1.Late-stage cascade of oxidation reactions during the biosynthesis of oxalicine B in Penicillium oxalicum.
Tao ZHANG ; Guowei GU ; Guodong LIU ; Jinhua SU ; Zhilai ZHAN ; Jianyuan ZHAO ; Jinxiu QIAN ; Guowei CAI ; Shan CEN ; Dewu ZHANG ; Liyan YU
Acta Pharmaceutica Sinica B 2023;13(1):256-270
Oxalicine B ( 1) is an α-pyrone meroterpenoid with a unique bispirocyclic ring system derived from Penicillium oxalicum. The biosynthetic pathway of 15-deoxyoxalicine B ( 4) was preliminarily reported in Penicillium canescens, however, the genetic base and biochemical characterization of tailoring reactions for oxalicine B ( 1) has remained enigmatic. In this study, we characterized three oxygenases from the metabolic pathway of oxalicine B ( 1), including a cytochrome P450 hydroxylase OxaL, a hydroxylating Fe(II)/α-KG-dependent dioxygenase OxaK, and a multifunctional cytochrome P450 OxaB. Intriguingly, OxaK can catalyze various multicyclic intermediates or shunt products of oxalicines with impressive substrate promiscuity. OxaB was further proven via biochemical assays to have the ability to convert 15-hydroxdecaturin A ( 3) to 1 with a spiro-lactone core skeleton through oxidative rearrangement. We also solved the mystery of OxaL that controls C-15 hydroxylation. Chemical investigation of the wild-type strain and deletants enabled us to identify 10 metabolites including three new compounds, and the isolated compounds displayed potent anti-influenza A virus bioactivities exhibiting IC50 values in the range of 4.0-19.9 μmol/L. Our studies have allowed us to propose a late-stage biosynthetic pathway for oxalicine B ( 1) and create downstream derivatizations of oxalicines by employing enzymatic strategies.
2.Exosomes Derived from Human Amniotic Mesenchymal Stem Cells Facilitate Diabetic Wound Healing by Angiogenesis and Enrich Multiple lncRNAs
Shangfeng FU ; Hongyan ZHANG ; Xiancai LI ; Qiling ZHANG ; Chunyan GUO ; Keqing QIU ; Junyun FENG ; Xiaoxiao LIU ; Dewu LIU
Tissue Engineering and Regenerative Medicine 2023;20(2):295-308
BACKGROUND:
Diabetic wound healing remains a major challenge due to the impaired functionality of angiogenesis by persistent hyperglycemia. Mesenchymal stem cell exosomes are appropriate candidates for regulating the formation of angiogenesis in tissue repair and regeneration. Here, we explored the effects of exosomes derived from human amniotic mesenchymal stem cell (hAMSC-Exos) on the biological activities of human umbilical vein endothelial cells (HUVECs) treated with high glucose and on diabetic wound healing and investigate lncRNAs related to angiogenesis in hAMSC-Exos.
METHODS:
hAMSCs and hAMSC-Exos were isolated and identified by flow cytometry or western blot. A series of functional assays such as cell counting kit-8, scratching, transwell and tube formation assays were performed to evaluate the potential effect of hAMSC-Exos on high glucose-treated HUVECs. The effect of hAMSC-Exos on diabetic wound healing were tested by measuring wound closure rates and immunohistochemical staining of CD31. Subsequently, the lncRNAs profiles in hAMSC-Exos and hAMSCs were examined to screen the lncRNAs related to angiogenesis.
RESULTS:
The isolated hAMSC-Exos had a size range of 30–150 nm and were positive for CD9, CD63 and CD81. The hAMSC-Exos facilitate the functional properties of high glucose-treated HUVECs including the proliferation, migration and the angiogenic activities as well as wound closure and angiogenesis in diabetic wound. hAMSC-Exos were enriched lncRNAs that related to angiogenesis, including PANTR1, H19, OIP5-AS1 and NR2F1-AS1.
CONCLUSION
Our findings demonstrated hAMSC-Exos facilitate diabetic wound healing by angiogenesis and contain several exosomal lncRNAs related to angiogenesis, which may represent a promising strategy for diabetic wound healing.
