo Anticancer, Analgesic, Neuroprotective and Other Activities, and the Clinical Translation Challenges.

Angelica gigas Nakai (AGN) root is a medicinal herbal widely used in traditional medicine in Korea. AGN root ethanolic extract dietary supplements are marketed in the United States for memory health and pain management. We comprehensively reviewed the anticancer, analgesic, pro-memory and other bio-activities of AGN extract and its signature phytochemicals decursin, decursinol angelate, and decursinol a decade ago in 2012 and updated their anticancer activities in 2015. In the last decade, significant progress has been made for understanding the pharmacokinetics (PK) and metabolism of these compounds in animal models and single dose human PK studies have been published by us and others. In addition to increased knowledge of the known bioactivities, new bioactivities with potential novel health benefits have been reported in animal models of cerebral ischemia/stroke, anxiety, sleep disorder, epilepsy, inflammatory bowel disease, sepsis, metabolic disorders, osteoporosis, osteoarthritis, and even male infertility. Herein, we will update PK and metabolism of pyranocoumarins, review in vivo bioactivities from animal models and human studies, and critically appraise the relevant active compounds, the cellular and molecular pharmacodynamic targets, and pertinent mechanisms of action. Knowledge gaps include whether human pyranocoumarin PK metrics are AGN dose dependent and subjected to metabolic ceiling, or metabolic adaptation after repeated use. Critical clinical translation challenges include sourcing of AGN extracts, product consistency and quality control, and AGN dose optimization for different health conditions and disease indications. Future research directions are articulated to fill knowledge gaps and address these challenges.

Novel treatment of recurrent orbital venolymphatic malformation with sirolimus and rivaroxaban.

Orbital venolymphatic malformations are rare vascular malformations that typically appear early in life and harbor acute and chronic threats to vision. Historically, there are four categories of management: observation, medication, sclerotherapy, and surgery. Currently, there is neither a gold standard for treatment nor randomized control trials comparing treatments.The authors present a 20-year-old male who presented with spontaneous hemorrhage of an orbital venolymphatic malformation occurring with increased frequency and involving more of the posterior orbit. Surgery and sclerotherapy were not feasible options due to the extensive intraorbital and intracranial involvement of the venolymphatic malformation. Systemic steroids treated symptoms but was not curative. To this end, a combination of sirolimus, an mTOR inhibitor, and rivaroxaban, a factor Xa inhibitor, were used to reduce the size of the lesion and minimize the risk of thromboembolic events. This treatment has successfully kept the patient's symptoms in remission for greater than 2 years.

Community pharmacists' perceptions of acceptability, appropriateness, and feasibility of a value-based care model for comprehensive medication management.

BACKGROUND: HealthPartners is an integrated health plan offering comprehensive medication management (CMM) under a value-based care model called Partners in Excellence (PIE). In PIE, participating organizations are incentivized to conduct CMM visits and are eligible for bonus payments if they achieve quality and engagement metrics. Engagement in PIE from community pharmacies has been lacking. Implementation science, specifically the assessment of implementation outcomes, provides key insights into the uptake of patient care services, such as CMM, into practice. OBJECTIVE: To evaluate the acceptability, appropriateness, and feasibility of the PIE program from the perspective of community pharmacists and pharmacy managers. METHODS: Semi-structured, one-on-one qualitative interviews were conducted with a group of 14 pharmacists and pharmacy managers participating in the PIE program. Interviews were coded inductively, and then codes were mapped to the implementation outcomes of acceptability, appropriateness, and feasibility. RESULTS: Twelve codes emerged from the interviews. Four codes (targeted conditions of PIE, achieving PIE metrics, comprehensiveness of PIE, and confusion and barriers) were mapped to acceptability; 3 codes (CMM documentation and billing, fitting CMM into limited time with patients, and community pharmacy's role in patient care) were mapped to appropriateness; and 1 code (collecting clinical patient information) was mapped to feasibility. Four codes (CMM payment model, targeting patients for CMM, personnel for CMM, and patient/provider buy-in of CMM) were considered a combination of more than 1 outcome. CONCLUSIONS: Although the acceptability, appropriateness, and feasibility of the PIE program was generally positive, participants cited a number of implementation challenges related to documentation and billing and producing a sustainable CMM model. The results shed light on how a value-based care model for CMM is perceived within community pharmacies and could inform the development and implementation of similar quality-based CMM programs. DISCLOSURES: This study was funded by the National Association of Chain Drug Stores (NACDS) Foundation and the UNC Eshelman Institute for Innovation. Pestka is affiliated with the University of Minnesota College of Pharmacy and reports grants from NACDS Foundation and UNC Eshelman Institute for Innovation for the conduct of the study; she has also received grants from UNC Eshelman Institute for Innovation and NACDS Foundation outside the submitted work. Stoa and Sorensen are also affiliated with the University of Minnesota College of Pharmacy. Blanchard is employed at the UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill. This work was presented as a virtual poster at the 2020 American College of Clinical Pharmacy Annual Meeting, October 19-30, 2020.

