Polydeoxyribonucleotide Ameliorates Inflammation and Apoptosis in Achilles Tendon-Injury Rats

Adenylate cyclase activates the cAMP signalling pathway to enhance platelet-rich plasma-treated Achilles tendon disease, a theoretical bioinformatics-based study

The effectiveness of platelet-rich plasma (PRP) for the treatment of Achilles tendon disorders still needs to be evaluated through a series of prospective studies, but genomic analysis can reveal the existence of complementary PRP treatment options. Based on the 96 platelet activation-related genes in the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, we performed Gene Ontology functional enrichment analysis and KEGG enrichment analysis, pathway correlation analysis, and enrichment mapping to determine the enrichment results of the gene set enrichment analysis and found that the cAMP signalling pathway may be the key to enhancing the effectiveness of PRP treatment. The cAMP signalling pathway interacts with the Rap1 signalling pathway and cGMP-PKG signalling pathway to mediate the entire pathophysiological process of Achilles tendon disease. Moreover, ADCY1-9 may be the key to the activation of the cAMP signalling network. Further based on the data in the Gene Expression Omnibus database, it was found that ADCY4 and ADCY7 may be the players that play a major role, associated with the STAT4-ADCY4-LAMA5 axis and the GRbeta-ADCY7-SEMA3C axis, which is expected to be a complementary target for enhancing the efficacy of PRP in the treatment of Achilles tendon disease.

Adenosine A2A Receptor Agonist, Polydeoxyribonucleotide Treatment Improves Locomotor Function and Thermal Hyperalgesia Following Neuropathic Pain in Rats

PURPOSE

Lithotomy position has been widely used in the various urologic surgery. Occasionally sensory and motor problems of the lower extremities are occurred due to the lithotomy position and these deficits may be related with sciatic nerve injury (SNI). Inflammatory process is a factor to induce functional impairment after SNI. Therefore, we evaluated the role of adenosine A2A receptor agonists, polydeoxyribonucleotide (PDRN) showing anti-inflammatory effect on locomotor function following SNI in rats.

METHODS

Sciatic nerve was compressed with surgical clips for 1 minute after exposing of right sciatic nerve. After 3 days of SNI, PDRN (2, 4, and 8 mg/kg) was applied to the damaged area of sciatic nerve once daily for 10 days. Walking track analysis was conducted for locomotor function and plantar test was performed for thermal pain sensitivity. Level of cyclic adenosine-3´,5´-monophosphate (cAMP) were measured using enzyme-linked immunosorbent assay. Western blot analysis was performed for tumor necrosis factor (TNF)-α, interleukin (IL)-1β, cAMP response element binding protein (CREP), vascular endothelial growth factor (VEGF). Immunofluorescence for neurofilament was also conducted.

RESULTS

Locomotor function was decreased and thermal pain sensitivity was increased by SNI. SNI enhanced proinflammatory cytokines' production, such as TNF-α and IL-1β, while suppressed CREP phosphorylation and cAMP level. SNI also reduced the expression of VEGF and neurofilaments. However, treatment with PDRN inhibited proinflammatory cytokines' production and upregulated CREP phosphorylation and cAMP expression. PDRN also enhanced the expression of VEGF and neurofilaments. As a result, PDRN improved locomotor function and alleviated thermal hyperalgesia after SNI.

CONCLUSION

PDRN has shown potential to be used as an effective treatment for neuropathic pain.

From fetal tendon regeneration to adult therapeutic modalities: TGF-β3 in scarless healing

Tendon injuries are common disorders that can significantly impact people's lives. Unfortunately, the limited regenerative ability of tendons results in tissue healing in a scar-mediated manner. The current therapeutic strategies fail to fully recover the functions of the injured tendons, and as such, the conception of 'scarless healing' has gained prominent attention in the field of regenerative medicine. Interestingly, injured fetal tendons possess the capability to heal through regeneration, which builds an ideal blueprint for adult tendon regeneration. Studies have shown that fetal biochemical cues have the potential to improve adult tendon healing. Here we review the biological factors that contribute to fetal tendon regeneration and how manipulation of these biochemical cues in the adult tendon healing process could achieve regeneration.

