Current Trends on Bioengineering Approaches for Ovarian Microenvironment Reconstruction.

Ovarian tissue has a unique microarchitecture and a complex cellular and molecular dynamics that are essential for follicular survival and development. Due to this great complexity, several factors may lead to ovarian insufficiency, and therefore to systemic metabolic disorders and female infertility. Techniques currently used in the reproductive clinic such as oocyte cryopreservation or even ovarian tissue transplant, although effective, have several limitations, which impair their wide application. In this scenario, mimetic ovarian tissue reconstruction comes as an innovative alternative to develop new methodologies for germ cells preservation and ovarian functions restoration. The ovarian extracellular matrix (ECM) is crucial for oocyte viability maintenance, once it acts actively in folliculogenesis. One of the key components of ovarian bioengineering is biomaterials application that mimics ECM and provides conditions for cell anchorage, proliferation, and differentiation. Therefore, this review aims at describing ovarian tissue engineering approaches and listing the main limitations of current methods for preservation and reestablishment of ovarian fertility. In addition, we describe the main elements that structure this study field, highlighting the main advances and the challenges to overcome to develop innovative methodologies to be applied in reproductive medicine. Impact Statement This review presents the main advances in the application of tissue bioengineering in the ovarian tissue reconstruction to develop innovative solutions for ovarian fertility reestablishment.

Immunohistochemical panel to characterize canine prostate carcinomas according to aberrant p63 expression.

An unusual variant of prostate adenocarcinoma (PC) expressing nuclear p63 in secretory cells instead of the typical basal expression has been reported in men. Nevertheless, the biological behavior and clinical significance of this phenomenon is unknown. In dogs, this unusual PC subtype has not been described. In this study, p63 immunoexpression was investigated in 90 canine PCs and 20 normal prostate tissues (NT). The p63 expression pattern in luminal or basal cells was confirmed in a selected group of 26 PCs and 20 NT by immunohistochemistry and/or Western blotting assays. Eleven canine PC samples aberrantly expressing p63 (p63+) in secretory cells were compared with 15 p63 negative (p63-) cases in the context of several molecular markers (high molecular weight cytokeratin-HMWC, CK8/18, CK5, AR, PSA, chromogranin, NKX3.1, PTEN, AKT and C-MYC). P63+ samples were positive for CK5, HMWC and CK8/18 and negative for PSA, NKX3.1, PTEN and chromogranin. Five p63+ PCs were negative for AR, and the remaining six samples had low AR expression. In contrast, p63- PC showed AR and PSA positive expression in all 15 samples. Only five p63- PCs were positive for CK5. Both p63+ and p63- PC samples showed higher cytoplasmic AKT expression and nuclear C-MYC staining in comparison with normal tissues. Metastatic (N = 12) and non-metastatic (N = 14) PCs showed similar immunoexpression for all markers tested. In contrast to human PC, canine PC aberrantly expressing p63 showed higher expression levels of HMWC and CK5 and lower levels of NKX3.1. Canine p63+ PC is a very rare PC group showing a distinct phenotype compared to typical canine PC, including AR and PSA negative expression. Although in a limited number of cases, p63 expression was not associated with metastasis in canine PC, and cytoplasmic p63 expression was observed in animals with shorter survival time, similar to human PC cases.

Ultrastructural analysis and residual DNA evaluation of rabbit vein scaffold.

PURPOSE: To investigate the ultrastructural characteristics and analysis of residual DNA in scaffold models, produced with decellularized vena cava in an experimental model with rabbits. METHODS: Three groups were created for ultrastructural and residual DNA analysis: group 1 - control, consisting of samples of vena cava in natura; group 2 - SD, consisting of vein fragments submitted to 2% sodium deoxycholate decellularization by shaking (160rpm - Shaker News Brunswick Scientific®) for 1 hour at controlled temperature shaker at 37°C; group 3 - SDS, consisting of vein fragments submitted to 1% sodium dodecyl sulfate decellularization under the same previous condition, for 2 hours. RESULTS: The ultrastructural matrix of the blood vessel maintained its vintegrity after either decellularization models. The results of the two quantification methods demonstrated a significant decrease in the DNA content of the decellularized vena cava samples as compared to the control samples and, differed statistically from each other, p <0.05. CONCLUSION: The 2% DS protocol for vein decellularization, in this experimental model, was considered the best protocol because it presented less amount of residual DNA without causing substantial destruction of the extracellular matrix.

