[Professor YANG Ji-guo's experience in treatment of functional gastrointestinal diseases with acupuncture combined with umbilicus moxibustion].

Professor YANG Ji-guo's clinical experience in treatment of functional gastrointestinal diseases was summerized. Professor YANG Ji-guo believes that this disease is caused by the deficiency of six fu organs. Dysfunction of six fu organs in descending transportation is the basic pathogenesis. The principle of acupoint selection includes benefiting gastrointestinal functions, unblocking and purging six fu, soothing liver qi and calming down the mind. In treatment, acupuncture is combined with umbilicus moxibustion. In acupuncture, the deqi promoting technique by rotating and trembling needle is adopted. Focusing on the deficiency of six fu organs, umbilicus moxibustion is adopted to benefit the spleen and stomach and harmonize the functions of six fu organs for both biao (symptoms) and ben (root cause).

[Exploration of the Suitable Culture Conditions for Extracellular Microvesicles Derived from Human Mesenchymal Stem Cells].

OBJECTIVE: To explore the appropriate procedures for preparing extracellular microvesicles (MV) derived from human mesenchymal stem cells (MSC). METHODS: Human MSCs from umbilical cords were cultured in a serum-free medium and maintained in a basal medium for 72 hours after the cell confluence reached to 80%. The supernatants of cultured cells were collected and MVs were enriched. MVs were identified by flow cytometry and electron microscopy. The total protein amount in MVs was used as a parameter for the content of MVs. The supernatants were adjusted to different pH values, and the output of MVs was detected. The supernatants were also collected for enriching the MV and detecting the protein content of MV after the cells were maintained in the basic medium for different time. RESULTS: Flow cytometric analysis showed that the MVs expressed CD9, CD63 and CD81, morphologically presented round under an electron microscope and the diameter of MV was around 100 nm. After enrichment of MV, the protein content of MVs in the supernatants was 416.8±128.1, 255.4±77.9 and 142.8±46.4 µg per 107 MSC，respectively at pH of supernatant 3, 7 and 9 (P＜0.05). The protein content of the supernatants per 107 MSC was 173.6±44.5, 262.4±49.6 and 364.2±37.8 µg respectively after starvation culture for 48, 72 and 96 hrs (P＜0.05). CONCLUSION: MVs can be readily collected after MSCs were starved for 96 hours, and the pH of the supernatants is adjusted at 3.0.

[Progesterone Promotes Human Bone Marrow Mesenchymal Stem Cells to Synthesize Fibronectin via ERK Pathway].

OBJECTIVE: To investigate whether the progesterone can promote fibronection (FN) synthesis by human bone marrow mesenchymal stem cells (MSCs) and to explore the potential underlying mechanism. METHODS: The human bone marrow MSCs were cultured in a serum-free medium with progesterone for 72 hours, the MTT test was performed to observe the proliferation status and adhension ability of the treated cells. Western blot was used to detect the content of FN in MSDs with GAPDH as the internal reference, the phosphorylation of ERK1/2, as well as the FN content in MSC treated by PD98059, a specific inhibitor of ERK1/2. RESULTS: The progesterone at a range of certain doses not effect on the proliferation of human bone marrow MSCs. Progesterone (25 µg/L) treatment enhanced the FN expression and adherent ability of marrow MSCs. Progesterone could induce prompt phosphorylation of ERK 1/2 and its promoting effects on FN synthesis was reversed by PD98059. CONCLUSION: The progesterone can promote FN synthesis by human bone marrow MSCs via ERK 1/2 pathway, and it might be used to culture MSCs in serum-free medium.

[Putrescine Promotes Human Marrow Mesenchymal Stem Cells to Differentiate along Osteogenic Pathway].

OBJECTIVE: To investigate the effects of putrescine on the growth and differentiation of human bone marrow mesenchymal stem cells (MSC) to develop a new inductive medium mixture for their osteogenic differentiation. METHODS: Human bone marrow MSC were collected from three healthy donors and were used to observe the growth-promoting activity of putrescine with MTT test. Experiments were divided into 3 groups: (1) putrescine group, (2) positive control group (presence of dexamethasone, ascorbate, and glycerol phosphate) and negative group (d-alpha with 5% FCS). The cellular expression level of Runx-2 was detected by PCR assay after the culture was maintained for 1 week. After 2 weeks, the intracellular activity of alkaline phosphatase was revealed by histochemistry staining, the phosphatase activity, and the protein concentration in the cell lysates were also detected. Furthermore, MSC were cultured in the presence of putrescine for 2 weeks and Oil-red O staining was performed to reveal the differentiated adipocytes; the cells induced by the standard agent cocktail were used as the positive control. RESULTS: Putrescine promoted the proliferation of human marrow MSC in a dose-dependent manner. MSC exposed to putrescine at a concentration of 100 µmol/L for 1 week expressed greatly higher level of Runx-2, compared with the negative control. Alkaline phosphatase activity was evidently observed after MSC were maintained in the presence of putrescine for 2 weeks. The phosphatase activity contrasted to the protein content in putrescine-treated MSC was significantly higher than that of the control cells (0.87±0.012 vs 0.52±0.010) (P<0.01), and also greatly higher than that of the positive control (0.83±0.029) (P=0.02). Oil red O staining showed that MSC treated by putrescine did not differentiate into adipoblasts. CONCLUSION: Putrescine can promote the proliferation and osteogenic differentiation of MSC, suggesting the potential application of putrescine as a novel inductive agent for in vitro osteogenesis of MSC.

