The Crosstalk between Intestinal Epithelial Cells and Mast Cells Is Modulated by the Probiotic Supplementation in Co-Culture Models.

The intestinal epithelium constitutes a selectively permeable barrier between the internal and external environment that allows the absorption of nutrients, electrolytes, and water, as well as an effective defense against intraluminal bacteria, toxins, and potentially antigenic material. Experimental evidence suggest that intestinal inflammation is critically dependent on an imbalance of homeostasis between the gut microbiota and the mucosal immune system. In this context, mast cells play a crucial role. The intake of specific probiotic strains can prevent the development of gut inflammatory markers and activation of the immune system. Here, the effect of a probiotic formulation containing L. rhamnosus LR 32, B. lactis BL04, and B. longum BB 536 on intestinal epithelial cells and mast cells was investigated. To mimic the natural host compartmentalization, Transwell co-culture models were set up. Co-cultures of intestinal epithelial cells interfaced with the human mast cell line HMC-1.2 in the basolateral chamber were challenged with lipopolysaccharide (LPS), and then treated with probiotics. In the HT29/HMC-1.2 co-culture, the probiotic formulation was able to counteract the LPS-induced release of interleukin 6 from HMC-1.2, and was effective in preserving the epithelial barrier integrity in the HT29/Caco-2/ HMC-1.2 co-culture. The results suggest the potential therapeutic effect of the probiotic formulation.

A Set of Dysregulated Target Genes to Reduce Neuroinflammation at Molecular Level.

Increasing evidence links chronic neurodegenerative diseases with neuroinflammation; it is known that neuroprotective agents are capable of modulating the inflammatory processes, that occur with the onset of neurodegeneration pathologies. Here, with the intention of providing a means for active compounds' screening, a dysregulation of neuronal inflammatory marker genes was induced and subjected to neuroprotective active principles, with the aim of selecting a set of inflammatory marker genes linked to neurodegenerative diseases. Considering the important role of microglia in neurodegeneration, a murine co-culture of hippocampal cells and inflamed microglia cells was set up. The evaluation of differentially expressed genes and subsequent in silico analysis showed the main dysregulated genes in both cells and the principal inflammatory processes involved in the model. Among the identified genes, a well-defined set was chosen, selecting those in which a role in human neurodegenerative progression in vivo was already defined in literature, matched with the rate of prediction derived from the Principal Component Analysis (PCA) of in vitro treatment-affected genes variation. The obtained panel of dysregulated target genes, including Cxcl9 (Chemokine (C-X-C motif) ligand 9), C4b (Complement Component 4B), Stc1 (Stanniocalcin 1), Abcb1a (ATP Binding Cassette Subfamily B Member 1), Hp (Haptoglobin) and Adm (Adrenomedullin), can be considered an in vitro tool to select old and new active compounds directed to neuroinflammation.

Physiological oxygen and co-culture with human fibroblasts facilitate in vivo-like properties in human renal proximal tubular epithelial cells.

Reliable prediction of compound mediated nephrotoxicity in humans is still unsatisfactory irrespective of the recent advancements in in silico, in vitro and in vivo models. Therefore, current in vitro approaches need refinement to better match the human in vivo situation, specifically with regard to the potential influence of other cell types (e.g. fibroblasts) and to the potential biases introduced by the excessive 21% O2 (AtmOx) as employed in routine cell culturing. We used a transwell co-culture model combining human renal proximal tubule epithelial cells (RPTEC/TERT1) and human fibroblasts (fHDF/TERT166) to compare the functional properties and expression of selected marker proteins at 21% O2 and at the physiologically normal 10% O2 tension (PhysOx) commensurate with in vivo conditions. Culturing at PhysOx and co-culturing with fibroblasts significantly improved epithelial barrier integrity, expression of transporters (e.g. aquaporin 2; OCT-MATE; MRP-OAT) and metabolism. Moreover, beyond culturing these human cells in co-culture for up to 41 days, we were able to demonstrate increased functionality of cation transport, as shown via ASP+ (OCT-MATE axis), and anion transport, as shown via LY (MRP-OAT axis). Thus, adjusting the in vitro system to near physiological conditions had a major impact on functionality and provides the basis for the future development of true flow-through microfluidic renal testing systems with better predictability of human renal proximal toxicity.

