Cost Analysis of Early vs Delayed Outpatient Repair of Inguinal Hernias in Premature Infants.

INTRODUCTION: Premature infants treated for inguinal hernias after hospital discharge require overnight post-operative observation for apnea monitoring until 50-60 weeks adjusted gestational age (AGA). This study aimed to compare costs associated with early (at time of diagnosis) versus delayed (at AGA not requiring overnight observation) repair of inguinal hernia in premature infants. METHODS: Costs were estimated using the average hospital charges at a single institution for three scenarios: 1) delayed repair 2) early repair requiring overnight observation, and 3) incarcerated inguinal hernia reduced but requiring delayed repair at 48 h. A decision analysis model was used to estimate the cost for premature infants undergoing delayed repair of inguinal hernia while considering the risk of incarceration and associated costs. The base model used 50 weeks AGA for delayed repair and an incarceration rate of 0.5%/week. Sensitivity analyses varied incarceration rate from 0.1 to 4%/week and delayed repair to 55 and 60 weeks AGA. RESULTS: In the base model, delayed repair incurred lower estimated costs than early repair at all time points of diagnosis. In sensitivity analyses, estimated cost for delayed repair only rose above the estimated cost for early repair when estimated incarceration risk reached 3%/week with repair at 60 weeks AGA (if repair before 38 weeks AGA) or 4%/week with repair at 55 weeks AGA (if repair before 39 weeks AGA). CONCLUSIONS: Using solely cost as a deciding factor, repair of premature inguinal hernias diagnosed as an outpatient should be delayed until overnight observation is no longer necessary. TYPE OF STUDY: Decision Analysis model. LEVEL OF EVIDENCE: III.

Early post-operative fever after colorectal surgery in infants is common and rarely associated with infection.

PURPOSE: Early post-operative fever (< 48 h) is common in adults and children and seldom indicative of an infection. Guidance to limit excessive evaluation in adults is well-characterized but similar studies for the pediatric population is scarce. This study was performed to better clarify which infants should undergo investigation for post-operative fever after colorectal reconstructive surgical procedures. METHODS: We performed a retrospective chart review of all infants under one year of age who underwent elective reconstruction for anorectal malformations (ARM) and Hirschsprung Disease (HD) between June 2018 and April 2020 at a single institution. Patient and perioperative characteristics were analyzed to evaluate for possible factors associated with infection. RESULTS: Sixty-eight infants met study criteria - 38 (55.9%) had HD and 30 (44.1%) had ARM. Twenty-two infants (32.4%) had early post-operative fever. A definitive infectious cause was identified in only two infants. The presence of a colostomy pre-operatively and longer operative times were associated with increased risk of post-operative fever (62.5% vs. 22.7% and 175 min vs. 150 min respectively, p < 0.05). CONCLUSION: Early post-operative fever in infants after colorectal surgery is common and rarely associated with an infection. Further research is needed to determine which infants require further work-up and which can be safely observed.

Non-surgical approaches to the management of chest wall deformities.

Chest wall deformities in children encompass a broad spectrum of disorders but pectus excavatum and carinatum are by far the most common. Treatment varies substantially by center, and depends on patient symptoms, severity of disease, and surgeon preference. Historically, surgical approaches were the mainstay of treatment for these disease processes but new advances in non-surgical approaches have demonstrated reasonable results in select patients. These non-surgical approaches include vacuum bell therapy, autologous fat grafting and hyaluronic acid injections for pectus excavatum, and orthotic brace therapy for pectus carinatum. There is debate with regards to optimal patient selection for these non-surgical approaches, as well as other barriers including reimbursement issues. This paper will review the current non-surgical approaches to chest wall deformities available, including optimal patient selection, treatment protocols, indications, contraindications, and outcomes.

Differential Responses of Retinal Neurons and Glia Revealed via Proteomic Analysis on Primary and Secondary Retinal Ganglion Cell Degeneration.

