Interventions to mitigate cancer-related medical financial hardship: A systematic review and meta-analysis.

BACKGROUND: This study systematically reviewed interventions mitigating financial hardship in patients with cancer and assessed effectiveness using a meta-analytic method. METHODS: PubMed, Cochrane, Scopus, CINAHL, and Web of Science were searched for articles published in English during January 2000-April 2023. Two independent reviewers selected prospective clinical trials with an intervention targeting and an outcome measuring financial hardship. Quality appraisal and data extraction were performed independently by two reviewers using a quality assessment tool. A random-effects model meta-analysis was performed. Reporting followed the preferred reporting items for systematic review and meta-analyses guidelines. RESULTS: Eleven studies (2211 participants; 55% male; mean age, 59.29 years) testing interventions including financial navigation, financial education, and cost discussion were included. Financial worry improved in only 27.3% of 11 studies. Material hardship and cost-related care nonadherence remained unchanged in the two studies measuring these outcomes. Four studies (373 participants; 37% male, mean age, 55.88 years) assessed the impact of financial navigation on financial worry using the comprehensive score of financial toxicity (COST) measure (score range, 0-44; higher score = lower financial worry) and were used for meta-analysis. There was no significant change in the mean of pooled COST score between post- and pre-intervention (1.21; 95% confidence interval, -6.54 to 8.96; p = .65). Adjusting for pre-intervention COST, mean change of COST significantly decreased by 0.88 with every 1-unit increase in pre-intervention COST (p = .02). The intervention significantly changed COST score when pre-intervention COST was ≤14.5. CONCLUSION: A variety of interventions have been tested to mitigate financial hardship. Financial navigation can mitigate financial worry among high-risk patients.

Nephrogenic Calciphylaxis Arising after Bariatric Surgery: A Case Series.

Nephrogenic calciphylaxis is associated with multiple risk factors including long-term dialysis dependence, hyperphosphatemia, hypercalcemia, parathyroid hormone derangements, vitamin K deficiency, obesity, diabetes mellitus, warfarin use, and female sex. Bariatric surgery is known to cause altered absorption, leading to mineral and hormonal abnormalities in addition to nutritional deficiency. Prior case reports on calciphylaxis development following bariatric surgery have been published, though are limited in number. We report a case series of five bariatric patients from a single institution who developed nephrogenic calciphylaxis between 2012 and 2018. These patients had a history of bariatric surgery, and at the time of calciphylaxis diagnosis, demonstrated laboratory abnormalities associated with surgery including hypercalcemia (n = 3), hyperparathyroidism (n = 2), hypoalbuminemia (n = 5), and vitamin D deficiency (n = 5), in addition to other medication exposures such as vitamin D supplementation (n = 2), calcium supplementation (n = 4), warfarin (n = 2), and intravenous iron (n = 1). Despite the multifactorial etiology of calciphylaxis and the many risk factors present in the subjects of this case series, we submit that bariatric surgery represents an additional potential risk factor for calciphylaxis directly stemming from the adverse impact of malabsorption and overuse of therapeutic supplementation. We draw attention to this phenomenon to encourage early consideration of calciphylaxis in the differential for painful skin lesions arising after bariatric surgery as swift intervention is essential for these high-risk patients.

Inhibitory modulation of action potentials in crayfish motor axons by fluoxetine.

