Anti-tumorigenic effects of naive and TLR4-primed adipose-derived mesenchymal stem cells on pancreatic ductal adenocarcinoma cells.

BACKGROUND: One of the main reasons for the unsuccessful treatment of pancreatic cancer is the intense desmoplastic pancreatic microenvironment. In the literature, the effects of mesenchymal stem cells (MSCs) and their inflammatory phenotypes on cancer cells have been a subject of controversy. Therefore, it is crucial to elucidate the underlying mechanisms of this interaction, especially in the context of pancreatic cancer. We aimed to investigate the effects of naive, TLR4-activated, and TLR4-inhibited phenotypes of adipose-derived MSCs (ADMSC) on pancreatic ductal cell line (Panc-1). METHODS AND MATERIALS: Adipose-derived MSCs were induced into a proinflammatory phenotype using a 0.5 µg/mL dose of TLR4 agonist, while an anti-inflammatory phenotype was generated in ADMSCs using a 25 µg/mL dose of TLR4 antagonist. We observed that the proliferation of Panc-1 cells was inhibited when naive ADMSCs:Panc-1(10:1) and proinflammatory ADMSCs:Panc-1(10:1) were directly cocultured. RESULTS: In indirect coculture, both naive and proinflammatory ADMSCs exhibited a significant 10-fold increase in their inhibitory effect on the proliferation and colony forming capacity of Panc-1 cells, with the added benefit of inducing apoptosis. In our study, both naive and proinflammatory ADMSCs were found to regulate the expression of genes associated with metastasis (MMP2, KDR, MMP9, TIMP1, IGF2R, and COL1A1) and EMT (CDH1, VIM, ZEB1, and CLDN1) in Panc-1 cells. Remarkably, both naive and proinflammatory ADMSCs demonstrated antitumor effects on Panc-1 cells. However, it was observed that anti-inflammatory ADMSCs showed tumor-promoting effects instead. Furthermore, we observed a reciprocal influence between ADMSCs and Panc-1 cells on each other's proinflammatory cytokine expressions, suggesting a dynamic interplay within the tumor microenvironment. CONCLUSIONS: These findings underscore the significance of both the naive state and different inflammatory phenotypes of MSCs in the microenvironment and represent a pivotal step toward the development of novel therapeutic approaches for pancreatic cancer. Understanding the intricate interactions between MSCs and cancer cells may open new avenues for targeted interventions in cancer therapy.

miRNA-193b-5p Suppresses Pancreatic Cancer Cell Proliferation, Invasion, Epithelial Mesenchymal Transition, and Tumor Growth by Inhibiting eEF2K.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is the 4th leading cause of cancer deaths in the US due to the lack of effective targeted therapeutics and extremely poor prognosis. OBJECTIVE: The study aims to investigate the role of miR-193b and related signaling mechanisms in PDAC cell proliferation, invasion, and tumor growth. METHODS: Using PDAC cell lines, we performed cell viability, colony formation, in vitro wound healing, and matrigel invasion assays following transfection with miR-193b mimic or control-miR. To identify potential downstream targets of miR-193b, we utilized miRNA-target prediction algorithms and investigated the regulation of eukaryotic elongation factor-2 kinase (eEF2K) and mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling pathways and mediators of epithelial mesenchymal transition (EMT). The role of miR-193b in PDAC tumorigenesis was evaluated in in vivo tumor growth of Panc-1 xenograft model in nude mice. RESULTS: We found that miR-193b is under expressed in PDAC cells compared to corresponding normal pancreatic epithelial cells and demonstrated that ectopic expression of miR-193b reduced cell proliferation, migration, invasion, and EMT through downregulation of eEF2K signaling in PDAC cells. miR-193b expression led to increased expression of E-Cadherin and Claudin-1 while decreasing Snail and TCF8/ZEB1 expressions via eEF2K and MAPK/ERK axis. In vivo systemic injection of miR-193b using lipid-nanoparticles twice a week reduced tumor growth of Panc-1 xenografts and eEF2K expression in nude mice. CONCLUSIONS: Our findings suggest that miR-193b expression suppresses PDAC cell proliferation, migration, invasion, and EMT through inhibition of eEF2K/MAPK-ERK oncogenic axis and that miR-193b-based RNA therapy might be an effective therapeutic strategy to control the growth of PDAC.

