► The designer peptide LRKKLGKA could self-assemble into nanofibers. ► Injection of LRKKLGKA peptides could promote the sustained delivery of VEGF. ► Injection of VEGF with LRKKLGKA peptides lead to ...sufficient angiogenesis. ► Injection of VEGF with LRKKLGKA peptides improves heart function.
Poor vascularization and insufficient oxygen supply are detrimental to the survival of residual cardiomyocytes or transplanted stem cells after myocardial infarction. To prolong and slow the release of angiogenic factors, which stimulate both angiogenesis and vasculogenesis, we constructed a novel self-assembling peptide by attaching the heparin-binding domain sequence LRKKLGKA to the self-assembling peptide RADA16. This designer self-assembling peptide self-assembled into nanofiber scaffolds under physiological conditions, as observed by atomic force microscopy. The injection of designer self-assembling peptides can efficiently provide the sustained delivery of VEGF for at least 1month. At 4weeks after transplantation, cardiac function was improved, and scar size and collagen deposition were markedly reduced in the group receiving VEGF with the LRKKLGKA scaffolds compared with groups receiving VEGF alone, LRKKLGKA scaffolds alone or VEGF with RADA16 scaffolds. The microvessel density in the VEGF with LRKKLGKA group was higher than that in the VEGF with RADA16 group. TUNEL and cleaved caspase-3 expression assays showed that the transplantation of VEGF with LRKKLGKA enhanced cell survival in the infarcted heart. These results present the tailor-made peptide scaffolds as a new generation of sustained-release biomimetic biomaterials and suggest that the use of angiogenic factors along with designer self-assembling peptides can lead to myocardial protection, sufficient angiogenesis, and improvement in cardiac function.
Although the benefits of electroacupuncture (EA) for peripheral nerve injury (PNI) are well accepted in clinical practice, the underlying mechanism remains incompletely elucidated. In our study, we ...observed that EA intervention led to a reduction in the expression of the long non-coding RNA growth-arrest-specific transcript 5 (GAS5) and an increased in miR-21 levels within the injured nerve, effectively promoting functional recovery and nerve regeneration following sciatic nerve injury (SNI). In contrast, administration of adeno-associated virus expressing GAS5 (AAV-GAS5) weakened the therapeutic effect of EA. On the other hand, both silencing GAS5 and introducing a miR-21 mimic prominently enhanced the proliferation activity and migration ability of Schwann cells (SCs), while also inhibiting SCs apoptosis. On the contrary, inhibition of SCs apoptosis was found to be mediated by miR-21. Additionally, overexpression of GAS5 counteracted the effects of the miR-21 mimic on SCs. Moreover, SCs that transfected with the miR-21 mimic promoted neurite growth in hypoxia/reoxygenation-induced neurons, which might be prevented by overexpressing GAS5. Furthermore, GAS5 was found to be widely distributed in the cytoplasm and was negatively regulated by miR-21. Consequently, the targeting of GAS5 by miR-21 represents a potential mechanism through which EA enhances reinnervation and functional restoration following SNI. Mechanistically, the GAS5/miR-21 axis can modulate the proliferation, migration, and apoptosis of SCs while potentially influencing the neurite growth of neurons.
AKT/GSK-3β/β-catenin signaling pathway plays an important role in the progression of colorectal cancer (CRC). Toosendanin (TSN) is a triterpenoid extracted from the bark or fruits of Melia toosendan ...Sieb et Zucc and possesses antitumour effects on various human cancer cells. However, its effect on CRC remains poorly understood. The present study investigated the effect of TSN on CRC SW480 cells and the AKT/GSK-3β/β-catenin signaling. Proliferation assay, flow cytometry and Hoechst 33342 nuclear staining demonstrated TSN dose-dependently inhibited cell viability and induced cell apoptosis as well as cell cycle arrest in S phase. Confocal laser scanning microscope showed β-catenin transferred to the outside of the nucleus in TSN-treated cells. Quantitative real-time PCR and western blot analysis found that TSN effectively modulated molecules related to apoptosis and AKT/GSK-3β/β-catenin signaling. Moreover, TSN administration significantly inhibited CRC growth in a mouse tumor xenograft model. In conclusion, our findings indicate that TSN inhibits growth and induces apoptosis in CRC cells through suppression of AKT/GSK-3β/β-catenin pathway, suggesting that TSN may have potential for use in CRC treatment.
