Bushen Jianpi Jiedu Liyan Formula Regulates Homing-associated Cell Adhesion Molecules in Rat Model of IgA Nephropathy / 中国实验方剂学杂志

ObjectiveTo investigate the effect of Bushen Jianpi Jiedu Liyan formula on the expression of integrin alpha 4 beta 1 （α4 β1）， vascular cell adhesion molecule-1 （VCAM-1）， stromal-derived factor-1 （SDF-1）， and chemokine receptor-4 （CXCR4） in the small intestine and bone marrow of the rat model of immunoglobulin A（IgA） nephropathy. MethodA total of 120 male SD rats were used to establish the IgA nephropathy model by intragastric administration of bovine serum albumin （BSA）， subcutaneous injection of CCl4， and tail vein injection of lipopolysaccharide （LPS）. The successfully modeled rats were randomized into blank， model， lotensin （63 mg·kg-1）， and low-， medium-， and high-dose （10.4， 20.81， 41.62 g·kg-1， respectively） Bushen Jianpi Jiedu Liyan formula groups （n=16）. The rats were treated with corresponding drugs according to their body weight. After 7 weeks of administration， the rats were sacrificed for the collection of samples， and the protein and mRNA levels of α4 β1， VCAM-1， SDF-1， and CXCR4 in the small intestine and bone marrow were determined by immunohistochemistry and real-time fluorescence quantitative polymerase chain reaction， respectively. ResultCompared with the blank group， the model group showed increased red blood cell count in the urine at the 10th， 12th， 14th， 16th weeks （P<0.01）， and such increases were reduced in the drug intervention groups （P<0.05）， especially in the medium-dose Bushen Jianpi Jiedu Liyan formula group （P<0.05）. Compared with those in the blank group， the protein levels of α4 β1， VCAM-1， SDF-1， and CXCR4 in the intestinal lamina propria in the model group were up-regulated （P<0.05）， and such un-regulations were inhibited in the drug intervention groups （P<0.05）. Compared with the model group， medium-dose Bushen Jianpi Jiedu Liyan formula down-regulated the protein levels of SDF-1 and CXCR4 in the intestinal lamina propria （P<0.05）. Compared with the blank group， the model group showed down-regulated mRNA levels of α4 β1 and SDF-1 and up-regulated mRNA levels of VCAM-1 and CXCR4 （P<0.05）. Compared with the model group， the drug intervention groups showed down-regulated mRNA levels of SDF-1 and CXCR4 （P<0.05）. ConclusionBushen Jianpi Jiedu Liyan formula regulates the expression of α4 β1， VCAM-1， SDF-1， and CXCR4 in the intestinal lamina propria to inhibit the homing effect of plasma cells， which may be associated with the Toll-like receptor-mediated activation of immune response. Bushen Jianpi Jiedu Liyan formula can down-regulate the expression of adhesion molecules to inhibit the proliferation of plasmocytes in circulation， so as to reduce the renal injury of IgA nephropathy.

The Antagonism of Neuropeptide Y Type I Receptor (Y1R) Reserves the Viability of Bone Marrow Stromal Cells in the Milieu of Osteonecrosis of Femoral Head (ONFH).

Neuropeptide Y (NPY)-Y1 receptor (Y1R) signaling is known to negatively affect bone anabolism. Our study aimed at investigating the impact of NPY-Y1R signaling in the pathogenesis of glucocorticoid-related osteonecrosis of the femoral head (ONFH). Femoral heads were retrieved from 20 patients with and without ONFH, respectively. The bone marrow stromal cells (BMSCs) from ONFH femoral heads were treated with Y1R agonists and antagonists for subsequent analysis. We showed that the local NPY expression level was lower in ONFH heads. The Y1R agonists and antagonists disturb and facilitate the survival of BMSCs. The transcription of stromal derived factor-1 (SDF-1) was enhanced by Y1R antagonists. Our study showed that the local NPY expression level was lower in ONFH heads. Y1R antagonists facilitate the survival of BMSCs and stimulate the transcription of SDF-1 by BMSCs. These findings shed light on the role of NPY-Y1R signaling in the pathogenesis of ONFH.

SDF-1 induces TNF-mediated apoptosis in cardiac myocytes.