Inflammation-related signaling pathways in tendinopathy

Tendon is a connective tissue that produces movement by transmitting the force produced by muscle contraction to the bones. Most tendinopathy is caused by prolonged overloading of the tendon, leading to degenerative disease of the tendon. When overloaded, the oxygen demand of tenocytes increases, and the tendon structure is special and lacks blood supply, which makes it easier to form an oxygen-deficient environment in tenocytes. The production of reactive oxygen species due to hypoxia causes elevation of inflammatory markers in the tendon, including PGE2, IL-1β, and TNF-α. In the process of tendon healing, inflammation is also a necessary stage. The inflammatory environment formed by cytokines and various immune cells play an important role in the clearance of necrotic material, the proliferation of tenocytes, and the production of collagen fibers. However, excessive inflammation can lead to tendon adhesions and hinder tendon healing. Some important and diverse biological functions of the body originate from intercellular signal transduction, among which cytokine mediation is an important way of signal transduction. In particular, NF-κB, NLRP3, p38/MAPK, and signal transducer and activator of transcription 3, four common signaling pathways in tendinopathy inflammatory response, play a crucial role in the regulation and transcription of inflammatory factors. Therefore, summarizing the specific mechanisms of inflammatory signaling pathways in tendinopathy is of great significance for an in-depth understanding of the inflammatory response process and exploring how to inhibit the harmful part of the inflammatory response and promote the beneficial part to improve the healing effect of the tendon.

Up-regulation of CREB-1 regulates tendon adhesion in the injury tendon healing through the CREB-1/TGF-β3 signaling pathway

AIM

To explore the mechanism of the healing of tendon tissue and anti-adhesion, and to discuss the role of the transforming growth factor-β3 (TGF-β3)/cAMP response element binding protein-1 (CREB-1) signaling pathway in the healing process of tendons.

METHOD

All mice were divided into four groups of 1, 2, 4, and 8 weeks respectively. Each time group was divided into four treatment groups: the amplification group, the inhibition group, the negative group, and the control group. When the tendon injury model was established, the CREB-1 virus was injected into the tendon injury parts. A series of methods such as gait behaviourism, anatomy, histological examination, immunohistochemical examination and collagen staining were employed to assess the tendon healing and the protein expression of TGF-β3, CREB-1, Smad3/7 and type I/III collagen (COL-I/III). CREB-1 virus was sent to tendon stem cells to assess the protein expression of TGF-β1, TGF-β3, CREB-1, COL-I/III by methods such as immunohistochemistry and Western blot.

RESULTS

The amplification group showed better gait behaviourism than the inhibition group in the healing process. The amplification group also had less adhesion than the negative group. Hematoxylin-eosin (HE) staining of tendon tissue sections showed that the number of fibroblasts in the amplification group was less than the inhibition group, and the immunohistochemical results indicated that the expression of TGF-β3, CREB-1, and Smad7 at each time point was higher than the inhibition group. The expression of COL-I/III and Smad3 in the amplification group was lower than the inhibition group at all time points. The collagen staining indicated that the ratio of type I/III collagen in the amplification group was higher than the negative group at 2,4,8 week. The CREB-1 amplification virus could promote the protein expression of TGF-β3, CREB-1 and inhibit the protein expression of TGF-β1 and COL-I/III in the tendon stem cells.

CONCLUSION

In the process of tendon injury healing, CREB-1 could promote the secretion of TGF-β3, so as to promote the tendon healing and have the effect of anti-adhesion in tendons. It might provide new intervention targets for anti-adhesion treatment of tendon injuries.

