Platelet-Rich Plasma Promotes the Proliferation of Human Keratinocytes via a Progression of the Cell Cycle. A Role of Prolidase

The Effectiveness of Treating Osgood-Schlatter Disease (OSD) with Leukocyte-Rich Platelet-Rich Plasma (LR-PRP) Depending on the Duration of the Disease

Background: Osgood-Schlatter disease (OSD) occurs mainly in physically active adolescents, causing significant physical activity restrictions. The aim of this study is to compare the effectiveness of treating OSD with leukocyte-rich platelet-rich plasma (LR-PRP) depending on the duration of the disease and to attempt to develop an alternative treatment method to the currently used conservative therapy. Methods: Treatment efficacy was evaluated using the VAS, Tegner, Lysholm, and KOOS scales. Subject satisfaction, return to sports activity, potential adverse effects, and X-ray evaluation were likewise used to assess the success of the procedure. Results: Analysis across all scales showed statistically significant treatment effectiveness with LR-PRP in both groups of patients. When comparing the two groups, significantly better treatment outcomes were achieved in the acute phase of OSD. Treatment satisfaction in the acute OSD group was 95%, compared to 64% in the chronic group. The MCID value after LR-PRP injection in acute OSD compared to chronic OSD reached 100% vs. 81% on the VAS scale, 95.5% vs. 55% on the Tegner scale, 95% vs. 47% on the Lysholm scale and 91% vs. 27% on the KOOS scale. No adverse effects were recorded in either group. Conclusions: The high efficacy of LR-PRP treatment in patients with acute OSD, in correlation with high safety, as well as rapid and lasting results, can be an effective and beneficial alternative to conservative treatment. This single procedure seems particularly justified in a group of young professional athletes, where absence from training can lead to serious consequences.

Effects of Testicular Platelet-Rich Plasma (PRP) Injection on Sperm Parameters in Men with Severe Oligoasthenoteratozoospermia (OAT): A Clinical Evaluation

BACKGROUND

Severe oligoasthenoteratozoospermia (OAT), characterized by a reduced sperm count, motility, and altered morphology, presents a significant challenge in the field of male infertility. Platelet-rich plasma (PRP), renowned for its regenerative capabilities, emerges as a potential intervention for this condition. This study aims to explore the impact of PRP on male infertility, focusing specifically on individuals with severe OAT.

MATERIALS AND METHODS

The clinical trial study involved 88 infertile men diagnosed with OAT and devoid of underlying diseases. These participants were referred to the infertility center and subsequently divided into two cohorts: a control (44 individuals) and an intervention group (44 individuals). Patients in the intervention group received 2 cc of PRP in each testicle, prepared by centrifuging the patients autologous blood samples. Sperm parameters and DNA fragmentation index (DFI) of the patients were measured before and after the procedure. Statistical analysis used SPSS version 16 software, with a significance level set at less than 5%.

RESULTS

The statistical analysis revealed a significant difference in concentration (11.32 ± 8.44 vs. 16.06 ± 15.16, P=0.030), progressive motility (8.86 ± 7.79 vs. 11.97 ± 11.82%, P=0.014) and DNA fragmentation (25.62 ± 12.84 vs. 17.23 ± 9.15%, P<0.001) between the control and intervention groups after PRP injection. However, no significant difference was found in normal morphology (1.63 ± 1.44 vs. 1.81 ± 3.68%, P=0.628) and volume (2.13 ± 0.82 vs. 2.24 ± 1.43, P=0.663) between the control and intervention groups after PRP injection.

CONCLUSION

This study demonstrates the effectiveness of PRP treatment in increasing sperm concentration and motility, while also reducing sperm DNA fragmentation. However, further studies are needed to validate these findings (registration number: IRCT20220317054318N2).

