Selective PP2A Enhancement through Biased Heterotrimer Stabilization.

Impairment of protein phosphatases, including the family of serine/threonine phosphatases designated PP2A, is essential for the pathogenesis of many diseases, including cancer. The ability of PP2A to dephosphorylate hundreds of proteins is regulated by over 40 specificity-determining regulatory "B" subunits that compete for assembly and activation of heterogeneous PP2A heterotrimers. Here, we reveal how a small molecule, DT-061, specifically stabilizes the B56α-PP2A holoenzyme in a fully assembled, active state to dephosphorylate selective substrates, such as its well-known oncogenic target, c-Myc. Our 3.6 Å structure identifies molecular interactions between DT-061 and all three PP2A subunits that prevent dissociation of the active enzyme and highlight inherent mechanisms of PP2A complex assembly. Thus, our findings provide fundamental insights into PP2A complex assembly and regulation, identify a unique interfacial stabilizing mode of action for therapeutic targeting, and aid in the development of phosphatase-based therapeutics tailored against disease specific phospho-protein targets.

Shaping the future of kidney genetics in Australia: proceedings from the KidGen policy implementation workshop 2023.

The KidGen Collaborative's Policy Implementation Workshop 2023 celebrated the 10th anniversary of Australia's first kidney genetics clinic in Brisbane. This event marked the establishment of a national network now comprising 19 kidney genetics clinics across Australia, all dedicated to providing equitable access to genomic testing for families affected by genetic kidney diseases. The workshop reflected on past progress and outlined future objectives for kidney genetics in Australia, recognising the collaborative efforts of clinical teams, researchers, and patients. Key insights from the workshop are documented in the proceedings.

Biased holoenzyme assembly of protein phosphatase 2A (PP2A): From cancer to small molecules.

Protein phosphatase 2A (PP2A) is a family of serine threonine phosphatases responsible for regulating protein phosphorylation, thus opposing the activity of cellular kinases. PP2A is composed of a catalytic subunit (PP2A Cα/ß) and scaffolding subunit (PP2A Aα/ß) and various substrate-directing B regulatory subunits. PP2A biogenesis is regulated at multiple levels. For example, the sequestration of the free catalytic subunit during the process of biogenesis avoids promiscuous phosphatase activity. Posttranslational modifications of PP2A C direct PP2A heterotrimeric formation. Additionally, PP2A functions as a haploinsufficient tumor suppressor, where attenuated PP2A enzymatic activity creates a permissive environment for oncogenic transformation. Recent work studying PP2A in cancer showed that its role in tumorigenesis is more nuanced, with some holoenzymes being tumor suppressive, while others are required for oncogenic transformation. In cancer biology, PP2A function is modulated through various mechanisms including the displacement of specific B regulatory subunits by DNA tumor viral antigens, by recurrent mutations, and through loss of carboxymethyl-sensitive heterotrimeric complexes. In aggregate, these alterations bias PP2A activity away from its tumor suppressive functions and toward oncogenic ones. From a therapeutic perspective, molecular glues and disruptors present opportunities for both the selective stabilization of tumor-suppressive holoenzymes and disruption of holoenzymes that are pro-oncogenic. Collectively, these approaches represent an attractive cancer therapy for a wide range of tumor types. This review will discuss the mechanisms by which PP2A holoenzyme formation is dysregulated in cancer and the current therapies that are aimed at biasing heterotrimer formation of PP2A for the treatment of cancer.

The Biochemical Assessment of Mitochondrial Respiratory Chain Disorders.

Mitochondrial respiratory chain (MRC) disorders are a complex group of diseases whose diagnosis requires a multidisciplinary approach in which the biochemical investigations play an important role. Initial investigations include metabolite analysis in both blood and urine and the measurement of lactate, pyruvate and amino acid levels, as well as urine organic acids. Recently, hormone-like cytokines, such as fibroblast growth factor-21 (FGF-21), have also been used as a means of assessing evidence of MRC dysfunction, although work is still required to confirm their diagnostic utility and reliability. The assessment of evidence of oxidative stress may also be an important parameter to consider in the diagnosis of MRC function in view of its association with mitochondrial dysfunction. At present, due to the lack of reliable biomarkers available for assessing evidence of MRC dysfunction, the spectrophotometric determination of MRC enzyme activities in skeletal muscle or tissue from the disease-presenting organ is considered the 'Gold Standard' biochemical method to provide evidence of MRC dysfunction. The purpose of this review is to outline a number of biochemical methods that may provide diagnostic evidence of MRC dysfunction in patients.