Caveolin-1 is involved in fatty infiltration and bone-tendon healing of rotator cuff tear

BACKGROUND

Caveolin-1 has been predicted, based on RNA transcriptome sequencing, as a key gene in rotator cuff tear (RCT) and it is related to fatty infiltration. This study aims to elucidate the upstream and downstream mechanism of Caveolin-1 in fatty infiltration and bone-tendon healing after RCT in rat models.

METHODS

Differentially expressed genes related to RCT were screened, followed by functional enrichment analysis and protein-protein interaction analysis. GATA6 was overexpressed and Caveolin-1 was knocked down in tendon stem cells (TSCs) to evaluate their effects on the adipogenic differentiation of TSCs. In addition, a RCT rat model was constructed and injected with lentivirus carrying oe-GATA6, oe-Caveolin-1 alone or in combination to assess their roles in fatty infiltration and bone-tendon healing. RESULTS AND CONCLUSION: Caveolin-1 was identified as a key gene involved in the RCT process. In vitro results demonstrated that Caveolin-1 knockdown inhibited adipogenic differentiation of TSCs by activating the cAMP/PKA pathway. GATA6 inhibited the transcription of Caveolin-1 and inhibited its expression, thus suppressing the adipogenic differentiation of TSCs. In vivo data confirmed that GATA6 overexpression activated the cAMP/PKA pathway by downregulating Caveolin-1 and consequently repressed fatty infiltration, promoted bone-tendon healing, improved biomechanical properties and reduced the rupture risk of injured tendon in rats after RCT. Overall, this study provides novel insights into the mechanistic action of Caveolin-1 in the fatty infiltration and bone-tendon healing after RCT.

Polydeoxyribonucleotide in the Treatment of Tendon Disorders, from Basic Science to Clinical Practice: A Systematic Review

Polydeoxyribonucleotide (PDRN) is a proprietary and registered drug with several beneficial effects, including tissue repairing, anti-ischemic action, and anti-inflammatory properties. The present study aims to summarize the current evidence about PRDN's clinical effectiveness in the management of tendon disorders. From January 2015 to November 2022, OVID-MEDLINE^®, EMBASE, Cochrane Library, SCOPUS, Web of Science, Google Scholar and PubMed were searched to identify relevant studies. The methodological quality of the studies was evaluated, and relevant data were extracted. Nine studies (two in vivo studies and seven clinical studies) were finally included in this systematic review. Overall, 169 patients (male: 103) were included in the present study. The effectiveness and safeness of PDRN has been investigated in the management of the following diseases: plantar fasciitis; epicondylitis; Achilles tendinopathy; pes anserine bursitis; chronic rotator cuff disease. No adverse effects have been recorded in the included studies and all the patients showed an improvement in clinical symptoms during the follow-up. PDRN are a valid emerging therapeutic drug in the treatment of tendinopathies. Further multicentric randomized clinical studies are needed to better define the therapeutic role of PDRN, especially in combined clinical protocols.

17β-Estradiol attenuates inflammation and tendon degeneration in a rat model of Achilles tendinitis

INTRODUCTION

17β-Estradiol (E2) is an immune-regulatory agent with anti-inflammatory effects. However, it is still unknown whether E2 exerts pharmacological properties against Achilles tendinitis (AT). This study aims to investigate the effects of E2 on AT and its underlying mechanisms.

MATERIALS AND METHODS

The established model of Achilles tendinitis was intraperitoneally injected with E2 (10, 20, or 30 μg/kg/d). After 8 weeks, biomechanical properties of the Achilles tendon were determined. Hydroxyproline content and tendon degeneration-related biomarkers were determined. The levels of inflammatory cytokines and apoptotic-related biomarkers in tendon tissues were determined. Furthermore, western blotting was determined to detect the expressions of ER-α and the PI3K/Akt pathway in tendon tissues.

RESULTS

E2 relieved AT-related symptoms in a dose-dependent manner. E2 ameliorated tendon degeneration by regulating tendon degeneration-related biomarkers (e.g., collagen type I and III, Decorin (DCN), and tenascin-C). Besides, treatment with E2 suppressed inflammatory cytokines and increased anti-inflammatory cytokines. Treatment with E2 also regulated cell apoptosis in tendon tissues. The underlying mechanism study revealed that treatment with E2 activated ER-α and upregulated the PI3K/Akt pathway.

