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COVID-19 stay-at-home (SAH) orders were impactful on adolescence, when social interactions affect development. This has the potential to change adolescent trauma. A post-hoc multicenter retrospective analysis of adolescent (13-17 years-old) trauma patients (ATPs) at 11 trauma centers was performed. Patients were divided into 3 groups based on injury date: historical control (CONTROL:3/19/2019-6/30/2019, before SAH (PRE:1/1/2020-3/18/2020), and after SAH (POST:3/19/2020-6/30/2020). The POST group was compared to both PRE and CONTROL groups in separate analyses. 726 ATPs were identified across the 3 time periods. POST had a similar penetrating trauma rate compared to both PRE (15.8% vs 13.8%, P = .56) and CONTROL (15.8% vs 14.5%, P = .69). POST also had a similar rate of suicide attempts compared to both PRE (1.2% vs 1.5%, P = .83) and CONTROL (1.2% vs 2.1%, P = .43). However, POST had a higher rate of drug positivity compared to CONTROL (28.6% vs 20.6%, P = .032), but was similar in all other comparisons of alcohol and drugs to PRE and POST periods (all P > .05). Hence ATPs were affected differently than adults and children, as they had a similar rate of penetrating trauma, suicide attempts, and alcohol positivity after SAH orders. However, they had increased drug positivity compared to the CONTROL, but not PRE group.

Purpose There is mounting evidence that surgical patients with COVID-19 have higher morbidity and mortality than patients without COVID-19. Infection is prevalent amongst the trauma population, but any effect of COVID-19 on trauma patients is unknown. We aimed to evaluate the effect of COVID-19 on a trauma population, hypothesizing increased mortality and pulmonary complications for COVID-19-positive (COVID) trauma patients compared to propensity-matched COVID-19-negative (non-COVID) patients. Methods A retrospective analysis of trauma patients presenting to 11 Level-I and II trauma centers in California between 1/1/2019–6/30/2019 and 1/1/2020–6/30/2020 was performed. A 1:2 propensity score model was used to match COVID to non-COVID trauma patients using age, blunt/penetrating mechanism, injury severity score, Glasgow Coma Scale score, systolic blood pressure, respiratory rate, and heart rate. Outcomes were compared between the two groups. Results A total of 20,448 trauma patients were identified during the study period. 53 COVID trauma patients were matched with 106 non-COVID trauma patients. COVID patients had higher rates of mortality (9.4% vs 1.9%, p = 0.029) and pneumonia (7.5% vs. 0.0%, p = 0.011), as well as a longer mean length of stay (LOS) (7.47 vs 3.28 days, p p = 0.008), compared to non-COVID patients. Conclusion This multicenter retrospective study found increased rates of mortality and pneumonia, as well as a longer LOS, for COVID trauma patients compared to a propensity-matched cohort of non-COVID patients. Further studies are warranted to validate these findings and to elucidate the underlying pathways responsible for higher mortality in COVID trauma patients.

Purpose The COVID-19 pandemic resulted in increased penetrating trauma and decreased length of stay (LOS) amongst the adult trauma population, findings important for resource allocation. Studies regarding the pediatric trauma population are sparse and mostly single-center. This multicenter study examined pediatric trauma patients, hypothesizing increased penetrating trauma and decreased LOS after the 3/19/2020 stay-at-home (SAH) orders. Methods A multicenter retrospective analysis of trauma patients ≤ 17 years old presenting to 11 centers in California was performed. Demographic data, injury characteristics, and outcomes were collected. Patients were divided into three groups based on injury date: 3/19/2019–6/30/2019 (CONTROL), 1/1/2020–3/18/2020 (PRE), 3/19/2020–6/30/2020 (POST). POST was compared to PRE and CONTROL in separate analyses. Results 1677 patients were identified across all time periods (CONTROL: 631, PRE: 479, POST: 567). POST penetrating trauma rates were not significantly different compared to both PRE (11.3 vs. 9.0%, p = 0.219) and CONTROL (11.3 vs. 8.2%, p = 0.075), respectively. POST had a shorter mean LOS compared to PRE (2.4 vs. 3.3 days, p = 0.002) and CONTROL (2.4 vs. 3.4 days, p = 0.002). POST was also not significantly different than either group regarding intensive care unit (ICU) LOS, ventilator days, and mortality (all p > 0.05). Conclusions This multicenter retrospective study demonstrated no difference in penetrating trauma rates among pediatric patients after SAH orders but did identify a shorter LOS.