Pre-implementation Evaluation of PARTNER-MH: A Mental Healthcare Disparity Intervention for Minority Veterans in the VHA.

To design PARTNER-MH, a peer-led, patient navigation program for implementation in Veterans Health Administration (VHA) mental health care settings, we conducted a pre-implementation evaluation during intervention development to assess stakeholders' views of the intervention and to explore implementation factors critical to its future adoption. This is a convergent mixed-methods study that involved qualitative semi-structured interviews and survey data. Data collection was guided by the Consolidated Framework for Implementation Research (CFIR). We interviewed and administered the surveys to 23 peers and 10 supervisors from 12 midwestern VHA facilities. We used deductive and inductive approaches to analyze the qualitative data. We also conducted descriptive analysis and Fisher Exact Test to compare peers and supervisors' survey responses. We triangulated findings to refine the intervention. Overall, participants viewed PARTNER-MH favorably. However, they saw the intervention's focus on minority Veterans and social determinants of health framework as potential barriers, believing this could negatively affect the packaging of the intervention, complicate its delivery process, and impact its adoption. They also viewed clinic structures, available resources, and learning climate as potential barriers. Peers and supervisors' selections and discussions of CFIR items were similar. Our findings informed PARTNER-MH development and helped identify factors that could impact its implementation. This project is responsive to the increasing recognition of the need to incorporate implementation science in healthcare disparities research. Understanding the resistance to the intervention's focus on minority Veterans and the potential barriers presented by contextual factors positions us to adjust the intervention prior to testing, in an effort to maximize implementation success.

Protein phosphatase 2A Aα regulates Aß protein expression and stability.

Protein phosphatase 2A (PP2A) represses many oncogenic signaling pathways and is an important tumor suppressor. PP2A comprises three distinct subunits and forms through a highly regulated biogenesis process, with the scaffolding A subunit existing as two highly related isoforms, Aα and Aß. PP2A's tumor-suppressive functions have been intensely studied, and PP2A inactivation has been shown to be a prerequisite for tumor formation. Interestingly, although partial loss of the Aα isoform is growth promoting, complete Aα loss has no transformative properties. Additionally, in cancer patients, Aα is found to be inactivated in a haploinsufficient manner. Using both cellular and in vivo systems, colorectal and endometrial cancer cell lines, and biochemical and cellular assays, here we examined why the complete loss of Aα does not promote tumorigenesis. CRISPR/Cas9-mediated homozygous Aα deletion resulted in decreased colony formation and tumor growth across multiple cell lines. Protein expression analysis of PP2A family members revealed that the Aα deletion markedly up-regulates Aß protein expression by increasing Aß protein stability. Aß knockdown in control and Aα knockout cell lines indicated that Aß is necessary for cell survival in the Aα knockout cells. In the setting of Aα deficiency, co-immunoprecipitation analysis revealed increased binding of specific PP2A regulatory subunits to Aß, and knockdown of these regulatory subunits restored colony-forming ability. Taken together, our results uncover a mechanism by which PP2A Aα regulates Aß protein stability and activity and suggests why homozygous loss of Aα is rarely seen in cancer patients.

Protein phosphatase 2A controls ongoing DNA replication by binding to and regulating cell division cycle 45 (CDC45).

Genomic replication is a highly regulated process and represents both a potential benefit and liability to rapidly dividing cells; however, the precise post-translational mechanisms regulating genomic replication are incompletely understood. Protein phosphatase 2A (PP2A) is a serine/threonine phosphatase that regulates a diverse array of cellular processes. Here, utilizing both a gain-of-function chemical biology approach and loss-of-function genetic approaches to modulate PP2A activity, we found that PP2A regulates DNA replication. We demonstrate that increased PP2A activity can interrupt ongoing DNA replication, resulting in a prolonged S phase. The impaired replication resulted in a collapse of replication forks, inducing dsDNA breaks, homologous recombination, and a PP2A-dependent replication stress response. Additionally, we show that during replication, PP2A exists in complex with cell division cycle 45 (CDC45) and that increased PP2A activity caused dissociation of CDC45 and polymerase α from the replisome. Furthermore, we found that individuals harboring mutations in the PP2A Aα gene have a higher fraction of genomic alterations, suggesting that PP2A regulates ongoing replication as a mechanism for maintaining genomic integrity. These results reveal a new function for PP2A in regulating ongoing DNA replication and a potential role for PP2A in the intra-S-phase checkpoint.