The neuropathological hallmarks of Alzheimer’s disease (AD) include the presence of extracellular amyloid-β peptide (Aβ) in the form of amyloid plaques and neuronal loss. Neural stem cell (NSC) is ...being scrutinized as a promising cell replacement therapy for various neurodegenerative diseases. However, the unfavorable niche at the site of degenerative disease is hostile to the survival and differentiation of transplanted cells. Here, we undertook in vitro and in vivo works to examine whether a designer self-assemble peptide (DSP), which contains one functional domain Tyr-Ile-Gly-Ser-Arg (YIGSR) derived from laminin, promotes the survival and neuronal differentiation of NSC and behavioral improvement. We found that DSP could undergo spontaneous assembly into well-ordered nanofibers, and it not only facilitated the cell viability in normal culture condition, but also decreased the number of apoptotic cells induced by Aβ in vitro. NSC seeded in DSP showed much more neuronal differentiation than that seeded in self-assemble peptide (SP) or alone. In the AD model, NSC transplantation in DSP-treated AD rats demonstrated much more obvious cognitive rescue with restoration of learning/memory function compared with NSC transplantation in SP, NSC alone, or DSP alone treated ones. Interestingly, DSP enhanced the survival and neuronal differentiation of transplanted NSC. Apoptosis levels in the CA1 region and Aβ level in the hippocampus were significantly decreased in the group of NSC transplantation in DSP. Moreover, synaptic function, indicated by the expression of pre-synaptic protein synapsin-1, was restored and the secretion of anti-inflammatory and neurotrophic factors were increased, such as IL-10, brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF), and insulin-like growth factor 1 (IGF-1), while the expression of pro-inflammatory factors were decreased, such as TNF-α and IL-1β. These data firstly unveiled that the biomaterial DSP can maximize the therapeutic benefits of NSC transplantation for AD through improving the survival and differentiation of transplanted stem cells and promoting the effects of neuroprotection, anti-neuroinflammatory and paracrine action. Our results may have important clinical implications for the design of future NSC-based strategies using the biomaterials for various neurodegenerative diseases including AD.
Acupuncture is a potential strategy for the treatment of Alzheimer’s disease (AD) and the possible mechanisms worth to be explored. In this study, we proposed and tested the hypothesis that whether ...Notch signaling pathway is involved in the effect of electroacupuncture (EA) treatment. Rats that received EA treatment on the acupoints of Baihui (Du 20) and Shenshu (BL 23) had shorter latency and remained in the original platform quadrant longer and crossed the former platform contained quadrant more frequently compared to the Aβ injection rats without EA treatment. EA obviously alleviated the cell apoptosis resulted by Aβ infusion in hippocampus CA1 regions through upregulating the expression of Bcl-2 and downregulating the expression of Bax. EA could further obviously promote the expression of synapsin-1 and synaptophysin in hippocampus. Aβ injection significantly increased the expression of Notch1, Jag1, and Hes1 mRNA, while EA treatment downregulated the level of Notch1 and Hes1 mRNA in hippocampus, but not Jag1 mRNA. Our data suggested that EA treatment improved learning and memory function in the AD rat model partially through downregulating Notch signaling pathway.
•High performance N-doped Na3V2(PO4)2F3/C is constructed by a PECVD technology.•Pyridinic, pyrrolic and graphitic nitrogen are generated at high energy condition.•The formation of defects on the ...carbon can accelerate the diffusion of sodium ions.•NVPF@N-3 delivers excellent rate, cyclic performance and structural stability.•The capacity retention of cathode NVPF@N-3 is 91.4% at 10 c after 1000 cycles.