BACKGROUND: The rapid spread of coronavirus disease 2019 in the United States led to a variety of mandates intended to decrease population movement and "flatten the curve." However, there is evidence some are not able to stay-at-home due to certain disadvantages, thus remaining exposed to both coronavirus disease 2019 and trauma. We therefore sought to identify any unequal effects of the California stay-at-home orders between races and insurance statuses in a multicenter study utilizing trauma volume data. METHODS: A posthoc multicenter retrospective analysis of trauma patients presenting to 11 centers in Southern California between the dates of January 1, 2020, and June 30, 2020, and January 1, 2019, and June 30, 2019, was performed. The number of trauma patients of each race/insurance status was tabulated per day. We then calculated the changes in trauma volume related to stay-at-home orders for each race/insurance status and compared the magnitude of these changes using statistical resampling. RESULTS: Compared to baseline, there was a 40.1% drop in total trauma volume, which occurred 20 days after stay-at-home orders. During stay-at-home orders, the average daily trauma volume of patients with Medicaid increased by 13.7 ± 5.3%, whereas the volume of those with Medicare, private insurance, and no insurance decreased. The average daily trauma volume decreased for White, Black, Asian, and Latino patients with the volume of Black and Latino patients dropping to a similar degree compared to White patients. CONCLUSION: This retrospective multicenter study demonstrated that patients with Medicaid had a paradoxical increase in trauma volume during stay-at-home orders, suggesting that the most impoverished groups remain disproportionately exposed to trauma during a pandemic, further exacerbating existing health disparities.

We analyzed data from two ongoing COVID-19 longitudinal serological surveys in Orange County, CA., between April 2020 and March 2021. A total of 8,476 finger stick blood specimens were collected before and after an aggressive mRNA vaccination campaign. IgG levels were determined using a multiplex antigen microarray containing 10 SARS-CoV-2 antigens, 4 SARS, 3 MERS, 12 Common CoV, and 8 Influenza antigens. Twenty-six percent of 3,347 specimens from unvaccinated Orange County residents in December 2020 were SARS-CoV-2 seropositive. The Ab response was predominantly against nucleocapsid (NP), full length spike and the spike S2 domain. Anti-receptor binding domain (RBD) reactivity was low and there was no cross-reactivity against SARS S1 or SARS RBD. An aggressive mRNA vaccination campaign at the UCI Medical Center started on December 16, 2020 and 6,724 healthcare workers were vaccinated within 3 weeks. Seroprevalence increased from 13% in December to 79% in January, 93% in February and 99% in March. mRNA vaccination induced much higher Ab levels especially against the RBD domain and significant cross-reactivity against SARS RBD and S1 was also observed. Nucleocapsid protein Abs can be used to distinguish individuals in a population of vaccinees to classify those who have been previously infected and those who have not, because nucleocapsid is not in the vaccine. Previously infected individuals developed higher Ab titers to the vaccine than those who have not been previously exposed. These results indicate that mRNA vaccination rapidly induces a much stronger and broader Ab response than SARS-CoV-2 infection.