To explore the temporal profile of retinal proteomes specific to primary and secondary retinal ganglion cell (RGC) loss. Unilateral partial optic nerve transection (pONT) was performed on the temporal side of the rat optic nerve. Temporal and nasal retinal samples were collected at 1, 4 and 8 weeks after pONT (n = 4 each) for non-biased profiling with a high-resolution hybrid quadrupole time-of-flight mass spectrometry running on label-free SWATHTM acquisition (SCIEX). An information-dependent acquisition ion library was generated using ProteinPilot 5.0 and OneOmics cloud bioinformatics. Combined proteome analysis detected 2531 proteins with a false discovery rate of <1%. Compared to the nasal retina, 10, 25 and 61 significantly regulated proteins were found in the temporal retina at 1, 4, and 8 weeks, respectively (p < 0.05, FC ≥ 1.4 or ≤0.7). Eight proteins (ALDH1A1, TRY10, GFAP, HBB-B1, ALB, CDC42, SNCG, NEFL) were differentially expressed for at least two time points. The expressions of ALDH1A1 and SNCG at nerve fibers were decreased along with axonal loss. Increased ALDH1A1 localization in the inner nuclear layer suggested stress response. Increased GFAP expression demonstrated regional reactivity of astrocytes and Muller cells. Meta-analysis of gene ontology showed a pronounced difference in endopeptidase and peptidase inhibitor activity. Temporal proteomic profiling demonstrates established and novel protein targets associated with RGC damage.

Visual Function and Survival of Injured Retinal Ganglion Cells in Aged Rbfox1 Knockout Animals.

Rbfox1 is a multifunctional RNA binding protein that regulates various aspects of RNA metabolism important for neuronal differentiation and normal physiology. Rbfox1 has been associated with neurodevelopmental and neurological conditions as well as age-related neurodegenerative diseases such as Alzheimer's and Parkinson's. We have shown that in mammalian retinas Rbfox1 is expressed in retinal ganglion cells (RGCs) and in amacrine cells (ACs). This study investigates the effect of advanced age (22-month-old mice) on visual function, retinal morphology and survival of injured retinal ganglion cells (RGC) in Rbfox1 knockout (KO) animals. A visual cliff test, which was used to evaluate visual function, showed that 22-month old Rbfox1 KO mice have profound depth perception deficiency. Retinal gross morphology in these animals appeared to be normal. Optic nerve crush (ONC) induced axonal injury resulted in approximately 50% of RGC loss in both Rbfox1 KO and age-matched control animals: the average RGC densities in uninjured control and Rbfox1 KO animals were 6274 ± 1673 cells/mm2 and 6004 ± 1531 cells/mm2, respectively, whereas 1 week after ONC, RGC numbers in the retinas of control and Rbfox1 KO mice were reduced to 2998 ± 858 cells/mm2 and 3036 ± 857 cells/mm2, respectively (Rbfox1 KO vs. Rbfox1 KO + ONC, p < 0.0001 and control vs. control + ONC, p < 0.0001). No significant difference between RGC numbers in Rbfox1 KO + ONC and age-matched control + ONC animals was observed, suggesting that Rbfox1 has no effect on the survival of injured RGCs. Interestingly, however, contrary to a commonly accepted view that the number of RGCs in old (18 month of age) compared to young animals is reduced by approximately 40%, the RGC densities in 22-month-old mice in this study were similar to those of 4-month-old counterparts.

Minimally Invasive Approaches and Use of a Patch Are Not Associated with Increased Recurrence Rates After Congenital Diaphragmatic Hernia Repair.

Background: Minimally invasive surgery (MIS) is increasingly used for repair of congenital diaphragmatic hernia (CDH). Reported recurrence after MIS repair varies and is limited by short follow-up and low volume. Our objective was to compare recurrence after MIS versus open repair of CDH. Materials and Methods: Infants who underwent CDH repair between 2010 and 2020 were identified using the PearlDiver Mariner database, a national patient claims data set allowing longitudinal follow-up of patients across systems. Kaplan-Meier analysis and Cox proportional hazards regression models were used to evaluate the association of surgical approach (MIS versus open) and use of a patch with time to recurrence while adjusting for comorbidities (congenital heart disease and pulmonary hypertension) and length of stay (LOS). Results: In a cohort of 629 infants, 25.6% (n = 161) underwent MIS repair with a median follow-up of 4.8 years and recurrence rate of 38.6% (n = 243). Rates of recurrence after MIS repair were lower than open (5 years: 38.6% versus 44.3%; P = .03) and higher with use of patch (5 years: 60.1% versus 40.1%; P = .02). After adjustment for comorbidities and LOS as a proxy for patient complexity, there was no significant difference in recurrence based on approach (adjusted hazard ratio [aHR]: 0.79; confidence interval [95% CI]: 0.57-1.10; P = .16) or use of patch (aHR: 1.22; 95% CI: 0.83-1.79; P = .32). Conclusions: Recurrence rates after repair of CDH were not different based on surgical approach or use of patch after adjustment. Previous data were likely biased by patient complexity, and surgeons should consider these factors in determining approach.