3.Research advances on severe burn infection and cytokine storm
Zhongyi CHEN ; Shiqiang HU ; Dewu LIU ; Hongyan ZHANG ; Guanghua GUO ; Yuangui MAO
Chinese Journal of Burns 2023;39(4):391-395
Mortality due to severe burns has always been at a high level. A large number of studies have shown that the rapid onset of infectious symptoms and rapid progression of severely burned patients are closely related to the occurrence of cytokine storm. However, in clinical practice, cytokine storm monitoring, early warning, and symptomatic treatment are still in exploratory stage. This article reviews the cytokine storm and its related cytokines, the mechanism, early warning, and treatment of cytokine storm induced by burn infection, aiming to provide clinical references for reducing infection and mortality in severely burned patients.
4.Multicenter retrospection and analysis of influencing factors on blood transfusion in patients with extensive burns
Deqing DUAN ; Yong CHEN ; Hong'ao DENG ; Shiqiang HU ; Yuangui MAO ; Dewu LIU ; Chunmao HAN ; Qinglian XU ; Hongyan ZHANG
Chinese Journal of Burns 2023;39(11):1047-1056
Objective:To retrospect the blood transfusion status of patients with extensive burns in multiple centers and analyze its influencing factors.Methods:A retrospective case series study was conducted. Clinical data of 455 patients with extensive burns who met the inclusion criteria and were admitted to the burn centers of 3 hospitals from January 2016 to June 2022 were collected, including 202 patients from the First Affiliated Hospital of Nanchang University, 179 patients from the Second Affiliated Hospital of Zhejiang University School of Medicine, and 74 patients from the First Affiliated Hospital of Anhui Medical University. The following data were collected from patients during their hospitalization, including infusion of red blood cells, plasma, and platelets during hospitalization; age, gender, body mass index, combined underlying diseases, cause of injury, time of admission after injury, type of admission, total burn area, full-thickness burn area, combination of inhalation injury, combination of other trauma, and combination of pulmonary edema; the blood lactic acid, serum creatinine, total bilirubin, and albumin values within 24 h of admission; combination of bloodstream, wound, lung, and urinary tract infection, and combination of sepsis; the number of escharectomy or tangential excision and skin grafting surgery (hereinafter referred to as surgery) and total surgical blood loss volume; occurrence of hemoglobin<70 g/L, admission to intensive care unit (ICU), conduction of mechanical ventilation and continuous renal replacement therapy (CRRT), length of hospital stay, and prognosis were recorded. In 602 surgeries of patients within 14 days after injury, data including area of escharectomy or tangential excision and skin graft harvesting, duration of operation, and surgical blood loss volume per surgery, operation site, and use of tourniquet and wound graft were collected. Data were statistically analyzed with Mann-Whitney U test, Kruskal-Wallis H test, and Spearman correlation analysis. Combined with the results of single factor analysis and clinical significance, multiple linear regression analysis was performed to screen the independent influencing factors of red blood cell infusion volume and plasma infusion volume, as well as blood loss volume per surgery. Results:During the whole hospitalization period, 437 (96.0%) patients received blood transfusion therapy, including 435 (95.6%) patients, 410 (90.1%) patients, and 73 (16.0%) patients who received transfusion of plasma, red blood cells, and platelets, respectively. The patients were mainly male, aged 18 to 92 years. There were statistically significant differences in the plasma infusion volume among patients with different combination of underlying disease, combination of inhalation injury, combination of other trauma, combination of pulmonary edema, combination of bloodstream infection, combination of wound infection, combination