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1.
Micromachines (Basel) ; 15(4)2024 Apr 04.
Article in English | MEDLINE | ID: mdl-38675307

ABSTRACT

We investigated the effects of gate bias regarding the degradation of electrical characteristics during gamma irradiation. Moreover, we observed the punch through failure of 1.2 kV rated commercial Silicon Carbide (SiC) Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) due to the influence of gate bias. In addition, the threshold voltage (VT) and on-resistance (Ron) of the SiC MOSFETs decreased significantly by the influence of gate bias during gamma irradiation. We extracted the concentration of carriers and fixed charge (QF) in oxide using N-type SiC MOS capacitors and Transmission Line Measurement (TLM) patterns to analyze the effects of gamma irradiation. The Total Ionizing Dose (TID) effect caused by high-energy gamma-ray irradiation resulted in an increase in the concentration of holes and QF in both SiC and oxide. To analyze the phenomenon for increment of hole concentration in the device under gate bias, we extracted the subthreshold swing of SiC MOSFETs and verified the origin of TID effects accelerated by the gate bias. The QF and doping concentration of p-well values extracted from the experiments were used in TCAD simulations (version 2022.03) of the planar SiC MOSFET. As a result of analyzing the energy band diagram at the channel region of 1.2 kV SiC MOSFETs, it was verified that punch-through can occur in 1.2 kV SiC MOSFETs when the gate bias is applied, as the TID effect is accelerated by the gate bias.

2.
J Dermatol ; 2024 Apr 17.
Article in English | MEDLINE | ID: mdl-38629720

ABSTRACT

Hypopigmented scars are challenging to treat, and the focus for successful treatment is to cause pigment cells to produce more melanin. In this study, we evaluated the repigmentation effects of 0.4 mm motorized-micropunch grafting with skin-seeding for hypopigmented scars. Twenty-one patients with hypopigmented scars on the face and neck that had been resistant to conventional treatment and who had finally undergone micropunch grafting with a skin-seeding technique (SST) were retrospectively reviewed. Repigmentation outcomes were evaluated with global assessment by a physician using a 4-point repigmentation scale. Adverse events were noted. The subjects were followed for a 2-year follow-up period post grafting. All 21 subjects exhibited excellent to complete repigmentation of more than 75% of the hypopigmented scars. More than 90% repigmentation was observed in 17 patients. The mean duration for repigmentation that the subjects were satisfied with was 5.5 months. No adverse effects or recurrence instances were observed. Motorized micropunch grafting is an effective and promising alternative treatment for repigmentation of hypopigmented scars.

3.
Cancer Res Treat ; 56(2): 652-664, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38037318

ABSTRACT

PURPOSE: The Korean Society of Pediatric Neuro-Oncology (KSPNO) conducted treatment strategies for children with medulloblastoma (MB) by using alkylating agents for maintenance chemotherapy or tandem high-dose chemotherapy (HDC) with autologous stem cell rescue (ASCR) according to the risk stratification. The purpose of the study was to assess treatment outcomes and complications based on risk-adapted treatment and HDC. MATERIALS AND METHODS: Fifty-nine patients diagnosed with MB were enrolled in this study. Patients in the standard-risk (SR) group received radiotherapy (RT) after surgery and chemotherapy using the KSPNO M051 regimen. Patients in the high-risk (HR) group received two and four chemotherapy cycles according to the KSPNO S081 protocol before and after reduced RT for age following surgery and two cycles of tandem HDC with ASCR consolidation treatment. RESULTS: In the SR group, 24 patients showed 5-year event-free survival (EFS) and overall survival (OS) estimates of 86.7% (95% confidence interval [CI], 73.6 to 100) and 95.8% (95% CI, 88.2 to 100), respectively. In the HR group, more infectious complications and mortality occurred during the second HDC than during the first. In the HR group, the 5-year EFS and OS estimates were 65.5% (95% CI, 51.4 to 83.4) and 72.3% (95% CI, 58.4 to 89.6), respectively. CONCLUSION: High intensity of alkylating agents for SR resulted in similar outcomes but with a high incidence of hematologic toxicity. Tandem HDC with ASCR for HR induced favorable EFS and OS estimates compared to those reported previously. However, infectious complications and treatment-related mortalities suggest that a reduced chemotherapy dose is necessary, especially for the second HDC.