BackgroundThe COVID-19 pandemic overwhelmed hospitals, forcing adjustments including discharging patients earlier and limiting intensive care unit (ICU) utilization. This study aimed to evaluate ICU admissions and length of stay (LOS) for blunt trauma patients (BTPs).MethodsA retrospective review of COVID (3/19/20-6/30/20) versus pre-COVID (3/19/19-6/30/19) BTPs at eleven trauma centers was performed. Multivariable analysis was used to identify risk factors for ICU admission.Results12,744 BTPs were included (6942 pre-COVID vs. 5802 COVID). The COVID cohort had decreased mean LOS (3.9 vs. 4.4 days, p=0.029), ICU LOS (0.9 vs. 1.1 days, p0.05). On multivariable analysis, the COVID period was associated with decreased risk of ICU admission (OR=0.82, CI 0.75-0.90, p&nbsp

Background: COVID-19 related stay-at-home (SAH) orders created many economic and social stressors, possibly increasing the risk of drug/alcohol abuse in the community and trauma population.Objectives: Describe changes in alcohol/drug use in traumatically injured patients after SAH orders in California and evaluate demographic or injury pattern changes in alcohol or drug-positive patients.Methods: A retrospective analysis of 11 trauma centers in Southern California (1/1/2020-6/30/2020) was performed. Blood alcohol concentration, urine toxicology results, demographics, and injury characteristics were collected. Patients were grouped based on injury date - before SAH (PRE-SAH), immediately after SAH (POST-SAH), and a historical comparison (3/19/2019-6/30/2019) (CONTROL) - and compared in separate analyses. Groups were compared using chi-square tests for categorical variables and Mann-Whitney U tests for continuous variables.Results: 20,448 trauma patients (13,634 male, 6,814 female) were identified across three time-periods. The POST-SAH group had higher rates of any drug (26.2% vs. 21.6% and 24.7%, OR = 1.26 and 1.08, p .05).Conclusion: This Southern California multicenter study demonstrated increased amphetamine, MDMA, and THC positivity in trauma patients after SAH, but no difference in alcohol positivity or blood concentration. Drug prevention strategies should continue to be adapted within and outside of hospitals during a pandemic.

Author(s): Assis, Rafael; Jain, Aarti; Nakajima, Rie; Jasinskas, Al; Kahn, Saahir; Palma, Anton; Parker, Daniel; Chau, Anthony; Leung, Amanda; Grabar, Christina; Muqolli, Fjolla; Khalil, Ghali; Escobar, Jessica Colin; Ventura, Jenny; Davies, Huw; Albala, Bruce; Boden-Albala, Bernadette; Schubl, Sebastian; Felgner, Philip | Abstract: We analyzed data from two ongoing COVID-19 longitudinal serological surveys in Orange County, CA., between April 2020 and March 2021. A total of 8,476 finger stick blood specimens were collected before and after an aggressive mRNA vaccination campaign. IgG levels were determined using a multiplex antigen microarray containing 10 SARS-CoV-2 antigens, 4 SARS, 3 MERS, 12 Common CoV, and 8 Influenza antigens. Twenty-six percent of 3,347 specimens from unvaccinated Orange County residents in December 2020 were SARS-CoV-2 seropositive. The Ab response was predominantly against nucleocapsid (NP), full length spike and the spike S2 domain. Anti-receptor binding domain (RBD) reactivity was low and there was no cross-reactivity against SARS S1 or SARS RBD. An aggressive mRNA vaccination campaign at the UCI Medical Center started on December 16, 2020 and 6,724 healthcare workers were vaccinated within 3 weeks. Seroprevalence increased from 13% in December to 79% in January, 93% in February and 99% in March. mRNA vaccination induced much higher Ab levels especially against the RBD domain and significant cross-reactivity against SARS RBD and S1 was also observed. Nucleocapsid protein Abs can be used to distinguish individuals in a population of vaccinees to classify those who have been previously infected and those who have not, because nucleocapsid is not in the vaccine. Previously infected individuals developed higher Ab titers to the vaccine than those who have not been previously exposed. These results indicate that mRNA vaccination rapidly induces a much stronger and broader Ab response than SARS-CoV-2 infection.