Chemokines are small secreted proteins with chemoattractant properties that play a key role in inflammation. One such chemokine, Stromal cell-derived factor-1 (SDF-1) also known as CXCL12, and its receptor, CXCR4, are expressed and functional in cardiac myocytes. SDF-1 both stimulates and enhances the cellular signal which attracts potentially beneficial stem cells for tissue repair within the ischemic heart. Paradoxically however, this chemokine is known to act in concert with the inflammatory cytokines of the innate immune response which contributes to cellular injury through the recruitment of inflammatory cells during ischemia. In the present study, we have demonstrated that SDF-1 has dose dependent effects on freshly isolated cardiomyocytes. Using Tunnel and caspase 3-activation assays, we have demonstrated that the treatment of isolated adult rat cardiac myocyte with SDF-1 at higher concentrations (pathological concentrations) induced apoptosis. Furthermore, ELISA data demonstrated that the treatment of isolated adult rat cardiac myocyte with SDF-1 at higher concentrations upregulated TNF-α protein expression which directly correlated with subsequent apoptosis. There was a significant reduction in SDF-1 mediated apoptosis when TNF-α expression was neutralized which suggests that SDF-1 mediated apoptosis is TNF-α-dependent. The fact that certain stimuli are capable of driving cardiomyocytes into apoptosis indicates that these cells are susceptible to clinically relevant apoptotic triggers. Our findings suggest that the elevated SDF-1 levels seen in a variety of clinical conditions, including ischemic myocardial infarction, may either directly or indirectly contribute to cardiac cell death via a TNF-α mediated pathway. This highlights the importance of this receptor/ligand in regulating the cardiomyocyte response to stress conditions.

Relationship of Circulating CXCR4+ EPC with Prognosis of Mild Traumatic Brain Injury Patients.

To investigate the changes of circulating endothelial progenitor cells (EPCs) and stromal cell-derived factor-1α (SDF-1α)/CXCR4 expression in patients with mild traumatic brain injury (TBI) and the correlation between EPC level and the prognosis of mild TBI. 72 TBI patients (57 mild TBI, 15 moderate TBI patients) and 25 healthy subjects (control) were included. The number of circulating EPCs, CD34+, and CD133+ cells and the percentage of CXCR4+ cells in each cell population at 1,4,7,14,21 days after TBI were counted by flow cytometer. SDF-1α levels in serum were detected by ELISA assay. The patients were divided into poor and good prognosis groups based on Extended Glasgow Outcome Scale and Activity of Daily Living Scale at 3 months after TBI. Correlation analysis between each detected index and prognosis of mild TBI was performed. Moderate TBI patients have higher levels of SDF-1α and CXCR4 expression than mild TBI patients (P < 0.05). The percentage of CXCR4+ EPCs at day 7 post-TBI was significantly higher in mild TBI patients with poor prognosis than the ones with good prognosis (P < 0.05). HAMA and HAMD scores in mild TBI patients were significantly lower than moderate TBI patients (P < 0.05) in early term. The percentage of CXCR4+ EPCs at day 7 after TBI was significantly correlated with the prognosis outcome at 3 months. The mobilization of circulating EPCs can be induced in mild TBI. The expression of CXCR4+ in EPCs at 7 days after TBI reflects the short-term prognosis of brain injury, and could be a potential biological marker for prognosis prediction of mild TBI.

SDF-1/CXCR4 axis in Tie2-lineage cells including endothelial progenitor cells contributes to bone fracture healing.

CXC chemokine receptor 4 (CXCR4) is a specific receptor for stromal-derived-factor 1 (SDF-1). SDF-1/CXCR4 interaction is reported to play an important role in vascular development. On the other hand, the therapeutic potential of endothelial progenitor cells (EPCs) in fracture healing has been demonstrated with mechanistic insight of vasculogenesis/angiogenesis and osteogenesis enhancement at sites of fracture. The purpose of this study was to investigate the influence of the SDF-1/CXCR4 pathway in Tie2-lineage cells (including EPCs) in bone formation. We created CXCR4 gene conditional knockout mice using the Cre/loxP system and set two groups of mice: Tie2-Cre(ER) CXCR4 knockout mice (CXCR4(-/-) ) and wild-type mice (WT). We report here that in vitro, EPCs derived from of CXCR4(-/-) mouse bone marrow demonstrated severe reduction of migration activity and EPC colony-forming activity when compared with those derived from WT mouse bone marrow. In vivo, radiological and morphological examinations showed fracture healing delayed in the CXCR4(-/-) group and the relative callus area at weeks 2 and 3 was significantly smaller in CXCR4(-/-) group mice. Quantitative analysis of capillary density at perifracture sites also showed a significant decrease in the CXCR4(-/-) group. Especially, CXCR4(-/-) group mice demonstrated significant early reduction of blood flow recovery at fracture sites compared with the WT group in laser Doppler perfusion imaging analysis. Real-time RT-PCR analysis showed that the gene expressions of angiogenic markers (CD31, VE-cadherin, vascular endothelial growth factor [VEGF]) and osteogenic markers (osteocalcin, collagen 1A1, bone morphogenetic protein 2 [BMP2]) were lower in the CXCR4(-/-) group. In the gain-of-function study, the fracture in the SDF-1 intraperitoneally injected WT group healed significantly faster with enough callus formation compared with the SDF-1 injected CXCR4(-/-) group. We demonstrated that an EPC SDF-1/CXCR4 axis plays an important role in bone fracture healing using Tie2-Cre(ER) CXCR4 conditional knockout mice.