Subject(s)
Cerebellar Neoplasms , Hematopoietic Stem Cell Transplantation , Medulloblastoma , Child , Humans , Medulloblastoma/therapy , Medulloblastoma/drug therapy , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Cerebellar Neoplasms/diagnosis , Cerebellar Neoplasms/drug therapy , Alkylating Agents/therapeutic use , Combined Modality Therapy
5.
Biomolecules ; 13(5)2023 04 26.
Article in English | MEDLINE | ID: mdl-37238617

ABSTRACT

The immunomodulatory imide drug (IMiD) class, which includes the founding drug member thalidomide and later generation drugs, lenalidomide and pomalidomide, has dramatically improved the clinical treatment of specific cancers, such as multiple myeloma, and it combines potent anticancer and anti-inflammatory actions. These actions, in large part, are mediated by IMiD binding to the human protein cereblon that forms a critical component of the E3 ubiquitin ligase complex. This complex ubiquitinates and thereby regulates the levels of multiple endogenous proteins. However, IMiD-cereblon binding modifies cereblon's normal targeted protein degradation towards a new set of neosubstrates that underlies the favorable pharmacological action of classical IMiDs, but also their adverse actions-in particular, their teratogenicity. The ability of classical IMiDs to reduce the synthesis of key proinflammatory cytokines, especially TNF-α levels, makes them potentially valuable to reposition as drugs to mitigate inflammatory-associated conditions and, particularly, neurological disorders driven by an excessive neuroinflammatory element, as occurs in traumatic brain injury, Alzheimer's and Parkinson's diseases, and ischemic stroke. The teratogenic and anticancer actions of classical IMiDs are substantial liabilities for effective drugs in these disorders and can theoretically be dialed out of the drug class. We review a select series of novel IMiDs designed to avoid binding with human cereblon and/or evade degradation of downstream neosubstrates considered to underpin the adverse actions of thalidomide-like drugs. These novel non-classical IMiDs hold potential as new medications for erythema nodosum leprosum (ENL), a painful inflammatory skin condition associated with Hansen's disease for which thalidomide remains widely used, and, in particular, as a new treatment strategy for neurodegenerative disorders in which neuroinflammation is a key component.


Subject(s)
Multiple Myeloma , Neurodegenerative Diseases , Humans , Thalidomide/pharmacology , Thalidomide/therapeutic use , Immunomodulating Agents , Neuroinflammatory Diseases , Multiple Myeloma/drug therapy , Ubiquitin-Protein Ligases/metabolism , Neurodegenerative Diseases/drug therapy
6.
Molecules ; 28(8)2023 Apr 21.
Article in English | MEDLINE | ID: mdl-37110854

ABSTRACT

High-performance liquid chromatography (HPLC) analysis of three commercial tomatine samples and another isolated from green tomatoes revealed the presence of two small peaks in addition to those associated with the glycoalkaloids dehydrotomatine and α-tomatine. The present study investigated the possible structures of the compounds associated with the two small peaks using HPLC-mass spectrophotometric (MS) methods. Although the two peaks elute much earlier on chromatographic columns than the elution times of the known tomato glycoalkaloids dehydrotomatine and α-tomatine, isolation of the two compounds by preparative chromatography and subsequent analysis by MS shows the two compounds have identical molecular weights, tetrasaccharide side chains, and MS and MS/MS fragmentation patterns to dehydrotomatine and α-tomatine. We suggest the two isolated compounds are isomeric forms of dehydrotomatine and α-tomatine. The analytical data indicate that widely used commercial tomatine preparations and those extracted from green tomatoes and tomato leaves consist of a mixture of α-tomatine, dehydrotomatine, an α-tomatine isomer, and a dehydrotomatine isomer in an approximate ratio of 81:15:4:1, respectively. The significance of the reported health benefits of tomatine and tomatidine is mentioned.