Background Cardiac injury is common in COVID‐19 patients and is associated with increased mortality. However, it remains unclear if reduced cardiac function is associated with cardiac injury, and additionally if mortality risk is increased among those with reduced cardiac function in COVID‐19 patients. Hypothesis The aim of this study was to assess cardiac function among COVID‐19 patients with and without biomarkers of cardiac injury and to determine the mortality risk associated with reduced cardiac function. Methods/Results This retrospective cohort study analyzed 143 consecutive COVID‐19 patients who had an echocardiogram during hospitalization between March 1, 2020 and May 5, 2020. The mean age was 67 ± 16 years. Cardiac troponin‐I was available in 131 patients and an increased value (>0.03 ng/dL) was found in 59 patients (45%). Reduced cardiac function, which included reduced left or right ventricular systolic function, was found in 40 patients (28%). Reduced cardiac function was found in 18% of patients without troponin‐I elevation, 42% with mild troponin increase (0.04‐5.00 ng/dL) and 67% with significant troponin increase (>5 ng/dL). Reduced cardiac function was also present in more than half of the patients on mechanical ventilation or those deceased. The in‐hospital mortality of this cohort was 28% (N = 40). Using logistic regression analysis, we found that reduced cardiac function was associated with increased mortality with adjusted odds ratio (95% confidence interval) of 2.65 (1.18 to 5.96). Conclusions Reduced cardiac function is highly prevalent among hospitalized COVID‐19 patients with biomarkers of myocardial injury and is independently associated with mortality.

Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by low platelet counts ( Current treatment strategies for ITP include non-specific immunosuppression (steroids, rituximab), inhibition of platelet clearance (immunoglobulins, splenectomy, anti-D immunoglobulin, and the Syk inhibitor fostamatinib) and stimulation of platelet production (thrombopoietin receptor agonists). In addition, therapeutics targeting the neonatal Fc receptor, responsible for IgG recycling, are under clinical investigation for ITP. Despite these treatment options, some patients with ITP are refractory or have inadequate responses to existing therapy. Here we describe a novel allogeneic cellular therapy, entitled platelet-like cells (PLC), that specifically targets pathogenic IgG for the treatment of thrombocytopenia in ITP. PLC are produced by differentiating a human induced pluripotent stem cell (hiPSC) line into megakaryocyte-like cells (MLC) which are further processed in a proprietary bioreactor that mimics the bone marrow environment and induces the release of anucleate PLC which are then cryopreserved. Analyses of PLC demonstrate sizes ranging between 65 nm and 10 μm. Expression of GPIIbIIIa protein as measured by enzyme-linked immunosorbent assay (ELISA) is evident in all particle sizes. PLC were administered intravenously (IV) into NOD-scid IL2Rgamma null (NSG) mice to evaluate their pharmacokinetics and biodistribution. PLC were rapidly cleared from the mouse circulation and predominantly distributed to the mouse liver where they colocalized primarily with Kupffer cells. PLC clearance through the liver was significantly inhibited by pre-treating mice with liposomes expressing phosphatidylserine (PS), indicating that one mechanism of PLC clearance is dependent on PS exposure on the PLC outer plasma membrane. The ability of PLC to bind anti-GPIIbIIIa autoantibodies was evaluated in an in vitro assay where PLC were incubated with ITP patient plasmas and subsequently removed by centrifugation and filtration. The concentration of anti-GPIIbIIIa autoantibodies remaining in the plasmas decreased following PLC treatment (96.6% ± 2.4%). The ability of PLC to clear anti-human GPIIbIIIa antibodies in circulation was evaluated by using a passive mouse model of ITP. Here, a fluorescently labeled mouse anti-human GPIIbIIIa monoclonal antibody (PAB-1) was dosed intravenously (IV) into NSG mice to achieve a circulating level of antibody comparable to those observed in ITP patients. The GPIIbIIIa antibody persisted in circulation for over 24 hours following a single dose in untreated mice and did not induce clearance of mouse platelets. Following administration of PLC in the passive ITP model, a decrease in antibody fluorescence in blood was observed within 2 minutes and full antibody clearance was observed at 3 hours post dosing. Furthermore, clearance of the antibody was observed to be both dose responsive and specific since PLC treatment did not affect the antibody concentration of an isotype matched control antibody. PLC activity in clearing the anti-GPIIbIIIa antibody was observed in all particle sizes. Fluorescence quantification of liver and spleen tissue demonstrated that PLC driven anti-GPIIbIIIa antibody clearance occurred preferentially in the liver. Taken together, these data indicate that by specifically binding and rapidly removing anti-platelet antibodies from circulation, PLC may disrupt the platelet degradation mechanisms underlying ITP pathogenesis and restore platelet counts. Disclosures Patel-Hett: PlateletBio: Current Employment. Giannini: Platelet Biogenesis: Current Employment. Peters: Platelet Biogenesis: Current Employment. Dykstra: Platelet Biogenesis: Current Employment. Lehmann: Platelet Biogenesis: Current Employment. Russo: Platelet Biogenesis: Current Employment. Kohnke: Platelet Biogenesis: Current Employment. Carpenter: Platelet Biogenesis: Current Employment. Tomczak: Platelet Biogenesis: Current Employment. Lazarus: Platelet Biogenesis: Consultancy. Masuko: Platelet Biogenesis: Current Employment. Leung: Platelet Biogenesis: Current Employment. Meredith: Platelet Biogenesis: Current Employment. Pete: Platelet Biogenesis: Current Employment. Lee: Platelet Biogenesis: Current Employment. Falb: Platelet Biogenesis: Current Employment.

