A Ternary Synergistic eNOS Gene Delivery System Based on Calcium Ion and L-Arginine for Accelerating Angiogenesis by Maximizing NO Production

Co-release of nitric oxide and L-arginine from poly (β-amino ester)-based adhesive reprogram macrophages for accelerated wound healing and angiogenesis in vitro and in vivo

Recently, insufficient angiogenesis and prolonged inflammation are crucial challenges of chronic skin wound healing. The sustained release of L-Arginine (L-Arg) and nitric oxide (NO) production can control immune responses, improve angiogenesis, enhance re-epithelialization, and accelerate wound healing. Here, we aim to improve wound healing via the controlled release of NO and L-Arg from poly (β-amino ester) (PβAE). In this regard, PβAE is functionalized with methacrylate poly-L-Arg (PAMA), and the role of PAMA content (50, 66, and 75 wt%) on the adhesive properties, L-Arg, and NO release, as well as collagen deposition, inflammatory responses, and angiogenesis, is investigated in vitro and in vivo. Results show that the PAMA/ PβAE could provide suitable adhesive strength (~25 kPa) for wound healing application. In addition, increasing the PAMA content from 50 to 75 wt% results in an increased release of L-Arg (approximately 1.4-1.7 times) and enhanced NO production (approximately 2 times), promoting skin cell proliferation and migration. The in vitro studies also show that compared to PβAE hydrogel, incorporation of 66 wt% PAMA (PAMA 66 sample) reveals superior collagen I synthesis (~ 3-4 times) of fibroblasts, controlled pro-inflammatory and improved anti-inflammatory cytokines secretion of macrophages, and accelerated angiogenesis (~1.5-2 times). In vivo studies in a rat model with a full-thickness skin defect also demonstrate the PAMA66 sample could accelerate wound healing (~98 %) and angiogenesis, compared to control (untreated wound) and Tegaderm™ commercial wound dressing. In summary, the engineered multifunctional PAMA functionalized PβAE hydrogel with desired NO and L-Arg release, and adhesive properties can potentially reprogram macrophages and accelerate skin healing for chronic wound healing.

Bioactive components and molecular mechanisms of Salvia miltiorrhiza Bunge in promoting blood circulation to remove blood stasis

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia miltiorrhiza Bunge (SM) is an outstanding herbal medicine with various traditional effects, especially promoting blood circulation to remove blood stasis. It has been widely used for centuries to treat blood stasis syndrome (BSS)-related diseases. BSS is one of the basic pathological syndromes of diseases such as cardiovascular and cerebrovascular diseases in traditional East Asian medicine, which is characterized by disturbance of blood circulation. However, the bioactive components and mechanisms of SM in the treatment of BSS have not been systematically reviewed. Therefore, this article outlines the anti-BSS effects of bioactive components of SM, concentrating on the molecular mechanisms.

AIM OF THE REVIEW

To summarize the bioactive components of SM against BSS and highlight its potential targets and signaling pathways, hoping to provide a modern biomedical perspective to understand the efficacy of SM on enhancing blood circulation to remove blood stasis.

MATERIALS AND METHODS

A comprehensive literature search was performed to retrieve articles published in the last two decades on bioactive components of SM used for BSS treatment from the online electronic medical literature database (PubMed).

RESULTS

Phenolic acids and tanshinones in SM are the main bioactive components in the treatment of BSS, including but not limited to salvianolic acid B, tanshinone IIA, salvianolic acid A, cryptotanshinone, Danshensu, dihydrotanshinone, rosmarinic acid, protocatechuic aldehyde, and caffeic acid. They protect vascular endothelial cells by alleviating oxidative stress and inflammatory damage and regulating of NO/ET-1 levels. They also enhance anticoagulant and fibrinolytic capacity, inhibit platelet activation and aggregation, and dilate blood vessels. Moreover, lowering blood lipids and improving blood rheological properties may be the underlying mechanisms of their anti-BSS. More notably, these compounds play an anti-BSS role by mediating multiple signaling pathways such as Nrf2/HO-1, TLR4/MyD88/NF-κB, PI3K/Akt/eNOS, MAPKs (p38, ERK, and JNK), and Ca2+/K+ channels.

CONCLUSIONS

Both phenolic acids and tanshinones in SM may act synergistically to target different signaling pathways to achieve the effect of promoting blood circulation.

Saponin of Aralia taibaiensis promotes angiogenesis through VEGF/VEGFR2 signaling pathway in cerebral ischemic mice

ETHNOPHARMACOLOGICAL RELEVANCE

Aralia taibaiensis is known for its ability to promote blood circulation and dispel blood stasis, activate meridians and remove arthralgia. The saponins of Aralia taibaiensis (sAT) are the main active components that are often used to treat cardiovascular and cerebrovascular diseases. However, it has not been reported whether sAT can improve ischemic stroke (IS) by promoting angiogenesis.

AIM OF THE STUDY

In this study, we investigated the potential of sAT to promote post-ischemic angiogenesis in mice and determined the underlying mechanism through in vitro experiments.

