Mammalian oocytes are heavily reliant on mitochondrial oxidative phosphorylation (OXPHOS) for ATP generation using pyruvate derived from surrounding cumulus cells (Eppig, 1976; Johnson, Freeman, Gardner, & Hunt, 2007). Notably, mitochondria produce the vast majority of cellular free radicals and reactive oxygen species (ROS), which arise as a by-product of OXPHOS (Figueira et al.,

Mammalian oocytes rely heavily on mitochondrial oxidative phosphorylation (OXPHOS) for generating ATP. However, mitochondria are also the primary source of damaging reactive oxygen species (ROS). Mitochondrial de-regulation, therefore, underpins poor oocyte quality associated with conditions such as obesity and aging.The mitochondrial sirtuin, Sirt3, is critical for mitochondrial respiration and redox regulation. Interestingly, however, Sirt3 knockout (Sirt3 −/− ) mice do not exhibit systemic compromise under basal conditions, only doing so under stressed conditions such as high-fat diet (HFD)-induced obesity. Mouse oocytes depleted of Sirt3 exhibit increased ROS in vitro, but it is unknown whether Sirt3 is necessary for female fertility in vivo. Here, we test this for the first time by investigating ovarian follicular reserve, oocyte maturation (including detailed spindle assembly and chromosome segregation), and female fertility in Sirt3 −/− females. We find that under basal conditions, young Sirt3 −/− females exhibit no defects in any parameters. Surprisingly, all parameters also remain intact following HFD-induced obesity. Despite markedly increased ROS levels in HFD Sirt3 −/− oocytes, ATP levels nevertheless remain normal. Our data support that ATP is sustained in vivo through increased mitochondrial mass possibly secondary to compensatory upregulation of another sirtuin, Sirt1, which has overlapping functions with Sirt3.

Analysis of the human genome revealed that only 1.2% encoded for proteins, which raised questions regarding the biological significance of the remaining genome. We now know that approximately 80% of the genome serves at least one biochemical function within the cell. A portion of this 80% consists of a family of non-coding regulatory RNAs, one important member being microRNAs (miRNAs). miRNAs can be detected in tissues and biofluids, where miRNAs in the latter can be bound to proteins or encapsulated within lipid vesicles such as exosomes. Gestational diabetes mellitus (GDM) is a complication of pregnancy, which has harmful health impacts on both the fetus as well as the mother. The incidence of GDM worldwide varies, but reached 18% in the HAPO cohort using the new International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria. Not only has GDM been associated with increased risks of further complications during pregnancy, but also poses long-term risks for both the mother and the baby. Thus, understanding the pathophysiology of GDM is important from a public health perspective. Literature has demonstrated that GDM is associated with elevated levels of circulating exosomes in maternal circulation. However, there is a paucity of data defining the expression, role, and diagnostic utility of miRNAs in GDM. This review briefly summarizes recent advances in the function and quantification of intracellular and extracellular miRNAs in GDM.

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Tissue engineering of corporal tissue is a new development in otherwise untreatable erectile dysfunction and in urethral reconstructions to treat hypospadias or severe urethral stricture disease. Multiple complications can arise with the current treatments, whereas engineered tissue, if well vascularized and existing of autologous cells, may lead to better results. The aim of this review was to provide an overview of literature on cell-seeded-based tissue engineering of corporal penile tissue. A literature search was performed following the PRISMA guidelines. Papers describing cell-seeded tissue engineering of corporal tissue were included. Studies using different techniques, such as intracavernous injection were excluded. Fifteen articles were included in the review. Twelve of these studies described engineering of the corpus cavernosum in animal models. Two articles were found on engineering of animal corpus spongiosum and one article on engineering of the human glans. Both synthetic scaffolds and biological scaffolds were used. The advantage of a biological, acellular scaffold was that the native, complex architecture of corporal tissue was maintained. Most studies used endothelial and smooth muscle cells from corporal origin, but stem cells were also investigated. Furthermore, dynamic culturing achieved an improved cell content and functionality. This review has summarized the developments in tissue engineering of corpus cavernosum and spongiosum tissue. Functional tissue has been developed in animal studies with the use of seeded cells on scaffolds. This knowledge will form a basis for the development of tissue engineering of corporal tissue for clinical applications.

