Kidney tissue regeneration using bioactive scaffolds incorporated with differentiating extracellular vesicles and intermediate mesoderm cells

차승규,임원규,김준용,이은혜,이승연,박정민,이정은,윤혜지,박천권,김범수,권태균,이영미,이동률,한동근 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background To overcome the limitations of current alternative therapies for chronic kidney disease (CKD), tissue engineering-mediated regeneration strategies have demonstrated the possibilities for complete kidney tissue regeneration. Given the challenges associated with the reproducibility of renal basal cells, the incorporation of intermediate mesoderm (IM) cells and bioactive materials to control bioactivities of cells with supported scaffolds should be considered as a viable approach to enable the regeneration of the complex kidney structure via renal differentiation. Methods We developed PMEZ scaffolds by combining crucial bioactive components, such as ricinoleic acid-grafted Mg(OH)2 (M), extracellular matrix (E), and alpha lipoic acid-conjugated ZnO (Z) integrated into biodegradable porous PLGA (P) platform. Additionally, we utilized differentiating extracellular vesicles (dEV) isolated during intermediate mesoderm differentiation into kidney progenitor cells, and IM cells were serially incorporated to facilitate kidney tissue regeneration through their differentiation into kidney progenitor cells in the 3/4 nephrectomy mouse model. Results The use of differentiating extracellular vesicles facilitated IM differentiation into kidney progenitor cells without additional differentiation factors. This led to improvements in various regeneration-related bioactivities including tubule and podocyte regeneration, anti-fibrosis, angiogenesis, and anti-inflammation. Finally, implanting PMEZ/dEV/IM scaffolds in mouse injury model resulted in the restoration of kidney function. Conclusions Our study has demonstrated that utilizing biodegradable PLGA-based scaffolds, which include multipotent cells capable of differentiating into various kidney progenitor cells along with supporting components, can facilitate kidney tissue regeneration in the mouse model that simulates CKD through 3/4 nephrectomy.

환추-축추 불안정성에 있어서 후방 경관절 나사못 고정술에 대한 수술적 경험

차승규,유찬종,Cha, Seung Kyu,You, Chan Jong 대한신경외과학회 2000 Journal of Korean neurosurgical society Vol.29 No.1

Objective : Posterior transarticular screw fixation is known to be one of the best surgical method for the atlantoaxial instability. We assessed the complication and operative risk in 15 patients. Patients and Methods : Between January 1997 and April 1998, 15 patients suffering from this condition were admitted to our institution. Atlantoaxial instability was caused by C1 or C2 fractures in 11, rheumatoid arthritis in 2, and os odontoideum in 2. This technique was used in the treatment of 13 patients and 2 patients was used in sublaminar wire fixation only. Bilateral C1-C2 screws were placed in 11 patients ; 2 patients had only one screw placed becauce of an anomalous vertebral artery and axial destruction. Follow-up period ranged from 5 to 20 months. Results : Most screws were positioned satisfactorily. One screw was malpositioned. No patients had neurological complications. Conclusion : Rigidly fixating C1-C2 instability with transarticular screws showed a significantly higher fusion rate than that achieved using wired grafts alone. The risk of screw malpositioning and catastrophic vascular or neural injury is small and can be minimized by assessing the position of the transverse foramen on preoperative computed tomographic scans and by correctly using intraoperative fluoroscopy and surgeon's precaution.

Intelligent scaffold with renal differentiation factors primed-extracellular vesicles and intermediate mesoderm for kidney regeneration

차승규,임원규,김준용,박현정,한동근 한국공업화학회 2023 한국공업화학회 연구논문 초록집 Vol.2023 No.1

파킨슨병 환자의 말초 혈액 PCR 분석을 이용한 Mitochondrial DNA의 결실에 관한 연구

차승규,유영미,이언 대한신경외과학회 1998 Journal of Korean neurosurgical society Vol.27 No.8

체중이동 과제 학습시 효과적인 운동학적 되먹임 유형과 상대적 빈도

차승규,박소연,정진호,김영호 한국전문물리치료학회 2000 한국전문물리치료학회지 Vol.7 No.1

Physical therapists have been using balance and weight shifting training to induce improvements in standing and walking. This study compared the effects of kinetic feedback frequency and concurrent kinetic feedback on the performance and learning of a weight shifting skill in young, nondisabled adults. Sixteen young adults without known impairment of the neuromusculoskeletal system volunteered for the study. Subjects in each of three kinetic feedback groups performed a weight shifting task in an attempt to minimize error between their effort and a center of pressure (COP) template for a 12 second period. Feedback was provided: 1) concurrently (concurrent feedback), 2) after each trial (100% feedback), 3) after ever other trial (50% feedback). Immediate and delayed (24 hous) retention tests were performed without feedback. During ascquistion phase, the concurrent feedback group exhibited less error than either of the post response feedback group. For the immediate retention test, the 50% feedback group exhibited less error than did the 100% feedback and concurrent feedback. During the delayed retention, 50% feedback group displayed less error than did the other groups. But no significant differences were found between groups. these results suggest that practice with concurrent feedback is beneficial for the immediate performance, but not for the learning of this weight shifting skill. Lower frequency of feedback resulted in more permanent changes in the subject's ability to complete the task.