The goal of this report is to explore how K2P channels modulate axonal excitability by using the crayfish ventral superficial flexor preparation. This preparation allows for simultaneous recording of motor nerve extracellular action potentials (eAP) and intracellular excitatory junctional potential (EJP) from a muscle fiber. Previous pharmacological studies have demonstrated the presence of K2P-like channels in crayfish. Fluoxetine (50 µM) was used to block K2P channels in this study. The blocker caused a gradual decline, and eventually complete block, of motor axon action potentials. At an intermediate stage of the block, when the peak-to-peak amplitude of eAP decreased to ∼60%-80% of the control value, the amplitude of the initial positive component of eAP declined at a faster rate than that of the negative peak representing sodium influx. Furthermore, the second positive peak following this sodium influx, which corresponds to the after-hyperpolarizing phase of intracellularly recorded action potentials (iAP), became larger during the intermediate stage of eAP block. Finally, EJP recorded simultaneously with eAP showed no change in amplitude, but did show a significant increase in synaptic delay. These changes in eAP shape and EJP delay are interpreted as the consequence of depolarized resting membrane potential after K2P channel block. In addition to providing insights to possible functions of K2P channels in unmyelinated axons, results presented here also serve as an example of how changes in eAP shape contain information that can be used to infer alterations in intracellular events. This type of eAP-iAP cross-inference is valuable for gaining mechanistic insights here and may also be applicable to other model systems.

Assessment of diagnostic delay, morbidity, and mortality outcomes in 302 calciphylaxis patients over a 17-year period: A retrospective cohort study.

BACKGROUND: Calciphylaxis patients historically have experienced diagnostic challenges and high morbidity, however limited data is available examining these characteristics over time. OBJECTIVE: The primary goals were to a) investigate factors associated with diagnostic delay of calciphylaxis and b) assess morbidity outcomes. The secondary goal was to provide updated mortality rates. METHODS: A retrospective review of 302 adult patients diagnosed with calciphylaxis between January 1, 2006 and December 31, 2022 was conducted. Univariate and multivariate statistical analyses were performed. RESULTS: Non-nephrogenic calciphylaxis (p=0.0004) and involvement of the fingers (p=0.0001) were significantly associated with an increased diagnostic delay, whereas involvement of the arms (p=0.01) and genitalia (p=0.022) resulted in fewer days to diagnosis. Almost all patients with genitalia, finger, or toe involvement had nephrogenic disease. The number of complications per patient decreased with time, especially for wound infections (p=0.028), increase in lesion number (p=0.012), and recurrent hospitalizations (p=0.020). Updated 1-year mortality rates were 36.70% and 30.77% for nephrogenic and non-nephrogenic calciphylaxis, respectively. LIMITATIONS: Limitations include the retrospective nature and data from a single institution. CONCLUSION: Diagnostic delay, particularly in non-nephrogenic calciphylaxis, and complications per patient decreased with time, highlighting the importance of continued awareness to expedite diagnosis. Mortality rates have continued to improve in recent years.

Gender diversity in neurosurgical training: an analysis of trends and resident program characteristics.

OBJECTIVE: Recent trends have shown more women entering neurosurgery, but large gender gaps in the number of female trainees continue to persist. A previous study on the gender diversity of residents and faculty in neurosurgery training programs found that only 18.2% of residents and 8.7% of faculty at neurosurgical training programs were female. The goal of this study was to better understand program characteristics that may affect the recruitment of female residents and the gender composition of neurosurgery residency programs. METHODS: The authors assessed publicly available information on websites and social media from 116 Accreditation Council for Graduate Medical Education (ACGME)-accredited neurosurgery residency programs from the 2022-2023 academic year. Data collected on residents included gender and postgraduate year (PGY), geographic region, accreditation year, and complement size for programs. The authors analyzed the distribution of female residents at each program and compared accreditation year, program size, program geographics, PGY, and acceptance rates. RESULTS: There were 1602 residents across the 116 programs included in this study: 1223 (76.3%) male and 379 (23.7%) female residents. The gender distribution of female residents showed 29 programs had 30% or more female residents, 50 programs had between 16% and 30%, and 37 had fewer than 16%, including 8 with none. There were significantly more PGY-1 than PGY-7 female residents (28.9% vs 16.4%, p < 0.01). Programs with ACGME accreditation before 1970 had significantly higher percentages of female residents (26.0%) compared with those accredited after 1970 (18.2%, p < 0.01). Program size was associated with a higher percentage of female residents (large = 25.2%, medium = 24.9%, and small = 19.6%), although the results were not significant. The distribution of female trainees across five geographic regions of the United States was fairly even: Northeast (24.5%), West (25.2%), South Atlantic (23.1%), South Central (21.8%), and North Central (21.2%). Residency acceptance rates were similar between genders. CONCLUSIONS: The underrepresentation of women in neurosurgery residency programs remains a significant issue. While some programs have achieved higher female representation than the overall average proportion of female neurosurgery residents, many still fall short. There are twice as many female PGY-1 compared with PGY-7 residents, suggesting increased recruitment over the past few years. Programs with longer accreditation histories have significantly higher proportions of female residents. Larger program size can also play a role in attracting more female residents, but geographic location did not impact gender composition of resident cohorts in this study.