DNA and RNA oxidative damage in the retina is associated with ganglion cell mitochondria.

This study examines retinas from a rat glaucoma model for oxidized nucleosides 8OHdG and 8OHG, biomarkers for oxidative damage of DNA and RNA, respectively. Immunohistochemical data indicate a predominant localization of 8OHdG/8OHG in retinal ganglion cells (RGCs). The levels for these oxidized DNA/RNA products were 3.2 and 2.8 fold higher at 1 and 2 weeks after intraocular pressure elevation compared to control retinas, respectively. 8OHdG/8OHG were almost exclusively associated with mitochondrial DNA/RNA: ~ 65% of 8OHdG/8OHG were associated with RNA isolated from mitochondrial fraction and ~ 35% with DNA. Furthermore, we analyzed retinas of the rd10 mouse, a model for retinitis pigmentosa, with severe degeneration of photoreceptors to determine whether high levels of 8OHdG/8OHG staining intensity in RGCs of control animals is related to the high level of mitochondrial oxidative phosphorylation necessary to support light-evoked RGC activity. No significant difference in 8OHdG/8OHG staining intensity between control and rd10 mouse retinas was observed. The results of this study suggest that high levels of 8OHdG/8OHG in RGCs of wild-type animals may lead to cell damage and progressive loss of RGCs observed during normal aging, whereas ocular hypertension-induced increase in the level of oxidatively damaged mitochondrial DNA/RNA could contribute to glaucomatous neurodegeneration.

Child physical abuse and COVID-19: Trends from nine pediatric trauma centers.

BACKGROUND: Economic, social, and psychologic stressors are associated with an increased risk for abusive injuries in children. Prolonged physical proximity between adults and children under conditions of severe external stress, such as witnessed during the COVID-19 pandemic with "shelter-in-place orders", may be associated with additional increased risk for child physical abuse. We hypothesized that child physical abuse rates and associated severity of injury would increase during the early months of the pandemic as compared to the prior benchmark period. METHODS: We conducted a nine-center retrospective review of suspected child physical abuse admissions across the Western Pediatric Surgery Research Consortium. Cases were identified for the period of April 1-June 30, 2020 (COVID-19) and compared to the identical period in 2019. We collected patient demographics, injury characteristics, and outcome data. RESULTS: There were no significant differences in child physical abuse cases between the time periods in the consortium as a whole or at individual hospitals. There were no differences between the study periods with regard to patient characteristics, injury types or severity, resource utilization, disposition, or mortality. CONCLUSIONS: Apparent rates of new injuries related to child physical abuse did not increase early in the COVID-19 pandemic. While this may suggest that pediatric physical abuse was not impacted by pandemic restrictions and stresses, it is possible that under-reporting, under-detection, or delays in presentation of abusive injuries increased during the pandemic. Long-term follow-up of subsequent rates and severity of child abuse is needed to assess for unrecognized injuries that may have occurred.

Differential Retinal Protein Expression in Primary and Secondary Retinal Ganglion Cell Degeneration Identified by Integrated SWATH and Target-Based Proteomics.