Co-cultured bone marrow mesenchymal stem cells repair thioacetamide-induced hepatocyte damage.

Adult stem cells, such as bone marrow mesenchymal stem cells (BMSCs), are postdevelopmental cells found in many bone tissues. They are capable of multipotent differentiation and have low immune-rejection characteristics. Hepatocytes may become inflamed and produce a large number of free radicals when affected by drugs, poisoning, or a viral infection. The excessive accumulation of free radicals in the extracellular matrix (ECM) eventually leads to liver fibrosis. This study aims to investigate the restorative effects of mouse bone marrow mesenchymal stem cells (mBMSCs) on thioacetamide (TAA)-induced damage in hepatocytes. An in vitro transwell co-culture system of HepG2 cells were co-cultured with mBMSCs. The effects of damage done to TAA-treated HepG2 cells were reflected in the overall cell survival, the expression of antioxidants (SOD1, GPX1, and CAT), the ECM (COL1A1 and MMP9), antiapoptosis characteristics (BCL2), and inflammation (TNF) genes. The majority of the damage done to HepG2 by TAA was significantly reduced when cells were co-cultured with mBMSCs. The signal transducer and activator of transcription 3 (STAT3) and its phosphorylated STAT3 (p-STAT3), as related to cell growth and survival, were detected in this study. The results show that STAT3 was significantly decreased in the TAA-treated HepG2 cells, but the STAT3 and p-STAT3 of HepG2 cells were significantly activated when the TAA-treated HepG2 co-cultured with mBMSCs. Strong expression of interleukin (Il6) messenger RNA in co-cultured mBMSCs/HepG2 indicated mBMSCs secret the cytokines IL-6, which promotes cell survival through downstream STAT3 activation and aid in the recovery of HepG2 cells damaged by TAA.

miR-200c/PAI-2 promotes the progression of triple negative breast cancer via M1/M2 polarization induction of macrophage.

PURPOSE: To investigate the effect of miR-200c/PAI-2 on macrophage polarization into M2-type TAMs in TNBC. METHODS AND MATERIALS: PAI-2 expression in MDA-MB-231con, MDA-MB-231miR-200ab and MDA-MB-231miR-200c breast cancer cells was evaluated by RT-PCR and immunofluorescence (IF), while the expression of the TAM marker F4/80 and the M2-type TAM marker CD206 in MDA-MB-231con, MDA-MB-231miR-200c and MDA-MB-231miR-200c/siPAI-2 mouse lung metastatic tumor tissues was examined with immunohistochemistry (IHC). The effects of RAW264.7 cells on MDA-MB-231con, MDA-MB-231miR-200c and MDA-MB-231miR-200c/siPAI-2 were examined by transwell co-culture. CD206 expression in RAW264.7 cells were confirmed by immunostaining. The level of PAI-2 and IL-10 in the co-culture supernatants were assessed using ELISA. RESULTS: 1. RT-PCR and IF analysis showed that PAI-2 was upregulated in MDA-MB-231miR-200c cells. 2. IHC assays analysis showed that the numbers of F4/80 and CD206 positive cells were increased in MDA-MB-231miR-200c tumor tissues, while in MDA-MB-231miR-200c/siPAI-2 tumor tissues were decreased. 3. Transwell co-culture assays analysis showed that MDA-MB-231miR-200c cells significantly promoted the cell migration ability compared with the control group, while knockdown PAI-2 significantly inhibited the cell migration ability (P < 0.05). 4. Transwell co-culture and immunostaining assays analysis showed that overexpression miR-200c in MDA-MB-231 cell line increased the CD206 expression in RAW264.7 cells, while knockdown PAI-2 decreased. 5. ELISA assays analysis showed that miR-200c-mediated MDA-MB-231 cells significantly increased the secretion of PAI-2 and IL-10, while decreased the secretion of PAI-2 and IL-10 in MDA-MB-231 miR-200c/siPAI-2 cells. CONCLUSIONS: miR-200c promotes the malignant progressions of TNBC by PAI-2 upregulation and M2 phenotype macrophages polarization.