Regulation of Smooth Muscle Cell Proliferation by Mitochondrial Ca2+ in Type 2 Diabetes.

Type 2 diabetes (T2D) is associated with increased risk of atherosclerotic vascular disease due to excessive vascular smooth muscle cell (VSMC) proliferation. Here, we investigated the role of mitochondrial dysfunction and Ca2+ levels in VSMC proliferation in T2D. VSMCs were isolated from normoglycemic and T2D-like mice induced by diet. The effects of mitochondrial Ca2+ uptake were studied using mice with selectively inhibited mitochondrial Ca2+/calmodulin-dependent kinase II (mtCaMKII) in VSMCs. Mitochondrial transition pore (mPTP) was blocked using ER-000444793. VSMCs from T2D compared to normoglycemic mice exhibited increased proliferation and baseline cytosolic Ca2+ levels ([Ca2+]cyto). T2D cells displayed lower endoplasmic reticulum Ca2+ levels, reduced mitochondrial Ca2+ entry, and increased Ca2+ leakage through the mPTP. Mitochondrial and cytosolic Ca2+ transients were diminished in T2D cells upon platelet-derived growth factor (PDGF) administration. Inhibiting mitochondrial Ca2+ uptake or the mPTP reduced VSMC proliferation in T2D, but had contrasting effects on [Ca2+]cyto. In T2D VSMCs, enhanced activation of Erk1/2 and its upstream regulators was observed, driven by elevated [Ca2+]cyto. Inhibiting mtCaMKII worsened the Ca2+ imbalance by blocking mitochondrial Ca2+ entry, leading to further increases in [Ca2+]cyto and Erk1/2 hyperactivation. Under these conditions, PDGF had no effect on VSMC proliferation. Inhibiting Ca2+-dependent signaling in the cytosol reduced excessive Erk1/2 activation and VSMC proliferation. Our findings suggest that altered Ca2+ handling drives enhanced VSMC proliferation in T2D, with mitochondrial dysfunction contributing to this process.

Graphene Nanobeacons with High-Affinity Pockets for Combined, Selective, and Effective Decontamination and Reagentless Detection of Heavy Metals.

Access to clean water for drinking, sanitation, and irrigation is a major sustainable development goal of the United Nations. Thus, technologies for cleaning water and quality-monitoring must become widely accessible and of low-cost, while being effective, selective, sustainable, and eco-friendly. To meet this challenge, hetero-bifunctional nanographene fluorescent beacons with high-affinity pockets for heavy metals are developed, offering top-rated and selective adsorption for cadmium and lead, reaching 870 and 450 mg g-1 , respectively. The heterobifunctional and multidentate pockets also operate as selective gates for fluorescence signal regulation with sub-nanomolar sensitivity (0.1 and 0.2 nm for Pb2+ and Cd2+ , respectively), due to binding affinities as low as those of antigen-antibody interactions. Importantly, the acid-proof nanographenes can be fully regenerated and reused. Their broad visible-light absorption offers an additional mode for water-quality monitoring based on ultra-low cost and user-friendly reagentless paper detection with the naked-eye at a limit of detection of 1 and 10 ppb for Pb2+ and Cd2+ ions, respectively. This work shows that photoactive nanomaterials, densely-functionalized with strong, yet selective ligands for targeted contaminants, can successfully combine features such as excellent adsorption, reusability, and sensing capabilities, in a way to extend the material's applicability, its life-cycle, and value-for-money.

