High-throughput Oligopaint screen identifies druggable 3D genome regulators.

The human genome functions as a three-dimensional chromatin polymer, driven by a complex collection of chromosome interactions1-3. Although the molecular rules governing these interactions are being quickly elucidated, relatively few proteins regulating this process have been identified. Here, to address this gap, we developed high-throughput DNA or RNA labelling with optimized Oligopaints (HiDRO)-an automated imaging pipeline that enables the quantitative measurement of chromatin interactions in single cells across thousands of samples. By screening the human druggable genome, we identified more than 300 factors that influence genome folding during interphase. Among these, 43 genes were validated as either increasing or decreasing interactions between topologically associating domains. Our findings show that genetic or chemical inhibition of the ubiquitous kinase GSK3A leads to increased long-range chromatin looping interactions in a genome-wide and cohesin-dependent manner. These results demonstrate the importance of GSK3A signalling in nuclear architecture and the use of HiDRO for identifying mechanisms of spatial genome organization.

Dual targeting of brain region-specific kinases potentiates neurological rescue in Spinocerebellar ataxia type 1.

A critical question in neurodegeneration is why the accumulation of disease-driving proteins causes selective neuronal loss despite their brain-wide expression. In Spinocerebellar ataxia type 1 (SCA1), accumulation of polyglutamine-expanded Ataxin-1 (ATXN1) causes selective degeneration of cerebellar and brainstem neurons. Previous studies revealed that inhibiting Msk1 reduces phosphorylation of ATXN1 at S776 as well as its levels leading to improved cerebellar function. However, there are no regulators that modulate ATXN1 in the brainstem-the brain region whose pathology is most closely linked to premature death. To identify new regulators of ATXN1, we performed genetic screens and identified a transcription factor-kinase axis (ZBTB7B-RSK3) that regulates ATXN1 levels. Unlike MSK1, RSK3 is highly expressed in the human and mouse brainstems where it regulates Atxn1 by phosphorylating S776. Reducing Rsk3 rescues brainstem-associated pathologies and deficits, and lowering Rsk3 and Msk1 together improves cerebellar and brainstem function in an SCA1 mouse model. Our results demonstrate that selective vulnerability of brain regions in SCA1 is governed by region-specific regulators of ATXN1, and targeting multiple regulators could rescue multiple degenerating brain areas.

Disruption of MeCP2-TCF20 complex underlies distinct neurodevelopmental disorders.

MeCP2 is associated with Rett syndrome (RTT), MECP2 duplication syndrome, and a number of conditions with isolated features of these diseases, including autism, intellectual disability, and motor dysfunction. MeCP2 is known to broadly bind methylated DNA, but the precise molecular mechanism driving disease pathogenesis remains to be determined. Using proximity-dependent biotinylation (BioID), we identified a transcription factor 20 (TCF20) complex that interacts with MeCP2 at the chromatin interface. Importantly, RTT-causing mutations in MECP2 disrupt this interaction. TCF20 and MeCP2 are highly coexpressed in neurons and coregulate the expression of key neuronal genes. Reducing Tcf20 partially rescued the behavioral deficits caused by MECP2 overexpression, demonstrating a functional relationship between MeCP2 and TCF20 in MECP2 duplication syndrome pathogenesis. We identified a patient exhibiting RTT-like neurological features with a missense mutation in the PHF14 subunit of the TCF20 complex that abolishes the MeCP2-PHF14-TCF20 interaction. Our data demonstrate the critical role of the MeCP2-TCF20 complex for brain function.

Picking Winners and Losers: Cell Competition in Tissue Development and Homeostasis.

Viable cells with reduced fitness are often eliminated by neighboring cells with greater fitness. This phenomenon, called cell competition, is an important mechanism for maintaining a high-quality population of cells in tissues. Foundational studies characterizing cellular competition and its molecular underpinnings were first carried out utilizing Drosophila as a model system. More recently, competitive behavior studies have extended into mammalian cell types. In this review, we highlight recent advances in the field, focusing on new insights into the molecular mechanisms regulating competitive behavior in various cellular contexts and in cancer. Throughout the review, we highlight new avenues to expand our understanding of the molecular underpinnings of cell competition and its role in tissue development and homeostasis.