Subject(s)
Solanum lycopersicum , Tomatine , Tomatine/chemistry , Tandem Mass Spectrometry
7.
J Biomed Sci ; 30(1): 16, 2023 Mar 06.
Article in English | MEDLINE | ID: mdl-36872339

ABSTRACT

BACKGROUND: Quelling microglial-induced excessive neuroinflammation is a potential treatment strategy across neurological disorders, including traumatic brain injury (TBI), and can be achieved by thalidomide-like drugs albeit this approved drug class is compromised by potential teratogenicity. Tetrafluorobornylphthalimide (TFBP) and tetrafluoronorbornylphthalimide (TFNBP) were generated to retain the core phthalimide structure of thalidomide immunomodulatory imide drug (IMiD) class. However, the classical glutarimide ring was replaced by a bridged ring structure. TFBP/TFNBP were hence designed to retain beneficial anti-inflammatory properties of IMiDs but, importantly, hinder cereblon binding that underlies the adverse action of thalidomide-like drugs. METHODS: TFBP/TFNBP were synthesized and evaluated for cereblon binding and anti-inflammatory actions in human and rodent cell cultures. Teratogenic potential was assessed in chicken embryos, and in vivo anti-inflammatory actions in rodents challenged with either lipopolysaccharide (LPS) or controlled cortical impact (CCI) moderate traumatic brain injury (TBI). Molecular modeling was performed to provide insight into drug/cereblon binding interactions. RESULTS: TFBP/TFNBP reduced markers of inflammation in mouse macrophage-like RAW264.7 cell cultures and in rodents challenged with LPS, lowering proinflammatory cytokines. Binding studies demonstrated minimal interaction with cereblon, with no resulting degradation of teratogenicity-associated transcription factor SALL4 or of teratogenicity in chicken embryo assays. To evaluate the biological relevance of its anti-inflammatory actions, two doses of TFBP were administered to mice at 1 and 24 h post-injury following CCI TBI. Compared to vehicle treatment, TFBP reduced TBI lesion size together with TBI-induction of an activated microglial phenotype, as evaluated by immunohistochemistry 2-weeks post-injury. Behavioral evaluations at 1- and 2-weeks post-injury demonstrated TFBP provided more rapid recovery of TBI-induced motor coordination and balance impairments, versus vehicle treated mice. CONCLUSION: TFBP and TFNBP represent a new class of thalidomide-like IMiDs that lower proinflammatory cytokine generation but lack binding to cereblon, the main teratogenicity-associated mechanism. This aspect makes TFBP and TFNBP potentially safer than classic IMiDs for clinical use. TFBP provides a strategy to mitigate excessive neuroinflammation associated with moderate severity TBI to, thereby, improve behavioral outcome measures and warrants further investigation in neurological disorders involving a neuroinflammatory component.


Subject(s)
Brain Injuries, Traumatic , Brain Injuries , Chick Embryo , Humans , Animals , Mice , Thalidomide , Neuroinflammatory Diseases , Immunomodulating Agents , Lipopolysaccharides , Inflammation
8.
Nanomaterials (Basel) ; 13(5)2023 Feb 27.
Article in English | MEDLINE | ID: mdl-36903774

ABSTRACT

Recently, we reported that device performance degradation mechanisms, which are generated by the γ-ray irradiation in GaN-based metal-insulator-semiconductor high electron mobility transistors (MIS-HEMTs), use extremely thin gate insulators. When the γ-ray was radiated, the total ionizing dose (TID) effects were generated and the device performance deteriorated. In this work, we investigated the device property alteration and its mechanisms, which were caused by the proton irradiation in GaN-based MIS-HEMTs for the 5 nm-thick Si3N4 and HfO2 gate insulator. The device property, such as threshold voltage, drain current, and transconductance varied by the proton irradiation. When the 5 nm-thick HfO2 layer was employed for the gate insulator, the threshold voltage shift was larger than that of the 5 nm-thick Si3N4 gate insulator, despite the HfO2 gate insulator exhibiting better radiation resistance compared to the Si3N4 gate insulator. On the other hand, the drain current and transconductance degradation were less for the 5 nm-thick HfO2 gate insulator. Unlike the γ-ray irradiation, our systematic research included pulse-mode stress measurements and carrier mobility extraction and revealed that the TID and displacement damage (DD) effects were simultaneously generated by the proton irradiation in GaN-based MIS-HEMTs. The degree of the device property alteration was determined by the competition or superposition of the TID and DD effects for the threshold voltage shift and drain current and transconductance deterioration, respectively. The device property alteration was diminished due to the reduction of the linear energy transfer with increasing irradiated proton energy. We also studied the frequency performance degradation that corresponded to the irradiated proton energy in GaN-based MIS-HEMTs using an extremely thin gate insulator.