Increase in serum and salivary neutrophil gelatinase-associated lipocalin levels with increased periodontal inflammation.

OBJECTIVE: This study aimed to determine serum and salivary levels of neutrophil gelatinase-associated lipocalin (NGAL) and evaluate NGAL correlation with key anti-interleukin 10 (IL-10) and pro-inflammatory (IL-1ß) cytokines in different severities of periodontal diseases. We also calculated the systemic inflammation using the periodontal inflamed surface area (PISA) to evaluate its correlation with NGAL in the study groups. METHODOLOGY: Eighty systemically healthy and non-smoking individuals were separated into four groups of 20: clinically healthy (Group 1), gingivitis (Group 2), stage I generalized periodontitis (Group 3, Grade A), and stage III generalized periodontitis (Group 4, Grade A). Sociodemographic characteristics and periodontal parameters were recorded, and PISA was calculated. The serum and salivary levels of interleukin (IL)-1ß, IL-10, and NGAL were determined using the enzyme-linked immunosorbent assay (ELISA). RESULTS: We observed a significant increase in serum and salivary NGAL levels from healthy to periodontitis groups (p=0.000). Group 2 presented significantly higher serum and salivary IL-10 levels and salivary IL-1ß levels than Group 3 (p=0.000). Serum and salivary parameters (IL-1ß, IL-10, and NGAL levels) were strongly positively correlated to periodontal parameters and PISA values (p=0.000). Groups 2 and 3 showed overlapping PISA values. CONCLUSION: The overlapping PISA values found in Groups 2 and 3 suggest that gingivitis might progress to a systemic inflammatory burden somewhat comparable to stage I periodontitis. This finding is supported by the higher serum and salivary cytokines/mediators levels in the gingivitis group than in stage I periodontitis group. Serum and salivary NGAL levels increased proportionally to disease severity and PISA. NGAL seems to play a role in the pathogenesis of periodontal disease, within the limitation of our study.

Ochratoxin A causes cell cycle arrest in G1 and G1/S phases through p53 in HK-2 cells.

Ochratoxin A (OTA) is a toxic metabolite produced by Aspergillus and Penicillium fungus. OTA found in the human and animal tissues can contaminate many foods that we daily consume in our lives. It accumulates especially in kidney. Although OTA is known to cause cell cycle arrest, the molecular mechanisms underlying this effect have not been fully understood, yet. We aimed to investigate the molecular details of OTA induced inhibitory response in G1 - G1/S phase of cell cycle and also the regulatory role of p53 in OTA mediated cell cycle arrest in human proximal tubule epithelial cells, HK-2. For this purpose, Cyclin E1 and Cyclin D1 mRNA expressions and Cyclin D1, Cdk4 and Cdk2 protein expressions were evaluated in HK-2 cells transfected with either 50 nM control siRNA or p53 siRNA for 72 h in the absence or presence of OTA using RT-PCR and Western blot analyses, respectively. Our findings showed that mRNA expressions of Cyclin D1 and Cyclin E1 and protein expressions of Cyclin D1, Cdk4 and Cdk2 were inhibited in HK-2 cells treated with two different doses of OTA, 10 µM and 25 µM, for 24 h. However, the downregulation of p53 led to enhance OTA-mediated increase in mRNA expressions of Cyclin D1 and Cyclin E1 and protein expressions of Cyclin D1, Cdk4 and Cdk2 compared to control siRNA transfected HK-2 cells. Our findings strongly suggest that the cell cycle arresting effect of OTA also performs via a p53 mediated mechanism besides other possible mechanisms.

