Search for Boosted Dark Matter in COSINE-100.

We search for energetic electron recoil signals induced by boosted dark matter (BDM) from the galactic center using the COSINE-100 array of NaI(Tl) crystal detectors at the Yangyang Underground Laboratory. The signal would be an excess of events with energies above 4 MeV over the well-understood background. Because no excess of events are observed in a 97.7 kg·yr exposure, we set limits on BDM interactions under a variety of hypotheses. Notably, we explored the dark photon parameter space, leading to competitive limits compared to direct dark photon search experiments, particularly for dark photon masses below 4 MeV and considering the invisible decay mode. Furthermore, by comparing our results with a previous BDM search conducted by the Super-Kamionkande experiment, we found that the COSINE-100 detector has advantages in searching for low-mass dark matter. This analysis demonstrates the potential of the COSINE-100 detector to search for MeV electron recoil signals produced by the dark sector particle interactions.

Regional and annual patterns in respiratory virus co-infection etiologies and antibiotic prescriptions for pediatric mycoplasma pneumoniae pneumonia.

OBJECTIVE: Mycoplasma pneumoniae (M. pneumoniae) pneumonia is the second-most common cause of community-acquired pneumonia (CAP). This study aimed at investigating into the prevalence of macrolide-resistant M. pneumoniae (MRMP) with respiratory virus co-infection and the antibiotic prescriptions in children with CAP in four provinces in Korea, and to assess the variations in the findings across regions and throughout the year. PATIENTS AND METHODS: This prospective study was conducted in 29 hospitals in Korea between July 2018 and June 2020. Among the enrolled 1,063 children with CAP, all 451 patients with M. pneumoniae underwent PCR assays of M. pneumoniae and respiratory viruses, and the presence of point mutations of residues 2063 and 2064 was evaluated. RESULTS: Gwangju-Honam (88.6%) showed the highest prevalence of MRMP pneumonia, while Daejeon-Chungcheong (71.3%) showed the lowest, although the differences in prevalence were not significant (p=0.074). Co-infection of M. pneumoniae pneumonia and respiratory virus was observed in 206 patients (45.4%), and rhinovirus co-infection (101 children; 22.2%) was the most frequent. The prevalence of MRMP pneumonia with respiratory virus co-infection and the antibiotic prescriptions differed significantly among the four provinces (p < 0.05). The monthly rate of MRMP pneumonia cases among all cases of M. pneumoniae pneumonia and tetracycline or quinolone prescriptions did not differ significantly among the four regions (trend p > 0.05) during the study period. CONCLUSIONS: The prevalence of M. pneumoniae pneumonia with virus co-infection and antibiotic prescriptions could differ according to region, although the MRMP pneumonia rate showed no difference within Korea.

The Results of Two-stage Revision for Methicillin-resistant Periprosthetic Joint Infection (PJI) of the Hip.

INTRODUCTION: Periprosthetic joint infection (PJI) of the hip due to methicillin-resistant bacteria is difficult to treat and remain a challenge for arthroplasty surgeon. MATERIAL AND METHODS: Retrospective review was done to the patients who received two-stage revisions with an antibiotic loaded cement-spacer for PJI of the hip between January 2010 to May 2015. We found 65 patients (65 hips) with positive culture findings. Eight patients were lost to follow-up and excluded from the study. Among the rest of the 57 patients, methicillin-resistant infection (MR Group) was found in 28 cases. We also evaluate the 29 other cases that caused by the other pathogen as control group. We compared all of the relevant medical records and the treatment outcomes between the two groups. RESULTS: The mean of follow-up period was 33.7 months in the methicillin-resistant group and 28.4 months in the control group (p = 0.27). The causal pathogens in the methicillin-resistant group were: Methicillin-resistant Staphylococcus aureus (MRSA) in 10 cases, Methicillin-resistant Staphylococcus epidermidis (MRSE) in 16 cases and Methicillin-resistant coagulase-negative Staphylococcus (MRCNS) in two cases. The reimplantation rate was 92.8% and 89.6% in the methicillin-resistant and control group, respectively (p= 0.66). The rates of recurrent infection after reimplantation were 23.1% (6/26) in the methicillin-resistant group and 7.6% (2/26) in the control group (p= 0.12). The overall infection control rate was 71.4% (20/28) and 89.6% (26/29) in the methicillin-resistant and control group, respectively (p = 0.08). Both groups showed comparable baseline data on mean age, BMI, gender distribution, preoperative ESR/CRP/WBC and comorbidities. CONCLUSIONS: Two-stage revision procedure resulted in low infection control rate and high infection recurrency rate for the treatment of methicillin-resistant periprosthetic joint infection (PJI) of the hip. Development of the treatment strategy is needed to improve the outcome of methicillin-resistant periprosthetic joint infection (PJI) of the hip.