of lung infection, combination of urinary tract infection, combination of sepsis, occurrence of hemoglobin value <70 g/L, admission to ICU, conduction of mechanical ventilation, and conduction of CRRT (with Z values of -2.06, -4.67, -2.11, -6.13, -9.56, -4.93, -8.08, -4.78, -9.12, -6.55, -9.37, -11.46, and -7.17, respectively, P<0.05). The total burn area, full-thickness burn area, blood lactic acid value within 24 h of admission, serum creatinine value within 24 h of admission, albumin value within 24 h of admission, number of surgeries, and total surgical blood loss volume were correlated with the plasma infusion volume of patients (with r values of 0.39, 0.51, 0.14, 0.28, -0.13, 0.47, and 0.56, respectively, P<0.05).There were statistically significant differences in the red blood cell infusion volume among patients with different gender, combination of inhalation injury, combination of other trauma, combination of pulmonary edema, combination of bloodstream infection, combination of wound infection, combination of lung infection, combination of urinary tract infection, combination of sepsis, occurrence of hemoglobin value <70 g/L, admission to ICU, conduction of mechanical ventilation, and conduction of CRRT (with Z values of -2.00, -4.34, -3.10, -4.22, -8.24, -7.66, -8.62, -4.75, -7.42, -9.36, -6.12, and -8.31, -6.64, respectively, P<0.05). The age, total burn area, full-thickness burn area, blood lactic acid value within 24 h of admission, serum creatinine value within 24 h of admission, total bilirubin value within 24 h of admission, number of surgeries, and total surgical blood loss volume were correlated with the red blood cell infusion volume of patients (with r values of 0.12, 0.22, 0.49, 0.09, 0.18, 0.13, -0.15, 0.69, and 0.77, respectively, P<0.05). Combined underlying diseases, full-thickness burn area, combined pulmonary edema, serum creatinine value within 24 h of admission, combined sepsis, conduction of CRRT, number of surgeries, and total surgical blood loss volume were the independent influencing factors for plasma infusion volume during hospitalization in patients with extensive burns (with standardized regression coefficients of 0.09, 0.16, 0.12, 0.07, 0.11, 0.15, 0.31, and 0.26, respectively, P<0.05). Female, full-thickness burn area, serum creatinine value within 24 h of admission, combined sepsis, occurrence of hemoglobin value <70 g/L, conduction of CRRT, and total surgical blood loss volume were the independent influencing factors for red blood cell infusion volume during hospitalization in patients with extensive burns (with standardized regression coefficients of 0.10, 0.12, 0.10, 0.11, 0.05, 0.19, and 0.54, respectively, P<0.05). There were statistically significant differences in blood loss volume per surgery of patients with different surgical site and wound graft (with Z values of -2.54 and -2.27, respectively, P<0.05). The area of escharectomy or tangential excision and skin graft harvesting and duration of operation were correlated with the blood loss volume per surgery of patients (with r values of 0.40 and 0.21, respectively, P<0.05). The area of escharectomy or tangential excision and skin graft harvesting, duration of operation, and active wound grafts were the independent influencing factors for blood loss volume per surgery of patients with extensive burns (with standardized regression coefficients of 0.41, 0.16, and 0.12, respectively, P<0.05). Conclusions:The major factors influencing blood transfusion status in patients with extensive burns are female, combined underlying diseases, full-thickness burn area, serum creatinine value within 24 h of admission, combined pulmonary edema, occurrence of hemoglobin value <70 g/L, combined sepsis, conduction of CRRT, number of surgery, and total surgical blood loss volume. In addition, the area of escharectomy or tangential excision and skin graft harvesting, duration of operation, and active wound grafts indirectly affect the patient's blood transfusion status by affecting the blood loss volume per surgery.