A patient presenting with chest pain yields a wide array of possible etiologies from common gastrointestinal causes, to life-threatening acute myocardial infarction. With such a vast differential, chest pain can prove to be a diagnostic challenge. A 54 year old male, with past medical history of

The visual responses of vertebrates are sensitive to the overall composition of retinal interneurons including amacrine cells, which tune the activity of the retinal circuitry. The expression of Paired-homeobox 6 (PAX6) is regulated by multiple cis-DNA elements including the intronic α-enhancer, which is active in GABAergic amacrine cell subsets. Here, we report that the transforming growth factor ß1-induced transcript 1 protein (Tgfb1i1) interacts with the LIM domain transcription factors Lhx3 and Isl1 to inhibit the α-enhancer in the post-natal mouse retina. Tgfb1i1-/- mice show elevated α-enhancer activity leading to overproduction of Pax6ΔPD isoform that supports the GABAergic amacrine cell fate maintenance. Consequently, the Tgfb1i1-/- mouse retinas show a sustained light response, which becomes more transient in mice with the auto-stimulation-defective Pax6ΔPBS/ΔPBS mutation. Together, we show the antagonistic regulation of the α-enhancer activity by Pax6 and the LIM protein complex is necessary for the establishment of an inner retinal circuitry, which controls visual adaptation. DOI: http://dx.doi.org/10.7554/eLife.21303.001, eLife digest The retina is a light-sensitive layer of tissue that lines the inside of the eye. This tissue is highly organized and comprises a variety of different nerve cells, including amacrine cells. Together, these cells process incoming light and then trigger electrical signals that travel to the brain, where they are translated into an image. Changes in the nerve cell composition of the retina, or in how the cells connect to each other, can alter the visual information that travels to the brain. The nerve cells of the retina are formed before a young animal opens its eyes for the first time. Proteins called transcription factors – which regulate the expression of genes – tightly control how the retina develops. For example, a transcription factor called Pax6 drives the development of amacrine cells. Several other transcription factors control the production of Pax6 by binding to a section of DNA known as the “α-enhancer”. However, it is not clear how regulating Pax6 production influences the development of specific sets of amacrine cells. Kim et al. reveal that a protein known as Tgfb1i1 interacts with two transcription factors to form a “complex” that binds to the α-enhancer and blocks the production of a particular form of Pax6. In experiments performed in mice, the loss of Tgfb1i1 led to increased production of this form of Pax6, which resulted in the retina containing more of a certain type of amacrine cell that produce a molecule called GABA. Mice lacking Tgfb1i1 show a stronger response to light and are therefore comparable to people who are too sensitive to light. On the other hand, mice with a missing a section of the α-enhancer DNA have fewer amacrine cells releasing GABA and become less sensitive to light and are comparable to people who have difficulty detecting weaker light signals. The findings of Kim et al. suggest that an individual’s sensitivity to light is related, at least in part, to the mixture of amacrine cells found in their retina, which is determined by certain transcription factors that target the α-enhancer. DOI: http://dx.doi.org/10.7554/eLife.21303.002