Search for a Dark Matter-Induced Annual Modulation Signal in NaI(Tl) with the COSINE-100 Experiment.

We present new constraints on the dark matter-induced annual modulation signal using 1.7 years of COSINE-100 data with a total exposure of 97.7 kg yr. The COSINE-100 experiment, consisting of 106 kg of NaI(Tl) target material, is designed to carry out a model-independent test of DAMA/LIBRA's claim of WIMP discovery by searching for the same annual modulation signal using the same NaI(Tl) target. The crystal data show a 2.7 cpd/kg/keV background rate on average in the 2-6 keV energy region of interest. Using a χ-squared minimization method we observe best fit values for modulation amplitude and phase of 0.0092±0.0067 cpd/kg/keV and 127.2±45.9 d, respectively.

First Direct Search for Inelastic Boosted Dark Matter with COSINE-100.

A search for inelastic boosted dark matter (IBDM) using the COSINE-100 detector with 59.5 days of data is presented. This relativistic dark matter is theorized to interact with the target material through inelastic scattering with electrons, creating a heavier state that subsequently produces standard model particles, such as an electron-positron pair. In this study, we search for this electron-positron pair in coincidence with the initially scattered electron as a signature for an IBDM interaction. No excess over the predicted background event rate is observed. Therefore, we present limits on IBDM interactions under various hypotheses, one of which allows us to explore an area of the dark photon parameter space that has not yet been covered by other experiments. This is the first experimental search for IBDM using a terrestrial detector.

Minimally Invasive Total Hip Arthroplasty in a Patient with Hereditary Multiple Exostoses: A Case Report.

Hip geometry abnormalities found in patients with hereditary multiple exostoses (HME) could promote premature hip joint degeneration which needs treatment. We report the case of a 45-year old male with right hip arthrosis who underwent two-incision minimally invasive (MIS-2) total hip arthroplasty (THA), with satisfactory outcome. This technique could be an alternative approach for performing THA in patients with hereditary multiple exostoses.

Nonlinear association between bone mineral density and all-cause mortality: the Dong-gu study.

There was a U-shaped association between hip BMD and all-cause mortality, with the lowest mortality in the 90th percentile in males. However, there was an inverse linear relationship in females. In contrast, the association between lumbar spine BMD and mortality was less evident in males, with no association in females. INTRODUCTION: Bone mineral density (BMD) is reported inversely associated with mortality. Although some previous studies provided evidence for nonlinear associations, these were not adequately assessed in most previous works. METHODS: We evaluated the nonlinear relationship between BMD and mortality in Asians. Our study involved 8629 participants in the Dong-gu study from 2007 to 2010. Cox proportional hazard regression was used to calculate hazard ratios (HRs) according to BMD categories after adjusting for potential confounders. During a follow-up of 6.7 ± 1.4 years, 712 participants died. RESULTS: There was a U-shaped association between hip BMD and all-cause mortality, with the lowest mortality in the 90th percentile in males. However, there was an inverse linear relationship in females. In males, compared with the 75th to 95th percentile group, the < 2.5th percentile group had a 3.89 (95% CI 2.41-6.28)-fold higher risk and the 2.5th to 5th percentile group had a 2.51 (95% CI 1.25-5.04)-fold higher risk. The HR was 2.51 (95% CI 1.25, 5.04) in the > 97.5th percentile group. In females, compared with that in the 75th to 95th percentile group, the HR was 2.33 (95% CI 1.24, 4.39) in the < 2.5th percentile group. In contrast, the association between lumbar spine BMD and mortality was less evident in males, with no association in females. CONCLUSION: In conclusion, this study shows that the association between BMD and mortality varies by gender and that high and low BMD are predictors of all-cause mortality in males.

Seven Years of Experiences of Preclinical Experiments of Xeno-Heart Transplantation of Pig to Non-Human Primate (Cynomolgus Monkey).