Sustainability of improvements in perinatal teamwork and safety climate.

The purposes of this study were to describe changes in perinatal nurse (n = 70) and physician (n = 88) perceptions of teamwork and safety climate after implementing a 6-month Crew Resource Management training program and compare responses between nurses and physicians. The Teamwork and Safety Climate Survey was administered prior to and 1 year after the intervention. There were significant improvements in nurse and physician perceptions of teamwork and safety climate; however, physicians perceived teamwork more positive than nurses.

Effects of Two Group Prenatal Care Interventions on Mental Health: An RCT.

INTRODUCTION: Perinatal depression and anxiety cost the U.S. health system $102 million annually and result in adverse health outcomes. Research supports that cognitive behavioral therapy improves these conditions, but barriers to obtaining cognitive behavioral therapy have prevented its success in pregnant individuals. In this study, the impact of a cognitive behavioral therapy-based intervention on anxiety, depression, stress, healthy lifestyle beliefs, and behaviors in pregnant people was examined. STUDY DESIGN: This study used a 2-arm RCT design, embedded in group prenatal care, with one arm receiving a cognitive behavioral therapy-based Creating Opportunities for Personal Empowerment program and the other receiving health promotion content. SETTING/PARTICIPANTS: Black and Hispanic participants (n=299) receiving prenatal care from 2018 to 2022 in New York and Ohio who screened high on 1 of 3 mental health measures were eligible to participate. INTERVENTION: Participants were randomized into the manualized Creating Opportunities for Personal Empowerment cognitive behavioral therapy-based program, with cognitive behavioral skill-building activities delivered by advanced practice nurses in the obstetrical setting. MAIN OUTCOME MEASURES: Outcomes included anxiety, depression, and stress symptoms using valid and reliable tools (Generalized Anxiety Disorder scale, Edinburgh Postnatal Depression Scale, and Perceived Stress Scale). The Healthy Lifestyle Beliefs and Behaviors Scales examined beliefs about maintaining a healthy lifestyle and reported healthy behaviors. RESULTS: There were no statistically significant differences between groups in anxiety, depression, stress, healthy beliefs, and behaviors. There were significant improvements in all measures over time. There were statistically significant decreases in anxiety, depression, and stress from baseline to intervention end, whereas healthy beliefs and behaviors significantly increased. CONCLUSIONS: Both cognitive behavioral therapy and health promotion content embedded in group prenatal care with advanced practice nurse delivery improved mental health and healthy lifestyle beliefs and behaviors at a time when perinatal mood generally worsens. TRIAL REGISTRATION: This study is registered with clinicaltrials.gov NCT03416010.

Integrated stress response plasticity governs normal cell adaptation to chronic stress via the PP2A-TFE3-ATF4 pathway.

The integrated stress response (ISR) regulates cell fate during conditions of stress by leveraging the cell's capacity to endure sustainable and efficient adaptive stress responses. Protein phosphatase 2A (PP2A) activity modulation has been shown to be successful in achieving both therapeutic efficacy and safety across various cancer models; however, the molecular mechanisms driving its selective antitumor effects remain unclear. Here, we show for the first time that ISR plasticity relies on PP2A activation to regulate drug response and dictate cellular fate under conditions of chronic stress. We demonstrate that genetic and chemical modulation of the PP2A leads to chronic proteolytic stress and triggers an ISR to dictate cell fate. More specifically, we uncovered that the PP2A-TFE3-ATF4 pathway governs ISR cell plasticity during endoplasmic reticular and cellular stress independent of the unfolded protein response. We further show that normal cells reprogram their genetic signatures to undergo ISR-mediated adaptation and homeostatic recovery thereby successfully avoiding toxicity following PP2A-mediated stress. Conversely, oncogenic specific cytotoxicity induced by chemical modulation of PP2A is achieved by activating chronic and irreversible ISR in cancer cells. Our findings propose that a differential response to chemical modulation of PP2A is determined by intrinsic ISR plasticity, providing a novel biological vulnerability to selectively induce cancer cell death and improve targeted therapeutic efficacy.