To investigate the retinal proteins associated with primary and secondary retinal ganglion cell (RGC) degeneration and explore their molecular pathways, SWATH label-free and target-based mass spectrometry was employed to identify the proteomes in various retinal locations in response to localized optic nerve injury. Unilateral partial optic nerve transection (pONT) was performed on adult Wistar rats and their retinas were harvested 2 weeks later. To confirm the separation of primary and secondary RGC degeneration, immunohistochemistry of RNA binding protein with multiple splicing (RBPMS) and glial fibrillary acidic protein (GFAP) was performed on retinal whole-mounts. Retinal proteomes in the temporal and nasal quadrants were evaluated with high resolution hybrid quadrupole time-of-flight mass spectrometry (QTOF-MS), and SWATH-based acquisition, and their expression was compared to the corresponding retinal quadrant in contralateral control eyes and further validated by multiple reaction monitoring mass spectrometry (MRM-MS). A total of 3641 proteins (FDR < 1%) were identified using QTOF-MS. The raw data are available via ProteomeXchange with the identifier PXD026783. Bioinformatics data analysis showed that there were 37 upregulated and 25 downregulated proteins in the temporal quadrant, whereas 20 and five proteins were upregulated and downregulated, respectively, in the nasal quadrant, respectively (n = 4, p < 0.05; fold change ≥ 1.4-fold or ≤0.7). Six proteins were regulated in both the temporal and the nasal quadrants, including CLU, GFAP, GNG5, IRF2BPL, L1CAM, and CPLX1. Linear regression analysis indicated a strong association between the data obtained by means of SWATH-MS and MRM-MS (temporal, R2 = 0.97; nasal, R2 = 0.96). Gene ontology analysis revealed statistically significant changes in the biological processes and cellular components of primary RGC degeneration. The majority of the significant changes in structural, signaling, and cell death proteins were associated with the loss of RGCs in the area of primary RGC degeneration. The combined use of SWATH-MS and MRM-MS methods detects and quantifies regional changes of retinal protein expressions after localized injury. Future investigation with this integrated approach will significantly increase the understanding of diverse processes of progressive RGC degeneration from a proteomic prospective.

Loss of Rbfox1 Does Not Affect Survival of Retinal Ganglion Cells Injured by Optic Nerve Crush.

Rbfox1 is a multifunctional RNA binding protein that regulates alternative splicing, transcription, mRNA stability and translation. Its roles in neurogenesis and neuronal functions are well established. Recent studies also implicate Rbfox1 in the regulation of gene networks that support cell survival during stress. We have earlier characterized the expression of Rbfox1 in amacrine and retinal ganglion cells (RGCs) and showed that deletion of Rbfox1 in adult animals results in depth perception deficiency. The current study investigates the effect of Rbfox1 downregulation on survival of RGCs injured by optic nerve crush (ONC). Seven days after ONC, animals sustained severe degeneration of RGC axons in the optic nerve and significant loss of RGC somas. Semi-quantitative grading of optic nerve damage in control + ONC, control + tamoxifen + ONC, and Rbfox1 -/- + ONC groups ranged from 4.6 to 4.8 on a scale of 1 (normal; no degenerated axons were noted) to 5 (total degeneration; all axons showed degenerated organelles, axonal content, and myelin sheath), indicating a severe degeneration. Among these three ONC groups, no statistical significance was observed when any two groups were compared. The number of RGC somas were quantitatively analyzed in superior, inferior, nasal and temporal retinal quadrants at 0.5, 1, and 1.5 mm from the center of the optic disc. The average RGC densities (cells/mm2) were: control 6,438 ± 1,203; control + ONC 2,779 ± 573; control + tamoxifen 6,163 ± 861; control + tamoxifen + ONC 2,573 ± 555; Rbfox1 -/- 6,437 ± 893; and Rbfox1 -/- + ONC 2,537 ± 526. The RGC loss in control + ONC, control + tamoxifen + ONC and Rbfox1 -/- + ONC was 57% (P = 1.44954E-42), 58% (P = 1.37543E-57) and 61% (P = 5.552E-59) compared to RGC numbers in the relevant uninjured groups, respectively. No statistically significant difference was observed between any two groups of uninjured animals or between any two ONC groups. Our data indicate that Rbfox1-mediated pathways have no effect on survival of RGCs injured by ONC.

Quantitative profiling of regional protein expression in rat retina after partial optic nerve transection using fluorescence difference two­dimensional gel electrophoresis.