Comparative evaluation of silver nanoparticles and human platelet rich-plasma versus traditional therapy in the treatment of murine chronic toxoplasmosis

Toxoplasmosis is a worldwide parasitic disease infecting about one-third of the human population. At present, licensed medications are incapable of curing human chronic infection. The present work aimed to evaluate for the first time the combination between (spiramycin and human platelet rich plasma), in addition to (spiramycin and silver-nanoparticles) in treating murine experimental toxoplasmosis using parasitological, biochemical, histopathological and immunohistochemical studies. Seventy-seven Swiss albino male mice divided into seven groups according to the treatment used as follows: (GI): control negative; (GII): control infected; (GIII): spiramycin; (GIV): Silver nanoparticles (AgNPs); (GV): Human platelet-rich plasma (HPRP); (GVI): combined spiramycin and AgNPs; (GVII): combined spiramycin and HPRP. Obtained results demonstrated that (spiramycin and AgNPs) treated group showed significant reduction of T. gondii tissue cysts number, the lowest level of serum malondialdehyde, remarkable improvement in pathological changes in different tissues of mice e.g. brain and liver and weak expression of EGFR in brain tissues of mice compared to control infected group. Moreover, AgNPs administered alone produced minimal anti-Toxoplasma results, whereas their combination with spiramycin exhibited significant therapeutic efficacy. In conclusion, combination therapy of spiramycin and AgNPs may represent a unique possible adjuvant therapy for reducing the pathogenic, toxic, and inflammatory consequences of toxoplasmosis on the brain and liver tissues in immunocompetent mice, and the expression of EGFR in brain tissues of mice is a good tool for evaluating the therapeutic improvement of murine toxoplasmosis.

Exploring the Association Between Age Groups and Success Patterns in Platelet-Rich Plasma Therapy: A Cohort Study

Objective This study aimed to comprehensively examine the correlation between success trends in platelet-rich plasma (PRP) therapy and the advancing age of patients undergoing fertility interventions. Methods Female participants were categorized randomly into five age groups undergoing PRP or conventional hormone replacement therapy. Procedures included controlled ovarian stimulation, escalating estrogen dosage, gonadotrophin injections, and embryo transfer post-ovulation trigger. A pivotal PRP intervention was provided to half of the age sub-groups, and endometrial thickness was assessed 24 hours prior to embryo transfer. Statistical analysis employed SPSS 26.0 for Windows Student Version (IBM Inc., Armonk, New York), incorporating descriptive statistics, one-way analysis of variance (ANOVA), Tukey's honestly significant difference (HSD) test to explore age-PRP success relationships (p<0.05). Results The study, involving 60 participants, revealed a balanced patient distribution across age groups, with 20-30 age groups contributing 23.33% each. Baseline characteristics showed no significant differences between PRP and hormone replacement therapy (HRT) groups. Post-intervention, PRP demonstrated consistently higher endometrial thickness (p<0.001) and clinical pregnancy rates (63.33%) compared to HRT (40%). These findings suggest a positive association between PRP therapy and improved outcomes, particularly in younger age cohorts. Conclusion The study challenges traditional perspectives on hormonal influences in fertility, highlighting a potential link between PRP therapy and favorable outcomes among younger age groups. Improved endometrial thickness and clinical pregnancy rates in the PRP group emphasize the need for further exploration of PRP's mechanisms and applications in reproductive medicine.

Enhanced Pain Relief and Function Improvement in Children with Osgood-Schlatter Disease: Leukocyte-Rich Platelet-Rich Plasma (LR-PRP) as a Complementary Treatment to Standard Conservative Therapy

BACKGROUND Osgood-Schlatter disease (OSD) causes pain and loss of function of the knee in growing children. This study aimed to evaluate pain and function of the knee joint in 152 growing children with chronic OSD before and after treatment with LR-PRP when used with standard conservative treatment. MATERIAL AND METHODS Treatment efficacy was evaluated using the VAS, Tegner, Lyshom, and KOOS scales. Patient satisfaction, post-surgery athletic performance, and X-ray assessment were also used to determine the success of the procedure. RESULTS We found that 75% of the subjects were satisfied with the results of the treatment, and 72% of the subjects returned to full physical activity. The analysis showed a significant decrease in the median VAS score after treatment compared to the pre-treatment score (P<0.05), and an increase in the median scores of the Tegner, Lysholm, and KOOS scales compared to the pre-treatment score (P<0.05; P<0.05; P<0.05, respectively). The results showed that the shorter the duration of the disease, the better the treatment results were received. Return to activity and patient satisfaction were highest in the study group previously rehabilitated. CONCLUSIONS LR-PRP injection of the tibial tuberosity in patients with chronic OSD with open growth cartilage is an effective and uncomplicated method. We did not observe any adverse effects, which suggests the relatively high safety of the procedure. The use of PRP in the earlier phase of the disease and additional rehabilitation before treatment significantly increases the effectiveness of treatment.