One N-doped carbon coated Na3V2(PO4)2F3/C cathode for sodium-ion batteries was successfully prepared by a Plasma enhanced chemical vapor deposition (PECVD) method. N2 gas is used as the nitrogen source and it is ionized to form chemically active nitrogen ion. It can easily react with the carbon atoms in sample Na3V2(PO4)2F3/C. Research results show that the introduction of N does not affect the crystal structure of the material. The N-doped carbon layer in sample Na3V2(PO4)2F3/C becomes more and more homogeneous. The formation of the pyridinic nitrogen, pyrrolic nitrogen and graphitic nitrogen in the carbon layer can generate additional active sites to shorten the transmission distance of sodium ions, which can improve the electrochemical performance of Na3V2(PO4)2F3/C cathode. The NVPF@N-3 cathode treated by PECVD for 30 min displays excellent rate performance (109.8 mAh•g−1 at 5 C) and cyclic performance, in which the capacity retention after 1000 cycles at 10 C is 91.4% and the crystal structure of NVPF@N-3 is well maintained. This research demonstrates that the pyrolytic carbon in Na3V2(PO4)2F3/C cathode for sodium-ion batteries can be effectively doped by Nitrogen through a novel PECVD technology.
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AIM： TO study the role of mitochondrial energy disorder in the pathogenesis of ethanol-induced gastric mucosa injury. METHODS： Wistar rats were used in this study. A gastric mucosal injury model was ...established by giving the rats alcohol. Gross and microscopic appearance of gastric mucosa and ultrastructure of mitochondria were evaluated. Malondiadehyde （MDA） in gastric mucosa was measured with thiobarbituric acid. Expression of ATP synthase （ATPase） subunits 6 and 8 in mitochondrial DNA （mtDNA） was determined by reverse transcription polymerase chain reaction （RTPCR）. RESULTS： The gastric mucosal lesion index was correlated with the MDA content in gastric mucosa. As the concentration of ethanol was elevated and the exposure time to ethanol was extended, the content of MDA in gastric mucosa increased and the extent of damage aggravated. The ultrastructure of mitochondria was positively related to the ethanol concentration and exposure time. The expression of mtDNA ATPase subunits 6 and 8 mRNA declined with the increasing MDA content in gastric mucosa after gavage with ethanol. CONCLUSION： Ethanol-induced gastric mucosa injury is related to oxidative stress, which disturbs energy metabolism of mitochondria and plays a critical role in the pathogenesis of ethanol-induced gastric mucosa injury.
As a common complication of diabetes, the pathogenesis of diabetic peripheral neuropathy (DPN) is closely related to high glucose but has not been clarified. Exosomes can mediate crosstalk between ...Schwann cells (SC) and neurons in the peripheral nerve. Herein, we found that miR-21 in serum exosomes from DPN rats was decreased. SC proliferation was inhibited, cell apoptosis was increased, and the expression of miR-21 in cells and exosomes was downregulated when cultured in high glucose. Increasing miR-21 expression reversed these changes, while knockdown of miR-21 led to the opposite results. When co-cultured with exosomes derived from SC exposed to high glucose, neurite outgrowth was inhibited. On the contrary, neurite outgrowth was accelerated when incubated with exosomes rich in miR-21. We further demonstrated that the SC-derived exosomal miR-21 participates in neurite outgrowth probably through the AKT signaling pathway. Thus, SC-derived exosomal miR-21 contributes to high glucose regulation of neurite outgrowth.