CORO7 functions as a scaffold protein for the core kinase complex assembly of the Hippo pathway.

The Hippo pathway controls organ size and tissue homeostasis through the regulation of cell proliferation and apoptosis. However, the exact molecular mechanisms underpinning Hippo pathway regulation are not fully understood. Here, we identify a new component of the Hippo pathway: coronin 7 (CORO7), a coronin protein family member that is involved in organization of the actin cytoskeleton. pod1, the Drosophila ortholog of CORO7, genetically interacts with key Hippo pathway genes in Drosophila. In mammalian cells, CORO7 is required for the activation of the Hippo pathway in response to cell-cell contact, serum deprivation, and cytoskeleton damage. CORO7 forms a complex with the core components of the pathway and functions as a scaffold for the Hippo core kinase complex. Collectively, these results demonstrate that CORO7 is a key scaffold controlling the Hippo pathway via modulating protein-protein interactions.

Von Hippel-Lindau tumor suppressor (VHL) stimulates TOR signaling by interacting with phosphoinositide 3-kinase (PI3K).

Cell growth is positively controlled by the phosphoinositide 3-kinase (PI3K)-target of rapamycin (TOR) signaling pathway under conditions of abundant growth factors and nutrients. To discover additional mechanisms that regulate cell growth, here we performed RNAi-based mosaic analyses in the Drosophila fat body, the primary metabolic organ in the fly. Unexpectedly, the knockdown of the Drosophila von Hippel-Lindau (VHL) gene markedly decreased cell size and body size. These cell growth phenotypes induced by VHL loss of function were recovered by activation of TOR signaling in Drosophila Consistent with the genetic interactions between VHL and the signaling components of PI3K-TOR pathway in Drosophila, we observed that VHL loss of function in mammalian cells causes decreased phosphorylation of ribosomal protein S6 kinase and Akt, which represent the main activities of this pathway. We further demonstrate that VHL activates TOR signaling by directly interacting with the p110 catalytic subunit of PI3K. On the basis of the evolutionarily conserved regulation of PI3K-TOR signaling by VHL observed here, we propose that VHL plays an important role in the regulation and maintenance of proper cell growth in metazoans.

BRD4 (Bromodomain-Containing Protein 4) Interacts with GATA4 (GATA Binding Protein 4) to Govern Mitochondrial Homeostasis in Adult Cardiomyocytes.

BACKGROUND: Gene regulatory networks control tissue homeostasis and disease progression in a cell type-specific manner. Ubiquitously expressed chromatin regulators modulate these networks, yet the mechanisms governing how tissue specificity of their function is achieved are poorly understood. BRD4 (bromodomain-containing protein 4), a member of the BET (bromo- and extraterminal domain) family of ubiquitously expressed acetyl-lysine reader proteins, plays a pivotal role as a coactivator of enhancer signaling across diverse tissue types in both health and disease and has been implicated as a pharmacological target in heart failure. However, the cell-specific role of BRD4 in adult cardiomyocytes remains unknown. METHODS: We combined conditional mouse genetics, unbiased transcriptomic and epigenomic analyses, and classic molecular biology and biochemical approaches to understand the mechanism by which BRD4 in adult cardiomyocyte homeostasis. RESULTS: Here, we show that cardiomyocyte-specific deletion of Brd4 in adult mice leads to acute deterioration of cardiac contractile function with mutant animals demonstrating a transcriptomic signature characterized by decreased expression of genes critical for mitochondrial energy production. Genome-wide occupancy data show that BRD4 enriches at many downregulated genes (including the master coactivators Ppargc1a, Ppargc1b, and their downstream targets) and preferentially colocalizes with GATA4 (GATA binding protein 4), a lineage-determining cardiac transcription factor not previously implicated in regulation of adult cardiac metabolism. BRD4 and GATA4 form an endogenous complex in cardiomyocytes and interact in a bromodomain-independent manner, revealing a new functional interaction partner for BRD4 that can direct its locus and tissue specificity. CONCLUSIONS: These results highlight a novel role for a BRD4-GATA4 module in cooperative regulation of a cardiomyocyte-specific gene program governing bioenergetic homeostasis in the adult heart.