Human norepinephrine (NE) deficiency (or dopamine β-hydroxylase (DBH) deficiency) is a rare congenital disorder of primary autonomic failure, in which neurotransmitters NE and epinephrine are undetectable. Although potential pathogenic mutations, such as a common splice donor site mutation (IVS1+2T→C) and various missense mutations, in NE deficiency patients were identified, molecular mechanisms underlying this disease remain unknown. Here, we show that the IVS1+2T→C mutation results in a non-detectable level of DBH protein production and that all three missense mutations tested lead to the DBH protein being trapped in the endoplasmic reticulum (ER). Supporting the view that mutant DBH induces an ER stress response, exogenous expression of mutant DBH dramatically induced expression of BiP, a master ER chaperone. Furthermore, we found that a pharmacological chaperone, glycerol, significantly rescued defective trafficking of mutant DBH proteins. Taken together, we propose that NE deficiency is caused by the combined abnormal processing of DBH mRNA and defective protein trafficking and that this disease could be treated by a pharmacological chaperone(s).

Disorders of the basal ganglia such as Parkinson's disease (PD) and Huntington's disease are commonly thought of primarily as motor disorders; however, the cognitive symptoms of these diseases such as executive dysfunction, learning, memory and attention deficits are prominent and often more disabling than the hallmark motor symptoms. Cognitive features of PD are often neglected in preclinical studies of PD, likely due to the lack of available animal models to study them. Aphakia mice, which are deficient in the transcription factor Pitx3, model the selective nigrostriatal DA loss in PD. Here we report that aphakia mice are impaired in striatum-dependent cognitive tasks including rotarod learning, T-maze and inhibitory avoidance tasks, but not the striatum-independent social transmission of food preference task. These results suggest that some neuropsychiatric symptoms in PD are related to the pathophysiology of the disease rather than stress associated with disease burden, or medications used to treat PD. Furthermore aphakia mice may be used as a novel model of non-motor symptoms in PD.

Implantation of left ventricular assist devices (LVAD) has increased because of improved safety profile and limited availability of heart transplantation. Although supervised exercise training (ET) programs are known to improve exercise capacity and quality of life (QoL) in heart failure (HF) patients, similar data is inconclusive in LVAD patients. Thus, we performed a systematic review on studies that incorporated supervised ET and measured peak oxygen uptake in LVAD patients. A total of 150 patients in exercise and 55 patients in control groups were included from 8 studies selected from our predefined criteria. Our systematic review suggests supervised ET has an inconsistent effect on exercise capacity and QoL when compared to control groups undergoing usual care. A quantitative sub-analysis was performed with 4 studies that provided enough data to compare peak oxygen uptake and QoL at baseline and at follow-up. After at least 6 weeks of training, LVAD patients undergoing supervised ET demonstrated significant improvement in exercise capacity (standardized mean difference [SMD] = 0.735, 95% Confidence Interval-[CI], 0.31-1.15 units of the standard deviation, P = 0.001) and QoL scores (SMD = 1.58, 95% CI 0.97-2.20 units of the standard deviation, P