Mycobacterium mageritense infection following mastectomy and breast reconstruction requiring triple antibiotic therapy and surgical debridement.

A 40-year-old woman was referred to infectious disease specialists for a Mycobacterium mageritense skin infection following mastectomy and bilateral reconstruction with deep inferior epigastric perforator flap. Her case demonstrates the difficulty in treating non-tuberculosis mycobacterial infections, especially the rarely seen species. She failed to respond to dual antibiotic therapy containing imipenem-cilastin despite reported sensitivity. Additionally, her course was complicated by intolerance to various regimens, including gastrointestinal distress, a drug rash with eosinophilia and systemic symptoms, and tendinopathy. With few published data, no treatment guidelines, and limited medications from which to choose for M. mageritense, her treatment posed a challenge. She ultimately required aggressive surgical intervention and a triple therapy antibiotic regimen. The duration of our patient's treatment and the extent of her complications suggest a potential need for early surgical intervention in postsurgical wounds infected with M. mageritense that do not respond to conventional treatment.

Chemical composition and biological effects of kratom (Mitragyna speciosa): In vitro studies with implications for efficacy and drug interactions.

The safety and efficacy of kratom (Mitragyna speciosa) for treatment of pain is highly controversial. Kratom produces more than 40 structurally related alkaloids, but most studies have focused on just two of these, mitragynine and 7-hydroxymitragynine. Here, we profiled 53 commercial kratom products using untargeted LC-MS metabolomics, revealing two distinct chemotypes that contain different levels of the alkaloid speciofoline. Both chemotypes were confirmed with DNA barcoding to be M. speciosa. To evaluate the biological relevance of variable speciofoline levels in kratom, we compared the opioid receptor binding activity of speciofoline, mitragynine, and 7-hydroxymitragynine. Mitragynine and 7-hydroxymitragynine function as partial agonists of the human µ-opioid receptor, while speciofoline does not exhibit measurable binding affinity at the µ-, δ- or ƙ-opioid receptors. Importantly, mitragynine and 7-hydroxymitragynine demonstrate functional selectivity for G-protein signaling, with no measurable recruitment of ß-arrestin. Overall, the study demonstrates the unique binding and functional profiles of the kratom alkaloids, suggesting potential utility for managing pain, but further studies are needed to follow up on these in vitro findings. All three kratom alkaloids tested inhibited select cytochrome P450 enzymes, suggesting a potential risk for adverse interactions when kratom is co-consumed with drugs metabolized by these enzymes.

Fungal Bioremediation of Selenium-Contaminated Industrial and Municipal Wastewaters.