Ultrastructural analysis and residual DNA evaluation of rabbit vein scaffold

Abstract Purpose: To investigate the ultrastructural characteristics and analysis of residual DNA in scaffold models, produced with decellularized vena cava in an experimental model with rabbits. Methods: Three groups were created for ultrastructural and residual DNA analysis: group 1 - control, consisting of samples of vena cava in natura; group 2 - SD, consisting of vein fragments submitted to 2% sodium deoxycholate decellularization by shaking (160rpm - Shaker News Brunswick Scientific®) for 1 hour at controlled temperature shaker at 37°C; group 3 - SDS, consisting of vein fragments submitted to 1% sodium dodecyl sulfate decellularization under the same previous condition, for 2 hours. Results: The ultrastructural matrix of the blood vessel maintained its vintegrity after either decellularization models. The results of the two quantification methods demonstrated a significant decrease in the DNA content of the decellularized vena cava samples as compared to the control samples and, differed statistically from each other, p <0.05. Conclusion: The 2% DS protocol for vein decellularization, in this experimental model, was considered the best protocol because it presented less amount of residual DNA without causing substantial destruction of the extracellular matrix.

Comparison between two different experimental models of osteoarthritis in rabbits. Intra-articular collagenase injection and anterior cruciate ligament transection.

PURPOSE:: To compare two different experimental models of osteoarthritis in rabbits: intra-articular collagenase injection and anterior cruciate ligament transection. METHODS:: Ten adult rabbits were randomly divided in two groups: COLL (collagenase group) and ACLT (anterior cruciate ligament transection). The COLL group was treated with 0.5 ml collagenase solution (2mg collagenase/0.5 ml sterile PBS), and the ACTL group was subjected to anterior cruciate ligament. After six and twelve weeks, respectively, the animals in the COLL and ACTL groups were euthanized. The gross appearance and histological examinations conducted in the cartilage articular surface was blindly scored according to the criteria developed by Yoshimi et al. (1994) and Mankin et al. (1971), respectively. RESULTS:: The gross morphologic observation, macroscopic score and histological examinations have demonstrated that the ACTL group presented the highest scores, and lesions more severe than those in the COLL group. CONCLUSIONS:: Both methods, anterior cruciate ligament transection and collagenase, applied to the stifle joint of the rabbits have effectively induced degenerative changes in the cartilage tissue, through statistically significant analysis (p≤0.05). The ACTL method has presented more severe lesions.

Comparison between two different experimental models of osteoarthritis in rabbits. Intra-articular collagenase injection and anterior cruciate ligament transection

ABSTRACT PURPOSE: To compare two different experimental models of osteoarthritis in rabbits: intra-articular collagenase injection and anterior cruciate ligament transection. METHODS: Ten adult rabbits were randomly divided in two groups: COLL (collagenase group) and ACLT (anterior cruciate ligament transection). The COLL group was treated with 0.5 ml collagenase solution (2mg collagenase/0.5 ml sterile PBS), and the ACTL group was subjected to anterior cruciate ligament. After six and twelve weeks, respectively, the animals in the COLL and ACTL groups were euthanized. The gross appearance and histological examinations conducted in the cartilage articular surface was blindly scored according to the criteria developed by Yoshimi et al. (1994) and Mankin et al. (1971), respectively. RESULTS: The gross morphologic observation, macroscopic score and histological examinations have demonstrated that the ACTL group presented the highest scores, and lesions more severe than those in the COLL group. CONCLUSIONS: Both methods, anterior cruciate ligament transection and collagenase, applied to the stifle joint of the rabbits have effectively induced degenerative changes in the cartilage tissue, through statistically significant analysis (p≤0.05). The ACTL method has presented more severe lesions.