Clinical Study of Platelet-Rich Plasma (PRP) for Lower Extremity Venous Ulcers: A Meta-Analysis and Systematic Review

To systematically evaluate the clinical effects of platelet-rich plasma in the treatment of lower limb venous ulcers by applying a meta-analysis method. The Pubmed, Cochrance Library, Embase, and OVID EBM Reviews databases were searched for the search terms'platelet-rich plasma" or "Plasma, Platelet-Rich" or "Platelet Rich Plasma" and "lower extremity venous ulcers' or "Leg Ulcers' or "Ulcer, Leg", and a meta-analysis was performed on the published research literature on platelet-rich plasma for lower extremity venous ulcers from January 1900 to April 2021. The outcome indicators were: post-treatment trauma area and healing rate. Revman 5.3 statistical software was applied for meta-analysis. A total of 294 patients with lower extremity venous ulcers were included in six publications, including 148 patients in the experimental group treated with PRP versus 146 patients in the control group treated with conventional therapy. There was a statistically significant difference in the Formula of an ellipse at the end of treatment (CM²) between the experimental group and the control group, with a mean difference of -1.19 (95% CI -1.80 to -0.58, P = .0001; 6 studies, 294 participants moderate quality of evidence). The difference between the healing rate of the experimental group and the control group was statistically significant, with a risk ratio (RR) of 5.73 (95% CI 3.29 - 9.99, P < .00001; 5 studies, 248 participants moderate quality of evidence).There may be publication bias for both Formula of an ellipse at the end of treatment and healing rate. This comprehensive meta-analysis of available evidence suggests that the application of PRP for lower extremity venous ulcers accelerates the wound healing process and improves wound healing rates.

PRF Lysates Enhance the Proliferation and Migration of Oral Squamous Carcinoma Cell Lines

Platelet-rich fibrin (PRF) is an autologous fibrin-rich matrix where activated platelets and leucocytes accumulate. PRF has a wide spectrum of clinical indications with the overall aim of supporting tissue regeneration which in dentistry includes the healing of healthy oral mucosa with epithelial cells. In oral squamous cell carcinoma lesions, however, epithelial cells undergo malignant transformation, indicated by their unrestricted proliferation and migration potential, which should not be further enhanced by a wound-healing formula. Yet, little is known about how oral squamous cell carcinomas respond to PRF lysates. The aim of the present study was, therefore, to test the capacity of PRF lysates to change the transcriptome of HSC2 oral squamous carcinoma cells and perform bioassays to support the findings. Based on the RNAseq analysis, PRF lysates caused an increase in the genes functionally linked to cell replication and migration. In support of this screening approach, PRF lysates enhanced the proliferation of HSC2 oral squamous carcinoma cells, as indicated by 3[H]-thymidine incorporation, cell counting, and the expression of proliferation-related genes. Moreover, PRF lysates sped up cell migration in a scratch assay requiring actin polymerization. Taken together, our data showing that PRF lysates are mitogenic and stimulate motility of oral squamous carcinoma cell lines could be an indication that treatment with PRF in cases of oral carcinoma should be carefully considered.

Engineering homologous platelet-rich plasma, platelet-rich plasma-derived exosomes, and mesenchymal stem cell-derived exosomes-based dual-crosslinked hydrogels as bioactive diabetic wound dressings