Selenium (Se) is an essential element for most organisms yet can cause severe negative biological consequences at elevated levels. The oxidized forms of Se, selenate [Se(VI)] and selenite [Se(IV)], are more mobile, toxic, and bioavailable than the reduced forms of Se such as volatile or solid phases. Thus, selenate and selenite pose a greater threat to ecosystems and human health. As current Se remediation technologies have varying efficiencies and costs, novel strategies to remove elevated Se levels from environments impacted by anthropogenic activities are desirable. Some common soil fungi quickly remove Se (IV and VI) from solution by aerobic reduction to solid or volatile forms. Here, we perform bench-scale culture experiments of two Se-reducing Ascomycota to determine their Se removal capacity in growth media conditions containing either Se(IV) or Se(VI) as well as in Se-containing municipal (∼25 µg/L Se) and industrial (∼2000 µg/L Se) wastewaters. Dissolved Se was measured throughout the experiments to assess Se concentration and removal rates. Additionally, solid-associated Se was quantified at the end of each experiment to determine the amount of Se removed to solid phases (e.g., Se(0) nanoparticles, biomass-adsorbed Se, or internal organic selenoproteins). Results show that under optimal conditions, fungi more efficiently remove Se(IV) from solution compared to Se(VI). Additionally, both fungi remove a higher percentage of Se from the filtered municipal wastewater compared to the industrial wastewater, though cultures in industrial wastewater retained a greater amount of solid-associated Se. Additional wastewater experiments were conducted with supplemental carbohydrate- or glycerin-based carbon products and additional nitrogen- and phosphorous-containing nutrients in some cases to enhance fungal growth. Relative to unamended wastewater experiments, supplemental carbohydrates promote Se removal from municipal wastewater but minimally impact industrial wastewater removal. This demonstrates that carbon availability and source impacts fungal Se reduction and removal from solution. Calculations to assess the leaching potential of solid-associated Se from fungal biomass show that wastewater Se release will not exceed regulatory limits. This study highlights the considerable potential for the mycoremediation of Se-contaminated wastewaters.

Twenty Years of Experience and Counting: Strategies for Growing Medication Therapy Management Services.

DISCLOSURES: No funding supported the writing of this commentary. Brummel has consulted, presented, or was engaged in an advisory board for UCB, Boerhinger Ingelheim, Pfizer, and Lilly. Sorenson has nothing to disclose.

Effects of Manure and Tillage on Edge-of-Field Phosphorus Loss in Seasonally Frozen Landscapes.

Environmental conditions and management practices affect nutrient losses in surface runoff, but their relative impacts on phosphorus (P) loss during frozen and nonfrozen ground periods have not been well quantified. More specifically, the relative importance of manure application, tillage, and soil-test P (STP) has not been assessed at the field scale. In this study, we compiled a dataset composed of 125 site-years of data from 26 fields that were continually monitored for edge-of-field P loss during snowmelt and storm events. Regression tree analyses were performed to rank the level of influence each environmental and management factor had on nutrient loads. Dissolved P (DP) was the majority of the total P (TP) during frozen conditions, but a small portion of TP during nonfrozen conditions. Manure application had a greater influence on the flow-weighted mean concentrations (FWMCs) of TP and DP during frozen conditions than during nonfrozen conditions. No-till resulted in greater TP and DP FWMCs during frozen conditions than conventional tillage, whereas the opposite effect for TP FWMC was seen during nonfrozen conditions. However, regression tree analysis revealed that STP (0- to 5-cm depth) was the most important factor in predicting DP and TP FWMCs during frozen conditions and DP FWMC during nonfrozen conditions. Extremely high STP values were associated with late-frozen manure applications and grazed pastures. Reducing surface P loss in seasonally frozen landscapes will require prioritizing management strategies that avoid manure application through early- and late-frozen conditions and lead to a drawdown of STP, particularly in the top 5 cm.

Trigeminal Autonomic Cephalalgias.

The trigeminal autonomic cephalalgias (TACs) are a group of primary headache syndromes all marked by unilateral headache and ipsilateral cranial autonomic features. The TACs include cluster headache, paroxysmal hemicrania, short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing, and hemicrania continua. Pathophysiology includes the trigeminal pain system, autonomic system, hypothalamus, and more recently an identified role for the vagus nerve. Diagnosis is made after looking at headache frequency, duration, and accompanying symptoms. Each TAC has its own unique treatment, which is discussed in depth.