Left ventricular outflow obstruction occurs immediately after exercise in patients with non-obstructive hypertrophic cardiomyopathy.

We evaluated the hemodynamic and geometric determinants of latent obstruction (LO, trans-left ventricular outflow tract (LVOT) gradient ≥30 mmHg with provocation) in patients with non-obstructive hypertrophic cardiomyopathy (HCMP). A total of 35 patients with non-obstructive HCMP underwent stepwise supine bicycle exercise echocardiography. Trans-LVOT pressure gradients, mitral geometric parameters, left ventricular ejection fractions (LVEF) and left ventricular end-systolic and diastolic dimensions (LVESD, LVEDD) were measured at each stage. The highest peak LVOT pressure gradient predominantly occurred immediately after exercise (n = 32, 91.3%) rather than during peak exercise (n = 3, 8.7%). Significant LO developed in nine patients (25%). No significant differences were found in resting echocardiographic parameters. Compared to the remaining patients, however, patients with LO had longer residual mitral leaflets (defined as residual portions of leaflets after coaptation; 4 ± 4 vs. 13 ± 4 mm, respectively; p = 0.001) and higher resting LVOT pressure gradients (7.4 ± 3.7 vs. 12.9 ± 5.8 mmHg, respectively; p = 0.001). Substantial decreases in mitral annular diameters from peak exercise to recovery after exercise were observed in the LO group, while mitral annular diameters increased after exercise in the non-LO group. In conclusion, the highest peak LVOT pressure gradient predominantly occurred immediately after exercise rather than during peak exercise, regardless of LO. Abrupt decrease of mitral annular diameter immediately after exercise, a longer residual mitral leaflet and a higher resting LVOT pressure gradient at rest might be related to LO.

Coronin 1B regulates the TNFα-induced apoptosis of HUVECs by mediating the interaction between TRADD and FADD.

Coronin 1B is an actin-binding protein that plays important roles in actin-dependent cellular processes. We previously reported that coronin 1B is involved in vascular endothelial cell growth factor-induced migration of human umbilical vein endothelial cells (HUVECs). However, the role of coronin 1B in tumor necrosis factor alpha (TNFα)-induced endothelial cell apoptosis remained unknown. In this study, we investigated whether coronin 1B affects TNFα-induced HUVEC apoptosis and sought to elucidate the mechanism by which coronin 1B regulates this cellular process. Depletion of coronin 1B by siRNA transfection decreased TNFα-induced apoptosis of HUVECs, as determined by MTT, terminal deoxynucleotidyl transferase dUTP nick end labeling and caspase-3 activity assays. Coronin 1B depletion also decreased caspase-8 cleavage via a JNK-independent pathway. Coronin 1B interacted with Fas-associated death domain protein (FADD) in both a plasmid overexpression system in HEK293T cells and at the endogenous protein level in TNFα-stimulated HUVECs. Immunoprecipitation and in situ proximity ligation assays showed that coronin 1B depletion diminished the interaction between TNFα-induced TNF receptor-1-associated death domain protein (TRADD) and FADD, suggesting that coronin 1B is required for the TNFα-induced TRADD and FADD interaction and subsequent caspase-8/caspase-3 cascade activation, ultimately leading to apoptosis.

Parkin Coordinates Platelet Stress Response in Diabetes Mellitus: A Big Role in a Small Cell.

