Nrf2 activation: a key mechanism in stem cell exosomes-mediated therapies.

Exosomes are nano-sized membrane extracellular vesicles which can be released from various types of cells. Exosomes originating from inflammatory or injured cells can have detrimental effects on recipient cells, while exosomes derived from stem cells not only facilitate the repair and regeneration of damaged tissues but also inhibit inflammation and provide protective effects against various diseases, suggesting they may serve as an alternative strategy of stem cells transplantation. Exosomes have a fundamental role in communication between cells, through the transfer of proteins, bioactive lipids and nucleic acids (like miRNAs and mRNAs) between cells. This transfer significantly impacts both the physiological and pathological functions of recipient cells. Nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor, is able to mitigate damage caused by oxidative stress and inflammation through various signaling pathways. The positive effects resulting from the activation of the Nrf2 signaling pathway in different disorders have been documented in various types of literature. Studies have confirmed that exosomes derived from stem cells could act as Nrf2 effective agonists. However, limited studies have explored the Nrf2 role in the therapeutic effects of stem cell-derived exosomes. This review provides a comprehensive overview of the existing knowledge concerning the role of Nrf2 signaling pathways in the impact exerted by stem cell exosomes in some common diseases.

Mitochondria-loaded alginate-based hydrogel accelerated angiogenesis in a rat model of acute myocardial infarction.

Here, mitochondria were isolated from mesenchymal stem cells (MSCs) after being treated with mitochondria-stimulating substrates, 50 µM metformin (Met), and 40 µM dichloroacetic acid (DCA). The isolated mitochondria (2 × 107 particles) were characterized and encapsulated inside 100 µl hydrogel composed of alginate (3 % w/v; Alg)/gelatin (Gel; 1 % w/v) enriched with 1 µM pyrrole (Pyr) solidified in the presence of 0.2 M FeCl3. The physicochemical properties and cytocompatibility of prepared hydrogels were assessed using FTIR, swelling, biodegradation, porosity assays, and scanning electron microscopy (SEM). The mitochondria-bearing hydrogel was injected into the ischemic area of rat hearts. FTIR absorption bands represented that the addition of FeCl3 led to polypyrrole (PPy) formation, polysaccharide oxidation, and interaction between Alg and Gel. SEM images exhibited porous structure and the size of pores was reduced in Alg/Gel + PPy group compared to Alg + PPy hydrogel. Based on the data, both Alg + PPy and Alg/Gel + PPy hydrogels can preserve the integrity and morphology of loaded mitochondria. It was noted that Alg/Gel + PPy hydrogel possessed a higher swelling ratio, degradation, and porosity compared to Alg + PPy group. Data confirmed that Alg/Gel + PPy hydrogel containing 1 µM Pyr yielded the highest survival rate compared to groups with 2 and 4 µM Pyr (p < 0.05). Injection of mitochondria-loaded Alg/Gel + PPy hydrogel yielded significant restoration of left ventricle thickness compared to the infarction, mitochondria, and Alg/Gel + PPy hydrogel groups 14 days post-injection (p < 0.05). Histological analyses revealed a significant increase of vWF+ capillaries and α-SMA+ arterioles in the mitochondria-loaded Alg/Gel + PPy hydrogel group (p < 0.05). Immunofluorescence imaging revealed the ability of rat cardiomyocytes to uptake mitochondria alone or after being loaded into Alg/Gel + PPy hydrogel. These effects were evident in the Alg/Gel + PPy group. Taken together, electroconductive Alg-based hydrogels are suitable platforms for the transplantation of cells and organelles and the regeneration of ischemic heart changes.

Exosomes as Theranostic Agents in Reproduction System.

Exosomes (Exos), belonging to extracellular vesicles, are cell-derived nano-sized vesicles with the potential to carry different kinds of biological molecules. Many studies have proved the impacts of exosomal cargo on several biological processes in female and male reproductive systems. It is also hypothesized that changes in exosomal cargo are integral to the promotion of certain pathological conditions, thus Exos can be used as valid biomarkers for the diagnosis of infertility and other abnormal conditions. Here, efforts are made to collect some recent data related to the physiological significance of Exos in the reproductive system, and their potential therapeutic effects. It is anticipated that the current review article will lay the groundwork for elucidating the source and mechanisms by which Exos control the reproductive system additionally supplying fresh methods and concepts for the detection and treatment of disorders associated with fertility for future studies.

Applications of engineered exosomes in drugging noncoding RNAs for cancer therapy.

