Bruno Colaço

Estimation of rat mammary tumor volume using caliper and ultrasonography measurements

Mammary tumors similar to those observed in women can be induced in rats by intraperitoneal administration of N-methyl-N-nitrosourea. Determining tumor volume is a useful and quantitative way to monitor tumor progression. In this study, the authors measured dimensions of rat mammary tumors using a caliper and using real-time compound B-mode ultrasonography. They then used different formulas to calculate tumor volume from these tumor measurements and compared the calculated tumor volumes with the real tumor volume to identify the formulas that gave the most accurate volume calculations. They found that caliper and ultrasonography measurements were significantly correlated but that tumor volumes calculated using different formulas varied substantially. Mammary tumors seemed to take on an oblate spheroid geometry. The most accurate volume calculations were obtained using the formula V = (W2 × L)/2 for caliper measurements and the formula V = (4/3) × π × (L/2) × (L/2) × (D/2) for ultrasonography measurements, where V is tumor volume, W is tumor width, L is tumor length and D is tumor depth.

Bladder cancer-induced skeletal muscle wasting: disclosing the role of mitochondria plasticity.

Loss of skeletal muscle is a serious consequence of cancer as it leads to weakness and increased risk of death. To better understand the interplay between urothelial carcinoma and skeletal muscle wasting, cancer-induced catabolic profile and its relationship with muscle mitochondria dynamics were evaluated using a rat model of chemically induced urothelial carcinogenesis by the administration of N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN). The histologic signs of non-muscle-invasive bladder tumors observed in BBN animals were related to 17% loss of body weight and high serum levels of IL-1β, TNF-α, TWEAK, C-reactive protein, myostatin and lactate and high urinary MMPs activities, suggesting a catabolic phenotype underlying urothelial carcinoma. The 12% loss of gastrocnemius mass was related to mitochondrial dysfunction, manifested by decreased activity of respiratory chain complexes due to, at least partially, the impairment of protein quality control (PQC) systems involving the mitochondrial proteases paraplegin and Lon. This was paralleled by the accumulation of oxidatively modified mitochondrial proteins. In overall, our data emphasize the relevance of studying the regulation of PQC systems in cancer cachexia aiming to identify therapeutic targets to counteract muscle wasting.

Molecular insights into mitochondrial dysfunction in cancer-related muscle wasting.

Alterations in muscle mitochondrial bioenergetics during cancer cachexia were previously suggested; however, the underlying mechanisms are not known. So, the goal of this study was to evaluate mitochondrial phospholipid remodeling in cancer-related muscle wasting and its repercussions to respiratory chain activity and fiber susceptibility to apoptosis. An animal model of urothelial carcinoma induced by exposition to N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) and characterized by significant body weight loss due to skeletal muscle mass decrease was used. Morphological evidences of muscle atrophy were associated to decreased respiratory chain activity and increased expression of mitochondrial UCP3, which altogether highlight the lower ability of wasted muscle to produce ATP. Lipidomic analysis of isolated mitochondria revealed a significant decrease of phosphatidic acid, phosphatidylglycerol and cardiolipin in BBN mitochondria, counteracted by increased phosphatidylcholine levels. Besides the impact on membrane fluidity, this phospholipid remodeling seems to justify, at least in part, the lower oxidative phosphorylation activity observed in mitochondria from wasted muscle and their increased susceptibility to apoptosis. Curiously, no evidences of lipid peroxidation were observed but proteins from BBN mitochondria, particularly the metabolic ones, seem more prone to carbonylation with the consequent implications in mitochondria functionality. Overall, data suggest that bladder cancer negatively impacts skeletal muscle activity specifically by affecting mitochondrial phospholipid dynamics and its interaction with proteins, ultimately leading to the dysfunction of this organelle. The regulation of phospholipid biosynthetic pathways might be seen as potential therapeutic targets for the management of cancer-related muscle wasting.

Everolimus combined with cisplatin has a potential role in treatment of urothelial bladder cancer.

Cisplatin (CDDP)-based chemotherapy is a commonly treatment for advanced urothelial carcinoma. However, episodes of cisplatin resistance have been referenced. Recently it has been reported that everolimus (RAD001) could have an important role to play in bladder-cancer treatment and that mTOR inhibitors may restore chemosensitivity in resistant tumours. The aim of this study was to assess RAD001 in vitro ability to enhance CDDP cytotoxicity in three human bladder-cancer cell lines. Over the course of 72h, the cells were exposed to different concentrations of CDDP and RAD001, isolated or combined. Treatment with CDDP statistically (P<0.05) decreased cell proliferation in cell lines in a dose-dependent manner. The anti-proliferative activity of CDDP used in combination with RAD001 was statistically significant (P<0.05) in the cell lines at all concentrations tested. RAD001 had a therapeutic effect when used in combination with CDDP and could therefore be a useful anti-cancer drug combination for patients with bladder cancer.