To examine the difference between primary and secondary retinal ganglion cell (RGC) degeneration, the protein expression at four regions of retina including superior, temporal, inferior and nasal quadrant in a rat model of partial optic nerve transection (pONT) using 2­D Fluorescence Difference Gel Electrophoresis (DIGE) were investigated. Unilateral pONT was performed on the temporal side of optic nerves of adult Wistar rats to separate primary and secondary RGC loss. Topographical quantification of RGCs labeled by Rbpms antibody and analysis of axonal injury by grading of optic nerve damage at 1 week (n=8) and 8 weeks (n=15) after pONT demonstrated early RGC loss at temporal region, which is considered as primary RGC degeneration and progressing RGC loss at nasal region, which is considered as secondary RGC degeneration. Early protein expression in each retinal quadrant (n=4) at 2 weeks after pONT was compared with the corresponding quadrant in the contralateral control eye by DIGE. For all comparisons, 24 differentially expressed proteins (>1.2­fold; P<0.05; ≥3 non­duplicated peptide matches) were identified by mass spectrometry (MS). Interestingly, in the nasal retina, serum albumin and members of crystallin family, including αA, αB, ßA2, ßA3, ßB2 and gamma S indicating stress response were upregulated. By contrast, only αB and ßA2 crystallin proteins were altered in temporal quadrant. In the superior and inferior quadrants, ßB2 crystallin, keratin type I, S­arrestin and lamin­B1 were upregulated, while heat shock cognate 71 kDa protein and heterogeneous nuclear ribonucleoproteins A2/B1 were downregulated. In summary, the use of DIGE followed by MS is useful to detect early regional protein regulation in the retina after localized optic nerve injury.

An educational intervention for medical students to improve self-efficacy in firearm injury prevention counseling.

BACKGROUND: Most physicians support counseling patients about firearm injury prevention (FIP), but infrequently do so due to lack of training and low confidence. Interventions to increase counseling frequency should focus on improving physician self-efficacy. Firearm injuries affect many clinical specialties; therefore, trainees would benefit from early FIP education. This study aims to determine if a 20-min educational intervention improves self-efficacy in FIP counseling in third-year medical students. Knowledge and beliefs were also assessed as secondary indicators of self-efficacy. METHODS: This was a prospective study performed at a medical school associated with a tertiary care children's hospital during the 2016-17 academic year. Groups of 12-15 different third-year medical students were selected to receive either a 20-min intervention or control lecture during their monthly pediatric lectures. The intervention consisted of two clinical vignettes, a brief discussion about the importance of FIP, and suggestions for clinical integration. The control session was a case-based lecture about pediatric emergencies. Participants completed baseline electronic assessments. Intervention students also completed post-intervention assessments immediately following each session. All participants completed final assessments at 6 months. Data were analyzed using Wilcoxon signed-rank tests and Wilcoxon rank-sum. RESULTS: We surveyed a total of 130 students. Sixty-five students completed the entire series of assessments - 22 from the control and 43 from the intervention group. There were no significant differences between the control and intervention groups at baseline. Immediately after, intervention, participants reported feeling more self-efficacious, had improved knowledge of FIP risk factors, and had beliefs more consistent with providing FIP anticipatory guidance (p <  0.001 for all three measures). After 6 months, participants sustained improvement in one of two self-efficacy questions ("I feel ready to counsel patients about firearm injury prevention") and retained knowledge of risk factors (p <  0.05 for both). However, their beliefs did not significantly favor FIP counseling, and they were not more likely to engage in a conversation about firearm safety. CONCLUSIONS: A 20-min educational intervention acutely improved self-efficacy in FIP counseling in third-year medical students, but improvements weakened after six months. Without further training, the beneficial effects of a one-time intervention will likely wane with time.

Comparative lipid profiling dataset of the inflammation-induced optic nerve regeneration.

In adult mammals, retinal ganglion cells (RGCs) fail to regenerate following damage. As a result, RGCs die after acute injury and in progressive degenerative diseases such as glaucoma; this can lead to permanent vision loss and, eventually, blindness. Lipids are crucial for the development and maintenance of cell membranes, myelin sheaths, and cellular signaling pathways, however, little is known about their role in axon injury and repair. Studies examining changes to the lipidome during optic nerve (ON) regeneration could greatly inform treatment strategies, yet these are largely lacking. Experimental animal models of ON regeneration have facilitated the exploration of the molecular determinants that affect RGC axon regeneration. Here, we analyzed lipid profiles of the ON and retina in an ON crush rat model using liquid chromatography-mass spectrometry. Furthermore, we investigated lipidome changes after ON crush followed by intravitreal treatment with Zymosan, a yeast cell wall derivative known to enhance RGC regeneration. This data is available at the NIH Common Fund's Metabolomics Data Repository and Coordinating Center (supported by NIH grant, U01-DK097430) website, the Metabolomics Workbench, http://www.metabolomicsworkbench.org, where it has been assigned Project ID: PR000661. The data can be accessed directly via it's Project DOI: doi: 10.21,228/M87D53.