Linking Cigarette Smoking/Tobacco Exposure and Cluster Headache: A Pathogenesis Theory.

INTRODUCTION: To propose a hypothesis theory to establish a linkage between cigarette smoking and cluster headache pathogenesis. BACKGROUND: Cluster headache is a primary headache syndrome grouped under the trigeminal autonomic cephalalgias. What distinguishes cluster headache from all other primary headache conditions is its inherent connection to cigarette smoking. It is undeniable that tobacco exposure is in some manner related to cluster headache. The connection to tobacco exposure for cluster headache is so strong that even if an individual sufferer never smoked, then that individual typically had significant secondary smoke exposure as a child from parental smoking behavior and in many instances both scenarios exist. The manner by which cigarette smoking is connected to cluster headache pathogenesis is unknown at present. If this could be determined this may contribute to advancing our understanding of cluster headache pathophysiology. METHODS/RESULTS: Hypothesis statement. CONCLUSION: The hypothesis theory will include several principles: (1) the need of double lifetime tobacco exposure, (2) that cadmium is possibly the primary agent in cigarette smoke that leads to hypothalamic-pituitary-gonadal axis toxicity promoting cluster headache, (3) that the estrogenization of the brain and its specific sexually dimorphic nuclei is necessary to develop cluster headache with tobacco exposure, and (4) that the chronic effects of smoking and its toxic metabolites including cadmium and nicotine on the cortex are contributing to the morphometric and orexin alterations that have been previously attributed to the primary headache disorder itself.

An integrative study on biologically recovered polyhydroxyalkanoates (PHAs) and simultaneous assessment of gut microbiome in yellow mealworm.

Polyhydroxyalkanoates (PHAs) are produced in microbes as a source of carbon and energy storage. They are biodegradable and have properties similar to synthetic plastics, which make them an interesting alternative to petroleum-based plastics. In this study, a refined method of recovering PHA from Cupriavidus necator biomass was proposed by incorporating the use of the yellow mealworm (the larval phase of the mealworm beetle, Tenebrio molitor) as partial purification machinery, followed by washing of the fecal pellets with distilled water and sodium hydroxide. The PHA contents of the cells used in this study were 55wt% (produced from palm olein) and 60 wt% (produced from waste animal fats). The treatment of distilled water and NaOH further increased the purity of PHA to 94%. In parallel, analysis of the 16S rRNA metagenomic sequencing of the mealworm gut microbiome has revealed remarkable changes in the bacterial diversity, especially between the mealworms fed with cells produced from palm olein and waste animal fats. This biological recovery of PHA from cells is an attempt to move towards a green and sustainable process with the aim of reducing the use of harmful solvents and strong chemicals during polymer purification. The results obtained show that - purities of >90%, without a reduction in the molecular weight, can be obtained through this integrative biological recovery approach. In addition, this study has successfully shown that the cells, regardless of their origins, were readily consumed by the mealworms, and there is a correlation between the feed type and the mealworm gut microbiome.

Magnetic Extraction of Acinetobacter baumannii Using Colistin-Functionalized γ-Fe2O3/Au Core/Shell Composite Nanoclusters.