Increased platelet activation and apoptosis are characteristic of diabetic (DM) platelets, where a Parkin-dependent mitophagy serves a major endogenous protective role. We now demonstrate that Parkin is highly expressed in both healthy platelets and diabetic platelets, compared to other mitochondria-enriched tissues such as the heart, muscle, brain, and liver. Abundance of Parkin in a small, short-lived anucleate cell suggest significance in various key processes. Through proteomics we identified 127 Parkin-interacting proteins in DM platelets and compared them to healthy controls. We assessed the 11 highest covered proteins by individual IPs and confirmed seven proteins that interacted with Parkin; VCP/p97, LAMP1, HADHA, FREMT3, PDIA, ILK, and 14-3-3. Upon further STRING analysis using GO and KEGG, interactions were divided into two broad groups: targeting platelet activation through (1) actions on mitochondria and (2) actions on integrin signaling. Parkin plays an important role in mitochondrial protection through mitophagy (VCP/p97), recruiting phagophores, and targeting lysosomes (with LAMP1). Mitochondrial ß-oxidation may also be regulated by the Parkin/HADHA interaction. Parkin may regulate platelet aggregation and activation through integrin signaling through interactions with proteins like FREMT3, PDIA, ILK, and 14-3-3. Thus, platelet Parkin may regulate the protection (mitophagy) and stress response (platelet activation) in DM platelets. This study identified new potential therapeutic targets for platelet mitochondrial dysfunction and hyperactivation in diabetes mellitus.

Effect of PTH and corticotomy on implant movement under mechanical force.

BACKGROUND: Osseointegrated implants are considered as clinically non-movable. Parathyroid hormone (PTH) is known to play a significant role in the regulation of bone remodeling and in intermittent, low doses, result in osteoanabolic effects. This study aimed to investigate the effects of PTH and corticotomy, both under traction force, on osseointegrated implants. METHODS: Four implants-two in each hemimandible-were placed in each of the three study mongrels. Each mongrels were designated as control, normal dose PTH (PTH-1), and high dose PTH (PTH-2) groups, with each groups further subdivided into non-surgery implant and surgery implant. After osseointegration, mechanical force with NiTi closed coil springs (500 g) was applied around each implants. Corticotomy was performed around one of four implants in each mongrels. Parathyroid hormone was administered locally on a weekly basis for 20 weeks. Clinical movement of the implants were evaluated with the superimposed 3D- scanned data, bone- microarchitectural and histologic examinations. RESULTS: Superimposition analysis showed continuous movement of the non-surgery implant of PTH-1 group. Movement was further justified with lowest bone implant contact (adjusted BIC; 44.77%) in histomorphometric analysis. Upregulation of bone remodeling around the implant was observed in the normal dose PTH group. In the surgery implants, the remarkably higher adjusted BIC compared to the non-surgery implants indicated increased bone formation around the implant surface. CONCLUSION: The results indicate that the catabolic and anabolic balance of osseointegrated implants in terms of bone remodeling can be shifted via various interventions including pharmacological, surgical and mechanical force. CLINICAL RELEVANCE: Upregulated bone remodeling by PTH and corticotomy under continuous mechanical force showed the possible implications for the movement of osseointegrated dental implant.

Outcomes over Time in Patients with Hostile Neck Anatomy Undergoing Endovascular Repair of Abdominal Aortic Aneurysm.

PURPOSE: To assess differences in outcome in an early and later time period in patients with hostile neck anatomy who underwent endovascular aneurysm repair (EVAR). MATERIALS AND METHODS: This single-center, institutional review board-approved retrospective study assessed patients who underwent EVAR between 2004 and 2013, divided into 2 time periods: 2004-2008 and 2009-2013. One hundred twenty-five patients had at least 1 hostile neck parameter that met inclusion criteria: 61 of 216 (28%) patients in the early period and 64 of 144 (44%) patients in the late period. Patients in the late group were younger compared to patients in the early group (late group, 74.5 ± 8.8 years vs early group, 77.5 ± 7.5 years; P = .046). No significant differences were observed in hostile neck anatomic factors between the early and late periods. RESULTS: No statistical difference was observed in periprocedural factors or outcome measures, except for abdominal aortic aneurysm (AAA) sac regression in the late period compared to the early period (late period, 73.5% vs early period, 55.7%; P = .038). A statistically significant increase was observed in type 1a endoleaks in patients in the late group with suprarenal fixation compared to patients with infrarenal fixation (suprarenal, 27.0% vs infrarenal, 7.9%; P = .025) and in the overall time studied (suprarenal, 20.3% vs infrarenal, 7.6%; P = .045). CONCLUSIONS: Except for AAA sac regression, no changes were observed in periprocedural factors and outcome measures over time in patients with hostile neck who underwent EVAR.