The management of diabetic wounds remains a critical therapeutic challenge. Platelet-rich plasma (PRP) gel, PRP-derived exosomes (PRP-Exos), and mesenchymal stem cell-derived exosomes (MSC-Exos) have demonstrated therapeutic potential in wound treatment. Unfortunately, their poor mechanical properties, the short half-lives of growth factors (GFs), and the burst release of GFs and exosomes have limited their clinical applications. Furthermore, proteases in diabetic wounds degrade GFs, which hampers wound repair. Silk fibroin is an enzyme-immobilization biomaterial that could protect GFs from proteases. Herein, we developed novel dual-crosslinked hydrogels based on silk protein (SP) (sericin and fibroin), including SP@PRP, SP@MSC-Exos, and SP@PRP-Exos, to promote diabetic wound healing synergistically. SP@PRP was prepared from PRP and SP using calcium gluconate/thrombin as agonist, while SP@PRP-Exos and SP@MSC-Exos were derived from exosomes and SP with genipin as crosslinker. SP provided improved mechanical properties and enabled the sustained release of GFs and exosomes, thereby overcoming the limitations of PRP and exosomes in wound healing. The dual-crosslinked hydrogels displayed shear-induced thinning, self-healing, and eradication of microbial biofilms in a bone-mimicking environment. In vivo, the dual-crosslinked hydrogels contributed to faster diabetic wound healing than PRP and SP by upregulating GFs expression, down-regulating matrix metalloproteinase-9 expression, and by promoting an anti-NETotic effect, angiogenesis, and re-epithelialization. Hence, these dual-crosslinked hydrogels have the potential to be translated into a new generation of diabetic wound dressings.

Combining the dual antibacterial and regenerative activities of platelet-rich plasma with β-lactams to mitigate MRSA-infected skin wounds

The emergence of multidrug-resistant bacteria contributes to the necessity of developing novel infection treatment approaches. This study was designed to evaluate the antimicrobial and wound healing activities of platelet-rich plasma (PRP) in combination with β-lactams (ampicillin and/or oxacillin) for the application on methicillin-resistant Staphylococcus aureus (MRSA)-infected skin. PRP was collected from the peripheral blood of healthy donors. The anti-MRSA activity was tested through a growth inhibition curve, colony-forming unit (CFU), and SYTO 9 assay. The PRP incorporation lowered the minimum inhibitory concentration (MIC) of ampicillin and oxacillin against MRSA. The combination of β-lactams together with PRP showed a three-log CFU reduction of MRSA. The major components of PRP for eliminating MRSA were found to be the complement system and iron sequestration proteins, according to the proteomic analysis. The adhesive bacterial colony in the microplate was decreased from 2.9 × 107 to 7.3 × 105 CFU after the treatment of cocktails containing β-lactams and PRP. The cell-based study indicated that keratinocyte proliferation was stimulated by PRP. The in vitro scratch and transwell experiments revealed that PRP improved keratinocyte migration. In the MRSA-infected mouse skin model, PRP appeared to show a synergistic effect for wound area reduction by 39% when combined with β-lactams. The MRSA burden in the infected area was lessened two-fold after topical administration of the combined β-lactams and PRP. PRP inhibited macrophage infiltration in the wound site to shorten the inflammatory phase and accelerate the initiation of the proliferative phase. No skin irritation was detected with the topical delivery of this combination. Our findings suggested that β-lactams plus PRP was applicable to alleviate the problems associated with MRSA via dual antibacterial and regenerative activities.

Recombinant Human Prolidase (rhPEPD) Induces Wound Healing in Experimental Model of Inflammation through Activation of EGFR Signalling in Fibroblasts

The potential of recombinant human prolidase (rhPEPD) to induce wound healing in an experimental model of IL-1β-induced inflammation in human fibroblasts was studied. It was found that rhPEPD significantly increased cell proliferation and viability, as well as the expression of the epidermal growth factor receptor (EGFR) and downstream signaling proteins, such as phosphorylated PI3K, AKT, and mTOR, in the studied model. Moreover, rhPEPD upregulated the expression of the β1 integrin receptor and its downstream signaling proteins, such as p-FAK, Grb2 and p-ERK 1/2. The inhibition of EGFR signaling by gefitinib abolished rhPEPD-dependent functions in an experimental model of inflammation. Subsequent studies showed that rhPEPD augmented collagen biosynthesis in IL-1β-treated fibroblasts as well as in a wound healing model (wound closure/scratch test). Although IL-1β treatment of fibroblasts increased cell migration, rhPEPD significantly enhanced this process. This effect was accompanied by an increase in the activity of MMP-2 and MMP-9, suggesting extracellular matrix (ECM) remodeling during the inflammatory process. The data suggest that rhPEPD may play an important role in EGFR-dependent cell growth in an experimental model of inflammation in human fibroblasts, and this knowledge may be useful for further approaches to the treatment of abnormalities of wound healing and other skin diseases.