Increase in serum and salivary neutrophil gelatinase-associated lipocalin levels with increased periodontal inflammation

Abstract Objective: This study aimed to determine serum and salivary levels of neutrophil gelatinase-associated lipocalin (NGAL) and evaluate NGAL correlation with key anti-interleukin 10 (IL-10) and pro-inflammatory (IL-1β) cytokines in different severities of periodontal diseases. We also calculated the systemic inflammation using the periodontal inflamed surface area (PISA) to evaluate its correlation with NGAL in the study groups. Methodology: Eighty systemically healthy and non-smoking individuals were separated into four groups of 20: clinically healthy (Group 1), gingivitis (Group 2), stage I generalized periodontitis (Group 3, Grade A), and stage III generalized periodontitis (Group 4, Grade A). Sociodemographic characteristics and periodontal parameters were recorded, and PISA was calculated. The serum and salivary levels of interleukin (IL)-1β, IL-10, and NGAL were determined using the enzyme-linked immunosorbent assay (ELISA). Results: We observed a significant increase in serum and salivary NGAL levels from healthy to periodontitis groups (p=0.000). Group 2 presented significantly higher serum and salivary IL-10 levels and salivary IL-1β levels than Group 3 (p=0.000). Serum and salivary parameters (IL-1β, IL-10, and NGAL levels) were strongly positively correlated to periodontal parameters and PISA values (p=0.000). Groups 2 and 3 showed overlapping PISA values. Conclusion: The overlapping PISA values found in Groups 2 and 3 suggest that gingivitis might progress to a systemic inflammatory burden somewhat comparable to stage I periodontitis. This finding is supported by the higher serum and salivary cytokines/mediators levels in the gingivitis group than in stage I periodontitis group. Serum and salivary NGAL levels increased proportionally to disease severity and PISA. NGAL seems to play a role in the pathogenesis of periodontal disease, within the limitation of our study.

MicroRNA-based Targeted Therapeutics in Pancreatic Cancer.

The discovery during the last decade of microRNAs (miRs, miRNA) and their role in regulating normal physiological processes as well as in the pathogenesis of human tumors has been a revolutionary development in molecular oncology. miRNAs activating or inhibiting oncogenic molecular pathways that are involved in tumorigenesis, cell progression, invasion, angiogenesis and metastasis are now considered of major impact in many cancer types. miRNA-based therapeutics that inhibit the levels of oncogenic miRNAs (oncomiRs) or elevate tumor suppressor miRs have enormous potential as molecular therapeutic targets. Thus, the development of new targeted cancer therapies based on miRNAs promise to revolutionize cancer treatment due to their increased efficacy compared to conventional chemoradiation-based therapies and hopefully to lower levels of adverse effects.

Elongation factor-2 kinase (eEF-2K) expression is associated with poor patient survival and promotes proliferation, invasion and tumor growth of lung cancer.

OBJECTIVES: Lung cancer is the leading cause of cancer related deaths in worldwide. Despite recent advances in treatment options, patient survival has not improved substantially due to lack of commonly expressed molecular targets and effective targeted therapeutics. Thus, better understanding of the biology of lung cancer and identification of novel therapeutic targets are urgently needed for development of highly effective molecularly targeted therapies. MATERIALS AND METHODS: Viability, proliferation and metastatic ability of lung cancer cells were evaluated using methylthiazoltetrazolium (MTT), colony formation and matrigel invasion assays, respectively. Western blotting, RT-PCR, and gene knockdown by siRNA transfections were carried out to investigate the effects of eEF-2K on lung cancer cells. Athymic Nu/Nu mice were treated with liposomal eEF-2KeEF-2K or control siRNA and tumor growth was evaluated in tumor xenograft models of lung cancer. RESULTS AND DISCUSSION: Here, we report that Eukaryotic Elongation Factor-2 kinase (eEF-2K), a member of an atypical alpha kinases family, is significantly upregulated in lung cancer cell lines and its expression is associated with shorter overall patient survival in lung cancer. Inhibition eEF-2K expression by siRNA or a chemical inhibitorsignificantly suppressed lung cancer cell proliferation, colony formation, survival, migration/invasion and tumorigenesis by inhibiting cyclin D1, Src and Mitogen-Activated Protein Kinases/Extracellular Signal-Regulated Kinase (MAPK/ERK) signaling. In vivo targeting of eEF-2K by systemically injected nanoliposomal eEF-2K siRNA resulted in a significant inhibition of lung cancer tumor xenografts in nude mice. Our results suggest, for the first time, that expression of eEF-2K is associated with poor patient prognosis and involved in regulation of critical pathways, including Src and MAPK/ERK and cyclin D1, promoting tumor growth and progression, and thus may be a novel potential therapeutic target in lung cancer.