BACKGROUND: The absolute shortage of donors compared with patients requiring transplantation is currently an unsolved problem, and the only possible solution may be xenotransplantation. To establish a successful clinical trial, a preclinical study using nonhuman primates is essential. Starting in November 2011, our team initiated heterotopic abdominal heart xenotransplantation, the first in the Republic of Korea. We present here the initial 7-year results. METHODS: A total of 22 xenotransplantation procedures have been performed since 2011. Single transgenic pig (alpha-galactosidase transferase knockout [GalT KO], n = 16), double transgenic pig (GalT KO + CD46, n = 3, and GalT KO + CD39, n = 2), and triple transgenic pig (GalT KO + CD46 + CD70, n = 1) models were used. Our baseline regimen of immunosuppressants comprised CD154 ab, rituximab, anti-thymocyte globulin, tacrolimus, mycophenolate mofetil, and steroids. RESULTS: The mean graft survival was 16 ± 16.27 days, and the mean graft survival was significantly longer in cases performed since 2014 (7.5 ± 8.03 days vs 24.67 ± 17.50; P = .01). Although the donor heart ischemic time was decreased per annum, no correlations could be found between ischemic time and survival days of the graft. Double or triple genetic manipulated hearts exhibited significantly better survival (11.63 ± 11.29 days vs 30.83 ± 20.34 days; P = .03). When the ratio of heart weight (grams) to nonhuman primate weight (kilograms) was lower, the results tended to be better (P < .05). The rate of immediate postoperative bleeding (9%, n = 2) causing death was relatively high in the earlier period, but there have been no serious surgical complications affecting graft survival since 2013. CONCLUSIONS: Investigation of effective and optimal target genes for each organ to further progression toward better results is important. In addition, the immunosuppressive regimen needs to be further studied and constantly refined.

MRI Features of Aquaporin-4 Antibody-Positive Longitudinally Extensive Transverse Myelitis: Insights into the Diagnosis of Neuromyelitis Optica Spectrum Disorders.

BACKGROUND AND PURPOSE: Longitudinally extensive transverse myelitis is a well-documented spinal manifestation of neuromyelitis optica spectrum disorders, however, other forms of nontumorous myelopathy can also manifest as longitudinally extensive transverse myelitis. Our aim was to evaluate the MR imaging features of aquaporin-4 antibody-positive longitudinally extensive transverse myelitis, which is strongly associated with neuromyelitis optica spectrum disorders. MATERIALS AND METHODS: We evaluated cervicomedullary junction involvement, cord expansion ratios, bright spotty lesions, the number of involved segments, skipped lesions, enhancement patterns, and axial distribution patterns using spinal MR imaging of 41 patients with longitudinally extensive transverse myelitis who underwent aquaporin-4 antibody testing. Univariate logistic regression analysis was performed to identify factors associated with aquaporin-4 antibody seropositivity, which were then used to develop a scoring system for diagnosing aquaporin-4 antibody-positive longitudinally extensive transverse myelitis. Interrater reliability for cord expansion ratio measurement and bright spotty lesions was determined using intraclass correlation coefficients and κ values, respectively. RESULTS: Fifteen patients with longitudinally extensive transverse myelitis were aquaporin-4 antibody-positive. Sex (female), cervicomedullary junction involvement, a cord expansion ratio of >1.4, and bright spotty lesions were significantly associated with aquaporin-4 antibody seropositivity. The sensitivity and specificity of the scoring system were 73.3% and 96.2%, respectively. The interclass correlation value for the cord expansion ratio was 0.78, and the κ value for bright spotty lesions was 0.61. CONCLUSIONS: Our scoring system, based on cervicomedullary junction involvement, higher cord expansion ratio, bright spotty lesions, and female sex, can facilitate the timely diagnosis of neuromyelitis optica spectrum disorders.

Background model for the NaI(Tl) crystals in COSINE-100.

The COSINE-100 dark matter search experiment is an array of NaI(Tl) crystal detectors located in the Yangyang Underground Laboratory (Y2L). To understand measured backgrounds in the NaI(Tl) crystals we have performed Monte Carlo simulations using the Geant4 toolkit and developed background models for each crystal that consider contributions from both internal and external sources, including cosmogenic nuclides. The background models are based on comparisons of measurement data with Monte Carlo simulations that are guided by a campaign of material assays and are used to evaluate backgrounds and identify their sources. The average background level for the six crystals (70 kg total mass) that are studied is 3.5 counts/day/keV/kg in the (2-6) keV energy interval. The dominant contributors in this energy region are found to be 210 Pb and 3 H.

