Comparison of wound healing effects between Oncorhynchus keta-derived polydeoxyribonucleotide (PDRN) and Oncorhynchus mykiss-derived PDRN

Comment on "Polydeoxyribonucleotide Exerts Therapeutic Effect by Increasing VEGF and Inhibiting Inflammatory Cytokines in Ischemic Colitis Rats"

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Therapeutic effects of polydeoxyribonucleotide in an in vitro neuronal model of ischemia/reperfusion injury

Polydeoxyribonucleotide (PDRN) is an agonist that selectively stimulates adenosine A_2A receptor (ADORA2A), which suppresses inflammatory responses. Ischemia/reperfusion (I/R) injury plays a major role in the pathogenesis of ischemic stroke by inducing neuroinflammation. Therefore, this study aimed to investigate the therapeutic effects of PDRN in an in vitro I/R injury model. The in vitro model was established with differentiated Neuro-2a cells under oxygen and glucose deprivation condition. The cells were treated with PDRN for 24 h under reoxygenation condition. As the results of RNA-seq transcriptome analysis, CSF1, IL-6, PTPN6, RAC2, and STAT1 were identified of its relation to the effect of PDRN on inflammatory responses in the model. To further investigate therapeutic effects of PDRN, RT-qPCR, western blotting, LDH assay, and TUNEL assay were performed. PDRN significantly reversed the expression of genes and proteins related to inflammatory responses. The elevated ADORA2A expression by PDRN treatment downregulated JAK/STAT pathway in the model. Furthermore, PDRN inhibited neuronal cell death in the model. Consequently, our results suggested that PDRN alleviated inflammatory responses through inhibition of JAK/STAT pathway by mediating ADORA2A expression and inhibited neuronal cell death in the model. These results provide significant insights into potential therapeutic approaches involving PDRN treatment for I/R injury.

Dietary administration of silk microparticles improves the epidermal and dermal regeneration after a skin wounding in gilthead seabream (Sparus aurata L.)

The impact of dietary supplementation with silk fibroin (SF) microparticles on the wound healing process in gilthead seabream (Sparus aurata) skin was studied. A control diet was enriched with different SF levels: 0 (control), 50 (SF50 diet), and 100 (SF100 diet) mg Kg^-1 to form three experimental diets and was fed to seabream for 30 days. Experimental wounds were performed and after 7 days post-wounding (dpw) skin mucus immunity, macroscopic wound closure, and skin regeneration were studied at a microscopic and genetic level. Results indicated that fish fed SF100 did not suffer the decreases in protease and IgM levels observed in the skin mucus of wounded fish fed with the control diet. Macroscopic findings illustrated that dietary SF100 significantly improved the wound closure ratio compared to those reared in the control group. At a microscopic level, changes in the shape of keratocyte cells were evident in the wounded fish. In addition, the intercellular spaces present between epidermal cells and their proliferation in the epidermis, as well as the presence of blood vessels in the dermis were significantly statistically higher in the skin of fish fed the SF100 diet and sampled at 7 dpw compared to those observed in the skin of fish fed the control or SF50 diets. Moreover, regarding the RNA: DNA ratio, statistically significant increases and decreases were observed in fish fed the control and SF100 diet, respectively, in non-wounded and wounded fish. Interestingly, dietary SF100 supplementation improved skin cell proliferation, enhanced the inflammatory phase, and increased the expression of important genes involved in tissue repair and extracellular matrix formation. In conclusion, the SF100 diet can be considered as an appropriate feed additive to improve wound healing in gilthead seabream.

Amelioration of alcohol‑induced gastric mucosa damage by oral administration of food‑polydeoxyribonucleotides