Enhancement of Immunosuppressive Activity of Mesenchymal Stromal Cells by Platelet-Derived Factors is Accompanied by Apoptotic Priming

The pro-inflammatory phase of bone healing, initiated by platelet activation and eventually hematoma formation, impacts bone marrow mesenchymal stromal cells (MSCs) in unknown ways. Here, we created platelet-rich plasma (PRP) hydrogels to study how platelet-derived factors modulate functional properties of encapsulated MSCs in comparison to a non-inflammatory fibrin (FBR) hydrogel environment. MSCs were isolated from human bone marrow, while PRP was collected from pooled apheresis thrombocyte concentrates and used for hydrogel preparation. After their encapsulation in hydrogels for 72 h, retrieved MSCs were analyzed for immunomodulatory activities, apoptosis, stem cell properties, senescence, CD9+, CD63+ and CD81+ extracellular vesicle (EV) release, and metabolism-related changes. PRP-hydrogels stimulated immunosuppressive functions of MSCs, along with their upregulated susceptibility to cell death in communication with PBMCs and augmented caspase 3/7 activity. We found impaired clonal growth and cell cycle progression, and more pronounced β-galactosidase activity as well as accumulation of LC3-II-positive vacuoles in PRP-MSCs. Stimuli derived from PRP-hydrogels upregulated AKT and reduced mTOR phosphorylation in MSCs, which suggests an initiation of survival-related processes. Our results showed that PRP-hydrogels might represent a metabolically stressful environment, inducing acidification of MSCs, reducing polarization of the mitochondrial membrane and increasing lipid accumulation. These features were not detected in FBR-MSCs, which showed reduced CD63+ and CD81+ EV production and maintained clonogenicity. Our data revealed that PRP-derived hematoma components cause metabolic adaptation of MSCs followed by increased immune regulatory functions. For the first time, we showed that PRP stimuli represent a survival challenge and “apoptotic priming” that are detrimental for stem cell-like growth of MSCs and important for their therapeutic consideration.

Graphical Abstract

The Highly Efficient Expression System of Recombinant Human Prolidase and the Effect of N-Terminal His-Tag on the Enzyme Activity

Prolidase is an enzyme hydrolyzing dipeptides containing proline or hydroxyprolineat the C-terminus and plays an important role in collagen turnover. Human prolidase is active as a dimer with the C-terminal domain containing two Mn2+ ions in its active site. The study aimed to develop a highly efficient expression system of recombinant human prolidase (rhPEPD) and to evaluate the effect of the N-terminal His-Tag on its enzymatic and biological activity. An optimized bacterial expression system and an optimized purification procedure for rhPEPD included the two-step rhPEPD purification procedure based on (i) affinity chromatography on an Ni2+ ion-bound chromatography column and (ii) gel filtration with the possibility of tag removal by selective digestion with protease Xa. As the study showed, a high concentration of IPTGand high temperature of induction led to a fast stimulation of gene expression, which as a result forced the host into an intensive and fast production of rhPEPD. The results demonstrated that a slow induction of gene expression (low concentration of inducing factor, temperature, and longer induction time) led to efficient protein production in the soluble fraction. Moreover, the study proved that the presence of His-Tag changed neither the expression pattern of EGFR-downstream signaling proteins nor the prolidase catalytic activity.

Recombinant Prolidase Activates EGFR-Dependent Cell Growth in an Experimental Model of Inflammation in HaCaT Keratinocytes. Implication for Wound Healing