Integrated stress response plasticity governs normal cell adaptation to chronic stress via the PP2A-TFE3-ATF4 pathway.

The integrated stress response (ISR) regulates cell fate during conditions of stress by leveraging the cell's capacity to endure sustainable and efficient adaptive stress responses. Protein phosphatase 2A (PP2A) activity modulation has been shown to be successful in achieving both therapeutic efficacy and safety across various cancer models. However, the molecular mechanisms driving its selective antitumor effects remain unclear. Here, we show for the first time that ISR plasticity relies on PP2A activation to regulate drug response and dictate cellular survival under conditions of chronic stress. We demonstrate that genetic and chemical modulation of the PP2A leads to chronic proteolytic stress and triggers an ISR to dictate whether the cell lives or dies. More specifically, we uncovered that the PP2A-TFE3-ATF4 pathway governs ISR cell plasticity during endoplasmic reticular and cellular stress independent of the unfolded protein response. We further show that normal cells reprogram their genetic signatures to undergo ISR-mediated adaptation and homeostatic recovery thereby avoiding toxicity following PP2A-mediated stress. Conversely, oncogenic specific cytotoxicity induced by chemical modulation of PP2A is achieved by activating chronic and irreversible ISR in cancer cells. Our findings propose that a differential response to chemical modulation of PP2A is determined by intrinsic ISR plasticity, providing a novel biological vulnerability to selectively induce cancer cell death and improve targeted therapeutic efficacy.

A comparative analysis of cryopreserved versus prehydrated human acellular dermal matrices in tissue expander breast reconstruction.

BACKGROUND: The use of human acellular dermal matrices (HADMs) in breast reconstruction has become routine practice for many reconstructive surgeons. Comparative studies between 2 more common iterations of human acellular dermis are scarce. Our study evaluated reconstructive outcomes of cryopreserved and prehydrated HADMs in comparative fashion. METHODS: This study is a retrospective review of 369 consecutive tissue expander breast reconstructions performed by 2 board-certified plastic surgeons whose practice focuses on breast reconstruction. Data were collected independently by 2 reviewers, and a comparative analysis for statistical significance of outcomes was performed using the Fisher exact test, 2-tailed independent t tests, and regression analysis where appropriate. RESULTS: Over a 5-year period, 255 patients (369 breasts) underwent breast reconstruction utilizing either cryopreserved or prehydrated HADM. Of the total, 136 breasts received cryopreserved and 233 breasts received prehydrated HADMs. The total complication rates for cryopreserved and prehydrated HADMs were 19.1% and 19.3% (P = 1.0), respectively. Additional complication rates were calculated for flap necrosis (8.1% vs 9.0%, P = 0.849), infection requiring intravenous antibiotics (10.3% vs 5.2%, P = 0.09), hematoma (2.9% vs 1.3%, P = 0.431), seroma (2.2% vs 1.0%, P = 1.0), expander exposure/dehiscence (5.9% vs 6.4%, P = 1.0), and number of breasts requiring autologous reconstruction after a complication (4.4% vs 6.4%, P = 0.491). On regression analysis, HADM type was not an independent risk factor for any complication subtype. CONCLUSIONS: The results of this study suggest that there are no significant differences in complication rates between cryopreserved and prehydrated HADMs.

A generic approach to construct pseudo components for oil weathering models.

Oil weathering models are essential for predicting the behavior of spilled oil in the environment. Most models use a "Pseudo Component" (PC) approach to represent the wide range of compounds found in petroleum products. Within the approach, rather than modeling each individual compound in an oil, a manageable number of PCs are developed that represent whole classes of compounds. However, previous studies focused mainly on traditional crude oils and did not develop a generic approach to create an optimal set of PCs for a variety of oils. In developing the updates to the NOAA oil weathering model, we propose herein a generic approach to construct PCs using oil distillation data to capture the complexity of oil evaporative weathering. We validated our approach with 899 oils from the Automated Data Inquiry for Oil Spills (ADIOS) oil library and found that an optimal set of sixteen PCs should be used. These PCs include two with low boiling point (below 144 °C), one with a high boiling point (above 400 °C), and thirteen constructed within a middle range of boiling points with a temperature resolution of 20 °C. Our simulation tests suggested that this set of sixteen PCs adequately characterizes oil evaporation processes for a wide variety of oils.