GRNN을 이용한 실시간 계층적 시선 식별

차승규(Seungju Tcha),박영철(Youngcheol Park),배철수(Cheolsoo Bae) 한국정보기술학회 2007 Proceedings of KIIT Conference Vol.2007 No.-

본 논문에서는 실시간 시선 식별 시스템을 위한 능동적 적외선 조명을 기반으로 한 컴퓨터 비전 시스템에 대하여 제안하고자 한다. 현존하는 대다수의 시선 식별 기술은 고정된 얼굴에서만 제대로 동작하고 개개인에 대한 교정 절차를 필요로 한다. 그러므로 본 논문에서는 교정 작업 없이 얼굴 움직임이 있는 경우에도 견실하고 정확하게 동작하는 시선 식별 시스템을 제안하고 있다. 제안된 시스템은 GRNN을 이용한 동공 매개 변수로부터 스크린 좌표로 할당하는 시선 교정 방법을 사용하여 계층적인 구조를 구성되었다. GRNN을 사용 함으로서, 시선 할당에 분석적 기능이나 얼굴 움직임에 대한 계산이 필요 없을 뿐 아니라 다른 개개인에 대하여 학습과정에서 할당 기능을 일반화 할 수 있었다. 시선 예측 정확도를 개선하고자 계층적 식별을 제안함으로써 오분류를 줄일 수 있었다. 공간 시선 해상도는 화면에서 1m 정도 떨어진 거리에서 수평으로 10cm, 수직으로 약 l3cm 정도인, 즉 수평으로 8도정도 수직으로 대략 5도 정도이었다. 실험 결과, 1차 시선 식별기보다 계층적 시선 식별기가 약 9% 정도 정확성이 향상되어 93%를 나타냄으로써 제안된 시스템의 유효성을 증명하였다.

결과에 대한 지식의 상대적 빈도와 지연간격 유형이 운동학습에 미치는 영향 비교

김대균,차승규,김범규,안수경,김종만 한국전문물리치료학회 1997 한국전문물리치료학회지 Vol.4 No.1

Several studies have evaluated the effects of types of relative frequency and delay interval of knowledge of results(KR) on motor skill learning independently. The purpose of this study was to determine more effective types of KR relative frequency and KR delay interval for motor learning. Forty-six healthy subjects (15 female, 31 male) with no previous experience with this experiment participated. The subjects ranged in age from 20 to 29 years (mean=23.9, SD=0.474). All subjects were assigned to one of four groups: a high-instant group, a high-delay group, a low-instant group, and a low-delay group. During the acquisition phase, subjects practiced movements to a target (400 mm) with either a high (83%) or low (33%) KR relative frequency, and with either an instantaneous or delayed (after 8s) KR. Four groups were evaluated on retention (after 3min and 24hr) and transfer (450 mm) tests. The major findings were as follows: (1) there were no between-group differences in acquisition and short-term retention (p>0.05, (2) a low (33%) KR relative frequency during practice was as effective for learning as measured by both long-tenn retention and transfer tests, compared with high (83%) KR practice conditions (p<0.05), (3) delayed (8s) KR enhanced learning as measured by both long-term retention and transfer tests, compared with instantaneous KR practice conditions (p<0.05), and (4) there were no interactions between KR relative frequency and KR delay interval during acquisition, retention, and transfer phases. The results suggest that relatively less frequent and delayed KR are more effective types for motor learning than more frequent and instantaneous KR.ㅂ

골반 신경절에 대한 GABA의 신경 흥분성 작용

길승배,차승규,김대란,장상근,장연규,공인덕 대한신경외과학회 2004 Journal of Korean neurosurgical society Vol.36 No.2