Development of a two-layer transwell co-culture model for the in vitro investigation of pyrrolizidine alkaloid-induced hepatic sinusoidal damage.

Pyrrolizidine alkaloids (PAs) are hepatotoxic and specifically damage hepatic sinusoidal endothelial cells (HSECs) via cytochrome P450 enzymes (CYPs)-mediated metabolic activation. Due to the lack of CYPs in HSECs, currently there is no suitable cell model for investigating PA-induced HSEC injury. This study aimed to establish a two-layer transwell co-culture model that mimics hepatic environment by including HepaRG hepatocytes and HSECs to evaluate cytotoxicity of PAs on their major target HSECs. In this model, PAs were metabolically activated by CYPs in HepaRG hepatocytes to generate reactive pyrrolic metabolites, which react with co-cultured HSECs leading to HSEC damage. Three representative PAs, namely retrorsine, monocrotaline, and clivorine, induced significant concentration-dependent cytotoxicity in HSECs in the co-culture model, but did no cause obvious cytotoxicity directly in HSECs. Using the developed co-cultured model, further mechanism studies of retrorsine-induced HSEC damage demonstrated that the reactive pyrrolic metabolite generated by CYP-mediated bioactivation in HepaRG hepatocytes caused formation of pyrrole-protein adducts, reduction of GSH content, and generation of reactive oxygen species in HSECs, leading to cell apoptosis. The established co-culture model is reliable and applicable for cytotoxic assessment of PA-induced HSEC damage and offers a novel platform for screening toxicity of different PAs on their target cells.

Biological features of tumor associated fibroblasts and effect of Transwell co-culture on proliferation and metastasis of gastric cancer cells / 中国药理学通报

; Aim To culture primary human gastric cancer associated fibroblasts (CAFs) and normal fibroblasts (NFs), and to explore the biological characteristics and their effects on gastric cancer cells. Methods After isolation and culture of CAFs and NFs, growth curve was drawn by MTT. The a-smooth muscle actin (ot-SMA) and Vimentin were detected by Immunofluorescence, Western blot and qRT-PCR. MGC-803 cells were co-cultured with CAFs and NFs in Transwell suspension mode. The migration and invasion ability of gastric cancer cells was detected by Transwell. The proliferation activity and AMD3100 on CAFs-gastric cancer co-culture system were compared by MTT. The acidic property, lactic acid and ROS contents of co-culture system were determined by PH meter, lactic acid and DCFH-DA method. Results The morphology of CAFs, NFs cells were in long spindle or flat star shape. The proliferation ability and overlapping growth phenomenon of CAFs were higher than those of NFs. The expression of ct-SMA and Vimentin cells was positive in CAFs, but low or negative in NFs cells. The activity of gastric cancer in low density co-culture group > medium density group > high density group, the PH value of CAFs co-culture system decreased, the content of lactic acid and ROS was high, and only CAFs low density co-culture group had significant effect on promoting cancer. Conclusions The co-culture of gastric cancer cells with CAFs and NFs is greatly affected by the proportion. Low density co-culture can significantly improve the proliferation and metastasis ability of gastric cancer cells. High density co-culture may in turn inhibit the growth and metastasis of cancer cells, which may be related to the content of lactic acid and ROS.

Effects of transplanted adipose derived stem cells on the expressions of α-SMA and DCN in fibroblasts of hypertrophic scar tissues in rabbit ears.