Therapeutic Targeting of AXL Receptor Tyrosine Kinase Inhibits Tumor Growth and Intraperitoneal Metastasis in Ovarian Cancer Models.

Despite substantial improvements in the treatment strategies, ovarian cancer is still the most lethal gynecological malignancy. Identification of drug treatable therapeutic targets and their safe and effective targeting is critical to improve patient survival in ovarian cancer. AXL receptor tyrosine kinase (RTK) has been proposed to be an important therapeutic target for metastatic and advanced-stage human ovarian cancer. We found that AXL-RTK expression is associated with significantly shorter patient survival based on the The Cancer Genome Atlas patient database. To target AXL-RTK, we developed a chemically modified serum nuclease-stable AXL aptamer (AXL-APTAMER), and we evaluated its in vitro and in vivo antitumor activity using in vitro assays as well as two intraperitoneal animal models. AXL-aptamer treatment inhibited the phosphorylation and the activity of AXL, impaired the migration and invasion ability of ovarian cancer cells, and led to the inhibition of tumor growth and number of intraperitoneal metastatic nodules, which was associated with the inhibition of AXL activity and angiogenesis in tumors. When combined with paclitaxel, in vivo systemic (intravenous [i.v.]) administration of AXL-aptamer treatment markedly enhanced the antitumor efficacy of paclitaxel in mice. Taken together, our data indicate that AXL-aptamers successfully target in vivo AXL-RTK and inhibit its AXL activity and tumor growth and progression, representing a promising strategy for the treatment of ovarian cancer.

A selective serotonin 5-HT1B receptor inhibition suppresses cells proliferation and induces apoptosis in human uterine leiomyoma cells.

OBJECTIVE: Uterine leiomyomas (fibroids or myomas) are the most common pelvic tumor in women with about 70% lifetime incidence rate. Currently, the only definitive treatment is surgery, causing undesirable side effects and negative impact on women's quality of life, reproductive ability, and a substantial impact on healthcare costs. Therefore, curative medical treatments are needed to be developed. In this study, we investigated the impact of serotonin receptor 5-HT1B on cell proliferation and survival in human uterine leiomyoma cells (huLM). STUDY DESIGN: The impact of 5-HT1B receptor on cell proliferation, survival and apoptosis was investigated using a selective 5-HTR1B antagonist SB216641 in huLM cells, utilizing MTS, colony formation assay and Annexin V staining, respectively. Mechanisms of inhibition of cell proliferation, survival and induction of apoptosis were investigated by Western blot analysis after treatment with various doses of HT1B antagonist. RESULTS: 5-HT1B receptor inhibition leads to a significant decrease in proliferation and colony formation in huLM cells, reduction of cyclin D1 and alpha-smooth muscle actin (α-SMA) expressions and the activity of Mitogen Activated Protein Kinase (MAPK) ERK and Elongation Factor 2 kinase (EF2K) pathways. 5-HT1B receptor blockage also induces apoptotic cell death by inducing cleavage of caspase-8, -9, and -3 and PARP. CONCLUSION: Our findings show for the first time that 5-HT1B receptor promotes uterine leiomyoma cell survival and proliferation and its inhibition may be a potential therapeutic approach for human uterine leiomyomas. Thus, 5-HT1B expression and antagonists should be further investigated in leiomyoma tumors.

Chronic administration of sildenafil improves erectile function in a rat model of chronic renal failure.