Noncoding RNAs (ncRNAs) are engaged in key cell biological and pathological events, and their expression alteration is connected to cancer progression both directly and indirectly. A huge number of studies have mentioned the significant role of ncRNAs in cancer prevention and therapy that make them an interesting subject for cancer therapy. However, there are several limitations, including delivery, uptake, and short half-life, in the application of ncRNAs in cancer treatment. Exosomes are introduced as promising options for the delivery of ncRNAs to the target cells. In this review, we will briefly discuss the application and barriers of ncRNAs. After that we will focus on exosome-based ncRNAs delivery and their advantages as well as the latest achievements in drugging ncRNAs with exosomes.

Melatonin and endothelial cell-loaded alginate-fibrin hydrogel promoted angiogenesis in rat cryopreserved/thawed ovaries transplanted to the heterotopic sites.

BACKGROUND: Ischemic niche can promote follicular atresia following the transplantation of cryopreserved/thawed ovaries to the heterotopic sites. Thus, the promotion of blood supply is an effective strategy to inhibit/reduce the ischemic damage to ovarian follicles. Here, the angiogenic potential of alginate (Alg) + fibrin (Fib) hydrogel enriched with melatonin (Mel) and CD144+ endothelial cells (ECs) was assessed on encapsulated cryopreserved/thawed ovaries following transplantation to heterotopic sites in rats. METHODS: Alg + Fib hydrogel was fabricated by combining 2% (w/v) sodium Alg, 1% (w/v) Fib, and 5 IU thrombin at a ratio of 4: 2: 1, respectively. The mixture was solidified using 1% CaCl2. Using FTIR, SEM, swelling rate, and biodegradation assay, the physicochemical properties of Alg + Fib hydrogel were evaluated. The EC viability was examined using an MTT assay. Thirty-six adult female rats (aged between 6 and 8 weeks) with a normal estrus cycle were ovariectomized and enrolled in this study. Cryopreserved/thawed ovaries were encapsulated in Alg + Fib hydrogel containing 100 µM Mel + CD144+ ECs (2 × 104 cells/ml) and transplanted into the subcutaneous region. Ovaries were removed after 14 days and the expression of Ang-1, and Ang-2 was monitored using real-time PCR assay. The number of vWF+ and α-SMA+ vessels was assessed using IHC staining. Using Masson's trichrome staining, fibrotic changes were evaluated. RESULTS: FTIR data indicated successful interaction of Alg with Fib in the presence of ionic cross-linker (1% CaCl2). Data confirmed higher biodegradation and swelling rates in Alg + Fib hydrogel compared to the Alg group (p < 0.05). Increased viability was achieved in encapsulated CD144+ ECs compared to the control group (p < 0.05). IF analysis showed the biodistribution of Dil+ ECs within hydrogel two weeks after transplantation. The ratio of Ang-2/Ang-1 was statistically up-regulated in the rats that received Alg + Fib + Mel hydrogel compared to the control-matched groups (p < 0.05). Based on the data, the addition of Mel and CD144+ ECs to Alg + Fib hydrogel reduced fibrotic changes. Along with these changes, the number of vWF+ and α-SMA+ vessels was increased in the presence of Mel and CD144+ ECs. CONCLUSIONS: Co-administration of Alg + Fib with Mel and CD144+ ECs induced angiogenesis toward encapsulated cryopreserved/thawed ovarian transplants, resulting in reduced fibrotic changes.

Novel Approaches Used in Ovarian Tissue Transplantation for Fertility Preservation: Focus on Tissue Engineering Approaches and Angiogenesis Capacity.

Due to the impact of the modern lifestyle, female infertility has been reduced because of different reasons. For example, in combined chemotherapeutic therapies, a small fraction of cancer survivors has faced different post-complications and side effects such as infertility. Besides, in modern society, delayed age of childbearing has also affected fertility. Nowadays, ovarian tissue cryopreservation and transplantation (OTC/T) is considered one of the appropriate strategies for the restoration of ovarian tissue and bioactivity in patients with the loss of reproductive function. In this regard, several procedures have been considered to improve the efficacy and safety of OTT. Among them, a surgical approach is used to transplant ovaries into the optimal sites, but the existence of ischemic changes and lack of appropriate revascularization can lead to bulk follicular atresia. Besides, the role of OTC/T is limited in women of advanced maternal age undergoing lifesaving chemo-radiation. As a correlate, the development of de novo approaches with efficacious regenerative outcomes is highly welcomed. Tissue engineering shows high therapeutic potentialities to restore fertility in males and females using the combination of biomaterials, cells, and growth factors. Unfortunately, most synthetic and natural materials are at the experimental stage and only the efficacy has been properly evaluated in limited cases. Along with these descriptions, strategies associated with the induction of angiogenesis in transplanted ovaries can diminish the injuries associated with ischemic changes. In this review, the authors tried to summarize recent techniques, especially tissue engineering approaches for improving ovarian function and fertility by focusing on angiogenesis and neovascularization.

