scholarly journals Therapeutic effects of Hypoxia-Inducible Factor-1α (HIF-1α) on bone formation around implants in diabetic mice

2018 ◽  
Author(s):  
Sang-Min Oh ◽  
Jin-Su Shin ◽  
Il-Koo Kim ◽  
Jae-Seung Moon ◽  
Jung-Ho Kim ◽  
...  

AbstractPatients with uncontrolled diabetes are susceptible to implant failure due to impaired bone metabolism. Hypoxia-Inducible Factor 1α (HIF-1α), a transcription factor that is up-regulated in response to reduced oxygen condition during the bone repair process after fracture or osteotomy, is known to mediate angiogenesis and osteogenesis. However, its function is inhibited under hyperglycemic conditions in diabetic patients. The aim of this study is to evaluate the effects of exogenous HIF-1α on bone formation around implants by applying HIF-1α to diabetic mice via a novel PTD-mediated DNA delivery system. Smooth surface implants (1mm in diameter; 2mm in length) were placed in the both femurs of diabetic and normal mice. HIF-1α and placebo gels were injected to implant sites of the right and left femurs, respectively: Normal mouse with HIF-1α gel (NH), Normal mouse with placebo gel (NP), Diabetic mouse with HIF-1α gel (DH), and Diabetic mouse with placebo gel (DP). RNA sequencing was performed 4 days after surgery. Based on RNA sequencing, Differentially Expressed Genes (DEGs) were identified and HIF-1α target genes were selected. Histologic and histomorphometric results were evaluated 2 weeks after the surgery. The results showed that bone-to-implant contact (BIC) and bone volume (BV) were significantly greater in the DH group than the DP group (p < 0.05). A total of 216 genes were differentially expressed in DH group compared to DP group. On the other hand, there were 95 DEGs in the case of normal mice. Twenty-one target genes of HIF-1α were identified in diabetic mice through bioinformatic analysis of DEGs. Among the target genes, NOS2, GPNMB, CCL2, CCL5, CXCL16 and TRIM63 were manually found to be associated with wound healing-related genes. In conclusion, local administration of HIF-1α via PTD may help bone formation around the implant and induce gene expression more favorable to bone formation in diabetic mice.

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 760 ◽  
Author(s):  
Sang-Min Oh ◽  
Jin-Su Shin ◽  
Il-Koo Kim ◽  
Jung-Ho Kim ◽  
Jae-Seung Moon ◽  
...  

Patients with uncontrolled diabetes are susceptible to implant failure due to impaired bone metabolism. Hypoxia-inducible factor 1α (HIF-1α), a transcription factor that is up-regulated in response to reduced oxygen during bone repair, is known to mediate angiogenesis and osteogenesis. However, its function is inhibited under hyperglycemic conditions in diabetic patients. This study thus evaluates the effects of exogenous HIF-1α on bone formation around implants by applying HIF-1α to diabetic mice and normal mice via a protein transduction domain (PTD)-mediated DNA delivery system. Implants were placed in the both femurs of diabetic and normal mice. HIF-1α and placebo gels were injected to implant sites of the right and left femurs, respectively. We found that bone-to-implant contact (BIC) and bone volume (BV) were significantly greater in the HIF-1α treated group than placebo in diabetic mice (p < 0.05). Bioinformatic analysis showed that diabetic mice had 216 differentially expressed genes (DEGs) and 21 target genes. Among the target genes, NOS2, GPNMB, CCL2, CCL5, CXCL16, and TRIM63 were found to be associated with bone formation. Based on these results, we conclude that local administration of HIF-1α via PTD may boost bone formation around the implant and induce gene expression more favorable to bone formation in diabetic mice.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yu Du ◽  
Haiyang Tang ◽  
Xia Gu ◽  
Yixin Shi ◽  
Ping Gong ◽  
...  