Assessing the incidence of skin and soft tissue infection in patients on biologics.

BACKGROUND: Biologic agents may predispose patients to skin and soft tissue infections (SSTIs). Guidelines recommend discontinuing the agent preoperatively; the true risk of infection is unclear. OBJECTIVES: To assess the incidence of SSTIs in patients receiving biologic agents for all clinical indications. A secondary aim was to assess those undergoing surgery to determine postoperative SSTI risk. METHODS: A retrospective medical record review was conducted at 2 urban tertiary care hospitals. Biologic agent use ranged from June 2013 to June 2018. Data were extracted on biologic agent injections, surgical procedures, and patient characteristics. RESULTS: Hypertension, former smoking, and corticosteroid use were significantly associated with SSTI risk (P < .05). There was no increased SSTI risk among biologic agents (P = .49). Biologic therapy with concomitant corticosteroid use increased risk of SSTI (P = .0049). There was no difference in postoperative SSTI risk in patients who stopped biologic therapy before surgery and those who did not. LIMITATIONS: This study is limited by its retrospective design. CONCLUSIONS: There was no increased risk of either postoperative or nonperioperative SSTI risk among biologic agents. Concomitant corticosteroid use increased SSTI risk. Current guidelines regarding stopping biologic agents before surgery warrant re-evaluation, because there was no difference in SSTI risk in patients who did so.

Penile calciphylaxis: A retrospective case-control study.

BACKGROUND: Calciphylaxis is a rare disorder characterized by skin necrosis caused by calcium deposition within vessels, thrombosis, and subsequent tissue ischemia. Penile involvement may rarely occur. OBJECTIVE: To identify risk factors, diagnosis, management, and mortality of patients with penile calciphylaxis. METHODS: A retrospective medical record review was conducted of 16 patients with penile calciphylaxis treated at 2 large urban tertiary care centers between January 2001 and December 2019. A control group of 44 male patients with nonpenile calciphylaxis at the same institution was included. RESULTS: The median survival of patients with penile calciphylaxis was 3.8 months (interquartile range, 27.0 months). Mortality was 50% at 3 months and 62.5% at 6 months for penile calciphylaxis, and 13.6% at 3 months and 29.5% at 6 months for controls (P = .008). Patients with penile calciphylaxis were less likely to be obese (P = .04) but more likely to have hyperparathyroidism (P = .0003) and end-stage renal disease (P = .049). LIMITATIONS: Retrospective study design and small sample size. CONCLUSIONS: This study further defines the disease course of penile calciphylaxis, which has high mortality. Imaging may be used to aid diagnosis. Risk factors include end-stage renal disease, hyperparathyroidism, and normal body mass index.

Clinical mimickers of calciphylaxis: A retrospective study.

BACKGROUND: Calciphylaxis is an ischemic vasculopathy with high morbidity and mortality. Early and accurate diagnosis is critical to management of calciphylaxis. Clinical mimickers may contribute to delayed or misdiagnosis. OBJECTIVE: To assess the rate and risk factors for misdiagnosis and to identify clinical mimickers of calciphylaxis. METHODS: A retrospective medical record review was conducted of patients with calciphylaxis at a large urban tertiary care hospital between 2006 and 2018. RESULTS: Of 119 patients diagnosed with calciphylaxis, 73.1% were initially misdiagnosed. Of patients not initially misdiagnosed, median time to diagnosis from initial presentation was 4.5 days (interquartile range, 1.0-23.3), compared to 33 days (interquartile range, 13.0-68.8) in patients who were initially misdiagnosed (P = .0002). The most common misdiagnoses were cellulitis (31.0%), unspecified skin infection (8.0%), and peripheral vascular disease (6.9%). Patients who were misdiagnosed frequently received at least 1 course of antibiotics. Patients with end-stage renal disease were less likely to be misdiagnosed than those without this disease (P = .001). LIMITATIONS: Single-center, retrospective study. CONCLUSIONS: Understanding the risk factors for misdiagnosis of calciphylaxis is an opportunity for further education concerning this rare disease.