Zinc and Respiratory Viral Infections: Important Trace Element in Anti-viral Response and Immune Regulation.

Influenza viruses, respiratory syncytial virus (RSV), and SARS-COV2 are among the most dangerous respiratory viruses. Zinc is one of the essential micronutrients and is very important in the immune system. The aim of this narrative review is to review the most interesting findings about the importance of zinc in the anti-viral immune response in the respiratory tract and defense against influenza, RSV, and SARS-COV2 infections. The most interesting findings on the role of zinc in regulating immunity in the respiratory tract and the relationship between zinc and acute respiratory distress syndrome (ARDS) are reviewed, as well. Besides, current findings regarding the relationship between zinc and the effectiveness of respiratory viruses' vaccines are reviewed. The results of reviewed studies have shown that zinc and some zinc-dependent proteins are involved in anti-viral defense and immune regulation in the respiratory tract. It seems that zinc can reduce the viral titer following influenza infection. Zinc may reduce RSV burden in the lungs. Zinc can be effective in reducing the duration of viral pneumonia symptoms. Zinc may enhance the effectiveness of hydroxychloroquine in reducing mortality rate in COVID-19 patients. Besides, zinc has a positive effect in preventing ARDS and ventilator-induced lung damage. The relationship between zinc levels and the effectiveness of respiratory viruses' vaccines, especially influenza vaccines, is still unclear, and the findings are somewhat contradictory. In conclusion, zinc has anti-viral properties and is important in defending against respiratory viral infections and regulating the immune response in the respiratory tract.

Review of ovarian tissue cryopreservation techniques for fertility preservation.

Ovarian failure and ovarian malfunction are among major fertility problems in women of reproductive age (18-35 years). It is known that various diseases, such as ovarian cancer and premature ovarian failure, besides certain treatments, such as radiotherapy and chemotherapy of other organs, can affect the normal process of folliculogenesis and cause infertility. In recent years, various procedures have been proposed for the treatment of infertility. One of the newest methods is the use of cryopreservation ovarian fragments after cancer treatment. According to some studies, this method yields very satisfactory results. Although ovarian tissue cryopreservation (OTC) is an accepted technique of fertility preservation, the relative efficacy of cryopreservation protocols remains controversial. Considering the controversies about these methods and their results, in this study, we aimed to compare different techniques of ovarian cryopreservation and investigate their advantages and disadvantages. Reviewing the published articles may be possible to identify appropriate strategies and improve infertility treatment in these patients.

The effects of curcumin on sperm parameters and nitric oxide production in varicocelized rats / Efectos de la cúrcuma sobre los parámetros espermáticos y producción de óxido nítrico en ratas varicocelizadas

One of the proposed mechanism by which varicocele induces its damage is excessive release of nitric oxide (NO). Several studies have shown the role of NO in poor sperm quality in infertile patients with varicocele. Scientific studies have demonstrated the beneficial effects of curcumin on the sperm parameters. Curcumin as an atoxic antioxidant can reduce production of NO. The aim of this study was to determine the effect of curcumin on NO levels and investigate if curcumin can improve sperm parameters in varicocelized male rats. Thirty male Wistar rats were randomly divided into 5 groups (V1 and V2 (varicocele), T (treatment), Sh (sham) and C was control). In groups V1, V2, T and Sh, the left renal vein was partially ligated to induce varicocele. In groups V1 and V2, sperm parameters and NO level were evaluated 8 and 16 weeks respectively after varicocele induction. Groups T and Sh received 100 mg/kg curcumin and placebo respectively, daily for 8 weeks after 2 months of induced varicocele. Sperm parameters (count, motility, viability and morphology), epididymis and testis weight and also NO concentration were measured. Sperm parameters (count, motility and viability) in groups V1, V2 and Sh were significantly low in comparison with control and treatment groups. The level of NO was significantly increased in serum of rats in groups V1 and V2, whereas group T rat serum in which curcumin was administered, showed decreased NO levels. The values of the epididymis and testis weight had no significant changes (P 0.05) in all groups. Administration of curcumin as a free radical scavenger, can decrease NO level and improve sperm parameters in varicocelized male rats.