Degree of ketonaemia and its association with insulin resistance after dapagliflozin treatment in type 2 diabetes.

BACKGROUND: Euglycaemic ketoacidosis has been reported after sodium-glucose cotransporter 2 (SGLT2) inhibitor treatment. However, the degree of ketonaemia and its metabolic effects have not been well investigated. Our study examined the degree of ketonaemia induced by SGLT2 inhibition and its association with metabolic profiles in type 2 diabetes mellitus (T2DM). METHODS: Biochemical parameters, including insulin, glucagon, free fatty acid (FFA), ß-hydroxybutyrate (BHB) and acetoacetate (ACA) levels, were measured in 119 T2DM patients after dapagliflozin treatment for>3 months, and compared with a matched control group. RESULTS: Levels of total ketones, BHB and ACA were significantly higher in the dapagliflozin group than in the control group: 283.7±311.0 vs 119.8±143.8µmol/L; 188.3±226.6 vs 78.0±106.7µmol/L; and 94.1±91.3 vs 41.8±39.1µmol/L, respectively (all P<0.001). After dapagliflozin treatment, BHB was higher than the upper limit of normal (>440µmol/L) in 13 (10.9%) patients who had no relevant symptoms. BHB level after dapagliflozin treatment correlated positively with HbA1c (r=0.280), FFA levels (r=0.596) and QUICKI (r=0.238), and negatively with BMI (r=-0.222), insulin-to-glucagon ratio (r=-0.199) and HOMA-IR (r=-0.205; all P<0.05). On multivariable linear regression analysis, QUICKI was independently associated with BHB level. CONCLUSION: Ketone levels were higher in T2DM patients treated with dapagliflozin than in controls, but with no clinical symptoms or signs of ketonaemia. Low-grade ketonaemia after dapagliflozin treatment may also be associated with improved insulin sensitivity.

Sterile Neutrino Search at the NEOS Experiment.

An experiment to search for light sterile neutrinos is conducted at a reactor with a thermal power of 2.8 GW located at the Hanbit nuclear power complex. The search is done with a detector consisting of a ton of Gd-loaded liquid scintillator in a tendon gallery approximately 24 m from the reactor core. The measured antineutrino event rate is 1976 per day with a signal to background ratio of about 22. The shape of the antineutrino energy spectrum obtained from the eight-month data-taking period is compared with a hypothesis of oscillations due to active-sterile antineutrino mixing. No strong evidence of 3+1 neutrino oscillation is found. An excess around the 5 MeV prompt energy range is observed as seen in existing longer-baseline experiments. The mixing parameter sin^{2}2θ_{14} is limited up to less than 0.1 for Δm_{41}^{2} ranging from 0.2 to 2.3 eV^{2} with a 90% confidence level.

Differential protein stability and clinical responses of EML4-ALK fusion variants to various ALK inhibitors in advanced ALK-rearranged non-small cell lung cancer.

Background: Anaplastic lymphoma kinase (ALK) inhibition using crizotinib has become the standard of care in advanced ALK-rearranged non-small cell lung cancer (NSCLC), but the treatment outcomes and duration of response vary widely. Echinoderm microtubule-associated protein-like 4 (EML4)-ALK is the most common translocation, and the fusion variants show different sensitivity to crizotinib in vitro. However, there are only limited data on the specific EML4-ALK variants and clinical responses of patients to various ALK inhibitors. Patients and methods: By multiplex reverse-transcriptase PCR, which detects 12 variants of known EML4-ALK rearrangements, we retrospectively determined ALK fusion variants in 54 advanced ALK rearrangement-positive NSCLCs. We subdivided the patients into two groups (variants 1/2/others and variants 3a/b) by protein stability and evaluated correlations of the variant status with clinical responses to crizotinib, alectinib, or ceritinib. Moreover, we established the EML4-ALK variant-expressing system and analyzed patterns of sensitivity of the variants to ALK inhibitors. Results: Of the 54 tumors analyzed, EML4-ALK variants 3a/b (44.4%) was the most common type, followed by variants 1 (33.3%) and 2 (11.1%). The 2-year progression-free survival (PFS) rate was 76.0% [95% confidence interval (CI) 56.8-100] in group EML4-ALK variants 1/2/others versus 26.4% (95% CI 10.5-66.6) in group variants 3a/b (P = 0.034) among crizotinib-treated patients. Meanwhile, the 2-year PFS rate was 69.0% (95% CI 49.9-95.4) in group variants 1/2/others versus 32.7% (95% CI 15.6-68.4) in group variants 3a/b (P = 0.108) among all crizotinib-, alectinib-, and ceritinib-treated patients. Variant 3a- or 5a-harboring cells were resistant to ALK inhibitors with >10-fold higher half maximal inhibitory concentration in vitro. Conclusion: Our findings show that group EML4-ALK variants 3a/b may be a major source of ALK inhibitor resistance in the clinic. The variant-specific genotype of the EML4-ALK fusion allows for more precise stratification of patients with advanced NSCLC.