9.
J Korean Neurosurg Soc ; 66(3): 274-280, 2023 May.
Article in English | MEDLINE | ID: mdl-36992611

ABSTRACT

Post-hemorrhagic hydrocephalus (PHH) in preterm infant is common, life-threatening and the main cause of bad developmental outcomes. Ventriculoperitoneal (VP) shunt is used as the ultimate treatment for PHH. Low birth weight and low gestational age are the combination of worse prognostic factors while the single most important prognostic factor of VP shunting is age. Aggressive and early intervention have better effect in intraventricular hemorrhage and intracranial pressures control. It reduces infection rate and brain damage resulted in delayed shunt insertion. It is extremely important to let PHH infants get older and gain weight to have internal organs to be matured before undergoing VP shunt. As premature infants undergo shunt after further growth, shunt-related complications would be reduced. So temporary surgical intervention is critical for PHH infants to have them enough time until permanently shunted.

10.
Yonsei Med J ; 64(3): 191-196, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36825345

ABSTRACT

PURPOSE: This study aimed to analyze the effect of foramen magnum decompression with C1 laminectomy (C1L) for Chiari malformation type 1 (CM-1) in terms of improving clinical symptoms, expanding posterior fossa volume, and decreasing syrinx volume. MATERIALS AND METHODS: Between January 2007 and June 2019, 107 patients with CM-1 were included. The median patient age was 13±13 years (range: 9 months-60 years), female-to-male ratio was 1:1, and average length of tonsil herniation was 13±5 mm (range: 5-24 mm). Surgical techniques were divided into four groups based on duraplasty or C1L usage. Among the study subjects, 38 patients underwent duraplasty and had their syrinx volumes measured separately on serial magnetic resonance imaging. A three-dimensional visualization software was used to evaluate the syrinx-volume decrease rate. RESULTS: Bony decompression exhibited a mere 20% volume expansion of the lower-half posterior fossa. C1L offered a 3% additional volume expansion, which rose to 5% when duraplasty was added (p=0.029). There were no significant differences in complication rate when C1L was combined with duraplasty (p=0.526). Syrinx volumes were analyzed in 38 patients who had undergone duraplasty. Among them, 28 patients who had undergone duraplasty without C1L demonstrated a 5.9% monthly decrease in syrinx volume, which was 7.5% in the remaining 10 patients with C1L (p=0.040). CONCLUSION: C1L was effective in increasing posterior fossa volume expansion, both with and without duraplasty. A more rapid decrease in syrinx volume occurred when C1L was combined with duraplasty.


Subject(s)
Arnold-Chiari Malformation , Plastic Surgery Procedures , Syringomyelia , Humans , Male , Female , Infant , Laminectomy , Decompression, Surgical/methods , Dura Mater/pathology , Dura Mater/surgery , Arnold-Chiari Malformation/diagnostic imaging , Arnold-Chiari Malformation/surgery , Syringomyelia/diagnostic imaging , Syringomyelia/surgery , Syringomyelia/pathology , Magnetic Resonance Imaging , Treatment Outcome , Retrospective Studies
11.
Ann Neurol ; 93(6): 1082-1093, 2023 06.
Article in English | MEDLINE | ID: mdl-36700525