Objectives. Radiotherapy is a common therapy in head and neck tumors, which may cause a side effect radiation bone injury (RBI). Furthermore, it has been investigated that microRNA (miRNA) expression levels were altered after radiotherapy. Exosomes play a role in bone formation as miRNA containers, while radiation affects exosomes composition, secretion, and function. So, our objective is to explore changes in miRNA levels during bone formation after radiotherapy and identify the differentially expressed miRNAs (DE-miRs) in plasma exosomes during the process of osteogenesis related to irradiation. Materials and Methods. In this study, we analyzed nine samples from three rabbits exposed twice to radiation (15 Gy each) and detected DE-miRs from irradiated plasma exosomes during the process of osteogenesis by RNA sequencing. Further, we identified DE-miRs with significant differences and predicted their target genes via the bioinformatics analysis tools Targetscan v7.2 and miRPathDB v2.0. Finally, we identified radiation-responsive miRNAs and predicted their target genes during osteogenesis. Results. Taken together, we have identified some DE-miRs in irradiated plasma exosomes, which were involved in several vital signaling pathways related to bone physiology, such as the Wnt pathway, MAPK cascade, and calcium modulating pathway. Conclusions. We have found that plasma exosomes are one of the ways by which radiation can affect bone metabolism and regeneration. However, the specific mechanisms of how these plasma exosomal miRNAs mediate the osteogenesis pathways must be further investigated. Clinical Relevance. Radiotherapy may cause radiation bone injury, and miRNA expression levels in rabbit plasma exosomes are altered after radiotherapy. High-throughput RNA sequencing can identify the differentially expressed miRNAs in irradiated plasma exosomes during the process of osteogenesis. These findings make sense to develop novel therapeutic strategies for treating radiation-induced bone injury disorders.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guodong Li ◽  
Chung-Nga Ko ◽  
Dan Li ◽  
Chao Yang ◽  
Wanhe Wang ◽  
...  

AbstractImpaired wound healing and ulcer complications are a leading cause of death in diabetic patients. In this study, we report the design and synthesis of a cyclometalated iridium(III) metal complex 1a as a stabilizer of hypoxia-inducible factor-1α (HIF-1α). In vitro biophysical and cellular analyses demonstrate that this compound binds to Von Hippel-Lindau (VHL) and inhibits the VHL–HIF-1α interaction. Furthermore, the compound accumulates HIF-1α levels in cellulo and activates HIF-1α mediated gene expression, including VEGF, GLUT1, and EPO. In in vivo mouse models, the compound significantly accelerates wound closure in both normal and diabetic mice, with a greater effect being observed in the diabetic group. We also demonstrate that HIF-1α driven genes related to wound healing (i.e. HSP-90, VEGFR-1, SDF-1, SCF, and Tie-2) are increased in the wound tissue of 1a-treated diabetic mice (including, db/db, HFD/STZ and STZ models). Our study demonstrates a small molecule stabilizer of HIF-1α as a promising therapeutic agent for wound healing, and, more importantly, validates the feasibility of treating diabetic wounds by blocking the VHL and HIF-1α interaction.


2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Shion Orikasa ◽  
Nobuyuki Kawashima ◽  
Kento Tazawa ◽  
Kentaro Hashimoto ◽  
Keisuke Sunada-Nara ◽  
...  

AbstractAccelerated dental pulp mineralization is a common complication in avulsed/luxated teeth, although the mechanisms underlying this remain unclear. We hypothesized that hypoxia due to vascular severance may induce osteo/odontoblast differentiation of dental pulp stem cells (DPSCs). This study examined the role of B-cell CLL/lymphoma 9 (BCL9), which is downstream of hypoxia-inducible factor 1α (HIF1α) and a Wnt/β-catenin transcriptional cofactor, in the osteo/odontoblastic differentiation of human DPSCs (hDPSCs) under hypoxic conditions. hDPSCs were isolated from extracted healthy wisdom teeth. Hypoxic conditions and HIF1α overexpression induced significant upregulation of mRNAs for osteo/odontoblast markers (RUNX2, ALP, OC), BCL9, and Wnt/β-catenin signaling target genes (AXIN2, TCF1) in hDPSCs. Overexpression and suppression of BCL9 in hDPSCs up- and downregulated, respectively, the mRNAs for AXIN2, TCF1, and the osteo/odontoblast markers. Hypoxic-cultured mouse pulp tissue explants showed the promotion of HIF1α, BCL9, and β-catenin expression and BCL9-β-catenin co-localization. In addition, BCL9 formed a complex with β-catenin in hDPSCs in vitro. This study demonstrated that hypoxia/HIF1α-induced osteo/odontoblast differentiation of hDPSCs was partially dependent on Wnt/β-catenin signaling, where BCL9 acted as a key mediator between HIF1α and Wnt/β-catenin signaling. These findings may reveal part of the mechanisms of dental pulp mineralization after traumatic dental injury.