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•The miR-21 was decreased in serum exosomes and sciatic nerve of DPN rats•High glucose inhibited SC viability and downregulated the expression of miR-21•Exosomes derived from SC cultured in high glucose inhibited the neurite outgrowth•SC-derived exosomes rich in miR-21 accelerated the neurite outgrowth of neuron
Biological sciences; Neuroscience; Molecular neuroscience; Diabetology
Cardiovascular disease has been established as a major cause of morbidity and mortality worldwide, resulting in a huge burden to patients, families, and society. Traditional Chinese Medicine (TCM) ...presents several advantages for the prevention and treatment of cardiovascular diseases including multitargets, multi-ingredients, fewer side effects, and low cost. In this study, a rat model of myocardial infarction (MI) was established by ligating the anterior descending branch of the left coronary artery, and the effect of the Taohong Siwu decoction (THSWD) on cardiac function was evaluated in MI rats. Following the intragastric administration of THSWD, the cardiac function was examined using echocardiography. The infarct size and collagen deposition in the infarct area were measured using Masson’s trichrome staining, and the number of CD31- and α-SMA-positive blood vessels in the peri-infarct and infarct area was evaluated by immunofluorescent staining. The mRNA expression of bFGF, IGF-1, and HGF was detected using RT-PCR assay. Cell apoptosis in the infarcted area was assessed by TUNEL staining, and the p-Akt level was detected using the western blot assay. The mitochondrial ROS production was measured using MitoSOX staining, and mitochondrial dynamics and mitophagy were evaluated with western blotting 7 days after THSWD treatment. THSWD increased the ejection fraction (EF) and fractional shortening (FS) values in the rat hearts; however, no statistical difference was found between the THSWD and MI groups 4 weeks after treatment. Furthermore, THSWD significantly decreased the value of the left ventricular end-systolic volume (LVESV). Compared with the model group, THSWD significantly increased the expression of IGF-1 and bFGF, reduced collagen deposition, promoted angiogenesis, reduced cell apoptosis, and activated the PI3K/Akt signaling pathway. Notably, THSWD significantly decreased mitochondrial ROS production and Fis1 expression. No statistical differences were observed in the expression of mitochondrial LC3B and Mfn1 between the THSWD and control groups. In summary, THSWD may possess a beneficial effect on cardiac function by improving the local ischemic microenvironment and by decreasing mitochondrial fission after MI. Hence, this may present a promising auxiliary strategy in the treatment of ischemic cardiomyopathy such as MI.
•Expression of miR-1b in injured sciatic nerve was significantly downregulated after sciatic nerve injury.•NDRG3 is the direct target gene of miR-1b.•miR-1b overexpression and NDRG3 knockdown ...inhibited the proliferation and migration of SCs.•miR-1b mediated SCs proliferation/migration/apoptosis through NDRG3.•Downregulation of miR-1b promoted the function recovery after sciatic nerve injury.
Peripheral nerve injury (PNI) is a global problem that leads to severe disability and high healthcare expenditure. Accumulating evidence suggested that the phenotypes of Schwann cells (SCs) could be regulated by microRNAs (miRNAs) and expressions of various miRNAs are altered after PNI. In this study, the expression of miR-1b in the injured nerve and hypoxia-treated SCs was detected through qRT-PCR. The target genes of miR-1b were predicted by bioinformatics prediction and dual-luciferase reporter assay and verified through qRT-PCR and western blot. The effects of miR-1b and its specific target gene on the proliferation, migration and apoptosis of SCs were determined and the regulation of miR-1b on peripheral nerve regeneration after PNI was further investigated in vivo. We found that miR-1b was obviously downregulated in the injured nerve in a rat sciatic nerve transection model and directly targeted N-myc downstream-regulated gene 3 (NDRG3) by binding to its 3′-UTR and caused both mRNA degradation and translation suppression of NDRG3. Overexpression of miR-1b or knockdown of NDRG3 decreased the proliferation and migration as well as increased the apoptosis of SCs. NDRG3 reversed the effects of miR-1b overexpression on proliferation/migration/apoptosis of RSC96. In addition, injection of miR-1b antagomir promoted the expression of NDRG3 in the injured nerve following sciatic nerve injury. Compared to the model group, the rats treated with miR-1b agomir had lower functional recovery rate, and downregulation of miR-1b through injection of specific antagomir improved the functional recovery rate according to the results of sciatic functional index and nerve conduction velocity. Overall, our results will contribute to the development of novel targets for promoting nerve regeneration after PNI.
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