Acinetobacter baumannii is a Gram-negative bacterium of increasing concern due to its virulence and persistence in combat and healthcare environments. The incidence of both community-acquired and nosocomial A. baumannii infections is on the rise in foreign and domestic healthcare facilities. Treatment options are limited due to the acquisition of multidrug resistance to the few effective antibiotics. Currently, the most effective pharmaceutically based treatment for multidrug-resistant A. baumannii infections is the antibiotic colistin (polymyxin E). To minimize side effects associated with administration of colistin or other toxic antimicrobial agents, we propose the development of a nanotechnology-mediated treatment strategy. In this design-based effort, colistin-functionalized multilayered, inorganic, magnetoplasmonic nanoconstructs were fabricated to bind to the surface of A. baumannii. This result, for the first time, demonstrates a robust, pharmaceutical-based motif for high affinity, composite nanoparticulates targeting the A. baumannii surface. The antibiotic-activated nanomaterials demonstrated cytocompatibility with human cells and no acute bacterial toxicity at nanoparticle to bacterial concentrations <10 000:1. The magnetomotive characteristics of the nanomaterial enabled magnetic extraction of the bacteria. In a macroscale environment, maximal separation efficiencies exceeding 38% were achieved. This result demonstrates the potential for implementation of this technology into micro- or mesofluidic-based separation environments to enhance extraction efficiencies. The future development of such a mesofluidic-based, nanotechnology-mediated platform is potentially suitable for adjuvant therapies to assist in the treatment of sepsis.

A Negative Allosteric Modulator for α5 Subunit-Containing GABA Receptors Exerts a Rapid and Persistent Antidepressant-Like Action without the Side Effects of the NMDA Receptor Antagonist Ketamine in Mice.

New antidepressant pharmacotherapies that provide rapid relief of depressive symptoms are needed. The NMDA receptor antagonist ketamine exerts rapid antidepressant actions in depressed patients but also side effects that complicate its clinical utility. Ketamine promotes excitatory synaptic strength, likely by producing high-frequency correlated activity in mood-relevant regions of the forebrain. Negative allosteric modulators of GABA-A receptors containing α5 subunits (α5 GABA-NAMs) should also promote high-frequency correlated electroencephalogram (EEG) activity and should therefore exert rapid antidepressant responses. Because α5 subunits display a restricted expression in the forebrain, we predicted that α5 GABA-NAMs would produce activation of principle neurons but exert fewer side effects than ketamine. We tested this hypothesis in male mice and observed that the α5 GABA-NAM MRK-016 exerted an antidepressant-like response in the forced swim test at 1 and 24 h after administration and an anti-anhedonic response after chronic stress in the female urine sniffing test (FUST). Like ketamine, MRK-016 produced a transient increase in EEG γ power, and both the increase in γ power and its antidepressant effects in the forced swim test were blocked by prior administration of the AMPA-type glutamate receptor antagonist 2,3-dioxo-6-nitro-1,2,3,4-tetrahydrobenzo[f]quinoxaline-7-sulfonamide (NBQX). Unlike ketamine, however, MRK-016 produced no impairment of rota-rod performance, no reduction of prepulse inhibition (PPI), no conditioned-place preference (CPP), and no change in locomotion. α5 GABA-NAMs, thus reproduce the rapid antidepressant-like actions of ketamine, perhaps via an AMPA receptor (AMPAR)-dependent increase in coherent neuronal activity, but display fewer potential negative side effects. These compounds thus demonstrate promise as clinically useful fast-acting antidepressants.

Sorafenib combined with HER-2 targeted vaccination can promote effective T cell immunity in vivo.

The tumor microenvironment (TME) is established and maintained through complex interactions between tumor cells and host stromal elements. Therefore, therapies that target multiple cellular components of the tumor may be most effective. Sorafenib, a multi-kinase inhibitor, alters signaling pathways in both tumor cells and host stromal cells. Thus, we explored the potential immune-modulating effects of sorafenib in a murine HER-2-(neu) overexpressing breast tumor model alone and in combination with a HER-2 targeted granulocyte-macrophage colony-stimulating factor (GM-CSF)-secreting vaccine (3T3neuGM). In vitro, sorafenib inhibited the growth of HER-2 overexpressing NT2.5 tumor cells, inducing apoptosis. Sorafenib also interfered with ERK MAPK, p38 MAPK, and STAT3 signaling, as well as cyclin D expression, but did not affect HER-2 or AKT signaling. In vivo, single agent sorafenib disrupted the tumor-associated vasculature and induced tumor cell apoptosis, effectively inducing the regression of established NT2.5 tumors in immune competent FVB/N mice. Immune depletion studies demonstrated that both CD4+ and CD8+ T cells were required for tumor regression. Sorafenib treatment did not impact the rate of tumor clearance induced by vaccination with 3T3neuGM in tumor-bearing FVB/N mice relative to either sorafenib treatment or vaccination alone. In vivo studies further demonstrated that sorafenib enhanced the accumulation of both CD4+ and CD8+ T cells into the TME of vaccinated mice. Together, these findings suggest that GM-CSF-secreting cellular immunotherapy may be integrated with sorafenib without impairing vaccine-based immune responses.