Temporal lobe epilepsy (TLE) has been modeled in mice using pilocarpine induction, with variable results depending on specific strains. To allow efficient xenotransplantation for the purpose of optimizing potential cell-based therapy of human TLE, we have determined the optimal dosing strategy to produce spontaneous recurring seizures in immunodeficient NodScid mice. Multiple 100 mg/kg injections of pilocarpine have been shown to be more effective than single 300–400 mg/kg injections for inducing spontaneous seizures in NodScid mice. Under our optimal conditions, 88.1+/−2.9% of the mice experienced status epilepticus (SE) with a survival rate of 61.8+/−5.9%. Surviving SE mice displayed spontaneous recurrent seizures at a frequency of 2.8+/−0.9 seizures/day for a duration of 41.1+/−3.5 sec. The widely used method of a single injection of pilocarpine was significantly less efficient in inducing seizures in NodScid mice. Therefore, we have determined that a multiple injection “ramping up” of 100 mg/kg of pilocarpine is optimal for inducing TLE-like spontaneous seizures in NodScid mice. Using this method, mice with SE efficiently developed SRS and expressed mossy fiber sprouting, a signature histopathological feature of TLE.

©2014 Elsevier Inc. Seizure disorders debilitate more than 65,000,000 people worldwide, with temporal lobe epilepsy (TLE) being the most common form. Previous studies have shown that transplantation of GABA-releasing cells results in suppression of seizures in epileptic mice. Derivation of interneurons from human pluripotent stem cells (hPSCs) has been reported, pointing to clinical translation of quality-controlled human cell sources that can enhance inhibitory drive and restore host circuitry. In this study, we demonstrate that hPSC-derived maturing GABAergic interneurons (mGINs) migrate extensively and integrate into dysfunctional circuitry of the epileptic mouse brain. Using optogenetic approaches, we find that grafted mGINs generate inhibitory postsynaptic responses in host hippocampal neurons. Importantly, even before acquiring full electrophysiological maturation, grafted neurons were capable of suppressing seizures and ameliorating behavioral abnormalities such as cognitive deficits, aggressiveness, and hyperactivity. These results provide support for the potential of hPSC-derived mGIN for restorative cell therapy for epilepsy.

Stem cell-based cell replacement of lost midbrain dopamine (mDA) neurons is a potential therapy for Parkinson's disease (PD). Toward this goal, it is critical to optimize various aspects of cell transplantation and to assess functional recovery through behavioral tests in validated animal model(s) of PD. At present, cell transplantation studies are being done almost exclusively in neurotoxin-based animal models, because few genetic models of PD exhibit robust mDA neuronal loss. Here we used a genetic model of PD, the aphakia mouse, which demonstrates selective degeneration of mDA neurons in the substantia nigra. We systematically investigated the functional effects of transplanting embryonic stem cell-derived cells at different stages of in vitro differentiation: embryoid body (EB), neural progenitor (NP), and neuronal differentiated (ND) stages. We found that transplantation of NP cells yielded the best outcomes for both survival and behavioral improvement, while transplantation of EB and ND cells resulted in high teratoma-like tumor formation and poor survival, respectively. In behavioral paradigms specific to basal ganglia, the NP cells group prominently improved motor behavioral defects 1 and 2 months posttransplantation. Furthermore, we found that NP cell transplantation also improved cognitive impairments of aphakia mice, as examined by the passive avoidance task. Importantly, these graft-induced functional improvements well correlated with survival of tyrosine hydroxylase-positive DA neurons. Taken together, we propose that the aphakia mouse can serve as a novel and useful platform for cell transplantation studies to assess both neurological and cognitive improvements and that NP stage cells represent an optimal stage for transplantation.

[Figure][1] [![Graphic][3] ][3][![Graphic][4] ][4] A 59-year-old woman was diagnosed with breast cancer in 1989. In 2002, she was diagnosed with ovarian carcinoma. A left ventricular mass was incidentally noted on a breast magnetic resonance imaging scan for routine screening.