ABSTRACT

OBJECTIVE: Brain somatic mutations in mTOR pathway genes are a major genetic etiology of focal cortical dysplasia type II (FCDII). Despite a greater ability to detect low-level somatic mutations in the brain by deep sequencing and analytics, about 40% of cases remain genetically unexplained. METHODS: We included 2 independent cohorts consisting of 21 patients with mutation-negative FCDII without apparent mutations on conventional deep sequencing of bulk brain. To find ultra-low level somatic variants or structural variants, we isolated cells exhibiting phosphorylation of the S6 ribosomal protein (p-S6) in frozen brain tissues using fluorescence-activated cell sorting (FACS). We then performed deep whole-genome sequencing (WGS; >90×) in p-S6+ cells in a cohort of 11 patients with mutation-negative. Then, we simplified the method to whole-genome amplification and target gene sequencing of p-S6+ cells in independent cohort of 10 patients with mutation-negative followed by low-read depth WGS (10×). RESULTS: We found that 28.6% (6 of 21) of mutation-negative FCDII carries ultra-low level somatic mutations (less than 0.2% of variant allele frequency [VAF]) in mTOR pathway genes. Our method showed ~34 times increase of the average mutational burden in FACS mediated enrichment of p-S6+ cells (average VAF = 5.84%) than in bulky brain tissues (average VAF = 0.17%). We found that 19% (4 of 21) carried germline structural variations in GATOR1 complex undetectable in whole exome or targeted gene sequencing. CONCLUSIONS: Our method facilitates the detection of ultra-low level somatic mutations, in specifically p-S6+ cells, and germline structural variations and increases the genetic diagnostic rate up to ~80% for the entire FCDII cohort. ANN NEUROL 2023;93:1082-1093.


Subject(s)
Epilepsy , Focal Cortical Dysplasia , Humans , TOR Serine-Threonine Kinases/genetics , Epilepsy/genetics , Mutation/genetics
13.
Article in English | MEDLINE | ID: mdl-36554328

ABSTRACT

A randomized controlled trial (RCT) was conducted to evaluate the effect of fermented sarco oysters (FSO) on muscle strength in postmenopausal females with low muscle mass. Fifty-two female participants were randomly divided into the experiment group (EG) or control group (CG). For 12 weeks, the EG was subjected to 1000 mg of FSO extract daily while the CG consumed the placebo extract. The muscle extension and flexion at an angular velocity of 60°/s and with respect to grip strength, body composition, and muscle growth-related blood factors were measured at the baseline and after the trial. The difference in the quadriceps muscle extension at an angular velocity of 60°/s, grip strength on both the left and right side, and insulin-like growth factor-1(IGF-1) between groups were significantly higher in the EG compared with the CG. However, no differences were found in body composition, blood pyruvate, lactate, or high-sensitivity C-reactive protein (hsCRP) concentration between the two groups. In conclusion, FSO supplements may improve muscle strength in postmenopausal females with relatively reduced muscle strength without a change in muscle mass.


Subject(s)
Crassostrea , Postmenopause , Female , Animals , Humans , Postmenopause/physiology , Muscle Strength , Hand Strength , Dietary Supplements , Body Composition , Double-Blind Method , Muscle, Skeletal/physiology
14.
Biomedicines ; 10(10)2022 Sep 30.
Article in English | MEDLINE | ID: mdl-36289711