Does Medical Acceleration Improve Outcomes in Ulcerative Colitis Patients Who Are in Clinical Remission but Have Endoscopic Inflammation?

BACKGROUND: Discrepancies between clinical symptoms and mucosal inflammation have been reported in up to 50% of patients with ulcerative colitis (UC). However, there are no guidelines and only limited information for appropriate treatment manipulation. AIM: We aimed to evaluate long-term outcomes according to treatment strategies and determine predictive factors for disease relapse in UC patients who are in clinical remission (CR) but still have endoscopic inflammation. METHODS: A total of 204 patients who were confirmed as achieving CR but still had mucosal inflammation were included. CR was defined as "partial Mayo score ≤ 1" with no changes in medications or use of any corticosteroids during the past 3 months. An active mucosal lesion was defined as "endoscopic Mayo subscore > 0." RESULTS: The mean patient age was 43.5 years, and 53.9% were male. The mean disease duration was 89.9 months. During a mean follow-up of 34 months, 90 patients (44%) experienced disease relapse. The cumulative relapse-free rate did not differ by treatment strategy (maintenance of current therapy vs. dose elevation or step-up therapy). Multivariate analysis revealed that left-side colitis or pancolitis at diagnosis (OR 2.10; 95% CI 1.04-4.27; P = 0.040) and number of extraintestinal manifestations ≥ 2 (OR 5.62; 95% CI 1.10-28.68; P = 0.038) were independent predictive factors for disease relapse. CONCLUSIONS: The current medical acceleration treatment strategy did not have a significant influence on the long-term outcomes of UC patients in CR but with active mucosal inflammation. Disease extent at diagnosis and extraintestinal manifestations were independently predictive of disease relapse.

Activating transcription factor 3 is a target molecule linking hepatic steatosis to impaired glucose homeostasis.

BACKGROUND & AIMS: Non-alcoholic fatty liver disease (NAFLD) contributes to impaired glucose tolerance, leading to type 2 diabetes (T2D); however, the precise mechanisms and target molecules that are involved remain unclear. Activating transcription factor 3 (ATF3) is associated with ß-cell dysfunction that is induced by severe stress signals in T2D. We aimed to explore the exact functional role of ATF3 as a mechanistic link between hepatic steatosis and T2D development. METHODS: Zucker diabetic fatty (ZDF) rats were utilized for animal experiments. An in vivo-jetPEI siRNA delivery system against ATF3 was used for loss-of-function experiments. We analyzed the baseline cross-sectional data derived from the biopsy-proven NAFLD registry (n=322). Human sera and liver tissues were obtained from 43 patients with biopsy-proven NAFLD and from seven healthy participants. RESULTS: ATF3 was highly expressed in the livers of ZDF rats and in human participants with NAFLD and/or T2D. Insulin resistance and hepatic steatosis were associated with increased ATF3 expression and decreased fatty acid oxidation via mitochondrial dysfunction and were attenuated by in vivo ATF3 silencing. Knockdown of ATF3 also ameliorated glucose intolerance, impaired insulin action, and inflammatory responses in ZDF rats. In patients with NAFLD and/or T2D, a significant positive correlation was observed between hepatic ATF3 expression and surrogate markers of T2D, mitochondrial dysfunction, and macrophage infiltration. CONCLUSIONS: Increased hepatic ATF3 expression is closely associated with hepatic steatosis and incident T2D; therefore, ATF3 may serve as a potential therapeutic target for NAFLD and hepatic steatosis-induced T2D. LAY SUMMARY: Hepatic activating transcription factor 3 (ATF3) may play an important role in oxidative stress-mediated hepatic steatosis and the development of type 2 diabetes (T2D) in a Zucker diabetic fatty (ZDF) rat model and in human patients with non-alcoholic fatty liver disease (NAFLD). Therefore, ATF3 may be a useful biomarker for predicting the progression of NAFLD and the development of T2D. Furthermore, given the significant association between hepatic ATF3 expression and both hepatic steatosis and impaired glucose homeostasis, in vivo ATF3 silencing may be a potential central strategy for preventing and managing NAFLD and T2D.