Arsenic exposure and seafood intake in Korean adults.

Arsenic (As) is widely distributed in the environment, and humans can be exposed to As from various sources such as air, water, soil, and food. This study was performed to evaluate the As exposure levels in Korean adults by measuring total As in urine and its relation with the consumption of seafood, a favorite food in Korea. A total of 2077 adults were the study subjects; they ranged in age from 19 to 83, and they were recruited by probability sampling stratified by area, sex, and age. None of the subjects had been exposed to As occupationally. We collected information about the demographic characteristics, lifestyles, and food consumption of study subjects using a questionnaire and followed urine sampling. Diet was assessed in individual interviews using the 24-h recall method. Total As in urine was analyzed using inductively coupled plasma mass spectrometry (PerkinElmer NEXION 300S; Concord, Ontario, Canada). The geometric mean concentration of total As in urine was observed to be 97.6 µg/L and was higher in males (103.9 µg/L) than in females (93.0 µg/L). Total As levels in urine were affected by sex, age, seafood intake, and geographic location. In this study, total As in urine was positively correlated with fish and shellfish consumption, and was mainly determined by As intake through fish and shellfish/grains/flavors. These findings suggest that seafood consumption might be a major contributor to urinary As levels in Korean adults.

Outcome of alternative approach to displaced acetabular fractures.

INTRODUCTION: Anatomical reduction of displaced acetabular fracture is not without its' limitations and complications. This study is conducted to assess clinical and radiological outcomes as well as complications of treating displaced acetabular fractures with emphasis on anatomical reduction in weight-bearing area, mainly the posterior column, and imperfect reduction of the anterior column is acceptable. However, stability of both columns is mandatory. METHODS: It was a retrospective study carried out in a Level 1 arthroplasty and trauma centre. 23 patients (17 males, 6 females) with average age of 50.1 years (range, 36-68 years) with displaced acetabular fracture treated with combined incisions and plate-cable systems were included. There were 3 elementary and 18 associated fractures according to Letournel classification. Average follow-up was 23.5 months (range, 12-38.7 months). Mean operation time was 160min (range: 75-320min). Functional scores were evaluated using Harris Hip Score (HHS) whilst reduction was assessed by Matta criteria. Any displacement of reduction, osteoarthritis, heterotopic ossification, and other complications was recorded. RESULT: 65.2% (15/23) of the patients obtained excellent HHS and 21.7% (5/23) had good HHS. There were 12 anatomical, 6 imperfect, and 5 poor reductions. No displacement was recorded in final follow-up. Complications documented: three lateral femoral cutaneous nerve injuries, two conversions to total hip arthroplasty, three Brooker stage 1 heterotrophic ossification, one pulmonary embolism and one screw irritation. No incidence of wound breakdown, infection and radiological osteoarthritis was reported. CONCLUSIONS: Imperfect reduction of the anterior column provided clinical outcomes that are as good as total anatomical reduction. This approach minimizes soft tissue damage and reduces perioperative morbidities.

Association between antiphospholipid antibodies and arterial thrombosis in patients with rheumatoid arthritis.