ABSTRACT

Traumatic brain injury (TBI) is a major risk factor for several neurodegenerative disorders, including Parkinson's disease (PD) and Alzheimer's disease (AD). Neuroinflammation is a cause of later secondary cell death following TBI, has the potential to aggravate the initial impact, and provides a therapeutic target, albeit that has failed to translate into clinical trial success. Thalidomide-like compounds have neuroinflammation reduction properties across cellular and animal models of TBI and neurodegenerative disorders. They lower the generation of proinflammatory cytokines, particularly TNF-α which is pivotal in microglial cell activation. Unfortunately, thalidomide-like drugs possess adverse effects in humans before achieving anti-inflammatory drug levels. We developed F-3,6'-dithiopomalidomide (F-3,6'-DP) as a novel thalidomide-like compound to ameliorate inflammation. F-3,6'-DP binds to cereblon but does not efficiently trigger the degradation of the transcription factors (SALL4, Ikaros, and Aiolos) associated with the teratogenic and anti-proliferative responses of thalidomide-like drugs. We utilized a phenotypic drug discovery approach that employed cellular and animal models in the selection and development of F-3,6'-DP. F-3,6'-DP significantly mitigated LPS-induced inflammatory markers in RAW 264.7 cells, and lowered proinflammatory cytokine/chemokine levels in the plasma and brain of rats challenged with systemic LPS. We subsequently examined immunohistochemical, biochemical, and behavioral measures following controlled cortical impact (CCI) in mice, a model of moderate TBI known to induce inflammation. F-3,6'-DP decreased CCI-induced neuroinflammation, neuronal loss, and behavioral deficits when administered after TBI. F-3,6'-DP represents a novel class of thalidomide-like drugs that do not lower classical cereblon-associated transcription factors but retain anti-inflammatory actions and possess efficacy in the treatment of TBI and potentially longer-term neurodegenerative disorders.

15.
PLoS Genet ; 18(9): e1010404, 2022 09.
Article in English | MEDLINE | ID: mdl-36121845

ABSTRACT

Most somatic mutations that arise during normal development are present at low levels in single or multiple tissues depending on the developmental stage and affected organs. However, the effect of human developmental stages or mutations of different organs on the features of somatic mutations is still unclear. Here, we performed a systemic and comprehensive analysis of low-level somatic mutations using deep whole-exome sequencing (average read depth ~500×) of 498 multiple organ tissues with matched controls from 190 individuals. Our results showed that early clone-forming mutations shared between multiple organs were lower in number but showed higher allele frequencies than late clone-forming mutations [0.54 vs. 5.83 variants per individual; 6.17% vs. 1.5% variant allele frequency (VAF)] along with less nonsynonymous mutations and lower functional impacts. Additionally, early and late clone-forming mutations had unique mutational signatures that were distinct from mutations that originated from tumors. Compared with early clone-forming mutations that showed a clock-like signature across all organs or tissues studied, late clone-forming mutations showed organ, tissue, and cell-type specificity in the mutation counts, VAFs, and mutational signatures. In particular, analysis of brain somatic mutations showed a bimodal occurrence and temporal-lobe-specific signature. These findings provide new insights into the features of somatic mosaicism that are dependent on developmental stage and brain regions.


Subject(s)
Mosaicism , Neoplasms , Gene Frequency , Humans , Mutation , Neoplasms/genetics , Exome Sequencing
16.
J Neurooncol ; 160(1): 41-53, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36045266

ABSTRACT

PURPOSE: Non-germinomatous germ cell tumors (NGGCTs) are rare pediatric conditions. This multicenter study using Asian multinational patient data investigated treatment outcomes and prognostic factors for NGGCTs. METHODS: Medical records of 251 patients with NGGCTs treated from 1995 to 2015 were retrospectively analyzed from participating centers in Asian countries (Korea, Taiwan, Singapore, and Japan). RESULTS: The median follow up was 8.5 years (95% CI 7.8-9.9). In the total cohort, 5-year event-free survival (EFS) and overall survival (OS) rates were 78.2% and 85.4%, respectively. In 17.9% of the patients, diagnosis was determined by tumor markers alone (alpha-fetoprotein ≥ 10 ng/mL (Korea) or > 25 ng/mL (Taiwan and Singapore), and/or ß-human chorionic gonadotropin (ß-hCG) ≥ 50 mIU/mL). Patients with immature teratomas and mature teratomas comprised 12.0% and 8.4%, respectively. The 5-year EFS rate was higher in patients with histologically confirmed germinoma with elevated ß-hCG (n = 28) than those in patients with malignant NGGCTs (n = 127). Among malignant NGGCTs, patients with choriocarcinoma showed the highest 5-year OS of 87.6%, while yolk sac tumors showed the lowest OS (68.8%). For malignant NGGCT subgroups, an increase in serum ß-hCG levels by 100 mIU/mL was identified as a significant prognostic factor associated with the EFS and OS. CONCLUSION: Our result shows excellent survival outcomes of overall CNS NGGCT. However, treatment outcome varied widely across the histopathologic subgroup of NGGCT. Hence, this study suggests the necessity for accurate diagnosis by surgical biopsy and further optimization of diagnosis and treatment according to the histopathology of NGGCTs. Future clinical trials should be designed for individualized treatments for different NGGCTs subsets.