Attitudes of Family Medicine Program Directors Toward Osteopathic Residents Under the Single Accreditation System.

BACKGROUND: Between 2015 and 2020, residency programs accredited through the American Osteopathic Association (AOA) are preparing the single graduate medical education (GME) system through the Accreditation Council for Graduate Medical Education (ACGME). OBJECTIVES: (1) To assess the attitudes of family medicine program directors in programs accredited dually by the AOA and ACGME (AOA/ACGME) or ACGME only toward the clinical and academic preparedness of osteopathic residency candidates and (2) to determine program director attitudes toward the perceived value of osteopathic-focused education, including osteopathic manipulative treatment (OMT) curricula. METHODS: A survey was sent to program directors of AOA/ACGME and ACGME-only accredited family medicine residency programs. Items concerned program directors' perception of the academic and clinical strength of osteopathic residents at the onset of residency, the presence of osteopathic faculty and residents currently in the program, and the presence of formal curricula for teaching OMT. The perceived value of osteopathic focus was obtained through a composite score of 5 items. RESULTS: A total of 38 AOA/ACGME family medicine residency program directors (17%) and 211 ACGME family medicine residency program directors (45.6%) completed the survey (N=249). No difference was found in the ranking of the perceived clinical preparation of osteopathic residents vs allopathic residents in programs with and without OMT curricula (P=.054). Directors of programs with OMT curricula perceived the academic preparation of their osteopathic residents vs allopathic residents more highly than those without OMT curricula (P=.039). Directors of AOA/ACGME programs perceived both the academic preparation and clinical preparation of their osteopathic residents more highly than those at ACGME-only programs (P=.004 and P=.002, respectively). CONCLUSION: Directors of AOA/ACGME programs, as well as those whose programs have an osteopathic focus in curricular offerings, were more likely to rank the academic preparation of osteopathic residents higher than directors of ACGME-only programs and those without OMT curricula. Further research is needed to determine the value of osteopathic recognition in attracting strong family medicine residency candidates.

The LUGPA Alternative Payment Model for Initial Therapy of Newly Diagnosed Patients With Organ-confined Prostate Cancer: Rationale and Development.

Over the past several decades, rapid expansion in healthcare expenditures has exposed the utilization incentives inherent in fee-for-service payment models. The passage of Medicare Access and CHIP Reauthorization Act of 2015 heralded a transition toward value-based care, creating incentives for practitioners to accept bidirectional risk linked to outcome and utilization metrics. At present, the limited availability of these vehicles excludes all but a handful of providers from participation in alternative payment models (APMs). The LUGPA APM supports the goals of the triple aim in improving the patient experience, enhancing population health and reducing expenditures. By requiring utilization of certified electronic health record technologies, tying payment to quality metrics, and requiring practices to bear more than nominal risk, the LUGPA APM qualifies as an advanced APM, thereby easing the reporting burden and creating opportunities for participating practices.

National Institutes of Health Pathways to Prevention Workshop: Advancing Research to Prevent Youth Suicide.