Depression, anxiety, and stress in pregnant Black people: A case for screening and evidence-based intervention.

BACKGROUND: Guidelines call for pregnant people to be screened for depression and anxiety. Screening may be particularly important for pregnant Black individuals who are reported to be more likely than non-Hispanic White pregnant people to experience prenatal stress, anxiety, and depressive symptoms. The purpose of this study was to determine if depression, anxiety, and stress co-occur in pregnant Black people and to identify which demographic factors are related to these mental health concerns. METHODS: A subset analysis of an ongoing randomized controlled trial examined the risk of coexisting mental health conditions in pregnant Black people who screened eligible to participate (that is, they had high levels of depression, anxiety, and/or stress) in two urban clinics using a descriptive correlational design. RESULTS: Of the 452 pregnant Black people who were screened for eligibility, 194 (42.9%) had elevated scores on depression, anxiety, and/or stress measures and were enrolled in the larger study. The average scores of the 194 enrolled participants were anxiety, mean (M) = 9.16 (standard deviation [SD] = 4.30); depression, M = 12.80 (SD = 4.27); and stress, M = 21.79 (SD = 4.76). More than one-third (n = 70, 36.1%) experienced two symptoms and 64 (33.0%) reported all three symptoms. CONCLUSION: Pregnant Black individuals experience high levels of comorbid mental health distress including depression, anxiety, and stress. The findings indicate that treatment for mental health concerns needs to be broad-based and effective for all three conditions. Prenatal interventions should aim to address mental health distress through screening and treatment of depression, anxiety, and stress, especially for pregnant Black individuals. This study furthers understanding of the prevalence of prenatal mental health conditions in pregnant Black people.

PP2A modulation overcomes multidrug resistance in chronic lymphocytic leukemia via mPTP-dependent apoptosis.

Targeted therapies such as venetoclax (VEN) (Bcl-2 inhibitor) have revolutionized the treatment of chronic lymphocytic leukemia (CLL). We previously reported that persister CLL cells in treated patients overexpress multiple antiapoptotic proteins and display resistance to proapoptotic agents. Here, we demonstrated that multidrug-resistant CLL cells in vivo exhibited apoptosis restriction at a pre-mitochondrial level due to insufficient activation of the Bax and Bak (Bax/Bak) proteins. Co-immunoprecipitation analyses with selective BH domain antagonists revealed that the pleiotropic proapoptotic protein (Bim) was prevented from activating Bax/Bak by "switching" interactions to other upregulated antiapoptotic proteins (Mcl-1, Bcl-xL, Bcl-2). Hence, treatments that bypass Bax/Bak restriction are required to deplete these resistant cells in patients. Protein phosphatase 2A (PP2A) contributes to oncogenesis and treatment resistance. We observed that small-molecule activator of PP2A (SMAP) induced cytotoxicity in multiple cancer cell lines and CLL samples, including multidrug-resistant leukemia and lymphoma cells. The SMAP (DT-061) activated apoptosis in multidrug-resistant CLL cells through induction of mitochondrial permeability transition pores, independent of Bax/Bak. DT-061 inhibited the growth of wild-type and Bax/Bak double-knockout, multidrug-resistant CLL cells in a xenograft mouse model. Collectively, we discovered multidrug-resistant CLL cells in patients and validated a pharmacologically tractable pathway to deplete this reservoir.

Small-Molecule-Mediated Stabilization of PP2A Modulates the Homologous Recombination Pathway and Potentiates DNA Damage-Induced Cell Death.