Cross-species comparison of mammalian saliva using an LC-MALDI based proteomic approach

Despite the importance of saliva in the regulation of oral cavity homeostasis, few studies have been conducted to quantitatively compare the saliva of different mammal species. Aiming to define a proteome signature of mammals’ saliva, an in‐depth SDS‐PAGE–LC coupled to MS/MS (GeLC–MS/MS) approach was used to characterize the saliva from primates (human), carnivores (dog), glires (rat and rabbit), and ungulates (sheep, cattle, horse). Despite the high variability in the number of distinct proteins identified per species, most protein families were shared by the mammals studied with the exception of cattle and horse. Alpha‐amylase is an example that seems to reflect the natural selection related to digestion efficacy and food recognition. Casein protein family was identified in all species but human, suggesting an alternative to statherin in the protection of hard tissues. Overall, data suggest that different proteins might assure a similar role in the regulation of oral cavity homeostasis, potentially explaining the specific mammals’ salivary proteome signature. Moreover, some protein families were identified for the first time in the saliva of some species, the presence of proline‐rich proteins in rabbits saliva being a good example.

Bisphosphonates induce the osteogenic gene expression in co-cultured human endothelial and mesenchymal stem cells.

Bisphosphonates (BPs) are known to affect bone homeostasis and also to have anti‐angiogenic properties. Because of the intimate relationship between angiogenesis and osteogenesis, this study analysed the effects of Alendronate (AL) and Zoledronate (ZL) in the expression of endothelial and osteogenic genes on interacting endothelial and mesenchymal stem cells, an issue that was not previously addressed. Alendronate and ZL, 10−12–10−6 M, were evaluated in a direct co‐culture system of human dermal microvascular endothelial cells (HDMEC) and human bone marrow mesenchymal stem cells (HMSC), over a period of 14 days. Experiments with the respective monocultures were run in parallel. Alendronate and ZL caused an initial dose‐dependent stimulation in the cell proliferation in the monocultures and co‐cultures, and did not interfere with their cellular organization. In HDMEC monocultures, the expression of the endothelial genes CD31, VE‐cadherin and VEGFR2 was down‐regulated by AL and ZL. In HMSC monocultures, the BPs inhibited VEGF expression, but up‐regulated the expression of the osteogenic genes alkaline phosphatase (ALP), bone morphogenic protein‐2 (BMP‐2) and osteocalcin (OC) and, to a greater extent, osteoprotegerin (OPG), a negative regulator of the osteoclastic differentiation, and increased ALP activity. In co‐cultured HDMEC/HMSC, AL and ZL decreased the expression of endothelial genes but elicited an earlier and sustained overexpression of ALP, BMP‐2, OC and OPG, compared with the monocultured cells; they also induced ALP activity. This study showed for the first time that AL and ZL greatly induced the osteogenic gene expression on interacting endothelial and mesenchymal stem cells.

Hypospadias in a Male (78,XY; SRY-Positive) Dog and Sex Reversal Female (78,XX; SRY-Negative) Dogs: Clinical, Histological and Genetic Studies

Hypospadias is rarely reported in dogs. In this study we pre-sent 2 novel cases of this disorder of sexual development and, in addition, a case of hereditary sex reversal in a female with an enlarged clitoris. The first case was a male Moscow watchdog with a normal karyotype (78,XY) and the presence of the SRY gene. In this dog, perineal hypospadias, bilateral inguinal cryptorchidism and testes were observed. The second case, representing the Cocker spaniel breed, had a small penis with a hypospadic orifice of the urethra, bilateral cryptorchidism, testis and a rudimentary gonad inside an ovarian bursa, a normal female karyotype (78,XX) and a lack of the SRY gene. This animal was classified as a compound sex reversal (78,XX, SRY-negative) with the hypospadias syndrome. The third case was a Cocker spaniel female with an enlarged clitoris and internally located ovotestes. Cytogenetic and molecular analyses revealed a normal female karyotype (78,XX) and a lack of the SRY gene, while histology of the gonads showed an ovotesticular structure. This case was classified as a typical hereditary sex reversal syndrome (78,XX, SRY-negative). Molecular studies were focused on coding sequences of the SRY gene (case 1) and 2 candidates for monogenic hypospadias, namely MAMLD1 (mastermind-like domain containing 1) and SRD5A2 (steroid-5-alpha-reductase, alpha polypeptide 2). Sequencing of the entire SRY gene, including 5′- and 3′-flanking regions, did not reveal any mutation. The entire coding sequence of MAMLD1 and SRD5A2 was analyzed in all the intersexes, as well as in 4 phenotypically normal control dogs (3 females and 1 male). In MAMLD1 2 SNPs, including 1 missense substitution in exon 1 (c.128A>G, Asp43Ser), were identified, whereas in SRD5A2 7 polymorphisms, including 1 missense SNP (c.358G>A, Ala120Thr), were found. None of the identified polymorphisms cosegregated with the intersexual phenotype, thus, we cannot confirm that hypospadias may be associated with polymorphism in the coding sequence of the studied genes.