The National Institutes of Health (NIH) Pathways to Prevention Workshop "Advancing Research to Prevent Youth Suicide" was cosponsored by the NIH Office of Disease Prevention, National Institute of Mental Health, National Institute on Drug Abuse, and National Center for Complementary and Integrative Health. A multidisciplinary working group developed the agenda, and an evidence-based practice center prepared an evidence report that addressed data systems relevant to suicide prevention efforts through a contract with the Agency for Healthcare Research and Quality. During the workshop, experts discussed the evidence and participants commented during open forums. After considering the data from the evidence report, expert presentations, and public comments, an independent panel prepared a draft report that was posted on the NIH Office of Disease Prevention Web site for 5 weeks for public comment. This abridged version of the final report provides a road map for optimizing youth suicide prevention efforts by highlighting strategies for guiding the next decade of research in this area. These strategies include recommendations for improving data systems, enhancing data collection and analysis methods, and strengthening the research and practice community.

Novel Approaches to the Management of Sleep-Disordered Breathing.

In the last several years, a variety of novel approaches to the treatment of sleep-disordered breathing have emerged. This new technology holds promise in serving to re-engage with patients who have previously been lost to follow-up due to continuous positive airway pressure intolerance. With more tools at our disposal, in turn more options can be offered to patients' growing demand for alternatives that are tailored to their individual needs. The key to proper deployment of alternative therapies will often depend on identification of certain phenotypic traits that trend toward a reasonable response to a given therapy.

Preclinical evaluation of RNAi as a treatment for transthyretin-mediated amyloidosis.

ATTR amyloidosis is a systemic, debilitating and fatal disease caused by transthyretin (TTR) amyloid accumulation. RNA interference (RNAi) is a clinically validated technology that may be a promising approach to the treatment of ATTR amyloidosis. The vast majority of TTR, the soluble precursor of TTR amyloid, is expressed and synthesized in the liver. RNAi technology enables robust hepatic gene silencing, the goal of which would be to reduce systemic levels of TTR and mitigate many of the clinical manifestations of ATTR that arise from hepatic TTR expression. To test this hypothesis, TTR-targeting siRNAs were evaluated in a murine model of hereditary ATTR amyloidosis. RNAi-mediated silencing of hepatic TTR expression inhibited TTR deposition and facilitated regression of existing TTR deposits in pathologically relevant tissues. Further, the extent of deposit regression correlated with the level of RNAi-mediated knockdown. In comparison to the TTR stabilizer, tafamidis, RNAi-mediated TTR knockdown led to greater regression of TTR deposits across a broader range of affected tissues. Together, the data presented herein support the therapeutic hypothesis behind TTR lowering and highlight the potential of RNAi in the treatment of patients afflicted with ATTR amyloidosis.

Arsenite Disrupts Zinc-Dependent TGFß2-SMAD Activity During Murine Cardiac Progenitor Cell Differentiation.

TGFß2 (transforming growth factor-ß2) is a key growth factor regulating epithelial to mesenchymal transition (EMT). TGFß2 triggers cardiac progenitor cells to differentiate into mesenchymal cells and give rise to the cellular components of coronary vessels as well as cells of aortic and pulmonary valves. TGFß signaling is dependent on a dynamic on and off switch in Smad activity. Arsenite exposure of 1.34 µM for 24-48 h has been reported to disrupt Smad phosphorylation leading to deficits in TGFß2-mediated cardiac precursor differentiation and transformation. In this study, the molecular mechanism of acute arsenite toxicity on TGFß2-induced Smad2/3 nuclear shuttling and TGFß2-mediated cardiac EMT was investigated. A 4-h exposure to 5 µM arsenite blocks nuclear accumulation of Smad2/3 in response to TGFß2 without disrupting Smad phosphorylation or nuclear importation. The depletion of nuclear Smad is restored by knocking-down Smad-specific exportins, suggesting that arsenite augments Smad2/3 nuclear exportation. The blockage in TGFß2-Smad signaling is likely due to the loss of Zn(2+) cofactor in Smad proteins, as Zn(2+) supplementation reverses the disruption in Smad2/3 nuclear translocation and transcriptional activity by arsenite. This coincides with Zn(2+) supplementation rescuing arsenite-mediated deficits in cardiac EMT. Thus, zinc partially protects cardiac EMT from developmental toxicity by arsenite.