To study the effects of transplanted adipose derived stem cells (ADSCs) on the expressions of α-smooth muscle actin (α-SMA) and decorin (DCN) in fibroblasts of hypertrophic scar tissues in rabbit ears. Twelve New Zealand white rabbits were selected; the normal subcutaneous adipose tissues in inguinal region were removed, ADSCs were extracted via enzyme digestion, cultured in Dulbecco's modified Eagle's medium (DMEM) and inoculated into the culture dish (3-5×104 cells/ml). After the rabbit ear hypertrophic scar model was established successfully, the fibroblasts of hypertrophic scar tissues in rabbit ears were separated and cultured using the mechanical method combined with enzyme digestion, and the ADSCs and scar fibroblasts were cultured in non-contact Transwell co-culture system for 21 days (experimental group); the corresponding scar fibroblasts were cultured in an ordinary 6-well plate without any treatment for 21 days (control group). The content of collagen I in fibroblasts was detected using the enzyme-linked immunosorbent assay (ELISA) kit, the mRNA expressions of α-SMA and DCN were detected via reverse transcription-polymerase chain reaction (RT-PCR), the protein expressions of α-SMA and DCN were detected via western blot analysis, and the expressions and distribution of α-SMA and DCN were detected via immunofluorescence assay. The results of ELISA showed that the content of collagen I in experimental group was decreased significantly (p<0.01). The results of RT-PCR and western blot analysis revealed that the mRNA and protein expression levels of α-SMA were significantly decreased (P<0.01, but those of DCN were significantly increased (p<0.01). Moreover, the results of immunofluorescence assay showed that the expression of α-SMA in experimental group was significantly decreased, while the expression of DCN was significantly increased. ADSCs can inhibit the mRNA and protein expressions of α-SMA and promote the mRNA and protein expressions of DCN in in vitro culture system, and they are expected to be used in the prevention and treatment of pathological scars.

Molecular influence of anterior cruciate ligament tear remnants on chondrocytes: a biologic connection between injury and osteoarthritis.

OBJECTIVE: Anterior cruciate ligament (ACL) injury initiates a cascade of events often leading to osteoarthritis (OA). ACL reconstruction does not alter the course of OA, suggesting that heightened OA risk is likely due to factors in addition to the joint instability. We showed that torn ACL remnants express periostin (POSTN) in the acute phase of injury. Considering that ACL injury predisposes to OA and that POSTN is associated with cartilage metabolism, we hypothesize that ACL injury affects chondrocytes via POSTN. DESIGN: Cartilage was obtained from osteoarthritic patients and ACL remnants were collected from patients undergoing ACL reconstruction. Crosstalk between ACL remnants and chondrocytes was studied in a transwell co-culture system. Expression of POSTN and other anabolic and catabolic genes was assessed via real-time polymerase chain reaction (PCR). Immunostaining for periostin was performed in human and mouse cartilage. The impact of exogenous periostin and siRNA-mediated ablation of periostin on matrix metabolism and cell migration was examined. Furthermore, the effect of anabolic (transforming growth factor beta 1 [TGF-ß1]) and catabolic (interleukin 1 beta [IL-1ß]) factors on POSTN expression was investigated. RESULTS: ACL remnants induced expression of POSTN, MMP13 and ADAMTS4. Periostin levels were significantly higher in osteoarthritic compared to normal cartilage. Exogenous periostin induced MMP13 expression and cell migration, and repressed COL1A1 expression while POSTN knockdown inhibited expression of both anabolic and catabolic genes and impeded cell migration. TGF-ß1 and IL-1ß treatment did not alter POSTN expression but influenced chondrocyte metabolism as determined by quantification of anabolic and catabolic genes via real-time PCR. CONCLUSIONS: ACL remnants can exert paracrine effects on cartilage, altering cellular homeostasis. Over time, this metabolic imbalance could contribute to OA development.