METHODS

To establish the middle cerebral artery occlusion (MCAO) mice model in vivo. First of all, we examined the neurological function, brain infarct volume, and degree of brain swelling in MCAO mice. We also observed pathological changes in brain tissue, ultrastructural changes in blood vessels and neurons, and the degree of vascular neovascularization. Additionally, we established the oxygen-glucose deprivation/reoxygenation (OGD/R) -human umbilical vein endothelial cells (HUVECs) model in vitro to detect the survival, proliferation, migration and tube formation of OGD/R HUVECs. Finally, we verified the regulatory mechanism of Src and PLCγ1 siRNA on sAT promoting angiogenesis by cell transfection technique.

RESULTS

In the cerebral ischemia-reperfusion mice, sAT distinctly improved the cerebral infarct volume, brain swelling degree, neurological dysfunction, and brain histopathological morphology due to cerebral ischemia/reperfusion injury. It also increased the double positive expression of BrdU and CD31 in brain tissue, promoted the release of VEGF and NO and decreased the release of NSE and LDH. In the OGD/R HUVECs, sAT significantly improved cell survival, proliferation, migration and tube formation, promoted the release of VEGF and NO, and increased the expression of VEGF, VEGFR2, PLCγ1, ERK1/2, Src and eNOS. Surprisingly, the effect of sAT on angiogenesis was inhibited by Src siRNA and PLCγ1 siRNA in OGD/R HUVECs.

CONCLUSION

The results proved that sAT promotes angiogenesis in cerebral ischemia-reperfusion mice and its mechanism is to regulate VEGF/VEGFR2 and then regulate Src/eNOS and PLCγ1/ERK1/2.

A Novel PTH-Related Peptide Combined With 3D Printed Macroporous Titanium Alloy Scaffold Enhances Osteoporotic Osseointegration

Previous parathyroid hormone (PTH)-related peptides (PTHrPs) cannot be used to prevent implant loosening in osteoporosis patients due to the catabolic effect of local sustained release. A novel PTHrP (PTHrP-2) that can be used locally to promote osseointegration of macroporous titanium alloy scaffold (mTAS) and counteract implant slippage in osteoporosis patients is designed. In vitro, PTHrP-2 enhances the proliferation, adhesion, and osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) within the mTAS. Further, it promotes proliferation, migration, angiogenesis-related protein expression, and angiogenesis in human umbilical vein endothelial cells (HUVECs). Compared to PTH(1-34), PTHrP-2 can partially weaken the osteoclast differentiation of RAW 264.7 cells. Even in an oxidative stress microenvironment, PTHrP-2 safeguards the proliferation and migration of BMSCs and HUVECs, reduces reactive oxygen species generation and mitochondrial damage, and partially preserves the angiogenesis of HUVECs. In the Sprague-Dawley (SD) rat osteoporosis model, the therapeutic benefits of PTHrP-2-releasing mTAS (mTASP2 ) and ordinary mTAS implanted for 12 weeks via micro-CT, sequential fluorescent labeling, and histology are compared. The results demonstrate that mTASP2 exhibits high bone growth rate, without osteophyte formation. Consequently, PTHrP-2 exhibits unique local synthesis properties and holds the potential for assisting the osseointegration of alloy implants in osteoporosis patients.

Effects of Nitric Oxide Supplementation on the Levels of Interleukin-6 in Saliva after Dental Implant Placement - A Prospective Study

Introduction

The purpose of the study was to evaluate and compare the levels of salivary Interleukin-6 (IL-6) before and after the placement of dental implants in patients who are supplemented with nitric oxide (NO).

Materials and Methods

The study comprised 34 patients, divided into control and study groups (17 in each group). The control group was given a placebo and in the study group, nitric oxide supplement was prescribed, whereas the control group received a placebo. Saliva samples were taken before placement of dental implants, first and third day after the implant placement. The levels of salivary IL-6 were assessed using an enzyme-linked immunosorbent assay test.

Results

Statistical analysis showed a significant P value (<0.05) with respect to IL-6 levels on first and third days after placement of dental implants. Salivary IL-6 levels in the study group declined significantly. On day three, the IL-6 values for the control and study groups were 0.0639 and 0.0443, respectively. Within the groups, it was observed that there was a significant decrease in IL-6 values from day one to day three.

Discussion

The levels of salivary IL-6 reduced from day one to day three more significantly and consistently in patients prescribed with NO supplements post-dental implant placement, suggesting better resolution of inflammation.