Biodistribution and fate of transplanted stem cells via longitudinal monitoring has been successfully achieved in the last decade using optical imaging. However, sensitive longitudinal imaging of transplanted stem cells in deep tissue like the brain remains challenging not only due to low light penetration but because of other factors such as low or inferior expression levels of optical reporters in stem cells and stem cell death after transplantation. Here we describe an optimized imaging protocol for sensitive long-term monitoring of bone marrow-derived human mesenchymal stem cells (hMSCs) expressing a novel bioluminescent/near infrared fluorescent (NIRF) fusion reporter transplanted in mouse brain cortex. Lentivirus expressing the luc2-iRFP720 reporter, a fusion between luc2 codon-optimized firefly luciferase (luc2) and the gene encoding NIRF protein iRFP720, was generated to transduce hMSCs. These cells were analyzed for their fluorescent and bioluminescent emission and checked for their differentiation potential. In vivo experiments were performed by transplanting decreasing amounts of luc2-iRFP720 expressing hMSCs in mouse brain, followed by fluorescence and bioluminescence imaging (BLI) starting 1 wk after cell injection when the blood–brain barrier was restored. Bioluminescent images were acquired when signals peaked and used to compare different luc2 substrate performances, that is, D-luciferin (D-Luc; 25 μM/kg or 943 μM/kg) or CycLuc1 (25 μM/kg). Results showed that luc2-iRFP720 expressing hMSCs maintained a good in vitro differentiation potential toward adipocytes, chondrocytes, and osteocytes, suggesting that lentiviral transduction did not affect cell behavior. Moreover, in vivo experiments allowed us to image as low as 1 × 105 cells using both fluorescence and BLI. The highest bioluminescent signals (∼1 × 107 photons per second) were achieved 15 min after the injection of D-Luc (943 μM/kg). This allowed us to monitor as low as 1 × 105 hMSCs for the subsequent 7 wk without a significant drop in bioluminescent signals, suggesting the sustained viability of hMSCs transplanted into the cortex.

Matrix production by nucleus pulposus (NP) cells, the cells residing in the center of the intervertebral disc, can be stimulated by growth factors. Bone morphogenetic proteins (BMPs) hold great promise. Although BMP2 and BMP7 have been used most frequently, other BMPs have also shown potential for NP regeneration. Heterodimers may be more potent than single homodimers, but it is not known whether combinations of homodimers would perform equally well. In this study, we compared BMP2, BMP4, BMP6, and BMP7, their combinations and heterodimers, for regeneration by human NP cells. The BMPs investigated induced variable matrix deposition by NP cells. BMP4 was the most potent, both in the final neotissue glysosaminoglycan content and incorporation efficiency. Heterodimers BMP2/6H and BMP2/7H were more potent than their respective homodimer combinations, but not the BMP4/7H heterodimer. The current results indicate that BMP4 might have a high potential for regeneration of the intervertebral disc. Moreover, the added value of BMP heterodimers over their respective homodimer BMP combinations depends on the BMP combination applied.

Biodistribution and fate of transplanted stem cells via longitudinal monitoring has been successfully achieved in the last decade using optical imaging. However, sensitive longitudinal imaging of transplanted stem cells in deep tissue like the brain remains challenging not only due to low light penetration but because of other factors such as low or inferior expression levels of optical reporters in stem cells and stem cell death after transplantation. Here we describe an optimized imaging protocol for sensitive long-term monitoring of bone marrow-derived human mesenchymal stem cells (hMSCs) expressing a novel bioluminescent/near infrared fluorescent (NIRF) fusion reporter transplanted in mouse brain cortex. Lentivirus expressing the luc2-iRFP720 reporter, a fusion between luc2 codon-optimized firefly luciferase (luc2) and the gene encoding NIRF protein iRFP720, was generated to transduce hMSCs. These cells were analyzed for their fluorescent and bioluminescent emission and checked for their differentiation potential. In vivo experiments were performed by transplanting decreasing amounts of luc2-iRFP720 expressing hMSCs in mouse brain, followed by fluorescence and bioluminescence imaging (BLI) starting 1 wk after cell injection when the blood-brain barrier was restored. Bioluminescent images were acquired when signals peaked and used to compare different luc2 substrate performances, that is, D-luciferin (D-Luc; 25 mM/kg or 943 mM/kg) or CycLuc1 (25 mM/kg). Results showed that luc2-iRFP720 expressing hMSCs maintained a good in vitro differentiation potential toward adipocytes, chondrocytes, and osteocytes, suggesting that lentiviral transduction did not affect cell behavior. Moreover, in vivo experiments allowed us to image as low as 1 Â 10 5 cells using both fluorescence and BLI. The highest bioluminescent signals (*1 Â 10 7 photons per second) were achieved 15 min after the injection of D-Luc (943 mM/kg). This allowed us to monitor as low as 1 Â 10 5 hMSCs for the subsequent 7 wk without a significant drop in bioluminescent signals, suggesting the sustained viability of hMSCs transplanted into the cortex.