Subject(s)
Brain Neoplasms , Germinoma , Neoplasms, Germ Cell and Embryonal , Male , Humans , Child , Retrospective Studies , Prognosis , Neoplasms, Germ Cell and Embryonal/diagnosis , Neoplasms, Germ Cell and Embryonal/therapy , Germinoma/pathology , Brain Neoplasms/therapy , Brain Neoplasms/drug therapy , Chorionic Gonadotropin, beta Subunit, Human
17.
Pharmazie ; 77(6): 186-190, 2022 06 01.
Article in English | MEDLINE | ID: mdl-35751164

ABSTRACT

The leucine-rich repeat LGI family member 3 (LGI3) has been reported to regulate various functions in epidermal keratinocytes. In this study, we investigated the effects of LGI3 on keratinocyte migration in environments with different glucose concentrations. Our results showed that cell migration is markedly impaired in high-glucose environments compared to in low-glucose environments (control). Nevertheless, the use of LGI3 in high-glucose environments restores cell migration to the normal level. Therefore, we performed LGI3 knockdown to identify the role of LGI3 in cell migration. It was observed that transfecting LGI3 siRNA into HaCaT cells reduces the expression of LGI3 and inhibits wound closure. These results indicate that LGI3 is deeply involved in wound healing in high-glucose environments. Western blot analysis showed that in high-glucose environments, LGI3 increases the phosphorylation of Akt, forkhead box protein O1, and focal adhesion kinase. However, no change was observed in the levels of glycogen synthase kinase 3ß, c-Jun N-terminal kinase, extracellular signal-regulated kinase, or p38 mitogen-activated protein kinase. Further results showed that LY294002, a specific inhibitor of phosphatidylinositol 3-kinase, reduced LGI3-induced cell migration. It is generally known that Akt activation leads to the accumulation of ß-catenin, an important mediator of keratinocyte migration. LGI3 greatly increased the expression of ß-catenin in high-glucose environments comparison to that in the low-glucose environments. Taken together, these data indicate that LGI3 induces keratinocyte migration in high-glucose environments as a result of ß-catenin accumulation via Akt phosphorylation. Therefore, LGI3 can be considered a new treatment option for diabetic wound healing.


Subject(s)
Keratinocytes/metabolism , Wound Healing , beta Catenin , Cell Movement , Glucose/metabolism , Humans , Nerve Tissue Proteins/metabolism , Proto-Oncogene Proteins c-akt/metabolism , beta Catenin/metabolism
18.
Pharmaceutics ; 14(5)2022 Apr 27.
Article in English | MEDLINE | ID: mdl-35631536

ABSTRACT

(1) Background: An important concomitant of stroke is neuroinflammation. Pomalidomide, a clinically available immunomodulatory imide drug (IMiD) used in cancer therapy, lowers TNF-α generation and thus has potent anti-inflammatory actions. Well-tolerated analogs may provide a stroke treatment and allow evaluation of the role of neuroinflammation in the ischemic brain. (2) Methods: Two novel pomalidomide derivatives, 3,6'-dithiopomalidomide (3,6'-DP) and 1,6'-dithiopomalidomide (1,6'-DP), were evaluated alongside pomalidomide in a rat middle cerebral artery occlusion (MCAo) stroke model, and their anti-inflammatory actions were characterized. (3) Results: Post-MCAo administration of all drugs lowered pro-inflammatory TNF-α and IL1-ß levels, and reduced stroke-induced postural asymmetry and infarct size. Whereas 3,6'- and 1,6'-DP, like pomalidomide, potently bound to cereblon in cellular studies, 3,6'-DP did not lower Ikaros, Aiolos or SALL4 levels-critical intermediates mediating the anticancer/teratogenic actions of pomalidomide and IMiDs. 3,6'-DP and 1,6'-DP lacked activity in mammalian chromosome aberration, AMES and hERG channel assays -critical FDA regulatory tests. Finally, 3,6'- and 1,6'-DP mitigated inflammation across rat primary dopaminergic neuron and microglia mixed cultures challenged with α-synuclein and mouse LPS-challenged RAW 264.7 cells. (4) Conclusion: Neuroinflammation mediated via TNF-α plays a key role in stroke outcome, and 3,6'-DP and 1,6'-DP may prove valuable as stroke therapies and thus warrant further preclinical development.