High-grade serous carcinoma (HGSC) is the most common and lethal ovarian cancer subtype. PARP inhibitors (PARPi) have become the mainstay of HGSC-targeted therapy, given that these tumors are driven by a high degree of genomic instability (GI) and homologous recombination (HR) defects. Nonetheless, approximately 30% of patients initially respond to treatment, ultimately relapsing with resistant disease. Thus, despite recent advances in drug development and an increased understanding of genetic alterations driving HGSC progression, mortality has not declined, highlighting the need for novel therapies. Using a small-molecule activator of protein phosphatase 2A (PP2A; SMAP-061), we investigated the mechanism by which PP2A stabilization induces apoptosis in patient-derived HGSC cells and xenograft (PDX) models alone or in combination with PARPi. We uncovered that PP2A genes essential for cellular transformation (B56α, B56γ, and PR72) and basal phosphatase activity (PP2A-A and -C) are heterozygously lost in the majority of HGSC. Moreover, loss of these PP2A genes correlates with worse overall patient survival. We show that SMAP-061-induced stabilization of PP2A inhibits the HR output by targeting RAD51, leading to chronic accumulation of DNA damage and ultimately apoptosis. Furthermore, combination of SMAP-061 and PARPi leads to enhanced apoptosis in both HR-proficient and HR-deficient HGSC cells and PDX models. Our studies identify PP2A as a novel regulator of HR and indicate PP2A modulators as a therapeutic therapy for HGSC. In summary, our findings further emphasize the potential of PP2A modulators to overcome PARPi insensitivity, given that targeting RAD51 presents benefits in overcoming PARPi resistance driven by BRCA1/2 mutation reversions.

Loss of LCMT1 and biased protein phosphatase 2A heterotrimerization drive prostate cancer progression and therapy resistance.

Loss of the tumor suppressive activity of the protein phosphatase 2A (PP2A) is associated with cancer, but the underlying molecular mechanisms are unclear. PP2A holoenzyme comprises a heterodimeric core, a scaffolding A subunit and a catalytic C subunit, and one of over 20 distinct substrate-directing regulatory B subunits. Methylation of the C subunit regulates PP2A heterotrimerization, affecting B subunit binding and substrate specificity. Here, we report that the leucine carboxy methyltransferase (LCMT1), which methylates the L309 residue of the C subunit, acts as a suppressor of androgen receptor (AR) addicted prostate cancer (PCa). Decreased methyl-PP2A-C levels in prostate tumors is associated with biochemical recurrence and metastasis. Silencing LCMT1 increases AR activity and promotes castration-resistant prostate cancer growth. LCMT1-dependent methyl-sensitive AB56αCme heterotrimers target AR and its critical coactivator MED1 for dephosphorylation, resulting in the eviction of the AR-MED1 complex from chromatin and loss of target gene expression. Mechanistically, LCMT1 is regulated by S6K1-mediated phosphorylation-induced degradation requiring the ß-TRCP, leading to acquired resistance to anti-androgens. Finally, feedforward stabilization of LCMT1 by small molecule activator of phosphatase (SMAP) results in attenuation of AR-signaling and tumor growth inhibition in anti-androgen refractory PCa. These findings highlight methyl-PP2A-C as a prognostic marker and that the loss of LCMT1 is a major determinant in AR-addicted PCa, suggesting therapeutic potential for AR degraders or PP2A modulators in prostate cancer treatment.

Critical role for leukocyte hypoxia inducible factor-1alpha expression in post-myocardial infarction left ventricular remodeling.

RATIONALE: Hypoxia inducible factor (HIF)-1alpha is a transcription factor stabilized by hypoxia. It regulates cytokines involved in the inflammatory response after ischemia and affects white blood cell (WBCs) function. The effect of HIF-1alpha on WBC function and inflammation following myocardial infarction (MI) is unknown. OBJECTIVE: We assessed peritoneal and myocardial inflammation in the setting of low WBC HIF-1alpha expression through bone marrow transplantation of hematopoietic stem cells transfected with scramble or HIF-1alpha small interfering (si)RNA. METHODS AND RESULTS: Rosa hematopoietic stem cells (lin(-), cKit(+)) were transfected with a green fluorescent protein (GFP) reporter lentivirus encoding a siRNA to HIF-1alpha or scramble. Irradiated 6- to 8-week-old C57/BL6J mice received 50 000 GFP(+) HIF-1alpha or scramble siRNA-transfected hematopoietic stem cells. Peritonitis or myocardial infarction via left anterior descending coronary artery ligation was induced 6 weeks after bone marrow transplantation. In the peritonitis model, HIF-1alpha siRNA group exhibited a significant decrease in neutrophil and monocyte entry to the peritoneum compared to scramble mice. Similarly neutrophil infiltration into the infarct zone was decreased in the HIF-1alpha siRNA group. No difference of myocardial infarct size was observed between groups. Interestingly, the ejection fraction were similar in both groups at baseline and 3 days post-MI but increased significantly in the HIF-1alpha siRNA group compared to control beginning 7 days after MI. Gene array studies demonstrated that downregulation of WBC HIF-1alpha was associated with decreased WBC CCR1, -2, and -4 expression. Chemotaxis assay results confirmed that decreased monocyte migration induced by downregulation of HIF-1alpha was partially reversed by overexpression of CCR2. CONCLUSIONS: Downregulation of leukocyte HIF-1alpha expression resulted in decreased recruitment of WBC to the sites of inflammation and improvement in cardiac function following MI. Downregulation of HIF-1alpha suppressed WBC cytokine receptors CCR1, -2, and -4, which are necessary for WBC mobilization and recruitment to inflammatory cytokines following MI. The effects of downregulation of leukocyte HIF-1alpha on WBC migration are attributable, at least in part, to the decreased CCR2 expression. These results demonstrate that WBC infiltration into the newly injured myocardium plays a significant role in left ventricular remodeling, but not infarct size.