Assessment of outcomes of calciphylaxis.

BACKGROUND: Calciphylaxis is a rare thrombotic vasculopathy characterized by high morbidity and mortality. There is a paucity of studies examining longitudinal outcomes. OBJECTIVE: To assess mortality, days spent in the hospital, and amputations in patients with calciphylaxis. METHODS: A retrospective medical record review was conducted in 145 patients diagnosed with calciphylaxis at an urban tertiary care hospital from January 2006 to December 2018. RESULTS: Six-month mortality was 37.2%, and 1-year mortality was 44.1%. Patients with nephrogenic calciphylaxis had worse survival than those with nonnephrogenic calciphylaxis (P = .007). This difference in survival disappeared when limiting mortality to deaths due to calciphylaxis. Age (P = .003) and end-stage renal disease (P = .01) were risk factors associated with 1-year mortality. Diabetes mellitus was associated with greater total hospitalization days (coefficient, 1.1; 95% confidence interval, 1.01-1.4); bedside debridement was associated with fewer hospitalization days (coefficient, 0.8; 95% confidence interval, 0.7-0.9). Amputations were not associated with any of the examined risk factors. The use of warfarin followed by a transition to nonwarfarin anticoagulation was associated with decreased hazard of death (P = .01). LIMITATIONS: Retrospective nature. CONCLUSIONS: Calciphylaxis remains a complex, heterogeneous disease. Mortality is lower in patients with nonnephrogenic disease. These findings may be incorporated during discussions regarding the goals of care to facilitate informed shared decision making.

Use of teledermatology by dermatology hospitalists is effective in the diagnosis and management of inpatient disease.

BACKGROUND: Patient outcomes are improved when dermatologists provide inpatient consultations. Inpatient access to dermatologists is limited, illustrating an opportunity to use teledermatology. Little is known about the ability of dermatologists to accurately diagnose disease and manage inpatients with teledermatology, particularly when using nondermatologist-generated clinical data. METHODS: This prospective study assessed the ability of teledermatology to diagnose disease and manage 41 dermatology consultations from a large urban tertiary care center, using internal medicine referral documentation and photographs. Twenty-seven dermatology hospitalists were surveyed. Interrater agreement was assessed by the κ statistic. RESULTS: There was substantial agreement between in-person and teledermatology assessment of the diagnosis with differential diagnosis (median κ = 0.83), substantial agreement in laboratory evaluation decisions (median κ = 0.67), almost perfect agreement in imaging decisions (median κ = 1.0), and moderate agreement in biopsy decisions (median κ = 0.43). There was almost perfect agreement in treatment (median κ = 1.0), but no agreement in follow-up planning (median κ = 0.0). There was no association between raw photograph quality and the primary plus differential diagnosis or primary diagnosis alone. LIMITATIONS: Selection bias and single-center nature. CONCLUSIONS: Teledermatology may be effective in the inpatient setting, with concordant diagnosis, evaluation, and management decisions.

Lymphoceles: impact on kidney transplant recipients, graft, and healthcare system.

INTRODUCTION: Following kidney transplantation, lymphoceles can impact patient and graft outcomes, while resulting in significant hospital resource utilization. We aimed to characterize the incidence, risk factors, outcomes, and clinical management of lymphoceles among kidney transplant recipients and review impact on health system utilization at a high-volume center. MATERIALS AND METHODS: We conducted a single-center, observational cohort study on adults transplanted between January 1, 2005 and December 31, 2017. Incidence, risk factors, and clinical outcomes were assessed using the Kaplan-Meier product-limit method, multivariable logistic regression model, and Cox proportional hazards model, respectively. RESULTS: Lymphoceles developed in 72 of 1881 patients (3.8%). Multivariate analysis demonstrated that a longer time on dialysis before transplant [HR 1.09 (95% CI: 1.02, 1.17)], laparoscopic donor nephrectomy [HR 2.31 (95% CI: 1.04, 5.12)], and depleting induction therapy [HR 0.39 (95% CI: 0.18, 0.87)] were significant risk factors for lymphocele development. Lymphoceles independently increased the likelihood of hospital readmission [HR 3.96 (95% CI: 2.99, 5.25)] but had no significant effect on the likelihood of graft failure or death with graft function. Of 72 cases, 44 received a radiological or surgical intervention. Fifteen of 44 lymphoceles required further intervention due to re-accumulation or complications. CONCLUSION: Patients with longer dialysis times, kidneys from laparoscopic donor nephrectomy, and depleting induction therapy were associated with an increased risk for developing symptomatic lymphoceles. Our center's treatment for symptomatic lymphoceles did not result in significant graft dysfunction, but significantly higher healthcare resource utilization was noted.