[Changes in the extracellular matrix due to diabetes and their impact on urinary continence]. / Alterações da matriz extracelular causadas pelo diabetes: o impacto sobre a continência urinária.

The prevalence of urinary incontinence in diabetic pregnant women is significantly high two years after cesarean section. Incontinence can be the most common consequence of hyperglycemia compared to other complications. Thus, identifying the risk factors for the development of urinary incontinence in diabetes is the major aim in the prevention of this very common condition. Recent surveys have shown that not only muscle but also the urethral extracellular matrix play an important role in the mechanism of urinary continence. Translational work on rats by our research group showed that diabetes during pregnancy damages the extracellular matrix and urethral striated muscle, a fact that may explain the high prevalence of urinary incontinence and pelvic floor dysfunction in women with gestational diabetes mellitus. Diabetes affects the expression, organization and change in extracellular matrix components in different organs, and tissue remodeling and fibrosis appear to be a direct consequence of it. Therefore, understanding the impact of modifiable risk factors, such as diabetes, which involves using preventive strategies, can reduce the rates of urinary incontinence and the health care costs, and improve the quality of life of women, especially during pregnancy and postpartum.

Alterações da matriz extracelular causadas pelo diabetes: o impacto sobre a continência urinária / Changes in the extracellular matrix due to diabetes and their impact on urinary continence

A prevalência de incontinência urinária em gestantes diabéticas é significantemente elevada e persiste por até dois anos após o parto cesárea, podendo ser a sequela mais frequente da hiperglicemia gestacional comparada a outras complicações. Dessa forma, identificar os fatores de risco para o desenvolvimento da incontinência urinária em diabéticas é o principal objetivo na prevenção dessa condição tão comum. Pesquisas recentes apontam que não apenas o músculo uretral mas também a matriz extracelular uretral desempenham papel importante no mecanismo da continência urinária. Os trabalhos do nosso grupo de pesquisa evidenciaram que, em ratas, o diabetes durante a prenhez lesa a matriz extracelular e o músculo estriado uretral, o que pode explicar a alta prevalência de incontinência e disfunção do assoalho pélvico em mulheres com diabetes mellitus gestacional. O diabetes exerce efeito sobre a expressão, organização e alteração dos componentes da matriz extracelular em diversos órgãos, e a remodelação do tecido e a fibrose parecem ser uma consequência direta dele. Assim, a compreensão do impacto de fatores de risco modificáveis, como o diabetes, permitirá que, utilizando estratégias preventivas, reduzamos as taxas de incontinência urinária, bem como os custos de assistência à saúde, e melhoremos a qualidade de vida das mulheres, especialmente na gestação e no pós-parto.

The prevalence of urinary incontinence in diabetic pregnant women is significantly high two years after cesarean section. Incontinence can be the most common consequence of hyperglycemia compared to other complications. Thus, identifying the risk factors for the development of urinary incontinence in diabetes is the major aim in the prevention of this very common condition. Recent surveys have shown that not only muscle but also the urethral extracellular matrix play an important role in the mechanism of urinary continence. Translational work on rats by our research group showed that diabetes during pregnancy damages the extracellular matrix and urethral striated muscle, a fact that may explain the high prevalence of urinary incontinence and pelvic floor dysfunction in women with gestational diabetes mellitus. Diabetes affects the expression, organization and change in extracellular matrix components in different organs, and tissue remodeling and fibrosis appear to be a direct consequence of it. Therefore, understanding the impact of modifiable risk factors, such as diabetes, which involves using preventive strategies, can reduce the rates of urinary incontinence and the health care costs, and improve the quality of life of women, especially during pregnancy and postpartum.