This study was conducted to investigate the proliferative capacity of recombinant human prolidase (rhPEPD) in a human model of inflammation induced by IL-1β in HaCaT keratinocytes. In this report, we provide evidence that IL-1β stimulates keratinocyte proliferation, and rhPEPD significantly augmented this process through activation of epidermal growth factor receptor (EGFR) and downstream signaling proteins as phosphorylated Akt, ERK1/2, and STAT3, which are implicated in keratinocyte migration, proliferation, and epithelialization during the wound healing process. Inhibition of PEPD-dependent EGFR signaling by gefitinib supported the finding. Moreover, during activation of EGFR in the presence of IL-1β the epithelial-to-mesenchymal transition (EMT) occurred via downregulation of E-cadherin and upregulation of N-cadherin. The phenomenon was accompanied by an increase in the activity of matrix metalloproteinase-9 (MMP-9), suggesting extracellular matrix (ECM) remodeling during the inflammatory process. MMP-9 activation may result from nuclear translocation of NF-κB through IKK-mediated IκBα degradation. Interestingly, some mutated variants of PEPD (rhPEPD-G448R, rhPEPD-231delY, and rhPEPD-E412K) evoked the ability to induce EGFR-dependent HaCaT cell proliferation. To the best of our knowledge, this is the first report on the cross-talk between PEPD and IL-1β in the process of keratinocyte proliferation. The data suggest that both enzymatically active and inactive rhPEPD may activate EGFR-dependent cell growth in an experimental model of inflammation in HaCaT keratinocytes and the knowledge may be useful for further approaches for therapy of wound healing disorders.

Proline Dehydrogenase/Proline Oxidase (PRODH/POX) Is Involved in the Mechanism of Metformin-Induced Apoptosis in C32 Melanoma Cell Line

The role of proline dehydrogenase/proline oxidase (PRODH/POX) in the mechanism of antineoplastic activity of metformin (MET) was studied in C32 melanoma cells. PRODH/POX is a mitochondrial enzyme-degrading proline that is implicated in the regulation of cancer cell survival/apoptosis. The enzyme is activated by AMP kinase (AMPK). It has been found that MET induced a significant decrease in cell viability and DNA biosynthesis accompanied by an increase in the expressions of AMPK and PRODH/POX in C32 cells. The mechanism for MET-dependent cytotoxicity on C32 cells was found at the level of PRODH/POX-induced ROS generation and activation of Caspase-3 and Caspase-9 expressions in these cells. The effects were not observed in MET-treated PRODH/POX knock-out C32 cells. Of interest is an MET-dependent increase in the concentration of proline, which is a substrate for PRODH/POX. This phenomenon is due to the MET-dependent inhibition of collagen biosynthesis, which is the main proline-utilizing process. It has been found that the underlying mechanism of anticancer activity of MET involves the activation of AMPK, PRODH/POX, increase in the cytoplasmic concentration of proline, inhibition of collagen biosynthesis, and stimulation of PRODH/POX-dependent ROS generation, which initiate the apoptosis of melanoma cells.

PRODH/POX-Dependent Celecoxib-Induced Apoptosis in MCF-7 Breast Cancer

Celecoxib (Cx), an inhibitor of cyclooxygenase 2, induces apoptosis of cancer cells. However, the mechanism of the chemopreventive effect remains not fully understood. We aimed to investigate the role of PRODH/POX that is involved in the regulation of apoptosis induced by celecoxib. MCF-7 breast cancer cell line and the corresponding MCF-7 cell line with silenced PRODH/POX (MCF-7^shPRODH/POX) were used. The effects of Cx on cell viability, proliferation, and cell cycle were evaluated. The expressions of protein markers for apoptosis (Bax, caspase 9, and PARP) and autophagy (Atg5, Beclin 1, and LC3A/B) were investigated by Western immunoblotting. To analyze the proline metabolism, collagen biosynthesis, prolidase activity, proline concentration, and the expression of proline-related proteins were evaluated. The generation of ATP, ROS, and the ratio of NAD+/NADH and NADP+/NADPH were determined to test the effect of Cx on energetic metabolism in breast cancer cells. It has been found that Cx attenuated MCF-7 cell proliferation via arresting the cell cycle. Cx induced apoptosis in MCF-7 breast cancer cells, while in MCF-7^shPRODH/POX, autophagy occurred more predominantly. In MCF-7 breast cancer cells, Cx affected proline metabolism through upregulation of proline biosynthesis, PRODH/POX and PYCRs expressions, PEPD activity, and downregulation of collagen biosynthesis. In MCF-7^shPRODH/POX clones, these processes, as well as energetic metabolism, were remarkably suppressed. The data for the first time suggest that celecoxib induces apoptosis through upregulation of PRODH/POX in MCF-7 breast cancer cells.