Multidisciplinary approach to the management of dermatofibrosarcoma protuberans.

BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is the most common cutaneous sarcoma. Tentacle-like extensions of neoplastic cells create a high incidence of local recurrence and pose challenges to resection and reconstruction. OBJECTIVE: Here we present a multidisciplinary approach to the management of DFSP incorporating the expertise of a Mohs micrographic surgeon, surgical oncologist, dermatopathologist, and plastic surgeon. METHODS: This was a single-institution, retrospective review of a prospectively maintained database of 19 consecutive patients who underwent resection and reconstruction of a DFSP from 1998 to 2010. All patients underwent Mohs micrographic surgery for mapping of peripheral margins (stage I excision), followed by wide local excision for delineation of the deep margin (stage II excision). Procedures were performed in consultation with a dermatopathologist who confirmed tumor-free margins, and a plastic surgeon who performed immediate reconstruction after the wide local excision (stage II reconstruction). RESULTS: Nineteen patients were included in this study. The average number of Mohs stages required for clearance of peripheral margins was 2.7 ± 0.7. The mean time between stage I and II procedures was 16 ± 11 days. The average defect size after the stage II operation was 87.3 cm(2) (range, 9-300 cm(2)). There were no cases of tumor recurrence. Mean follow-up time was 17 months (range, 1-53 months). LIMITATIONS: This is a retrospective review of a single-institution experience. CONCLUSION: A multidisciplinary approach to the management of DFSP optimizes both oncologic and reconstructive outcomes, minimizing the risk for local recurrence and limiting the functional and cosmetic morbidity associated with surgical resection.

A novel prospective three-dimensional analysis of nasolabial fold augmentation.

BACKGROUND: There are many products approved for aesthetic soft tissue augmentation. Despite this abundance, there is limited objective data regarding safety, longevity, and complication rates. Instead, most reports rely on subjective measures to report volume changes and outcomes, making product comparison difficult. OBJECTIVES: The authors developed and validated a mathematical model to prospectively calculate and analyze three-dimensional (3D) volumetric changes associated with nasolabial fold augmentation based on human acellular dermis. METHODS: Seven consecutive patients were included in this prospective review. The patients underwent nasolabial fold treatment with BellaDerm (Musculoskeletal Transplant Foundation, Edison, NJ), administered by a single surgeon. 3D photographs were obtained and analyzed with a novel mathematical model to determine absolute volumetric changes and objective longevity. RESULTS: Mean preoperative nasolabial fold volume was 0.17 mL. The mean one-, three-, and six-month postoperative fill volumes were 0.35, 0.19, and 0.07 mL, respectively. Fill volumes and contour changes returned to baseline by 24 weeks postoperatively in the majority of patients. CONCLUSIONS: The mathematical model utilized in this study provided prospective and objective data regarding longevity and volumetric changes associated with nasolabial fold augmentation. The analysis demonstrated minimal objective filler permanence beyond six months, with peak volume enhancement between one and three months. Adoption of objective 3D mathematical metrics into the assessment of soft tissue filler outcomes is critical to obtaining more accurate product-to-product comparisons.