19.
Alzheimers Dement ; 18(11): 2327-2340, 2022 11.
Article in English | MEDLINE | ID: mdl-35234334

ABSTRACT

OBJECTIVE: Evaluating the efficacy of 3,6'-dithioPomalidomide in 5xFAD Alzheimer's disease (AD) mice to test the hypothesis that neuroinflammation is directly involved in the development of synaptic/neuronal loss and cognitive decline. BACKGROUND: Amyloid-ß (Aß) or tau-focused clinical trials have proved unsuccessful in mitigating AD-associated cognitive impairment. Identification of new drug targets is needed. Neuroinflammation is a therapeutic target in neurodegenerative disorders, and TNF-α a pivotal neuroinflammatory driver. NEW HYPOTHESIS: AD-associated chronic neuroinflammation directly drives progressive synaptic/neuronal loss and cognitive decline. Pharmacologically mitigating microglial/astrocyte activation without altering Aß generation will define the role of neuroinflammation in AD progression. MAJOR CHALLENGES: Difficulty of TNF-α-lowering compounds reaching brain, and identification of a therapeutic-time window to preserve the beneficial role of neuroinflammatory processes. LINKAGE TO OTHER MAJOR THEORIES: Microglia/astroglia are heavily implicated in maintenance of synaptic plasticity/function in healthy brain and are disrupted by Aß. Mitigation of chronic gliosis can restore synaptic homeostasis/cognitive function.


Subject(s)
Alzheimer Disease , Cognitive Dysfunction , Animals , Mice , Amyloid beta-Peptides , Cognition , Disease Models, Animal , Mice, Inbred C57BL , Mice, Transgenic , Microglia , Neuroinflammatory Diseases , Neuronal Plasticity , Tumor Necrosis Factor-alpha
20.
J Clin Neurol ; 18(1): 71-78, 2022 Jan.
Article in English | MEDLINE | ID: mdl-35021279

ABSTRACT

BACKGROUND AND PURPOSE: A multifactorial antiepileptic mechanism underlies the ketogenic diet (KD), and one of the proposed mechanisms of action is that the KD inhibits the mammalian target of rapamycin (mTOR) pathway. To test this clinically, this study aimed to determine the efficacy of the KD in patients with pathologically confirmed focal cortical dysplasia (FCD) due to genetically identifiable mTOR pathway dysregulation. METHODS: A cohort of patients with pathologically confirmed FCD after epilepsy surgery and who were screened for the presence of germline and somatic mutations related to the mTOR pathway in peripheral blood and resected brain tissue was constructed prospectively. A retrospective review of the efficacy of the prior KD in these patients was performed. RESULTS: Twenty-five patients with pathologically confirmed FCD and who were screened for the presence of detectable somatic mTOR pathway mutations had received a sufficient KD. Twelve of these patients (48.0%) had germline or somatic detectable mTOR pathway mutations. A response was defined as a ≥50% reduction in seizure frequency. The efficacy of the KD after 3 months of dietary therapy was superior in patients with detectable mTOR pathway mutations than in patients without detectable mTOR pathway mutations, although the difference was not statistically significant (responder rates of 58.3% vs. 38.5%, p=0.434). CONCLUSIONS: A greater proportion of patients with mTOR pathway responded to the KD, but there was no statistically significant difference in efficacy of the KD between patients with and without detectable mTOR pathway mutations. Further study is warranted due to the smallness of the sample and the limited number of mTOR pathway genes tested in this study.

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