Uno de los mecanismos propuestos por el cual los varicoceles inducen daño es la excesiva liberación de óxido nítrico (ON). Varios estudios han demostrado el efecto del ON en la mala calidad del semen en pacientes infértiles con varicocele. Investigaciones han demostrado los efectos beneficiosos de la cúrcuma sobre los parámetros de esperma. La cúrcuma como un antioxidanteatóxico puede reducir la producción de ON. El objetivo de este estudio fue determinar el efecto de la cúrcuma en el nivel de ON e investigar si la cúrcuma puede mejorar los parámetros del semen en ratas macho. Treinta ratas macho Wistar fueron divididas aleatoriamente en 5 grupos (V1y V2 (varicocele), T (tratamiento), Sh (simulado) y C (control)). En los grupos V1, V2, T y Sh, la vena renal izquierda fue parcialmente ligada para inducir varicocele. En los grupos de V1 y V2, los parámetros de semen y nivel de ON se evaluaron a las 8 y 16 semanas respectivamente, después de la inducción de varicocele. Los grupos T y Sh recibieron diariamente 100 mg/kg de cúrcuma y placebo durante 8 semanas, después de 2 meses de inducir el varicocele. Fueron medidos los parámetros del semen (recuento, motilidad, viabilidad y morfología espemática), peso del epidídimo y testículos, junto con la concentración del ON. El recuento, motilidad y viabilidad de los espermatozoides en los grupos V1, V2 y Sh fueron significativamente más bajos en comparación con los grupos C y T. El nivel de ON se incrementó significativamente en el suero de las ratas de los grupos V1 y V2, mientras que el suero del grupo T, en el que se administró cúrcuma, hubo una disminución de los niveles de ON. El peso del epidídimo y testículos tuvieron cambios significativos (P 0,05) en todos los grupos. La administración de cúrcuma como un eliminador de radicales libres, puede disminuir el nivel de ON y mejorar los parámetros espermáticos en ratas macho varicocelizadas.

Effects of ovarian varicose vein on mitochondrial structure, malondialdehyde and prooxidants: antioxidants balance in rat ovaries / Efectos de las venas ováricas varicosas sobre la estructura mitocondrial, niveles de malondialdehído y balance prooxidantes: antioxidantes en ovarios de ratas

Oxidative stress is increased in varicose veins. Many studies have implicated oxidative stress in the pathogenesis of infertility causing diseases of the female reproductive tract. The aim of this study was to determine whether varicocele can cause raised levels of reactive oxygen species and denaturation of mitochondrial structure in ovaries of female rats or not. In each experimental study, 15 weaning-age female rats were divided equally in 3 groups: Unilateral Varicose Vein (A), Sham (B) and Control (C) groups. Mitochondrial structure and malondialdehyde levels as a product of lipid peroxidation and Prooxidants-Antioxidants Balance were evaluated 60 days after intervention in proestrus stage. Comparisons between groups were made by the measured test. After 2 months, our results showed that mitochondrial structure ultra-structurally was denatured with histologic examination, malondialdehyde and prooxidants-antioxidants balance levels of left ovaries increased significantly in varicocele group compared to control and sham groups (P0.05). In the right side, malondialdehyde increased significantly, but in prooxidants-antioxidants balance levels, there is no significant differences between groups. The data of control and sham groups were the same. These findings may support the concept that increased levels of malondialdehyde and PAB in varicocele may cause negative effects on fertility, so using antioxidants maybe useful.

El estrés oxidativo aumenta en las venas varicosas. Diversas investigaciones han implicado al estrés oxidativo en la patogénesis de las enfermedades que causan la infertilidad del tracto reproductivo femenino. El objetivo de este estudio fue determinar si el varicocele puede provocar niveles de especies reactivas del oxígeno y la desnaturalización de la estructura mitocondriales en los ovarios de ratas. En cada estudio experimental, cinco ratas hembras en edad de destete se dividieron por igual en 3 grupos: Várices unilateral (A), simulado (B) y control (C). La estructura mitocondrial y los niveles de malondialdehído como un producto de la peroxidación lipídica y el balance pro-oxidantes-antioxidantes (BPA) se evaluaron 60 días después de la intervención en la etapa proestro. Las comparaciones entre grupos se realizaron mediante la prueba de medición. Después de 2 meses, observamos que la estructura mitocondrial se desnaturalizó ultraestructuralmente, los niveles malondialdehído y el balance prooxidantes-antioxidantes de los ovarios izquierdos aumentaron significativamente en el grupo A en comparación con los grupos B y C (P0.05). En el lado derecho, los niveles de malondialdehído aumentaron significativamente, pero el BPA, no mostró diferencias significativas entre los grupos. Los datos de los grupos B y C eran los mismos. Estos hallazgos pueden apoyar el concepto de que el aumento de niveles de malondialdehído y BPA en presencia de varicocele, puede causar efectos negativos sobre la fertilidad, por tanto el uso de antioxidantes puede resultar útil.