Objective : In the central nervous system, γ-aminobutyric acid (GABA) is well known to act as an inhibitory neurotransmitter by hyperpolarizing postsynaptic neurons through gating GABA-activated Cl- channels. To date, however, the functional roles of GABA remain unclear in the autonomic nervous system. In the present study, we characterize GABA-activated Cl- currents in the neurons of major pelvic ganglia (MPG). Methods : MPG neurons, located on the lateral surfaces of the prostate gland, from male rats were enzymatically dissociated. Ionic currents were recorded using whole-cell variant patch-clamp technique. Membrane potential was recorded under current clamp mode. Current traces were filterd at 2kHz by using 4-pole Bassel filter in the amplifier. Results : Application of GABA (100㎛) induced inward currents in the neurons, with holding potentials being maintained below the Cl- equilibrium potential (ECl). The GABA response was concentration-dependent and its reversal potential was close to the theoretical ECl. The GABA-induced Cl- currents were largely blocked by bicuculline (10㎛, n=5), a GABAA receptor antagonist, but were not affected by 9-AC and niflumic acid, chloride channel blockers. GABA also produced significant membrane depolarization (19mV, n=28). As in the case of the Cl- currents, the GABAinduced depolarizations were largely blocked by bicuculline(10㎛, n=6), but not by DIDS(50㎛, n=4), another chloride channel blocker. Conclusion : The data suggest that GABAergic roles may be due to it's activation of excitatory GABAA receptors, which are expressed in MPG neurons.

사람 망막아세포종 세포에 발현된 니코틴성 수용성의 특성

김대란,차승규,공인덕,정세환,라상훈 대한안과학회 2005 대한안과학회지 Vol.46 No.6

Purpose: To identify the characteristics and physiological function of the nicotinic receptor expressed in human retinoblastoma cells. Methods: We measured possible nicotinic signaling in WERI-Rb-1 cells using the Ca2+ imaging technique and the patch clamp method. Results: 1) Nicotine-induced [Ca2+]i rise arose entirely through Ca2+ influx, which was completely abolished by hexamethonium (100 μM). 2) Nicotine also induced remarkable depolarization from -56.6±3.7 mV to -29.6±3.6 mV (n=4) under current clamp mode, but it failed to directly activate the T-type Ca2+ channel expressed in retinoblastoma cells. Conclusions: Nicotinic activation can increase the intracellular calcium level through calcium influx in the undifferentiated retinoblastoma cells, which may play important roles in cell proliferation, differentiation, and cell death. 목적 : 사람의 망막아세포종 세포에 발현되어 있을 것으로 예상되는 니코틴성 수용체의 특성과 그 생리적 기능의 일부를 규명하고자 하였다. 대상과 방법 : 니코틴성 수용체의 활성화를 확인하기 위해 망막아세포종 세포주의 하나인 WERI-Rb-1 세포를 대상으로 칼슘 이미징(imaging) 기법을 이용하여 세포내 칼슘농도([Ca2+]i)를 측정하였으며, patch clamp 기법으로 세포막을 통한 이온전류를 측정하였다. 결과 : 1) 니코틴에 의한 [Ca2+]i 증가는 모두 세포막을 통한 Ca2+ 유입에 의한 것으로 나타났다. 2) 니코틴 투여시 내향성 전류를 유발하였으며, 막전압의 뚜렷한 탈분극(대조군: -56.6±3.7 mV, 니코틴 투여군: -29.6±3.6 mV, n=4)을 초래하였다. 이와 같은 변화는 니코틴 수용체 차단제(hexamethoniun, 100 μM)에 의해 완전히 억제되었다. 3) 니코틴 투여가 망막아세포종 세포에 이미 발현되어 있는 T-형 칼슘 전류에는 직접적인 영향을 주지 않았다. 결론 : 망막아세포종 세포에는 니코틴성 수용체가 발현되어 있으며, 세포막에 발현된 니코틴성 수용체를 통한 Ca2+ 유입 및 탈분극에 따른 세포내 칼슘유입은 세포분화, 증식, 세포사멸 등의 조절기전에 관여하리라 사료된다.

사람 망막아세포종 세포에 발현된 니코틴성 수용체의 특성

김대란,차승규,공인덕,정세환,라상훈.Dae-Ran Kim. Ph.D.. Seung-Kyu Cha. Ph.D.. In-Deok Kong. M.D.. Se-Hwan Jung. M.D. Sang Hoon Rah. M.D. 대한안과학회 2005 대한안과학회지 Vol.46 No.6

Purpose: To identify the characteristics and physiological function of the nicotinic receptor expressed in human retinoblastoma cells. Methods: We measured possible nicotinic signaling in WERI-Rb-1 cells using the Ca2+ imaging technique and the patch clamp method. Results: 1) Nicotine-induced [Ca2+]i rise arose entirely through Ca2+ influx, which was completely abolished by hexamethonium (100 μM). 2) Nicotine also induced remarkable depolarization from -56.6±3.7 mV to -29.6±3.6 mV (n=4) under current clamp mode, but it failed to directly activate the T-type Ca2+ channel expressed in retinoblastoma cells. Conclusions: Nicotinic activation can increase the intracellular calcium level through calcium influx in the undifferentiated retinoblastoma cells, which may play important roles in cell proliferation, differentiation, and cell death.