2020 ◽  
Author(s):  
Koichiro Kajiwara ◽  
Yoshihiko Sawa ◽  
Takahiro Fujita ◽  
Sachio Tamaoki

Abstract Background We recently reported that the glomerular endothelium expresses toll-like receptor (TLR)2 and TLR4 in diabetic environments and established that the TLR2 ligand Porphyromonas (P.) gingivalis lipopolysaccharides (LPS) induces nephropathy in diabetic mice. It is thought that P. gingivalis LPS promotes the chronic inflammation with the overexpression of leukocyte adhesion molecules and renal-specific metabolic enzymes by the recognition of P. gingivalis LPS via TLR in the diabetic kidneys. The present study aims to examine the expression of leukocyte adhesion molecules and renal metabolic factors in mouse kidneys with periodontal pathogen P. gingivalis LPS-induced diabetic nephropathy that was recently established. Methods The immunohistochemical investigation was performed on mouse kidney with P. gingivalis LPS-induced diabetic nephropathy model with glomerulosclerosis in glomeruli. Results There were no vessels which expressed vascular cell adhesion molecule-1 (VCAM-1), E-selectin, or fibroblast growth factor (FGF) 23 in diabetic mice, or in healthy mice administered P. gingivalis LPS. However, in diabetic mouse kidneys with P. gingivalis LPS-induced nephropathy the expression of VCAM-1 and the accumulation of FGF23 were established in renal tubules and glomeruli, and the expression of E-selectin was established in renal parenchyma and glomeruli. The angiotensin-converting enzyme 2 (ACE2) was detected in the proximal tubules but not in other regions including not in distal tubules of diabetic mice without LPS, and not in healthy mice administered P. gingivalis LPS. In diabetic mouse kidneys with P. gingivalis LPS-induced nephropathy ACE2 was detected both in renal tubules as well as in glomeruli. The macrophage-1 (Mac-1) and podoplanin-positive cells increased in the renal parenchyma with diabetic condition and there was accumulation in P. gingivalis LPS-induced diabetic nephropathy. As the expression of VCAM-1 and E-selectin is upregulated in glomeruli, tubules, and intertubular capillaries, it is thought that the inflammatory infiltration of the monocyte-macrophage lineage promoted in kidneys with P. gingivalis LPS-induced the diabetic nephropathy. Conclusions P. gingivalis LPS may progressively accelerate the development of the renal inflammatory environment in LPS-accumulated glomeruli with the macrophage infiltration via the renal expression of VCAM-1 and E-selectin, and with ACE2 overexpression and FGF23 accumulation. Periodontitis may be a critical factor in the progress of nephropathy in diabetic patients.


2011 ◽  
Vol 18 (1) ◽  
pp. 83-94 ◽  
Author(s):  
Eric Guérin ◽  
Wolfgang Raffelsberger ◽  
Erwan Pencreach ◽  
Armin Maier ◽  
Agnès Neuville ◽  
...  