Effect of oxygen glucose deprivation-reperfusion in astrocytes overexpressing endothelin-1 on the proliferation of neural stem/progenitor cells / 器官移植

Objective To investigate the effect of oxygen glucose deprivation-reperfusion (OGD-R) in astrocytes overexpressing endothelin (ET)-1 on the proliferation of neural stem/progenitor cells (NSPCs). Methods OGD-R models of negative control astrocytes (C6-Mock) and astrocytes over-expressing ET-1 (C6-ET-1) were constructed. Transwell co-culture system of astrocytes and NSPCs was established. Morphologic observation and identification of the astrocytes and primary NSPCs were performed. The cells were divided into four groups: C6-Mock+NSPCs, OGD-R+C6-Mock+NSPCs, C6-ET-1+NSPCs and OGD-R+C6-ET-1+NSPCs groups and co-cultured for 0, 24, 48 and 72 h respectively. The diameter of neurosphere was measured in each group. Results In the C6-Mock and C6-ET-1 cells, type Ⅰ astrocytes in fibrous morphology were observed. Glial fibrillary acidic protein (GFAP) was expressed in the cytoplasm of these two types of cells. Primary NSPCs were positive for nestin staining. After co-culture for 48 and 72 h, the neurosphere diameter in the OGD-R+C6-Mock+NSPCs group was significantly greater than that in the C6-Mock+NSPCs group. The neurosphere diameter in the OGD-R+C6-ET-1+NSPCs group was considerably greater than that in the C6-ET-1+NSPCs group. The neurosphere diameter in the OGD-R+C6-ET-1+NSPCs group was significantly greater compared with that in the OGD-R+C6-Mock+NSPCs group (all P<0.05). Conclusions OGD-R astrocytes can promote the proliferation of NSPCs. ET-1 over-expression further accelerates the proliferation of NSPCs.

An in vitro investigation of immunomodulatory properties of Lactobacillus plantarum and L. delbrueckii cells and their extracellular polysaccharides.

Many probiotic lactobacilli and their extracellular polysaccharides (EPS) have beneficial immunological properties. However, it is unclear how they elicit the host immune response. We thus investigated the immunological properties of UV-killed Lactobacillus delbrueckii TU-1 and L. plantarum KM-9 cells as well as their extracellular polysaccharides (EPSs). High-performance liquid chromatography and ion exchange chromatography analyses showed that their EPSs differ in sugar composition and sugar fractionation. The immunological properties were evaluated in a semi-intestinal model using a Transwell co-culture system that employed human intestinal epithelial (Caco-2) cells on the apical side and murine macrophage (RAW264.7) cells on the basolateral side. The UV-killed cells and EPSs were added to the apical side to allow direct contact with Caco-2 cells and incubated for 6 hr. After incubation, the amounts of tumor necrosis factor-α and several cytokines released by RAW264.7 or Caco-2 cells were quantified by cytotoxic activity on L929 cells (murine fibrosarcoma cell line) and quantitative reverse-transcriptase PCR. We found that the UV-killed cells and their EPSs had immunological effects on RAW264.7 cells via Caco-2 cells. The RAW264.7 cells showed different cytokine production profiles when treated with UV-killed cells and EPSs. The UV-killed cells and EPSs promoted a Th1-type cellular response. Furthermore, we found that the UV-killed cells sent positive signals through Toll-like receptor (TLR) 2. Meanwhile, neither EPS sent a positive signal through TLR4 and TLR2. This evidence suggests that both UV-killed cells of the lactobacillus strains and their EPSs trigger a Th1-type immune response in a human host, with the former triggering the response via the TLRs expressed on its epithelium and the latter employing a mechanism yet to be determined, possibly involving a novel receptor that is designed to recognize specific patterns of repeating sugar in the EPSs.

The role of gut microbiota in health and disease: In vitro modeling of host-microbe interactions at the aerobe-anaerobe interphase of the human gut.