The relationship between erectile dysfunction (ED) and chronic renal failure (CRF) has been reported in several studies. This study aimed to investigate whether the chronic use of sildenafil could enhance the erectile capacity in CRF-induced rats. In addition, we assessed the effect of that treatment on certain molecules, which have been suggested to play crucial roles in erectile physiology and CRF-related ED as well. Three groups of animals were utilized: (1) age-matched control rats, (2) CRF-induced rats, (3) CRF-induced rats treated with chronic administration of sildenafil (5 mg kg-1 p.o. for 6 weeks [treatment started after 6 weeks of CRF induction]). At 3 months, all animals underwent cavernosal nerve stimulation (CNS) to assess erectile function. Penile tissue advanced glycation end products (AGE's)/5-hydroxymethyl-2-furaldehyde, malondialdehyde (MDA), cGMP (ELISA), inducible nitric oxide synthase (iNOS) and neuronal NOS (nNOS) (Western blot) analyses were performed in all rat groups. CRF-induced rats had a significant decrease in erectile function when compared to control rats (P < 0.05). The increase in both intracavernosal pressure (ICP) and area under the curve of CRF-induced rats treated with sildenafil (Group 3) was greater than CRF-induced rats (Group 2). Additionally, sildenafil treatment decreased AGE, MDA and iNOS levels, while it preserved nNOS and cGMP contents in CRF-induced penile tissue. Decreased AGE, MDA, iNOS and increased nNOS, cGMP levels at the sildenafil-treated group increased both ICP and Total ICP to CNS, which led to improve erectile function in CRF-induced rats. The results of the present study revealed the therapeutic effect of chronic sildenafil administration on erectile function in CRF-induced rats.

Cystine dimethyl ester induces apoptosis through regulation of PKC-δ and PKC-ε in prostate cancer cells.

Protein kinase C-δ (PKC-δ) and PKC-ε are reported to be effective in cancer prevention via S-thiolation-mediated mechanisms. This may be through stimulation of the pro-apoptotic, tumor-suppressive isozyme PKC-δ and/or inactivation of the growth stimulatory, oncogenic isozyme PKC-ε. We investigated oxidative regulatory responses of PKC-δ and PKC-ε to cystine dimethyl ester (CDME), a metabolic precursor of cystine, which, by inducing release of cellular cystine stimulates apoptosis in different prostate cancer cells, PC3 and LNCaP, compared to normal RWPE1 cells. Treatment of CDME in doses of 0.5mM and 5mM significantly induces apoptosis due to regulation of concentration-dependent PKC-δ stimulation and PKC-ε reduction in these prostate cancer cells. This apoptotic regulation was confirmed by immunoblot analyses and specific PKC enzyme assays in immunoprecipitated samples. Additionally, inhibition of PKC-δ by small interfering RNA (siRNA) proved that CDME-induced cell death was dependent on PKC-δ activity in prostate cancer cells. These data demonstrated that CDME induces apoptosis by cysteinylation of both PKC-δ and PKC-ε in tumorigenic prostate epithelial cells compared to control nontumorigenic cells. Cellular cystine may play a critical role in treatment and/or prevention of prostate cancer by regulating PKC activity.

Down-regulation of 5-HT1B and 5-HT1D receptors inhibits proliferation, clonogenicity and invasion of human pancreatic cancer cells.

Pancreatic ductal adenocarcinoma is characterized by extensive local tumor invasion, metastasis and early systemic dissemination. The vast majority of pancreatic cancer (PaCa) patients already have metastatic complications at the time of diagnosis, and the death rate of this lethal type of cancer has increased over the past decades. Thus, efforts at identifying novel molecularly targeted therapies are priorities. Recent studies have suggested that serotonin (5-HT) contributes to the tumor growth in a variety of cancers including prostate, colon, bladder and liver cancer. However, there is lack of evidence about the impact of 5-HT receptors on promoting pancreatic cancer. Having considered the role of 5-HT-1 receptors, especially 5-HT1B and 5-HT1D subtypes in different types of malignancies, the aim of this study was to investigate the role of 5-HT1B and 5-HT1D receptors in PaCa growth and progression and analyze their potential as cytotoxic targets. We found that knockdown of 5-HT1B and 5-HT1D receptors expression, using specific small interfering RNA (siRNA), induced significant inhibition of proliferation and clonogenicity of PaCa cells. Also, it significantly suppressed PaCa cells invasion and reduced the activity of uPAR/MMP-2 signaling and Integrin/Src/Fak-mediated signaling, as integral tumor cell pathways associated with invasion, migration, adhesion, and proliferation. Moreover, targeting 5-HT1B and 5-HT1D receptors down-regulates zinc finger ZEB1 and Snail proteins, the hallmarks transcription factors regulating epithelial-mesenchymal transition (EMT), concomitantly with up-regulating of claudin-1 and E-Cadherin. In conclusion, our data suggests that 5-HT1B- and 5-HT1D- mediated signaling play an important role in the regulation of the proliferative and invasive phenotype of PaCa. It also highlights the therapeutic potential of targeting of 5-HT1B/1D receptors in the treatment of PaCa, and opens a new avenue for biomarkers identification, and valuable new therapeutic targets for managing pancreatic cancer.