5.Clinical effects of different types of tissue flaps in repairing the wounds with steel plate exposure and infection after proximal tibial fracture surgery
Wenjian LIU ; Hongyan ZHANG ; Dewu LIU
Chinese Journal of Burns 2023;39(12):1140-1148
Objective:To investigate the clinical effects of different types of tissue flaps in repairing the wounds with steel plate exposure and infection after proximal tibial fracture surgery.Methods:A retrospective observational study was conducted. From January 2015 to December 2021, 11 patients with steel plate exposure and infected wounds after proximal tibial fracture surgery who met the inclusion criteria were admitted to Jiangxi Provincial General Hospital of Armed Police, including 9 males and 2 females, aged 26 to 61 years. The wounds were located on the lateral side of the proximal leg in 5 cases, on the medial side of the proximal leg in 2 cases, and on the medial side of the proximal leg and the anterior tibia below the knee in 4 cases. After debridement, the wound area was 14 cm×6 cm-22 cm×11 cm. The wounds were repaired with different types of tissue flaps, and the steel plates were removed immediately if necessary, according to the infection around the steel plates. The reverse anterolateral thigh myocutaneous flap pedicled with the muscle containing the terminal small branch of the descending branch of the lateral circumflex femoral artery was used in 3 cases; the medial gastrocnemius muscle flap combined with the medial half of soleus muscle flap was used in 6 cases, and the lateral gastrocnemius muscle flap combined with the anterior tibial muscle flap was used in 2 cases. After the muscle flaps had stable blood supply, the wounds were closed with thin intermediate thickness skin graft from the healthy thigh. The area of myocutaneous flap ranged from 15 cm×7 cm to 18 cm×8 cm, and the area of muscle flap ranged from 6.0 cm×4.0 cm to 18.0 cm×12.0 cm. Among the 3 patients who were treated with reverse anterolateral thigh myocutaneous flap, the wounds of flap donor site on thighs were closed by direct suturing in 2 cases, and the wound in the flap donor site of thigh in 1 case that was not closed after suture was repaired with thin intermediate thickness skin graft from healthy thigh. The incisions in the flap donor sites of 8 cases treated with calf muscle flaps were sutured directly. After surgery, the survivals of tissue flap and skin graft on the muscle flap, wound healing status and wound healing time in recipient sites of tissue flaps, suture site healing in flap donor site, and survival of skin graft were observed and recorded. Whether the steel plate was removed after operation and during follow-up was recorded. During follow-up, the shape and texture of tissue flap, whether the recipient site of tissue flap had redness, swelling, ulceration, or sinus formation were observed, the fracture healing time was recorded. At the last follow-up, the knee joint flexion and extension range of motion was measured and the knee joint function was evaluated according to Hohl's knee joint function evaluation criteria; the plantar flexor muscle strength of ankle joint was measured in 8 patients who were treated with calf muscle flaps for wound repair; the Vancouver scar scale (VSS) was used to evaluate the scar condition in the flap donor site, and whether the scar affected the movement of the affected limbs was observed.Results:Tissue flaps of 11 patients all survived after surgery. The distal end of the reverse anterolateral thigh myocutaneous flaps was necrotic in 1 patient, and the wound was healed after dressing change and grafting with thin intermediate thickness skin from healthy thigh. The distal muscle necrosis of the medial gastrocnemius muscle flap was observed in 2 patients, and the granulation tissue grew well after dressing change. The skin graft on the muscle flap survived well. All the wounds in the recipient sites of tissue flaps were healed, and the healing time was 13 to 42 days after tissue flap transplantation. The suture site of flap donor site healed, and the skin graft survived well. In 1 patient, the steel plate was removed when the wound was repaired with the medial gastrocnemius muscle flap combined with the medial half of soleus muscle flap. One patient still had exudation after 3 weeks of wound repair with the reverse anterolateral thigh myocutaneous flap pedicled with the muscle containing the terminal small branch of the descending branch of the lateral circumflex femoral artery, and the wound was healed after removing the steel plate. The steel plates of the other patients were preserved. During the follow-up of 6-25 months, except for 1 reverse anterolateral thigh myocutaneous flap had bloated pedicle, the other tissue flaps had good appearance and texture. One patient had redness and swelling in the recipient site of the tissue flap at 6 weeks after discharge, and the redness and swelling subsided without recurrence after anti-infection treatment. In 1 patient, repeated rupture and exudation occurred in the recipient site of tissue flap in 3 months after discharge, resulting in sinus tract formation, which was healed after the removing of steel plate. The fracture healing time of patients ranged from 6 to 15 months after injury. At the last follow-up, the knee joint function was evaluated as excellent in 4 cases, good in 6 cases, and poor in 1 case. Among the 8 patients who were treated with calf muscle flaps for wound repair, 7 patients had ankle joint plantar flexor muscle strength of grade Ⅵ, and 1 patient had ankle plantar flexor muscle strength of grade Ⅴ. The VSS scores of scars in the flap donor sites ranged from 2 to 7, and scars did not significantly affect the movement of the affected limbs.Conclusions:The reverse anterolateral thigh myocutaneous flap pedicled with the muscle containing the terminal small branch of the descending branch of the lateral circumflex femoral artery and the gastrocnemius muscle flap combined with soleus muscle flap or anterior tibial muscle flap are the derived types of the commonly used reverse anterolateral thigh myocutaneous flap and gastrocnemius muscle flap. Using them to repair the wounds with steel plate exposure and infection after proximal tibial fracture surgery can not only ensure the smooth operation, but also preserve the steel plate and promote fracture healing as much as possible, without significantly affecting the function of the affected limb.