The microbiota of the gut has many crucial functions in human health. Dysbiosis of the microbiota has been correlated to a large and still increasing number of diseases. Recent studies have mostly focused on analyzing the associations between disease and an aberrant microbiota composition. Functional studies using (in vitro) gut models are required to investigate the precise interactions that occur between specific bacteria (or bacterial mixtures) and gut epithelial cells. As most gut bacteria are obligate or facultative anaerobes, studying their effect on oxygen-requiring human gut epithelial cells is technically challenging. Still, several (anaerobic) bacterial-epithelial co-culture systems have recently been developed that mimic host-microbe interactions occurring in the human gut, including 1) the Transwell "apical anaerobic model of the intestinal epithelial barrier", 2) the Host-Microbiota Interaction (HMI) module, 3) the "Human oxygen-Bacteria anaerobic" (HoxBan) system, 4) the human gut-on-a-chip and 5) the HuMiX model. This review discusses the role of gut microbiota in health and disease and gives an overview of the characteristics and applications of these novel host-microbe co-culture systems.

Synthesis, selective cytotoxicities and probable mechanism of action of 7-methoxy-3-arylflavone-8-acetic acids.

Thirteen new analogues of flavone-8-acetic acid, that is, compounds 10a-m bearing a methoxy group at the 7-position and diverse subsitiuents on the benzene ring at the 2- and 3-positions of flavone nucleus, were synthesized and evaluated for their direct antiproliferative effects on two human tumor cell lines and for their indirect antiproliferative activities in the transwell co-culture system. The results indicated that most of compounds 10a-m showed moderate direct cytotoxicities. Among them, compound 10i exhibited higher direct cytotoxicity and selectivity for both cell lines over BJ human foreskin fibroblast cells than 5,6-dimethylxanthenone-4-acetic acid (DMXAA). Interestingly, compared with DMXAA, compound 10e showed comparable indirect cytotoxicity and higher selectivity. In addition, compound 10e was found to be able to induce tumor necrosis factor α (TNF-α) production in human peripheral blood mononuclear cells.

Overexpression of vasostatin-1 protects hypoxia/reoxygenation injuries in cardiomyocytes-endothelial cells transwell co-culture system.

Vasostatin-1 (VS-1) plays important roles in myocardial ischemia/reperfusion injury. We have explored the protective effects of VS-1 on cardiomyocytes using cardiomyocyte-endothelial cells Transwell Co-culture System. Cardiomyocytes and rat aortic endothelial cells (RAECs) were prepared from ventricles and thoraco-abdominal aorta of Sprague-Dawley rats. The experiment used cardiomyocytes alone culture group (C) and cardiomyocytes-RAECs co-culture group (T), each with three subgroups: C-Ad-Null, C-Ad-VS-1, C-Hb (Ad-VS-1 + NO scavenger Hb), or T-Ad-Null, T-Ad-VS-1 transfection, T-Hb. After 48 h incubation, all groups were treated with hypoxia for 60 min and then reoxygenated for 120 min. We also investigated endothelial cells-mediated cardiomyocytes protection. RAECs were treated with hypoxia for 30 min and reoxygenated with normal cardiomyocytes for 120 min. The cardiomyocytes apoptosis rate, aspartate aminotransferase (AST) and creatine kinase isozyme MB (CK-MB) were recorded. As expected, cardiomyocytes apoptosis, AST and CK-MB were significantly increased in the T-Ad-Null group than in the C-Ad-Null group. VS transfection significantly reduced these levels. However, apoptosis, AST and CK-MB levels were increased again after Hb treatment, returning to the similar level of the C-Ad-null group in the C-Hb group, but still significantly lower in the T-Hb group compared with the T-Ad-null group. RAEC injury caused cardiomyocyte injury, and VS-1 transfection of the RAEC decreased apoptosis and the levels of AST and CK-MB. The findings suggest that VS-1 exerts protective effects on the cardiomyocytes directly or indirectly by cardiomyocyte-endothelial cells interaction.