The effect of celastrol on the ocular hypertension-induced degeneration of retinal ganglion cells.

Celastrol, a quinine methide triterpene extracted from the perennial vine Tripterygium wilfordii, has been identified as a neuroprotective agent in various models of neurodegenerative disorders. We have reported earlier that systemic and intravitreal administration of celastrol stimulate the survival of retinal ganglion cells (RGCs) injured by optic nerve crush (ONC) and that mechanisms underlying celastrol׳s RGC protection may be associated with inhibition of TNF-alpha-mediated cell death. The present study evaluates the effect of celastrol on the survival of RGCs injured by ocular hypertension. Intraocular pressure (IOP) elevation resulted in approximately 23% of RGCs loss. Reduction in RGC numbers was observed in all four retinal quadrants: 30% in superior, 17% in inferior, 11% in nasal and 35% in temporal regions. Celastrol (1 mg/kg) or vehicle (DMSO) was administered three times per week by intraperitoneal injection, starting on the day of laser photocoagulation of the TM and continued for the entire duration of the experiment (5 weeks). Celastrol treatment stimulated RGC survival by an average of 24% in the entire retina compared to the vehicle-treated group. RGC numbers were increased in all four quadrants: approximately 40%, 17%, 15% and 30% more RGCs were counted in the superior, inferior, nasal and temporal regions, respectively. The average RGC numbers for the entire retinas of the celastrol/IOP group were only ∼5% and 10% lower than that in vehicle- or celastrol-injected animals with normal IOP, respectively. Our data indicate a significant celastrol-mediated neuroprotection against elevated IOP-induced injury.

Optic Nerve Regeneration After Crush Remodels the Injury Site: Molecular Insights From Imaging Mass Spectrometry.

Purpose: Mammalian central nervous system axons fail to regenerate after injury. Contributing factors include limited intrinsic growth capacity and an inhibitory glial environment. Inflammation-induced optic nerve regeneration (IIR) is thought to boost retinal ganglion cell (RGC) intrinsic growth capacity through progrowth gene expression, but effects on the inhibitory glial environment of the optic nerve are unexplored. To investigate progrowth molecular changes associated with reactive gliosis during IIR, we developed an imaging mass spectrometry (IMS)-based approach that identifies discriminant molecular signals in and around optic nerve crush (ONC) sites. Methods: ONC was performed in rats, and IIR was established by intravitreal injection of a yeast cell wall preparation. Optic nerves were collected at various postcrush intervals, and longitudinal sections were analyzed with matrix-assisted laser desorption/ionization (MALDI) IMS and data mining. Immunohistochemistry and confocal microscopy were used to compare discriminant molecular features with cellular features of reactive gliosis. Results: IIR increased the area of the crush site that was occupied by a dense cellular infiltrate and mass spectral features consistent with lysosome-specific lipids. IIR also increased immunohistochemical labeling for microglia and macrophages. IIR enhanced clearance of lipid sulfatide myelin-associated inhibitors of axon growth and accumulation of simple GM3 gangliosides in a spatial distribution consistent with degradation of plasma membrane from degenerated axons. Conclusions: IIR promotes a robust phagocytic response that improves clearance of myelin and axon debris. This growth-permissive molecular remodeling of the crush injury site extends our current understanding of IIR to include mechanisms extrinsic to the RGC.

A Molecular Tweezer Ameliorates Motor Deficits in Mice Overexpressing α-Synuclein.