CONCLUSION

The regulatory effects of E2 on inflammation and tendon degeneration in a rat model of AT were associated with the ER-α and the PI3K/Akt signaling pathways.

Evaluation of Therapeutic Effects of Quercetin Against Achilles Tendinopathy in Rats via Oxidative Stress, Inflammation, Apoptosis, Autophagy, and Metalloproteinases

BACKGROUND

Achilles tendinopathy, seen in athletes and manual labor workers, is an inflammatory condition characterized by chronic tendon pain. Owing to the toxicity that develops in various organs attributed to the use of anti-inflammatory drugs, there is a need for new therapeutic agents.

PURPOSE

In the present study, the effects of quercetin (Que), the one that attracted the most attention of researchers studying this group of flavonoids, were investigated against collagenase-induced tendinopathy.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 35 Sprague-Dawley rats were used in the study. Tendinopathy was created by injecting a single dose of collagenase (10 μL; 10 mg/mL) into the tendons of rats. Thirty minutes after the injection, Que was administered at doses of 25 or 50 mg/kg. Que administration was carried out for 7 days. Animals underwent a motility test at the end of the study. In addition, markers of oxidative stress, inflammation, apoptosis, and autophagy, as well as the expression levels of matrix metalloproteinases (MMPs 2, 3, 9, and 13), ICAM-1, and STAT3, were measured in tendon tissues with biochemical, molecular, and Western blot techniques.

RESULTS

The results showed that oxidative stress, inflammation, apoptosis, and autophagy were triggered by the injection of collagenase. In addition, MMPs, ICAM-1, and STAT3 were activated to participate in the development of tendinopathy. Que was found to reduce ICAM-1 levels in tendon tissue. Moreover, Que showed antioxidant, anti-inflammatory, antiapoptotic, and antiautophagic effects on tendons against tendinopathy. More important, Que suppressed the expression of MMPs in the tendon tissues.

CONCLUSION

Que has protective properties against collagenase-induced tendon damage in rats.

CLINICAL RELEVANCE

We believe that with further study, Que may be shown to be an alternative treatment option for athletes or others who experience tendon injuries.

Study on the pathogenesis of liver injury caused by alcohol and drugs

In the present study, alcohol, lipopolysaccharide (LPS), and carbon tetrachloride (CCL₄) were administered to experimental mice. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 concentrations, and collagen type 1alpha (COL-1A) and fibronectin expressions were measured to evaluate pathophysiology of liver injury. Levels of ALT and AST were significantly increased by alcohol treatment. Alcohol with LPS treatment increased ALT and AST levels more than alcohol alone treatment, but it was not statistically significant. Alcohol with CCL₄ treatment significantly increased ALT and AST levels more than alcohol alone treatment. Alcohol with LPS and CCL₄ treatment significantly increased ALT and AST levels more than alcohol with CCL₄ treatment. Concentrations of TNF-α, IL-1β, and IL-6 were significantly enhanced by alcohol treatment. Alcohol with LPS treatment significantly enhanced concentrations of TNF-α, IL-1β, and IL-6 more than alcohol alone treatment. Alcohol with CCL₄ treatment significantly enhanced TNF-α, IL-1β, and IL-6 concentrations more than alcohol alone treatment. Alcohol with LPS and CCL₄ treatment increased TNF-α, IL-1β, and IL-6 concentrations more than alcohol with CCL₄ treatment, but it was not statistically significant. COL-1A and fibronectin expressions were significantly increased by alcohol treatment. Alcohol with LPS treatment significantly increased COL-1A and fibronectin expressions more than alcohol alone treatment. Alcohol with CCL₄ treatment significantly increased COL-1A and fibronectin expressions more than alcohol alone treatment. Alcohol with LPS and CCL₄ treatment increased COL-1A and fibronectin expressions more than alcohol with CCL₄ treatment, but it was not statistically significant.