Diabetic vascular diseases: molecular mechanisms and therapeutic strategies

Vascular complications of diabetes pose a severe threat to human health. Prevention and treatment protocols based on a single vascular complication are no longer suitable for the long-term management of patients with diabetes. Diabetic panvascular disease (DPD) is a clinical syndrome in which vessels of various sizes, including macrovessels and microvessels in the cardiac, cerebral, renal, ophthalmic, and peripheral systems of patients with diabetes, develop atherosclerosis as a common pathology. Pathological manifestations of DPDs usually manifest macrovascular atherosclerosis, as well as microvascular endothelial function impairment, basement membrane thickening, and microthrombosis. Cardiac, cerebral, and peripheral microangiopathy coexist with microangiopathy, while renal and retinal are predominantly microangiopathic. The following associations exist between DPDs: numerous similar molecular mechanisms, and risk-predictive relationships between diseases. Aggressive glycemic control combined with early comprehensive vascular intervention is the key to prevention and treatment. In addition to the widely recommended metformin, glucagon-like peptide-1 agonist, and sodium-glucose cotransporter-2 inhibitors, for the latest molecular mechanisms, aldose reductase inhibitors, peroxisome proliferator-activated receptor-γ agonizts, glucokinases agonizts, mitochondrial energy modulators, etc. are under active development. DPDs are proposed for patients to obtain more systematic clinical care requires a comprehensive diabetes care center focusing on panvascular diseases. This would leverage the advantages of a cross-disciplinary approach to achieve better integration of the pathogenesis and therapeutic evidence. Such a strategy would confer more clinical benefits to patients and promote the comprehensive development of DPD as a discipline.

pH-responsive organic/inorganic hybrid nanocolloids for transcellular delivery of ribonucleolytic payloads toward targeted anti-glioma therapy

Proteins have been appreciated to be a superlative modality of therapeutics in view of their direct roles in regulating diverse sets of biological events, nonetheless, the clinical applications of the proteinic therapeutics have been strictly limited to act on the cell surface receptors owing to their inherent cell-impermeable character of the proteins. To this obstacle, we contrived carboxylation reaction upon the proteins (RNase A) into the overall negatively charged pro-RNase, followed by elaboration of intelligent pH-responsive pro-RNase delivery nanocolloids based on co-precipitation of pro-RNase and Arg-Gly-Asp (RGD)-functionalized poly(ethylene glycol) (PEG)-block-polyanion with aids of inorganic calcium phosphate (CaP). The resulting nanocolloids appeared to actively accumulate into glioma due to the specific binding affinities of RGD and glioma-enriched α_Vβ₃ and α_Vβ₅ integrins. Furthermore, the pH responsiveness to the acidic endolysosomal microenvironment of all compositions of nanocolloids (including: decarboxylation of pro-RNase composition to restore the native RNase A, ionization of CaP composition to elicit osmotic pressure, and charge reversal of PEG-block-polyanion into membrane-disruptive polycation) could stimulate not only efficient endolysosomal escape for translocation into the cytosol but also structural disassembly for ready liberation of the RNase A payloads, eventually exerting non-specific RNA degradation for apoptosis of the affected cells. Systemic dosage of the proposed nanocolloids demonstrated potent anti-tumor efficacies towards xenograft glioma due to massive RNA degradation. Therefore, our proposed RNase A prodrug nanocolloids could represent as a versatile platform for engineering transcellular protein delivery systems, which are expected to spur thriving emergence of a spectrum of proteins in precision intervention of intractable diseases.

EXPERIMENTAL PARTICIPATION OF PHARMACOLOGICAL SUBSTANCES IN MECHANISMS OF LEAD ACETATE TOXICITY

The aim of the work is to study pharmacological substances that play a role of eNOS expression regulators in the modification of lead intoxication effects in the experiment.

Materials and methods. In the experiment, linear male rats of the same age were used: intact and with lead intoxication (120 heads). The study design was the following: group 1 – control; group 2 – intoxication with a lead acetate solution; group 3 – intact + L-nitroarginine methyl ester; group 4 – lead acetate + L-nitroarginine methyl ester; group 5 – intact + L-arginine; group 6 – lead acetate + L-arginine. The research carried out the study state of the redox reactions, the content of nitric oxide (NOx) stable metabolites, a lipid profile, the level of NO-synthase (eNOS) expression in the vascular endothelium, the main processes of urination and the activity of Na+/K+-ATPase in the renal tissue layers, as well as in the liver. The results were subjected to statistical processing.

Results. Saturnism caused the oxidative stress development, a decrease in the NOx content in blood plasma, a violation of the L-arginine for eNOS bioavailability, and an endothelial dysfunction. Indicators of the impaired renal function were a decrease in the glomerular filtration rate (GFR), the tubular reabsorption of water, sodium, and the Na+/K+-ATPase activity. The damage to hepatocytes was evidenced by changes in the activity of organ-specific enzymes in the blood and Na+/K+-ATPase. L-arginine exhibited antioxidant properties, increased the NOx content and the level of eNOS expression. The eNOS L-nitroarginine methyl ester inhibitor showed the effects opposite to L-arginine.

Conclusion. Biochemical markers of damage to kidney and liver cells during saturnism are indicators of the oxidative stress, NOx deficiency and hemodynamic disturbances in them. These mechanisms involved the following pharmacological substances: an eNOS inhibitor, L-nitroarginine methyl ester, which caused a decrease in the expression level of the enzyme, and an eNOS inducer, L-arginine, which increased this indicator severity. The lead toxicity mechanisms have been implicated in the impaired cholesterol metabolism, contributing to the L-arginine reduced availability for eNOS and the NOx production. Therefore, the use of L-arginine can be recommended as a regulator of the oxidative stress and an NO-producing endothelial function in other pathologies.