Gastritis refers to inflammation caused by injury to the gastric epithelium, which is usually due to excessive alcohol consumption and prolonged use of nonsteroidal anti-inflammatory drugs. Millions of individuals worldwide suffer from this disease. However, the lack of safe and promising treatments makes it urgent to explore and develop leads from natural resources. Therefore, food as medicine may be the best approach for the treatment of these disorders. The present study described the protective effects of food-polydeoxyribonucleotides (f-PDRNs) in a rat model of gastric mucosal injury induced by HCl-EtOH. Administration of f-PDRN was performed with low-PRF002 (26 mg/kg/day), medium-PRF002 (52 mg/kg/day) and high-PRF002 (78 mg/kg/day) on the day of autopsy. The site of damage to the mucous membrane was also analysed. In addition, an increase in gastric juice pH, total acidity of gastric juice and decrease in gastric juice secretion were confirmed, and gastric juice secretion-related factors corresponding to the administration of f-PDRN were analysed. Administration of f-PDRN reduced the mRNA expression of histamine H2 receptor, muscarinic acetylcholine receptor M3, cholecystokinin 2 receptor and H⁺/K⁺ ATPase related to gastric acid secretion and downregulation of histamine, myeloperoxidase and cyclic adenosine monophosphate. In addition, it was histologically confirmed that the loss of epithelial cells and the distortion of the mucosa were recovered in the group in which f-PDRN was administered compared to the model group with gastric mucosa damage. In summary, the present study suggested that f-PDRN has therapeutic potential and may have beneficial effects if taken regularly as a food supplement.

Applications of Marine Organism-Derived Polydeoxyribonucleotide: Its Potential in Biomedical Engineering

Polydeoxyribonucleotides (PDRNs) are a family of DNA-derived drugs with a molecular weight ranging from 50 to 1500 kDa, which are mainly extracted from the sperm cells of salmon trout or chum salmon. Many pre-clinical and clinical studies have demonstrated the wound healing and anti-inflammatory properties of PDRN, which are mediated by the activation of adenosine A2A receptor and salvage pathways, in addition to promoting osteoblast activity, collagen synthesis, and angiogenesis. In fact, PDRN is already marketed due to its therapeutic properties against various wound healing- and inflammation-related diseases. Therefore, this review assessed the most recent trends in marine organism-derived PDRN using the Google Scholar search engine. Further, we summarized the current applications and pharmacological properties of PDRN to serve as a reference for the development of novel PDRN-based technologies.

Effect of additive-assisted fat transplantation on fat graft survival rate: A preliminary experimental study based on a rabbit animal model

BACKGROUND

Improving the survival rate of fat grafts is yet a difficult problem in the field of autologous fat transplantation. Prevailing methods such as making nanofat and SVF are time-consuming. Hence, the role of additives application in the improvement of fat graft survival during fat transplantation was considered and preliminarily evaluated in a rabbit animal model.

METHODS

A rabbit animal model was established where rabbit ears were injected with a mixture of 1.5mL of adipose tissue and 1mL of saline (group A), 1.5mL of adipose tissue and 1mL of botulinum toxin A (BoNTA) (group B), 1.5mL of adipose tissue and 1mL of prostaglandin E2 (groupC), 1.5mL of adipose tissue and 1mL of PDRN (group D) respectively. Then, the extents of neovascularization and inflammation were evaluated on the 7th, 14th, 28th, 42nd, 56th and 70th day after injection by ELISA assays and H&E and immunofluorescence staining.

RESULTS

The results showed that pre-treatment with BoNTA, prostaglandin E2 and PDRN improved graft volume and weight. The H&E and immunofluorescence staining revealed that BoNTA, prostaglandin E2 and PDRN improved the graft angiogenesis. Simultaneously, TNF-α expression level detected by ELISA was the lowest in the PDRN group.

CONCLUSION

Henceforth, the present preliminary study suggests that pre-transplantation treatment with BoNTA, prostaglandin E2 and PDRN can improve the fat graft angiogenesis and graft integrity, whereby the effect of adding PDRN may be significant.

The effects of polydeoxyribonucleotide on wound healing and tissue regeneration: a systematic review of the literature

Aim: The present study evaluated the effects of polydeoxyribonucleotide (PDRN) on tissue regeneration, paying special attention to the molecular mechanisms that underlie its tissue remodeling actions to better identify its effective therapeutic potential in wound healing. Materials & methods: Strategic searches were conducted through MEDLINE/PubMed, Google Scholar, Scopus, Web of Science and the Cochrane Central Register of Controlled Trials, from their earliest available dates to March 2020. The studies were included with the following eligibility criteria: studies evaluating tissue regeneration, and being an in vitro, in vivo and clinical study. Results: Out of more than 90 articles, 34 fulfilled the eligibility criteria. All data obtained proved the ability of PDRN in promoting a physiological tissue repair through salvage pathway and adenosine A2A receptor activation. Conclusion: Up to date PDRN has proved promising results in term of wound regeneration, healing time and absence of side effects.