OBJECTIVES: Antiphospholipid antibodies (aPL) are present in a proportion of patients with rheumatoid arthritis but their clinical significance remains unclear. We investigated the association between aPL and thrombotic events in rheumatoid arthritis patients. METHODS: In this cross-sectional study, aPL profiles were evaluated in 376 rheumatoid arthritis patients in accordance with the standard guidelines. Clinical and radiographic data were retrospectively collected. RESULTS: aPL were identified in 39 patients (10.4%). Lupus anticoagulant was the most common subtype (n = 25, 6.6%); anti-cardiolipin antibodies and anti-ß2 glycoprotein I antibodies were detected in six and 12 patients (1.6% and 3.2%), respectively. Compared to the aPL-negative group, aPL-positive patients included more male patients (41.0% vs. 15.4%, P < 0.001) and more smokers (41.0% vs. 16.0%, P = 0.001). There was no difference between the two groups in age, disease duration and body mass index, or the frequency of diabetes, hypertension or dyslipidaemia. Of note, arterial thromboses were more common in the aPL-positive than the aPL-negative group (12.8% vs. 2.1%, P = 0.004), whereas the frequency of venous thrombosis did not differ between the two groups (0.0% vs. 0.9%, P = 1.000). On multivariate regression analysis, aPL, age, hypertension, dyslipidaemia and baseline C-reactive protein level were independently associated with arterial thrombotic events (all P values < 0.05). CONCLUSION: aPL was found in a subset of rheumatoid arthritis patients, who were more often smokers, and aPL was independently associated with development of arterial thrombosis. This result suggests that aPL may contribute to an increased risk of arterial thrombosis in rheumatoid arthritis patients.

Migratory Bone Marrow Edema Syndrome of the Hips: A Case Report.

Migratory bone marrow edema syndrome (BMES) of the hip is a rare entity. We report the case of a 41-year old male with migratory BMES of the hip with eight months interval period between onset of the pain and consultation. This patient was successfully treated non-surgically. It is important to always inform the patient with unilateral BMES of the hip regarding the possibility of future involvement of the contralateral hip.

Sarcopenia as a Predictor of Future Cognitive Impairment in Older Adults.

OBJECTIVES: We investigated the association between the indices of sarcopenia and future risk of cognitive impairment in older adults. DESIGN: Community-based prospective cohort study. SETTING: Community. PARTICIPANTS: A total of 297 participants aged ≥65 years without cognitive impairment at baseline (mean age, 71.9 ± 6.6 years; men:women, 158:139) and who underwent cognitive evaluation at the 5-year follow-up. MEASUREMENTS: Sarcopenia parameters including appendicular lean mass (ALM), handgrip strength, and the Short Physical Performance Battery (SPPB) score at baseline were compared according to the later progression of mild cognitive impairment (MCI) and/or dementia. The operational criteria suggested by the Foundation for the National Institutes of Health Sarcopenia Project were used. We performed multivariate logistic regression analysis to identify the independent indicators of the progression of cognitive impairment. RESULTS: Among the 297 participants, 242 (81.5%) remained cognitively normal (nonprogression group), whereas 55 (18.5%) showed progression of cognitive impairment (50 subjects (16.8%) to MCI and 5 subjects (1.7%) to dementia) (progression group). Compared with the nonprogression group, subjects in the progression group were older, had a lower educational level, and had lower physical function as assessed by the SPPB; a higher percentage were depressed. Other baseline markers of sarcopenia, including the ALM-to-body mass index ratio and handgrip strength did not differ significantly between the groups. The association between a low SPPB score (<9) and progression of cognitive impairment was maintained after adjustment for conventional risk factors for cognitive impairment (hazard ratio 2.222, 95% confidence interval 1.047-4.716, P = 0.038). CONCLUSION: Decreased physical performance, as assessed by the SPPB, but not other markers of sarcopenia, was independently associated with the risk of later cognitive impairment in older adults.

PPARγ neddylation essential for adipogenesis is a potential target for treating obesity.

The preadipocyte-to-adipocyte differentiation (adipogenesis) is a key process in fat mass increase and thus it is regarded as a compelling target for preventing or treating obesity. Of adipogenic hormone receptors, peroxisome proliferator-activated receptor gamma (PPARγ) has crucial roles in adipogenesis and lipid accumulation within adipocytes. Here we demonstrate that the NEDD8 (neuronal precursor cell expressed, developmentally downregulated 8)-based post-translation modification (neddylation) of PPARγ is essential for adipogenesis. During adipogenesis, NEDD8 is robustly induced in preadipocytes and conjugates with PPARγ, leading to PPARγ stabilization. When the neddylation process was blocked by NEDD8-targeting siRNAs (or viral vectors) or an inhibitor MLN4924, adipocyte differentiation and fat tissue development were substantially impaired. We also demonstrate that MLN4924 effectively prevents the high-fat diet-induced obesity and glucose intolerance in mice. This study provides a better understanding of how the PPARγ signaling pathway starts and lasts during adipogenesis and a potential anti-obesity strategy that targets the neddylation of PPARγ.