Effect of ß-blocker on aneurysm sac behavior after endovascular abdominal aortic repair.

OBJECTIVE: This study was conducted to determine whether ß-blocker (BB) therapy is associated with abdominal aortic aneurysm (AAA) sac regression after endovascular abdominal aortic repair (EVAR). METHODS: A total of 198 patients (mean age, 76 years) who underwent EVAR were analyzed (104 in the BB group and 94 in the non-BB group). The primary end point was the incidence of AAA sac regression at 1 and 2 years. RESULTS: Hypertension, coronary artery disease, and hyperlipidemia were more common in the BB group. The BB group was also more likely to have been prescribed an aspirin and a statin than the non-BB group. The length of proximal neck was significantly longer in the non-BB group than in the BB group. All study patients were monitored for at least 1 year after EVAR, and 2-year follow-up was available in 104 patients (52.5%). There was no statistically significant difference in the incidence of aneurysm sac regression in either group at 1 year (52.1% in the non-BB group vs 45.2% in the BB group; P = .330) and 2 years (58.5% in the non-BB group vs 64.7% in the BB group; P = .515). The difference of the change of AAA maximum diameter between two groups did not reach statistical significance at 1 year (-6.0 ± 7.0 mm in the non-BB group vs -5.5 ± 8.1 mm in the BB group; P = .644) and 2 years (-9.0 ± 10.5 mm in the non-BB group vs -9.0 ± 10.0 mm in the BB group; P = .977). BB therapy was not associated with increased odds of AAA sac regression. The effect of third-generation BBs on AAA sac regression was not significant. CONCLUSIONS: BB therapy had no effect on AAA sac regression. At the present time, there is insufficient evidence to recommend BB therapy for the purpose of AAA sac regression.

Influence of Statin Therapy on Aneurysm Sac Regression after Endovascular Aortic Repair.

PURPOSE: To determine whether statin therapy is associated with abdominal aortic aneurysm (AAA) sac regression after endovascular aneurysm repair (EVAR). MATERIALS AND METHODS: A total of 109 patients treated with EVAR were retrospectively analyzed (no-statin group, n = 45; statin group, n = 64). The primary endpoint was the incidence of AAA sac regression. To investigate independent predictors of AAA sac regression, regression analysis was performed. The mean age was 74 years (range, 55-90 y), and 87.2% of patients were men. RESULTS: The no-statin group had higher rates of AAA sac regression than the statin group at 1 year (no-statin group, 66.7%; statin group, 45.3%; P = .028). The incidence of AAA sac regression increased over time in the statin group, and no statistical difference was seen between the two groups at 2 years (no-statin group, 66.7%; statin group, 57.8%; P = .350). The difference between the changes in maximum AAA diameter was significant between groups at 1 year (no-statin group vs statin group, -4.9 mm ± 5.9; P = .041), but the difference did not reach statistical significance at 2 years (no-statin group, -10.0 mm ± 10.1; statin group, -8.0 mm ± 9.6; P = .306). Statin therapy was not associated with AAA sac regression on univariate (odds ratio [OR], 0.685; 95% confidence interval [CI], 0.310-1.516; P = .351) and multivariate analyses (OR, 0.617; 95% CI, 0.215-1.772; P = .369). CONCLUSIONS: Statin therapy had no effect on AAA sac regression at 2 years. There is insufficient evidence to recommend statin therapy for AAA sac regression.

Prevalence of secondary impairments of adults with cerebral palsy according to gross motor function classification system.

[Purpose] This study aimed to investigate the prevalence of secondary impairments in adults with cerebral palsy. [Subjects and Methods] The study sample included 52 adults with cerebral palsy who attended a convalescent or rehabilitation center for disabled individuals or a special school for physical disabilities in South Korea. [Results] The univariate analysis showed that the Gross Motor Functional Classification System level was a significant predictor of spondylopathies, general pain, arthropathies, and motor ability loss. The prevalence of these impairments at Gross Motor Functional Classification System level I and II was low compared with the prevalence found at Gross Motor Functional Classification System level III-V. The prevalence of secondary impairments among adults with cerebral palsy at Gross Motor Functional Classification System level III-V was high: loss of motor ability, 42.3%; spondylopathies, 38.4%; general pain, 32.7%; and arthropathies, 28.8%. [Conclusion] In this study, adults with severe cerebral palsy showed a high prevalence of motor ability loss, spondylopathies, arthropathies, and pain. It is necessary to develop intervention programs to prevent secondary impairments in adults with cerebral palsy.