6.Knockdown the expression of ku70 and lig4 in HEK293T cells by CRISPR/Cas13 system.
Haoqiang WANG ; Guoling LI ; Guangyan HUANG ; Zicong LI ; Enqin ZHENG ; Zheng XU ; Huaqiang YANG ; Zhenfang WU ; Xianwei ZHANG ; Dewu LIU
Chinese Journal of Biotechnology 2020;36(7):1414-1421
Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated proteins (Cas) system is a hotspot of gene editing and gene expression research, in which CRISPR/Cas13 system provides a new direction for RNA interference and editing. In this study, we designed and synthesized the corresponding gRNAs of CRISPR/Cas13a and CRISPR/Cas13b systems in non-homologous end joining (NHEJ) pathway, such as Ku70 and Lig4, and then detected the expression of ku70 and lig4 in HEK293T cells. The CRISPR/Cas13a system could efficiently knockdown the mRNA expression of ku70 and lig4 more than 50%, and CRISPR/Cas13b system also suppressed ku70 and lig4 about 92% and 76%, respectively. Also, CRISPR/Cas13a, b systems could down-regulate Ku70 and Lig4 proteins level to 68% and 53%, respectively. The study demonstrates that the CRISPR/Cas13 system could effectively knockdown the expression of RNA and protein in HEK293T cells, providing a new strategy for gene function and regulation research.
CRISPR-Cas Systems
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DNA Ligase ATP
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genetics
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Gene Expression Regulation
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genetics
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Gene Knockdown Techniques
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HEK293 Cells
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Humans
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Ku Autoantigen
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genetics
7.Effects and mechanism of rat epidermal stem cells treated with exogenous vascular endothelial growth factor on healing of deep partial-thickness burn wounds in rats
Yan SHI ; Longxiang TU ; Qin DENG ; Yaping ZHANG ; Yanghong HU ; Dewu LIU
Chinese Journal of Burns 2020;36(3):195-203
Objective:To explore the effects and mechanism of rat epidermal stem cells (ESCs) that were treated with exogenous vascular endothelial growth factor (VEGF) on the healing of deep partial-thickness burn wounds in rats.Methods:ESCs were isolated and cultured from the trunk skin of a 3-month-old female Sprague-Dawley (SD) rat. The third passage of cultured cells in the logarithmic growth phase was used in experiments (1)-(3). (1) The cells were routinely cultured in keratinocytes-specified serum-free medium (K-SFM) (the same routine culture condition below). The morphology of cells cultured for 3 and 5 days was observed under the inverted optical microscope. (2) After 24 hours in routine culture, the expression of cell surface markers CD44, CD45, CD11b, and CD11c was detected by flow cytometer, with triplicate samples. (3) Four batches of cells were collected, and each batch was divided into VEGF group or blank control group according to the random number table. The cells in blank control group were routinely cultured, while the cells in VEGF group were cultured in K-SFM containing VEGF in the final mass concentration of 10 ng/mL. The protein expressions of cytokeratin 19 (CK19) and CK10 in cells cultured for 10 days were detected by Western blotting. The Nanog mRNA expression in cells cultured for 0 (immediately), 2, 4, 6, 8, and 10 day (s) was detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction. The absorbance value was detected with cell counting kit-8 in cells cultured for 2, 4, 6, 8, and 10 days. The clone number of more than 50 cells was observed and counted under the optical microscope in cells cultured for 10 days, and the cell colony formation rate was calculated. Three samples at each time point was analysed. (4) Thirty-six 3-month-old SD rats (either male or female) were used for the study, and two deep partial-thickness burn wounds (10 mm in diameter) were created in each rat by pressing a 100 ℃ electric iron plate on symmetric dorsal side. According to the random number table, the injured rats were divided into VEGF+ ESCs group, ESCs alone group, and blank control group, with 12 rats and 24 wounds in each group. From 0 (immediately) to 2 day (s) after injury, 20 μL phosphate buffer solution (PBS) was injected into each wound in