Biodegradation, biocompatibility, and osteoconduction evaluation of collagen‐nanohydroxyapatite cryogels for bone tissue regeneration

Designing biomimetic biomaterials inspired by the natural complex structure of bone and other hard tissues is still a challenge nowadays. The control of the biomineralization process onto biomaterials should be evaluated before clinical application. Aiming at bone regeneration applications, this work evaluated the in vitro biodegradation and interaction between human bone marrow stromal cells (HBMSC) cultured on different collagen/nanohydroxyapatite cryogels. Cell proliferation, differentiation, morphology, and metabolic activity were assessed through different protocols. All the biocomposite materials allowed physiologic apatite deposition after incubation in simulated body fluid and the cryogel with the highest nanoHA content showed to have the highest mechanical strength (DMA). The study clearly showed that the highest concentration of nanoHA granules on the cryogels were able to support cell types survival, proliferation, and individual functionality in a monoculture system, for 21 days. In fact, the biocomposites were also able to differentiate HBMSCs into osteoblastic phenotype. The composites behavior was also assessed in vivo through subcutaneous and bone implantation in rats to evaluate its tissue-forming ability and degradation rate. The cryogels Coll/nanoHA (30 : 70) promoted tissue regeneration and adverse reactions were not observed on subcutaneous and bone implants. The results achieved suggest that scaffolds of Coll/nanoHA (30 : 70) should be considered promising implants for bone defects that present a grotto like appearance with a relatively small access but a wider hollow inside. This material could adjust to small dimensions and when entering into the defect, it could expand inside and remain in close contact with the defect walls, thus ensuring adequate osteoconductivity.

The effects of repeated oral gavage on the health of male CD-1 mice

Oral gavage is a widely used method for administering substances to animals in pharmacological and toxicological studies. The authors evaluated whether oral gavage causes behavioral indicators of stress, increased mortality rate, alterations in food and water consumption and body weight or histological lesions in CD-1 mice. Gavage was carried out once per d for 5 d per week over 6 consecutive weeks. The mortality rate of mice in this study was 15%. Mice subjected to gavage did not undergo changes in food or water consumption during the study, and their mean body weights and relative organ weights were similar to those of mice in the control group. Serum cortisol levels at the time of euthanasia in mice in both groups were within the normal range. Histopathology showed acute esophagitis and pleurisy, indicative of perforation of the esophagus, in the two mice that died but no abnormalities in the other mice. The results suggest that animal stress and mortality related to oral gavage can be minimized when the procedure is carried out by an experienced technician.

High doses of olive leaf extract induce liver changes in mice

Virtually ever since it was first commercialized in 1995, there have been several studies focusing on the use of olive leaf extract (OLE) as a natural therapy and its medical properties. The aim of this study was to investigate the effects of three different concentrations of OLE on the function of mice livers over the course of 14 weeks. Female ICR mice were divided into four groups, depending on OLE concentration used: 0%, 0.25%, 0.5%, and 0.75%. Alanine aminotransferase, alkaline phosphatase, total bilirubin and albumin serum concentrations were all measured. Histopathological changes of the liver were observed after haematoxylin and eosin, reticulin, and Massons trichrome staining was carried out while liver mitochondrial bioenergetics were also evaluated. Alanine aminotransferase and alkaline phosphatase serum enzyme activities increased significantly in the groups in which 0.5% and 0.75% OLE concentrations were used. Histologically, all the groups exposed to OLE exhibited hyperplasia of the bile ducts, cholestasis, hepatocyte necrosis and inflammatory infiltrated. Hepatic fibrosis was observed in the groups featuring 0.5% and 0.75% OLE concentrations. The mitochondrial membrane potential, respiratory control ratio and ADP/O of samples from animals fed the higher OLE concentration was significantly decreased when compared to the control group.