Experimental Comparison in Sensing Breast Cancer Mutations by Signal ON and Signal OFF Paper-Based Electroanalytical Strips.

The development of paper-based electroanalytical strips as powerful diagnostic tools has gained a lot of attention within the sensor community. In particular, the detection of nucleic acids in complex matrices represents a trending topic, especially when focused toward the development of emerging technologies, such as liquid biopsy. DNA-based biosensors have been largely applied in this direction, and currently, there are two main approaches based on target/probe hybridization reported in the literature, namely Signal ON and Signal OFF. In this technical note, the two approaches are evaluated in combination with paper-based electrodes, using a single strand DNA relative to H1047R (A3140G) missense mutation in exon 20 in breast cancer as the model target. A detailed comparison among the analytical performances, detection protocol, and cost associated with the two systems is provided, highlighting the advantages and drawbacks depending on the application. The present work is aimed to a wide audience, particularly for those in the field of point-of-care, and it is intended to provide the know-how to manage with the design and development stages, and to optimize the platform for the sensing of nucleic acids using a paper-based detection method.

Antioxidant supplementation partially rescues accelerated ovarian follicle loss, but not oocyte quality, of glutathione-deficient mice†.

The tripeptide thiol antioxidant glutathione (GSH) has multiple physiological functions. Female mice lacking the modifier subunit of glutamate cysteine ligase (GCLM), the rate-limiting enzyme in GSH synthesis, have decreased GSH concentrations, ovarian oxidative stress, preimplantation embryonic mortality, and accelerated age-related decline in ovarian follicles. We hypothesized that supplementation with thiol antioxidants, N-acetyl cysteine (NAC), or α-lipoic acid (ALA) will rescue this phenotype. Gclm-/- and Gclm+/+ females received 0 or 80 mM NAC in drinking water from postnatal day (PND) 21-30; follicle growth was induced with equine chorionic gonadotropin (eCG) on PND 27, followed by an ovulatory dose of human CG and mating with a wild type male on PND 29 and zygote harvest 20 h after hCG. N-acetyl cysteine supplementation failed to rescue the low rate of second pronucleus formation in zygotes from Gclm-/- versus Gclm+/+ females. In the second study, Gclm-/- and Gclm+/+ females received diet containing 0, 150, or 600 mg/kg ALA beginning at weaning and were mated with wild type males from 8 to 20 weeks of age. α-Lipoic acid failed to rescue the decreased offspring production of Gclm-/- females. However, 150 mg/kg diet ALA partially rescued the accelerated decline in primordial follicles, as well as the increased recruitment of follicles into the growing pool and the increased percentages of follicles with γH2AX positive oocytes or granulosa cells of Gclm-/- females. We conclude that ovarian oxidative stress is the cause of accelerated primordial follicle decline, while GSH deficiency per se may be responsible for preimplantation embryonic mortality in Gclm-/- females.

Metabolic Stress.

Mitochondria regulate major aspects of cell function by producing ATP, contributing to Ca2+ signaling, influencing redox potential, and controlling levels of reactive oxygen species. In this review, we will discuss recent findings that illustrate how mitochondrial respiration, Ca2+ handling, and production of reactive oxygen species affect vascular smooth muscle cell function during neointima formation. We will review mitochondrial fission/fusion as fundamental mechanisms for smooth muscle proliferation, migration, and metabolism and examine the role of mitochondrial mobility in cell migration. In addition, we will summarize novel aspects by which mitochondria regulate apoptosis.