Effect of Polydeoxyribonucleotide on Chondrocutaneous Composite Grafts Survival

BACKGROUND

A composite graft is considered the best choice for facial reconstruction because of proper texture, color, and simple surgical techniques. However, due to revascularization by the bridging phenomenon, it has limitations with unpredictable survival rates and can be applied only to small defects. Polydeoxyribonucleotide (PDRN) plays an important role in multiple vascular processes such as angiogenesis via production of a vascular endothelial growth factor and by providing an anti-inflammatory effect by reducing pro-inflammatory cytokines through the adenosine A2 receptor stimulation. Thus, here, we investigated PDRN as a supportive method to improve survival of composite grafts.

METHODS

Chondrocutaneous composite grafts were applied to both ears of 20 New Zealand White rabbits. The grafts were then rotated and returned to their positions to prevent the original blood flow from the base of the grafts. On postoperative days 1, 3, 6, 9, and 12, PDRN was injected intradermally into the experimental group (20 ears) and normal saline was injected into the control group (20 ears) to exclude bias of pressure effect. After 12 days, graft survival and cutaneous blood flow were examined under laser speckle contrast imaging.

RESULTS

Gross observation indicated that the graft viability in the PDRN group was significantly higher than that in the control group (p < 0.05). Through laser speckle contrast imaging, signal intensity increased from the periphery and progressed centrally with treatment.

CONCLUSION

Our findings suggest that PDRN may increase blood flow around at the base of the graft, restore the perfusion, and improve the survival of the composite grafts.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The Effect of Polydeoxyribonucleotide Extracted from Salmon Sperm on the Restoration of Bisphosphonate-Related Osteonecrosis of the Jaw

Bisphosphonates (BPs) used for treating skeletal diseases can induce bisphosphonate-related osteonecrosis of the jaw (BRONJ). Despite much effort, effective remedies are yet to be established. In the present study, we investigated the feasibility of polydeoxyribonucleotide (PDRN) extracted from salmon sperm for the treatment of BRONJ, in a BRONJ-induced rat model. Compared with BRONJ-induced samples, PDRN-treated samples exhibited lower necrotic bone percentages and increased numbers of blood vessels and attached osteoclast production. Moreover, local administration of PDRN at a high concentration (8 mg/kg) remarkably resolved the osteonecrosis. Findings from this study suggest that local administration of PDRN at a specific concentration may be considered clinically for the management of BRONJ.

An effective range of polydeoxyribonucleotides is critical for wound healing quality

Wound healing is a physiological restorative response to tissue and cell injury. This process occurs in collaboration with a complex cascade of cellular events, including biochemical alterations to the extracellular matrix. Polydeoxyribonucleotide (PDRN) is a fragmented DNA mixture from Oncorhynchus mykiss or Oncorhynchus keta sperm known to promote tissue regeneration under different pathophysiological conditions. However, the most effective molecular size of PDRNs for promoting the wound healing process and quality has not been established. In the present study, the regeneration quality with low (<50 kDa), middle [classic PDRN; 50‑1,500 kDa] and high (>1,500 kDa) molecular weight PDRNs in a skin wound healing mouse model was examined using hematoxylin and eosin, as well as Masson's trichrome stain. A 4 mm biopsy punch was used to produce wounds in the skin of the mice. PDRN‑mediated cellular behavior and signaling were evaluated by in vitro scratch assay and western blot analysis, respectively. It was observed that the apparent surface wound healing processes were not significantly different between PDRN molecular sizes. Immunohistochemical analysis revealed that classic PDRN‑injected mice exhibited less lipid accumulation with increased collagen composition. These results suggested that 50‑1,500 kDa PDRN offers an effective DNA mixture to improve wound healing quality. Furthermore, classic PDRN increased cell migration via c‑Jun N‑terminal kinase signaling in human fibroblasts. The present study suggests an optimal PDRN molecular weight to promote wound healing, and novel approaches for therapeutic strategies to improve tissue regeneration quality.