the three groups in one time, once a day, with the solution in VEGF+ ESCs group containing 0.8×10 6 cells/mL of ESCs treated by 10 ng/mL VEGF for 10 days, the solution in ESCs alone group containing 0.8×10 6 cells/mL of ESCs without any treatment, and the solution in blank control group being PBS only. On post first injection day (PFID) 0 (immediately), 3, 7, and 14, three rats from each group were taken respectively according to the random number table for wound healing assessment, and the wound healing rates on PFID 3, 7, and 14 were calculated. The mice at each time point were sacrificed with wound tissue harvested for histology, and the skin structure was observed by hematoxylin-eosin staining. Data were statistically analyzed with independent sample t test, analysis of variance for factorial design, least significant difference test, and Bonferroni correction. Results:(1) By day 3 in culture, cells distributed in slowly-growing clusters. By day 5, the clusters were large and round, in which the cells mainly with large and round nuclei and little cytoplasm were observed. The above results were consistent with the morphological characteristics of ESCs. (2) The positive expression rate of CD44 was (94.3±1.2) %, and the expressions of CD45, CD11b, and CD11c were negative. The cells were confirmed as ESCs. (3) Compared with those of blank control group, the protein expression of CK19 in the cells of VEGF group was significantly increased after 10 days in culture ( t=3.756, P<0.05), while the protein expression of CK10 was significantly decreased ( t=3.149, P<0.05). Compared with those of blank control group, the Nanog mRNA expression in the cells cultured for 0 and 2 day (s) and absorbance values of the cells cultured for 2 and 4 day (s) were not significantly changed in VEGF group ( t=0.58, 0.77, 0.53, 3.02, P>0.05), while the Nanog mRNA expression in the cells cultured for 4, 6, 8, and 10 days and absorbance values of the cells cultured for 6, 8, and 10 days were significantly increased in VEGF group ( t=6.34, 5.00, 5.58, 4.61, 5.65, 10.78, 15.51, P<0.01). After 10 days in culture, the cell colony-forming rate in VEGF group was (56.4±1.3) %, significantly higher than (31.5±1.3) % of blank control group ( t=13.96, P<0.01). (4) The burn wounds of rats in the three groups were confined to the superficial dermis of the skin on PFID 0. On PFID 3, normal skin tissue at wound margins slightly contracted in the rats of VEGF+ ESCs group, which was earlier than that in the other two groups. On PFID 7, the newly generated epidermis covered most parts of the rat wounds in VEGF+ ESCs group, and some of the epithelium crawled around the rat wounds in ESCs alone group, but no obvious epithelialization was observed in the rat wounds in blank control group. On PFID 14, the rat wounds in VEGF+ ESCs group were basically healed, while some parts of the rat wounds were unhealed in ESCs alone group, and most parts of the rat wounds were unhealed in blank control group. On PFID 3, the wound healing rates of rats in the three groups were similar ( P>0.05). On PFID 7 and 14, the wound healing rates of rats in ESCs alone group, respectively (26.0±2.0) % and (64.4±4.7) %, were obviously higher than (12.4±1.1) % and (29.1±3.3) % of blank control group ( P<0.01), all of which were obviously lower than (41.0±2.4) % and (91.3±3.5) % of VEGF+ ESCs group ( P<0.01). On PFID 3, infiltration of a large number of inflammatory cells were observed in the rat wounds in VEGF+ ESCs group, which was earlier than those in the other two groups. On PFID 7, a large number of endothelial cells were observed in the rat wounds in VEGF+ ESCs group, while proliferation of a few endothelial cells were observed in the rat wounds in ESCs alone group, and a large number of inflammatory cells infiltrated the rat wounds in blank control group. On PFID 14, the newly generated epidermal cells covered nearly all the rat wounds in VEGF+ ESCs group and most parts of the rat wounds in ESCs alone group, while a large number of endothelial cells were observed and the newly generated epidermal cells covered some parts of the rat wounds in blank control group. Conclusions:ESCs of rats treated with exogenous VEGF can promote the healing of deep partial-thickness burn wounds in rats, which may be related to VEGF′s roles in promoting the proliferation of ESCs and reducing its differentiation level, so as to maintain the potency of stem cells.