Elongation factor-2 kinase regulates TG2/ß1 integrin/Src/uPAR pathway and epithelial-mesenchymal transition mediating pancreatic cancer cells invasion.

Pancreatic ductal adenocarcinoma is one of the lethal cancers with extensive local tumour invasion, metastasis, early systemic dissemination and poorest prognosis. Thus, understanding the mechanisms regulating invasion/metastasis and epithelial-mesenchymal transition (EMT), is the key for developing effective therapeutic strategies for pancreatic cancer (PaCa). Eukaryotic elongation factor-2 kinase (eEF-2K) is an atypical kinase that we found to be highly up-regulated in PaCa cells. However, its role in PaCa invasion/progression remains unknown. Here, we investigated the role of eEF-2K in cellular invasion, and we found that down-regulation of eEF-2K, by siRNA or rottlerin, displays impairment of PaCa cells invasion/migration, with significant decreases in the expression of tissue transglutaminase (TG2), the multifunctional enzyme implicated in regulation of cell attachment, motility and survival. These events were associated with reductions in ß1 integrin/uPAR/MMP-2 expressions as well as decrease in Src activity. Furthermore, inhibition of eEF-2K/TG2 axis suppresses the EMT, as demonstrated by the modulation of the zinc finger transcription factors, ZEB1/Snail, and the tight junction proteins, claudins. Importantly, while eEF-2K silencing recapitulates the rottlerin-induced inhibition of invasion and correlated events, eEF-2K overexpression, by lentivirus-based expression system, suppresses such rottlerin effects and potentiates PaCa cells invasion/migration capability. Collectively, our results show, for the first time, that eEF-2K is involved in regulation of the invasive phenotype of PaCa cells through promoting a new signalling pathway, which is mediated by TG2/ß1 integrin/Src/uPAR/MMP-2, and the induction of EMT biomarkers which enhance cancer cell motility and metastatic potential. Thus, eEF-2K could represent a novel potential therapeutic target in pancreatic cancer.

Down-regulation of 5-HT1B and 5-HT1D receptors inhibits proliferation, clonogenicity and invasion of human pancreatic cancer cells.

Pancreatic ductal adenocarcinoma is characterized by extensive local tumor invasion, metastasis and early systemic dissemination. The vast majority of pancreatic cancer (PaCa) patients already have metastatic complications at the time of diagnosis, and the death rate of this lethal type of cancer has increased over the past decades. Thus, efforts at identifying novel molecularly targeted therapies are priorities. Recent studies have suggested that serotonin (5-HT) contributes to the tumor growth in a variety of cancers including prostate, colon, bladder and liver cancer. However, there is lack of evidence about the impact of 5-HT receptors on promoting pancreatic cancer. Having considered the role of 5-HT-1 receptors, especially 5-HT1B and 5-HT1D subtypes in different types of malignancies, the aim of this study was to investigate the role of 5-HT1B and 5-HT1D receptors in PaCa growth and progression and analyze their potential as cytotoxic targets. We found that knockdown of 5-HT1B and 5-HT1D receptors expression, using specific small interfering RNA (siRNA), induced significant inhibition of proliferation and clonogenicity of PaCa cells. Also, it significantly suppressed PaCa cells invasion and reduced the activity of uPAR/MMP-2 signaling and Integrin/Src/Fak-mediated signaling, as integral tumor cell pathways associated with invasion, migration, adhesion, and proliferation. Moreover, targeting 5-HT1B and 5-HT1D receptors down-regulates zinc finger ZEB1 and Snail proteins, the hallmarks transcription factors regulating epithelial-mesenchymal transition (EMT), concomitantly with up-regulating of claudin-1 and E-Cadherin. In conclusion, our data suggests that 5-HT1B- and 5-HT1D-mediated signaling play an important role in the regulation of the proliferative and invasive phenotype of PaCa. It also highlights the therapeutic potential of targeting of 5-HT1B/1D receptors in the treatment of PaCa, and opens a new avenue for biomarkers identification, and valuable new therapeutic targets for managing pancreatic cancer.