During early development, midbrain dopaminergic (mDA) neuronal progenitors (NPs) arise from the ventral mesencephalic area by the combined actions of secreted factors and their downstream transcription factors. These mDA NPs proliferate, migrate to their final destinations, and develop into mature mDA neurons in the substantia nigra and the ventral tegmental area. Here, we show that such authentic mDA NPs can be efficiently isolated from differentiated ES cells (ESCs) using a FACS method combining two markers, Otx2 and Corin. Purified Otx2 + Corin + cells coexpressed other mDA NP markers, including FoxA2, Lmx1b, and Glast. Using optimized culture conditions, these mDA NPs continuously proliferated up to 4 wk with almost 1,000-fold expansion without significant changes in their phenotype. Furthermore, upon differentiation, Otx2 + Corin + cells efficiently generated mDA neurons, as evidenced by coexpression of mDA neuronal markers (e.g., TH, Pitx3, Nurr1, and Lmx1b) and physiological functions (e.g., efficient DA secretion and uptake). Notably, these mDA NPs differentiated into a relatively homogenous DA population with few serotonergic neurons. When transplanted into PD model animals, aphakia mice, and 6-OHDA–lesioned rats, mDA NPs differentiated into mDA neurons in vivo and generated well-integrated DA grafts, resulting in significant improvement in motor dysfunctions without tumor formation. Furthermore, grafted Otx2 + Corin + cells exhibited significant migratory function in the host striatum, reaching >3.3 mm length in the entire striatum. We propose that functional and expandable mDA NPs can be efficiently isolated by this unique strategy and will serve as useful tools in regenerative medicine, bioassay, and drug screening.

During development, sympathetic neurons and chromaffin cells originate from bipotential sympathoadrenal (SA) progenitors arising from neural crests (NC) in the trunk regions. Recently, we showed that AP-2β, a member of the AP2 family, plays a critical role in the development of sympathetic neurons and locus coeruleus and their norepinephrine (NE) neurotransmitter phenotype. In the present study, we investigated the potential role of AP-2β in the development of NC-derived neuroendocrine chromaffin cells of the adrenal medulla and the epinephrine (EPI) phenotype determination. In support of its role in chromaffin cell development, AP-2β is prominently expressed in both embryonic and adult adrenal medulla. In adrenal chromaffin cells of the AP-2β(-/-) mouse, the expression levels of catecholamine biosynthesizing enzymes, dopamine β-hydroxylase (DBH) and phenylethanolamine-N-methyl-transferase (PNMT), as well as the SA-specific transcription factor, Phox2b, are significantly reduced compared to wild type. In addition, ultrastructural analysis demonstrated that the formation of large secretory vesicles, a hallmark of differentiated chromaffin cells, is defective in AP-2β(-/-) mice. Furthermore, the level of EPI content is largely diminished (>80%) in the adrenal gland of AP-2β(-/-) mice. Chromatin immunoprecipitation (ChIP) assays of rat adrenal gland showed that AP-2β binds to the upstream promoter of the PNMT gene in vivo; strongly suggesting that it is a direct target gene. Overall, our data suggest that AP-2β plays critical roles in the epinephrine phenotype and maturation of adrenal chromaffin cells.

Selective degeneration of midbrain dopaminergic (mDA) neurons is associated with Parkinson’s disease (PD), and thus an in-depth understanding of molecular pathways underlying mDA development will be crucial for optimal bioassays and cell replacement therapy for PD. In this study, we identified a novel Wnt1-Lmx1a autoregulatory loop during mDA differentiation of ES cells, and confirmed its in vivo presence during embryonic development. We found that the Wnt1-Lmx1a autoregulatory loop directly regulates Otx2 through the β-catenin complex and Nurr1 and Pitx3 through Lmx1a. We also found that Lmx1a and Lmx1b co-operatively regulate mDA differentiation with overlapping and cross-regulatory functions. Furthermore, co-activation of both Wnt1 and SHH pathways by exogenous expression of Lmx1a, Otx2 and FoxA2 synergistically enhanced the differentiation of ES cells to mDA neurons. Together with previous works, this study shows that two regulatory loops (Wnt1-Lmx1a and SHH-FoxA2) critically link extrinsic signals to cell-intrinsic factors and cooperatively regulate mDA neuron development.