[Slowly-adhered primary bone marrow mesenchymal stem cells may exhibit more potent immuno-regulatory activity].

OBJECTIVE: This study was to investigate the relationship between the adherent ability of freshly isolated MSCs with their inhibitory effect on lymphocyte activation. METHODS: Human bone marrow mononucleated cells were maintained in culture for 48 hours, the attached and the non-attached cells were then cultured separately and the adherent cells were collected and passaged. Cellular surface markers were analyzed with flow cytometry. Alkaline phosphatase activity and the intracellular lipid droplets were measured by histological staining, the in vitro osteogenesis and adipogenesis were identified. One-way mixed lymphocyte reaction was used to evaluate the suppressive activity of the adherent cells on lymphocyte proliferation, the prostaglandin E2 level in supernatant of cultured cells was detected by ELISA. RESULTS: Some cells attached to the plastic after the bone marrow mononucleated cells were allowed to adhere for 48 hours. The slowly-attached cells were fibroblast-like in morphology, homogenously positive for CD44 and CD73 and negative for CD31 and CD45. They could be coaxed into osteoblasts and adipoblasts under the standard inductive conditions. These cells were able to inhibit lymphocyte proliferation in mixed lymphocyte reaction and their effect was more potent than those from the adherent cells appeared within 48 hours. The concentration of prostaglandin E-2 in the supernatants of the slowly-adhered cells was significantly higher than that in the MSCs cultured with the traditional method (90.8 ± 10.37 ng/ml vs 70.2 ± 8.98 ng/ml) (P < 0.01). CONCLUSIONS: The MSCs exist in the marrow mononucleated cells after adherent culture for 48 hours, and the MSCs may exhibit more potently inhibitory activity on lymphocyte activation.

[Exploration of conditions for releasing microvesicle from human bone marrow mesenchymal stem cells].

The release of microvesicles(MV) is one of the critical mechanisms underlying the angiogenesis-promoting activity of mesenchymal stem cells(MSC). This study was aimed to explore the appropriate condition under which MSC releases MV. Bone marrow samples from 5 healthy adults were collected, and MSC were isolated, culture-expanded and identified. MSC at passage 5 were suspended in medium without or medium with 10% fetal(FCS) calf serum and seeded into culture dishes. The culture was separately maintained in hypoxia (1% oxygen) or normoxia (around 20% oxygen), and 20 dishes of cells (2×10(6)/dish) were used for each group. The supernatants were collected for MV harvesting. The cell number was counted with trypan blue exclusion test and the protein contents in the MV were determined. MV were identified by observation under an electron microscope. The surface markers on MV were analyzed by flow cytometry. MTT test was performed to observe the pro-proliferative activity of MV that were added into the culture of human umbilical cord vein endothelial cells at a concentration of 10 µg/ml. The results showed that the majority of MV released by MSC were with diameters of less than 100 nm, and MV took the featured membrane-like structure with a hypodense center. They expressed CD29, CD44, CD73 and CD105, while they were negative for CD31 and CD45. The increase multiples of the adherent trypan blue-resistant cells cultured in normoxia with serum, in normoxia without serum, in hypoxia with serum and hypoxia in the absence of serum were 4.05 ± 0.73, 1.77 ± 0.48, 5.80 ± 0.65 and 3.69 ± 0.85 respectively, and the estimated protein contents per 10(8) cells were 463.48 ± 138.74 µg, 1604.07 ± 445.28 µg, 2389.64 ± 476.75 µg and 3141.18 ± 353.01 µg. MTT test showed that MV collected from MSC in hypoxia seemed to promote the growth of endothelial cells more efficiently than those from cells in normoxia. It is concluded that hypoxia can enhance the release of microvesicles from MSC, and cultivation of MSC in hypoxia and medium without serum may provide an appropriate condition for MV harvesting.

Microvesicles derived from human umbilical cord mesenchymal stem cells stimulated by hypoxia promote angiogenesis both in vitro and in vivo.

Although mesenchymal stem cells (MSCs) have been increasingly trialed to treat a variety of diseases, the underlying mechanisms remain still elusive. In this study, human umbilical cord (UC)-derived MSCs were stimulated by hypoxia, and the membrane microvesicles (MVs) in the supernatants were collected by ultracentrifugation, observed under an electron microscope, and the origin was identified with the flow cytometric technique. The results showed that upon hypoxic stimulus, MSCs released a large quantity of MVs of ~100 nm in diameter. The MVs were phenotypically similar to the parent MSCs, except that the majority of them were negative for the receptor of platelet-derived growth factor. DiI-labeling assay revealed that MSC-MVs could be internalized into human UC endothelial cells (UC-ECs) within 8 h after they were added into the culture medium. Carboxyfluorescein succinimidyl ester-labeling technique and MTT test showed that MSC-MVs promoted the proliferation of UC-ECs in a dose-dependent manner. Further, MVs could enhance in vitro capillary network formation of UC-ECs in a Matrigel matrix. In a rat hindlimb ischemia model, both MSCs and MSC-MVs were shown to improve significantly the blood flow recovery compared with the control medium (P<0.0001), as assessed by laser Doppler imaging analysis. These data indicate that MV releasing is one of the major mechanisms underlying the effectiveness of MSC therapy by promoting angiogenesis.