Hypogonadism and erectile dysfunction: an overview.

In humans androgen decline is presented as a clinical picture which includes decreased sexual interest, diminished erectile capacity, delayed or absent orgasms and reduced sexual pleasure. Additionally, changes in mood, diminished well being, fatigue, depression and irritability are also associated with androgen insufficiency. The critical role of androgens on the development, growth, and maintenance of the penis has been widely accepted. Although, the exact effect of androgens on erectile physiology still remains undetermined, recent experimental studies have broaden our understanding about the relationship between androgens and erectile function. Preclinical studies showed that androgen deprivation leads to penile tissue atrophy and alterations in the nerve structures of the penis. Furthermore, androgen deprivation caused to accumulation of fat containing cells and decreased protein expression of endothelial and neuronal nitric oxide synthases (eNOS and nNOS), and phosphodiesterase type-5 (PDE-5), which play crucial role in normal erectile physiology. On the light of the recent literature, we aimed to present the direct effect of androgens on the structures, development and maintenance of penile tissue and erectile physiology as well. Furthermore, according to the clinical studies we conclude the aetiology, pathophysiology, prevalence, diagnosis and treatment options of hypogonadism in aging men.

Transmission electron microscopy and autofluorescence findings in the cornea of diabetic rats treated with aminoguanidine.

BACKGROUND: The accumulation of advanced glycation end products (AGEs) has been implicated in the pathogenesis of diabetic keratopathy. The present study was aimed to understand if aminoguanidine (AG), an AGE inhibitor, was protective against the development of corneal complications in a diabetic rat model. METHODS: Wistar rats were divided into three experimental groups: control, diabetic, and AG-treated diabetic. Diabetes was induced in rats via a single intraperitoneal injection (60 mg/kg) of streptozocin (STZ) and AG was administered in drinking water at a dose of 1 g/L. All animals were sacrificed at the end of 10 weeks and corneas from diabetic and nondiabetic rats were analyzed via transmission electron microscopy (TEM). Corneal autofluorescence measurements were also performed in all experimental groups. RESULTS: Electron microscopic evaluation revealed that aminoguanidine treatment in diabetic rats prevented the formation of intracellular spaces between neighbouring cells in the superficial corneal epithelium. Hyperglycemia-induced degeneration of intracellular organelles and formation of cytoplasmic vacuoles in the corneal stroma was also prevented with the treatment of AG. Corneal autofluorescence detected in the diabetic group (5.98 +/- 2.17 Fi/mg protein) was found to be significantly greater than the control (3.92 +/- 0.56 Fi/mg protein) and the AG-treated diabetic group (4.18 +/- 0.59 Fi/mg protein) (p < 0.05). INTERPRETATION: The presented data provide evidence that AG is preventive against corneal alterations in experimental diabetes.

Biochemical and cytochemical evaluation of heterozygote individuals with glucose-6-phosphate dehydrogenase deficiency.

The aim of this study was to diagnose heterozygous glucose-6-phosphate dehydrogenase (G6PD) deficient females by an inexpensive cytochemical G6PD staining method that is easy to perform, allowing diagnosis of G6PD deficiency without cumbersome genetic analysis. Three subject groups were included in the study. The first group consisted of 15 hemizygous deficient males. The second and the third group were composed of 15 heterozygous deficient females and 15 healthy individuals, respectively. Biochemical determination and cytochemical staining of G6PD activity were performed in samples of all subjects. Results obtained with the cytochemical staining method correlated significantly with the biochemical data (p < 0.001), but a only 51-68% of the erythrocytes were stained positively in females with normal biochemical G6PD activity despite their having a G6PD-deficient child. This observation clearly indicates that these individuals are heterozygously deficient. These findings show that the cytochemical staining method to detect G6PD activity in erythrocytes is reliable, sensitive and specific and is superior to the biochemical method. Therefore, this method can be used routinely to detect heterozygous G6PD deficiency.