Effect of neurodevelopmental treatment-based physical therapy on the change of muscle strength, spasticity, and gross motor function in children with spastic cerebral palsy.

[Purpose] This study aimed to investigate the effectiveness of neurodevelopmental treatment-based physical therapy on muscle tone, strength, and gross motor function in children with spastic cerebral palsy. [Subjects and Methods] One-hundred-seventy-five children with spastic cerebral palsy (88 diplegia; 78 quadriplegia) received neurodevelopmental treatment-based physical therapy for 35 minutes per day, 2-3 times per week for 1 year. Spasticity, muscle strength, and gross motor function were measured before and after treatment with the Modified Ashworth Scale, Manual Muscle Testing, and Gross Motor Function Measure, respectively. [Results] Spasticity was significantly reduced after 1 year of treatment. The Gross Motor Functional Classification System levels I-II group showed a significant increase in muscle strength compared with the Gross Motor Functional Classification System levels III-V, and the latter showed a significant decrease in spasticity compared with the former. [Conclusion] Neurodevelopmental treatment-based physical therapy in children with cerebral palsy seems to be effective in reducing spasticity, but does not improve gross motor function. Therefore, other interventional approaches are needed to improve gross motor function in children with cerebral palsy.

Drosophila Low Temperature Viability Protein 1 (LTV1) Is Required for Ribosome Biogenesis and Cell Growth Downstream of Drosophila Myc (dMyc).

During animal development, various signaling pathways converge to regulate cell growth. In this study, we identified LTV1 as a novel cell growth regulator in Drosophila. LTV1 mutant larvae exhibited developmental delays and lethality at the second larval stage. Using biochemical studies, we discovered that LTV1 interacted with ribosomal protein S3 and co-purified with free 40S ribosome subunits. We further demonstrated that LTV1 is crucial for ribosome biogenesis through 40S ribosome subunit synthesis and preribosomal RNA processing, suggesting that LTV1 is required for cell growth by regulating protein synthesis. We also demonstrated that Drosophila Myc (dMyc) directly regulates LTV1 transcription and requires LTV1 to stimulate ribosome biogenesis. Importantly, the loss of LTV1 blocked the cell growth and endoreplication induced by dMyc. Combined, these results suggest that LTV1 is a key downstream factor of dMyc-induced cell growth by properly maintaining ribosome biogenesis.

A mitochondrial division inhibitor, Mdivi-1, inhibits mitochondrial fragmentation and attenuates kainic acid-induced hippocampal cell death.

BACKGROUND: Kainic acid (KA)-induced excitotoxicity promotes cytoplasmic calcium accumulation, oxidative stress, and apoptotic signaling, leading to hippocampal neuronal death. Mitochondria play a critical role in neuroinflammation and the oxidative stress response. Mitochondrial morphology is disrupted during KA-induced seizures; however, it is not clear whether mitochondrial fission or fusion factors are involved in KA-induced neuronal death. RESULTS: We investigated the effect of Mdivi-1, a chemical inhibitor of the mitochondrial fission protein Drp1, on mitochondrial morphology and function in KA-injected mice. Mdivi-1 pretreatment significantly reduced seizure activity and increased survival rates of KA-treated mice. Mdivi-1 was protective against mitochondrial morphological disruption, and it reduced levels of phosphorylated Drp1 (Ser616) and Parkin recruitment to mitochondria. By contrast, levels of mitochondrial fusion factors did not change. Mdivi-1 also reduced KA-induced neuroinflammation and glial activation. CONCLUSIONS: We conclude that inhibition of mitochondrial fission attenuates Parkin-mediated mitochondrial degradation and protects from KA-induced hippocampal neuronal cell death.