Aberrant accumulation and self-assembly of α-synuclein are tightly linked to several neurodegenerative diseases called synucleinopathies, including idiopathic Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy. Deposition of fibrillar α-synuclein as insoluble inclusions in affected brain cells is a pathological hallmark of synucleinopathies. However, water-soluble α-synuclein oligomers may be the actual culprits causing neuronal dysfunction and degeneration in synucleinopathies. Accordingly, therapeutic approaches targeting the toxic α-synuclein assemblies are attractive for these incurable disorders. The "molecular tweezer" CLR01 selectively remodels abnormal protein self-assembly through reversible binding to Lys residues. Here, we treated young male mice overexpressing human wild-type α-synuclein under control of the Thy-1 promoter (Thy1-aSyn mice) with CLR01 and examined motor behavior and α-synuclein in the brain. Intracerebroventricular administration of CLR01 for 28 days to the mice improved motor dysfunction in the challenging beam test and caused a significant decrease of buffer-soluble α-synuclein in the striatum. Proteinase-K-resistant, insoluble α-synuclein deposits remained unchanged in the substantia nigra, whereas levels of diffuse cytoplasmic α-synuclein in dopaminergic neurons increased in mice receiving CLR01 compared with vehicle. More moderate improvement of motor deficits was also achieved by subcutaneous administration of CLR01, in 2/5 trials of the challenging beam test and in the pole test, which requires balance and coordination. The data support further development of molecular tweezers as therapeutic agents for synucleinopathies.

Heat shock proteins in the retina: Focus on HSP70 and alpha crystallins in ganglion cell survival.

Heat shock proteins (HSPs) belong to a superfamily of stress proteins that are critical constituents of a complex defense mechanism that enhances cell survival under adverse environmental conditions. Cell protective roles of HSPs are related to their chaperone functions, antiapoptotic and antinecrotic effects. HSPs' anti-apoptotic and cytoprotective characteristics, their ability to protect cells from a variety of stressful stimuli, and the possibility of their pharmacological induction in cells under pathological stress make these proteins an attractive therapeutic target for various neurodegenerative diseases; these include Alzheimer's, Parkinson's, Huntington's, prion disease, and others. This review discusses the possible roles of HSPs, particularly HSP70 and small HSPs (alpha A and alpha B crystallins) in enhancing the survival of retinal ganglion cells (RGCs) in optic neuropathies such as glaucoma, which is characterized by progressive loss of vision caused by degeneration of RGCs and their axons in the optic nerve. Studies in animal models of RGC degeneration induced by ocular hypertension, optic nerve crush and axotomy show that upregulation of HSP70 expression by hyperthermia, zinc, geranyl-geranyl acetone, 17-AAG (a HSP90 inhibitor), or through transfection of retinal cells with AAV2-HSP70 effectively supports the survival of injured RGCs. RGCs survival was also stimulated by overexpression of alpha A and alpha B crystallins. These findings provide support for translating the HSP70- and alpha crystallin-based cell survival strategy into therapy to protect and rescue injured RGCs from degeneration associated with glaucomatous and other optic neuropathies.

Programmed cell death-1 is expressed in large retinal ganglion cells and is upregulated after optic nerve crush.

Programmed cell death-1 (PD-1) is a key negative receptor inducibly expressed on T cells, B cells and dendritic cells. It was discovered on T cells undergoing classical programmed cell death. Studies showed that PD-1 ligation promotes retinal ganglion cell (RGC) death during retinal development. The purpose of this present study is to characterize PD-1 regulation in the retina after optic nerve crush (ONC). C57BL/6 mice were subjected to ONC and RGC loss was monitored by immunolabelling with RNA-binding protein with multiple splicing (Rbpms). Time course of PD-1 mRNA expression was determined by real-time PCR. PD-1 expression was detected with anti-PD-1 antibody on whole mount retinas. PD-1 staining intensity was quantitated. Colocalization of PD-1 and cleaved-caspase-3 after ONC was analyzed. Real-time PCR results demonstrated that PD-1 gene expression was significantly upregulated at day 1, 3, 7, 10 and 14 after ONC. Immunofluorescent staining revealed a dramatic increase of PD-1 expression following ONC. In both control and injured retinas, PD-1 tended to be up-expressed in a subtype of RGCs, whose somata size were significantly larger than others. Compared to control, PD-1 intensity in large RGCs was increased by 82% in the injured retina. None of the large RGCs expressed cleaved-caspase-3 at day 5 after ONC. Our work presents the first evidence of PD-1 induction in RGCs after ONC. This observation supports further investigation into the role of PD-1 expression during RGC death or survival following injury.