A novel SWCNT-amplified "signal-on" electrochemical aptasensor for the determination of trace level of bisphenol A in human serum and lake water.

A novel "signal-on" electrochemical aptasensor was developed for ultrasensitive and specific detection of BPA, using single-walled carbon nanotubes (SWCNT) as the electro-catalytic probe for further signal amplification. The multi-walled carbon nanotubes (MWCNT), amino-functionalized magnetite, and gold nanoparticles (NH2-Fe3O4/Au NPs) were applied first to modify the glassy carbon electrode (GCE) surface and to form a nanomaterial film with satisfactory conductive properties, stability, and biocompatibility. The BPA aptamer was then loaded onto the sensing platform by hybridization with complementary DNA (CDNA). In the presence of BPA it combines with the aptamer and the BPA-aptamer conjugate was released from the electrode;subsequently the added SWCNT and CDNA assembled quickly. Thus, the dual-amplification of the "signal-on" electrochemical aptasensor takes effect. The [Fe (CN)6]3-/4- redox probe signal (∆I) detected by DPV (differential pulse voltammetry) is proportional to the negative logarithm of BPA concentration between 10-19 M and 10-14 M. The detection limit is 0.08 aM. Importantly, the proposed biosensor represents a successful application for determination of BPA in human serum and lake water. Schematic representation of SWCNT-amplified "signal-on" electrochemical aptasensor for the detection of trace level of bisphenol A in human serum and lake water.

CaMKII (Ca2+/Calmodulin-Dependent Kinase II) in Mitochondria of Smooth Muscle Cells Controls Mitochondrial Mobility, Migration, and Neointima Formation.

OBJECTIVE: The main objective of this study is to define the mechanisms by which mitochondria control vascular smooth muscle cell (VSMC) migration and impact neointimal hyperplasia. APPROACH AND RESULTS: The multifunctional CaMKII (Ca2+/calmodulin-dependent kinase II) in the mitochondrial matrix of VSMC drove a feed-forward circuit with the mitochondrial Ca2+ uniporter (MCU) to promote matrix Ca2+ influx. MCU was necessary for the activation of mitochondrial CaMKII (mtCaMKII), whereas mtCaMKII phosphorylated MCU at the regulatory site S92 that promotes Ca2+ entry. mtCaMKII was necessary and sufficient for platelet-derived growth factor-induced mitochondrial Ca2+ uptake. This effect was dependent on MCU. mtCaMKII and MCU inhibition abrogated VSMC migration and mitochondrial translocation to the leading edge. Overexpression of wild-type MCU, but not MCU S92A, mutant in MCU-/- VSMC rescued migration and mitochondrial mobility. Inhibition of microtubule, but not of actin assembly, blocked mitochondrial mobility. The outer mitochondrial membrane GTPase Miro-1 promotes mitochondrial mobility via microtubule transport but arrests it in subcellular domains of high Ca2+ concentrations. In Miro-1-/- VSMC, mitochondrial mobility and VSMC migration were abolished, and overexpression of mtCaMKII or a CaMKII inhibitory peptide in mitochondria (mtCaMKIIN) had no effect. Consistently, inhibition of mtCaMKII increased and prolonged cytosolic Ca2+ transients. mtCaMKII inhibition diminished phosphorylation of focal adhesion kinase and myosin light chain, leading to reduced focal adhesion turnover and cytoskeletal remodeling. In a transgenic model of selective mitochondrial CaMKII inhibition in VSMC, neointimal hyperplasia was significantly reduced after vascular injury. CONCLUSIONS: These findings identify mitochondrial CaMKII as a key regulator of mitochondrial Ca2+ uptake via MCU, thereby controlling mitochondrial translocation and VSMC migration after vascular injury.