Gait analysis combined with the expression of TGF-β1, TGF-β3 and CREB during Achilles tendon healing in rat

PURPOSE

To observe the changes of gait behavior and the expression of wound healing factors of transforming growth factor-β1 (TGF-β1), TGF-β3 and cAMP response element binding protein-1 (CREB-1) during the healing of Achilles tendon in a rat model, and to investigate whether gait analysis can be used to evaluate the tendon healing.

METHODS

Achilles tendon of 40 healthy male Sprague-Dawley rats were transected and sutured to establish the Achilles tendon injury (ATI) model. They were randomly divided into 4 groups based on the observational time point at 1, 2, 4 and 6 weeks after injury (n = 10 for each group). Before modeling, 9 rats were randomly selected for CatWalk gait analysis, which contained step cycle, single stance time and average speed. Data were recorded as the normal controls. After then, ATI models were established in the left hind limbs of the all 40 rats (ATI group), while the right hind limbs were only cut and sutured without injury of the Achilles tendon (sham operation group). At 1, 2, 4 and 6 weeks after injury, the gait behavior of the corresponding group of rats (n = 9) as observed and recorded by CatWalk platform. After then, the rats were sacrificed and Achilles tendon of both limbs was harvested. The tendon healing was observed by gross anatomy and histological examination, and the protein and mRNA expression of TGF-β1, TGF-β3, CREB-1 were observed by immunohistochemistry and qPCR. The results of tendon gross grading were analyzed by Wilcoxon rank sum test, and other data were analyzed by one-way analysis of variance among multiple groups.

RESULTS

Compared with normal controls, all gait indexes (step cycle, single stance time and average speed) were greatly affected following ATI, which however improved with time. The step cycle was significantly lower at 1, 2 and 4 weeks after ATI (compared with normal controls, all p < 0.05), but almost returned to the normal level at 6 weeks ((0.694 ± 0.102) vs. (0.503 ± 0.094) s, p > 0.05). The single stance time of the ATI group was significantly shorter at 1 and 2 weeks after operation ((0.078 ± 0.010) s at 1 week, (0.078 ± 0.020) s at 2 weeks, all p < 0.001) and revealed no significant difference at 4 weeks (p = 0.120). The average speed of ATI group at 1, 2, 4, 6 weeks was significantly lower than that in the normal control group (all p < 0.001). Gross observation showed that the grade of local scar adhesion in ATI group increased significantly at 2, 4 and 6 weeks, compared with the sham operation group (all p < 0.001). Extensive adhesion was formed at 6 weeks after ATI. The results of HE staining showed that the number of fibroblast increased gradually and arranged more orderly in ATI group at 1, 2 and 4 weeks (all p < 0.001), and decreased at 6 weeks, but it was still significantly higher than that of the sham operation group (p < 0.001). Immunohistochemistry showed that the positive expression of TGF-β1, TGF-β3, CREB-1 in ATI group was higher than that in the sham operation group at 4 time points (all p < 0.05), which reached the peak at 2 weeks after operation and decreased at 4 weeks (p = 0.002, p < 0.001, p = 0.041, respectively). The results of qPCR suggested that the mRNA expression of TGF-β1, TGF-β3, CREB-1 in ATI group was higher than that in the sham operation group at all-time points (all p < 0.05), which reached the peak at 2 weeks after operation, decreased at 4 weeks, and significantly decreased at 6 weeks (all p < 0.001).

CONCLUSION

Gait behavior indexes are associated with Achilles tendon healing. The study gives an insight of TGF-β1, TGF-β3, CREB-1 changes in the coursing of Achilles tendon healing and these cytokines may be able to be used to regulate the Achilles tendon healing.