Author(s):  
Ilgin Yildirim Simsir ◽  
Nur Sinem Sengoz Coskun ◽  
Yasemin Yildirim Akcay ◽  
Sevki Cetinkalp

Reduced life expectancy has resulted from an increased incidence of chronic complications in patients with diabetes. The diabetic foot is one of these complications and generally presents together with diabetic neuropathy and vascular insufficiency. Hypoxia-inducible factor-1α (HIF-1α) is important in developing the adaptation response to hypoxia and facilitates healing through regulation of keratinocyte migration and epithelium restoration in wounds. Fetuin-A is a transporter protein that is synthesized in the liver and inhibits vascular and ectopic calcifications. It has been observed that altered fetuin-A is associated with peripheral artery disease through vascular calcification and is associated with inflammation and metabolic syndrome occurrence in diabetic patients. Fibrinogen is an acute-phase reactant and has a major role in homeostasis, tissue repair, and wound healing. Increased fibrinogen blood level is one of the factors that facilitates the hypercoagulability in diabetics. Homocysteine has atherogenic features and causes vascular toxicity by enhancing low-density lipoprotein oxidation. We evaluated the association of serum HIF-1α, fetuin-A, fibrinogen, and homocysteine levels with amputation in 31 patients diagnosed with diabetes mellitus. According to our evaluation, a negative correlation was determined between fetuin-A and amputation level ( P = .012, r = −0.450), which was statistically significant. Unfortunately, there was no significant correlation between HIF-1α, fibrinogen, homocysteine, and amputation level ( P > .05). As a result, it was suggested that vascular calcification due to fetuin-A deficiency may be important in the diabetic foot pathogenesis and that fetuin-A levels may be a predictor for amputation level.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Kexin Wang ◽  
Feng Song ◽  
Hongxing Wang ◽  
Jun-hui Wang ◽  
Yu Sun

Diabetic patients are at increased risk for developing memory and cognitive deficit. Prior studies indicate that neuroinflammation might be one important underlying mechanism responsible for this deficit. Quetiapine (QTP) reportedly exerts a significant neuroprotective effect in animal and human studies. Here, we investigated whether QTP could prevent memory deterioration and cognitive impairment in a streptozotocin- (STZ-) induced diabetic mouse model. In this study, we found that STZ significantly compromised the behavioral performance of mice in a puzzle box test, but administering QTP effectively attenuated this behavioral deficit. Moreover, our results showed that QTP could significantly inhibit the activation of astrocytes and microglia in these diabetic mice and reduce the generation and release of two cytokines, tumor necrosis factor-α (TNF-α) and monocyte chemoattractant protein-1 (MCP-1). Meanwhile, QTP also prevented the protein loss of the synaptic protein synaptophysin (SYP) and myelin basic protein (MBP). Here, our results indicate that QTP could inhibit neuroinflammatory response from glial cells and block the injury of released cytokines to neurons and oligodendrocytes in diabetic mice (DM). These beneficial effects could protect diabetic mice from the memory and cognitive deficit. QTP may be a potential treatment compound to handle the memory and cognitive dysfunction in diabetic patients.


2008 ◽  
Vol 414 (3) ◽  
pp. 461-469 ◽  
Author(s):  
Dominador J. Manalo ◽  
Paul W. Buehler ◽  
Jin Hyen Baek ◽  
Omer Butt ◽  
Felice D'agnillo ◽  
...  

Hb (haemoglobin)-based blood substitutes represent a class of therapeutics designed to correct oxygen deficit under conditions of anaemia and traumatic blood loss. The influences of these agents on HIF-1α (hypoxia-inducible factor-1α) target genes involved in adaptation to hypoxia have so far not been studied. In the study presented here, rats underwent 80% ET (exchange transfusion) with either HS (hetastarch) or a polymerized Hb OG (Oxyglobin®). HS induced dramatic EPO (erythropoietin) gene transcription, reaching a maximum at 4 h post-ET. In contrast, OG suppressed EPO transcription until approx. 24 h post-ET. Large plasma EPO levels that were observed post-ET with HS were significantly blunted in animals transfused with OG. OG, unlike HS, induced a sharp increase in HO-1 (haem oxygenase-1) transcription at 4 h, which declined rapidly within 24 h, whereas modest increases in iNOS [inducible (nitric oxide synthase)] and constitutive NOS [eNOS (endothelial NOS)] were detected over the control. Our results demonstrate for the first time that severe haemodilution-induced erythropoietic responses in kidneys were attenuated by a low-oxygen-affinity cell-free Hb and suggest that tissue-specific oxygen-sensing pathways can be influenced by allosterically modified Hbs.


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