8.Development of maintenance learning machine of ventilator for teaching
Guangxing ZHANG ; Dewu YANG ; Zhun QIU
China Medical Equipment 2017;14(4):45-48
Objective: To design a new type of maintenance learning machine of ventilator for teaching and experiment combined with electronic technology course of higher vocational education. Methods: ACM804 ventilator was chosen as prototype machine and the electronic technology course of higher vocational education was chosen as theory basis. The designs of internal circuit and gas circuit of prototype machine were improved, besides, some test points and failure points were designed for teaching in classroom. Results: This machine not only could realize all functions of prototype machine, but also could carry forward test teaching and contribute students to maintain common failure in accordance with course content. Conclusion: Through the design of teaching experiment and using of learning machine, the new machine has achieved better teaching effect for students to grasp machine theory and operate actual circuit.
9.Pulmonary expression of HIF-1α and its relationship with GRP78 in the pathogenesis of hepatopulmonary syndrome in rats
Xujiong LI ; Huiying ZHANG ; Xiaoxia TIAN ; Yunxia CHENG ; Li MENG ; Lina LAI ; Zhongfu ZHAO ; Dewu HAN ; Ji CHENG
Journal of Xi'an Jiaotong University(Medical Sciences) 2016;37(4):513-517,524
ABSTRACT:Objective To explore the role of HIF‐1αin the pathogenesis of hepatopulmonary syndrome (HPS) and its relationship with GRP78 .Methods The HPS model in rats was induced by multiple pathogenic factor .The samples were assessed by using Western blotting analysis for HIF‐lα, GRP78 and VEGF164 . The expressions of VEGFR‐2 and CD105 were observed by using immunohistochemical staining .Results The protein level of HIF‐1αwas significantly increased in HPS group at week 8 compared with that at week 4 and 6 groups and corresponding normal control groups .With the development of HPS ,protein level of GRP78 was gradually increased at each time point significantly and reached the highest level at week 8 ;protein level of VEGF164 showed a similar change with GRP78 ,but the peak was at week 6 .Immunohistochemical results showed that the protein expressions of VEGFR‐2 and CD105 were gradually increased in lung tissue as HPS progressed .The protein level of GRP78 was positively correlated with HIF‐1α,VEGF164 ,VEGFR‐2 and CD105 ,respectively (P<0 .05) .Conclusion HIF‐1αis most likely together with GRP78 to play a critical role in promoting pulmonary microvascular remodeling in the pathogenesis of HPS in rats .
10.The anti-neuroinflammatory effects of dehydromiltirone and related mechanisms
Dechuan LI ; Xiuqi BAO ; Dewu ZHANG ; Hua SUN ; Jungui DAI ; Dan ZHANG
Chinese Pharmacological Bulletin 2016;(2):177-183
Aim To investigate the anti-neuroinflam-matory activities of dehydromiltirone and the underlying mechanisms in LPS-stimulated microglial cell line BV2 cells. Methods BV2 cells were pre-treated with de-hydromiltirone, then stimulated by LPS. The levels of nitric oxide( NO) were measured by Griess assay, and the concentrations of pro-inflammatory cytokines were measured by ELISA assay. Confocal fluorescence mi-croscopy was used to measure the expression of MAC-1, the biomarker of activated BV2 cells. The levels of-inducible nitric oxide synthase ( iNOS ) , cyclooxygen-ase-2 ( COX-2 ) , NF-κB and PI3 K/Akt were deter-mined by Western blot analysis. Results The treat-ment of dehydromiltirone significantly inhibited the pro-duction of NO, TNF-α and IL-6, attenuated the ex-pression of iNOS and COX-2 protein, and dampened the microglial activation in LPS-stimulated BV2 cells. The mechanistic study revealed that dehydromiltirone inhibited the phosphorylation of PI3 K and Akt in LPS-stimulated BV2 cells, and decreased NF-κB activation by suppressing the degradation of IκB. Conclusion dehydromiltirone shows significant anti-neuroinflamma-tory effects through inhibiting PI3 K/Akt phosphoryla-tion and then inhibiting NF-κB signaling pathway.

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