Metformin and Sildenafil Attenuate Inflammation and Suppress Apoptosis After Ischemia/Reperfusion Injury in Rat Urinary Bladder

Purpose

Although metformin and sildenafil can protect various organs against ischemia/reperfusion (I/R) injury, their effects and mechanisms of action in bladder I/R injury remain unknown. This study investigated the effects and mechanisms of action of metformin and sildenafil against bladder I/R insult in rats.

Methods

One hundred male Sprague-Dawley rats were randomly divided into five groups each of twenty rats: a sham-operated group, a bladder I/R group, and bladder I/R groups treated with metformin, sildenafil, or both agents. Ischemia was induced by clamping the bilateral common iliac arteries with atraumatic vascular clamps for 2 hours, followed by reperfusion for 7 days. During this period, rats were injected once daily with 4 mg/kg metformin and/or 1 mg/kg sildenafil.

Results

The increased malondialdehyde (MDA) levels and myeloperoxidase (MPO) activities and the decreased superoxide dismutase (SOD) activities induced by I/R injury were reduced by treatment with metformin and/or sildenafil. The I/R group had significantly higher JNK, p38 MAPK, Bax, caspase-3, and NF-κB levels, and lower ERK and Bcl-2 levels in the bladder than the sham-operated group; these changes were significantly ameliorated by metformin and/or sildenafil treatment. No differences in the levels of these markers were observed between rats co-administered metformin and sildenafil and those treated with either agent alone.

Conclusions

Metformin and sildenafil protected rat bladder against I/R injury. This effect may be due to the inhibition of ROS production through MAPKs, Bax, and Bcl-2 activation, and the restoration of inflammation through NF-κB inhibition. However, the combination of metformin and sildenafil was no more effective than either agent alone.

A Systematic Review of Therapeutic Approaches Used in Experimental Models of Interstitial Cystitis/Bladder Pain Syndrome

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a multifactorial, chronic bladder disorder with limited therapeutic options currently available. The present review provides an extensive overview of therapeutic approaches used in in vitro, ex vivo, and in vivo experimental models of IC/BPS. Publications were identified by electronic search of three online databases. Data were extracted for study design, type of treatment, main findings, and outcome, as well as for methodological quality and the reporting of measures to avoid bias. A total of 100 full-text articles were included. The majority of identified articles evaluated therapeutic agents currently recommended to treat IC/BPS by the American Urological Association guidelines (21%) and therapeutic agents currently approved to treat other diseases (11%). More recently published articles assessed therapeutic approaches using stem cells (11%) and plant-derived agents (10%), while novel potential drug targets identified were proteinase-activated (6%) and purinergic (4%) receptors, transient receptor potential channels (3%), microRNAs (2%), and activation of the cannabinoid system (7%). Our results show that the reported methodological quality of animal studies could be substantially improved, and measures to avoid bias should be more consistently reported in order to increase the value of preclinical research in IC/BPS for potential translation to a clinical setting.

Polydeoxyribonucleotide Attenuates Airway Inflammation Through A2AR Signaling Pathway in PM10-Exposed Mice

Purpose

Inhalation of air containing high amounts of particular matter (PM) causes various respiratory disorders including asthma, chronic obstructive pulmonary disease, and lung cancer. The changes of expression of inflammatory factors by polydeoxyribonucleotide (PDRN) administration in the PM₁₀-exposed trachea inflammation model were evaluated.

Methods

PM₁₀ was administered to mouse trachea to induce acute inflammatory damage, and changes in inflammatory factors were observed after administration of PDRN and 3,7-dimethyl-1-propargylxanthine (DMPX) for 3 days daily. Expression of inflammatory cytokines, adenosine A_2A receptor (A_2AR), protein kinase A (PKA), 3΄,5΄-cyclic adenosine monophosphate responsive element binding protein (CREB) were detected by enzyme‐linked immunosorbent assay, immunofluorescence, and western blot assay.

Results

PM-exposed trachea showed increased tumor necrosis factor (TNF)-α and interleukin (IL)-1β expression, and expression of TNF-α and IL-1β was inhibited by PDRN treatment in PM-exposed mice. PM-exposed trachea showed increased nuclear factor (NF)-κB phosphorylation, and phosphorylation of nuclear factor-kappa B was inhibited by PDRN treatment in PM-exposed mice. PM-exposed trachea showed increased expression of A_2AR, but PDRN treatment more enhanced A_2AR expression in PM-exposed mice. PKA phosphorylation was not changed and CREP phosphorylation was decreased, however PDRN treatment increased phosphorylation of PKA and CREB in PM-exposed mice. DMPX treatment blocked all the effects of PDRN on PM-exposed mice, demonstrating that the action of PDRN occurs via A_2AR.

Conclusions

PDRN treatment attenuated inflammation in the trachea of the PM₁₀-exposed mice. This improving effect of PDRN can be ascribed to the activation of A_2AR through the cAMP-PKA pathway.

Voluntary Wheel Running Exercise Improves Aging-Induced Sarcopenia via Activation of Peroxisome Proliferator-Activated Receptor Gamma Coactivator-1α/Fibronectin Type III Domain-Containing Protein 5/Adenosine Monophosphate-Activated Protein Kinase Signaling Pathway

Purpose

In this study, the protective effect of voluntary wheel running exercise on muscle loss and muscle weakness in gastrocnemius of old rats was investigated. The association of voluntary wheel exercise with the peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α)/fibronectin type III domain-containing protein 5 (FNDC5)/adenosine monophosphate- activated protein kinase (AMPK) signaling pathway and vascular endothelial growth factor (VEGF) expression was also evaluated.

Methods

Six-month-old and 22-month-old male rats were used for this experiment. The rats in voluntary wheel running exercise groups were performed wheel running for 2 months. Weight bearing test for walking strength, rotarod test for motor coordination and balance, hematoxylin and eosin (H&E) staining for histological changes in the muscle tissues, Western blot analysis for PGC-1α, FNDC5, AMPK, immunofluorescence for VEGF were conducted.

Results

Decreased muscle mass, strength, and coordination due to aging were associated with a decrease in the PGC-1α/FNDC5/AMPK signaling pathway in the gastrocnemius. Voluntary wheel running exercise enhanced VEGF expression by activating the PGC-1α/FNDC5/AMPK signaling pathway, then increased muscle mass, strength, and coordination.

Conclusions

It has been suggested that voluntary wheel running exercise alleviates symptoms of urological diseases that are difficult to treat. Wheel running exercise is a good therapeutic strategy to prevent or treat aging-related sarcopenia.

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.

NLRP3 Inflammasome: A New Pharmacological Target for Reducing Testicular Damage Associated with Varicocele

Many bioactive natural compounds are being increasingly used for therapeutics and nutraceutical applications to counteract male infertility, particularly varicocele. The roles of selenium and Polydeoxyribonucleotide (PDRN) were investigated in an experimental model of varicocele, with particular regard to the role of NLRP3 inflammasome. Male rats underwent sham operation and were daily administered with vehicle, seleno-L-methionine (Se), PDRN, and with the association Se-PDRN. Another group of rats were operated for varicocele. After twenty-eight days, sham and varicocele rats were sacrificed and both testes were weighted and analyzed. All the other rats were challenged for one month with the same compounds. In varicocele animals, lower testosterone levels, testes weight, NLRP3 inflammasome, IL-1β and caspase-1 increased gene expression were demonstrated. TUNEL assay showed an increased number of apoptotic cells. Structural and ultrastructural damage to testes was also shown. PDRN alone significantly improved all considered parameters more than Se. The Se-PDRN association significantly improved all morphological parameters, significantly increased testosterone levels, and reduced NLRP3 inflammasome, caspase-1 and IL-1β expression and TUNEL-positive cell numbers. Our results suggest that NLRP3 inflammasome can be considered an interesting target in varicocele and that Se-PDRN may be a new medical approach in support to surgery.