Mitotic Kinases Aurora-A, Plk1, and Cdk1 Interact with Elk-1 Transcription Factor through the N-Terminal Domain.

Elk-1 is a member of the ETS domain transcription factor superfamily that is phosphorylated upon mitogen-activated protein kinase (MAPK) pathway activation, which in turn regulated its interaction with partner protein serum response factor (SRF), leading to formation of a ternary complex with DNA. It has previously been reported that Elk-1 interacts with a mitotic kinase Aurora-A, although the mechanisms or the relevance of this interaction was unclear. Elk-1 was also reported to be phosphorylated by CDK5 on Thr417 residue. In this study, we show for the first time that this transcription factor interacts not only with Aurora-A but also with other mitotic kinases Aurora-B, Plk1, and Cdk1, and we define the interaction domain on Elk-1 to the first N-terminal 205 amino acids. We also describe putative phosphorylation sites of these mitotic kinases on Elk-1 and show that Elk-1 peptides containing these residues get phosphorylated by the mitotic kinases in in vitro kinase assays. We also perform bioinformatic analysis of mitotic phosphoproteomes and determine potential interaction partners for Elk-1 in Plk or Aurora phosphoproteomes. We propose that understanding the dynamic phosphorylation of Elk-1 by mitotic kinases is important and that it can present a novel target for anticancer strategies.

Effects of chronic high fat diet on mediobasal hypothalamic satiety neuron function in POMC-Cre mice.

OBJECTIVE: The prevalence of obesity has increased over the past three decades. Proopiomelanocortin (POMC) neurons in the hypothalamic arcuate nucleus (ARC) play a vital role in induction of satiety. Chronic consumption of high-fat diet is known to reduce hypothalamic neuronal sensitivity to hormones like leptin, thus contributing to the development and persistence of obesity. The functional and morphological effects of a high-calorie diet on POMC neurons and how these effects contribute to the development and maintenance of the obese phenotype are not fully understood. For this purpose, POMC-Cre transgenic mice model was exposed to high-fat diet (HFD) and at the end of a 3- and 6-month period, electrophysiological and morphological changes, and the role of POMC neurons in homeostatic nutrition and their response to leptin were thoroughly investigated. METHODS: Effects of HFD on POMC-satiety neurons in transgenic mice models exposed to chronic high-fat diet were investigated using electrophysiological (patch-clamp), chemogenetic and Cre recombinase advanced technological methods. Leptin, glucose and lipid profiles were determined and analyzed. RESULTS: In mice exposed to a high-fat diet for 6 months, no significant changes in POMC dendritic spine number or projection density from POMC neurons to the paraventricular hypothalamus (PVN), lateral hypothalamus (LH), and bed nucleus stria terminalis (BNST) were observed. It was revealed that leptin hormone did not change the electrophysiological activities of POMC neurons in mice fed with HFD for 6 months. In addition, chemogenetic stimulation of POMC neurons increased HFD consumption. In the 3-month HFD-fed group, POMC activation induced an orexigenic response in mice, whereas switching to a standard diet was found to abolish orexigenic behavior in POMC mice. CONCLUSIONS: Chronic high fat consumption disrupts the regulation of POMC neuron activation by leptin. Altered POMC neuron activation abolished the neuron's characteristic behavioral anorexigenic response. Change in nutritional content contributes to the reorganization of developing maladaptations.

Programmed Cell Death Ligand 1 Expression in CD163 + Tumor-associated Macrophages in Cancer Gland Rupture Microenvironment.

In this study, we aimed to examine the relationship among cancer gland rupture microenvironment, programmed cell death ligand 1 (PD-L1) expression in CD163 + tumor-associated macrophages (TAMs), and prognosis in colon adenocarcinoma. A total of 122 patients were diagnosed with colon adenocarcinoma between 2010 and 2019. PD-L1 + (clone 22C3) "macrophage scores" in the microenvironment of cancer gland rupture were calculated. The effects of these variables on prognosis were statistically analyzed. CD163 + TAMs were denser in the cancer gland rupture microenvironment. PD-L1 + TAMs were observed in the tumor periphery, and there was a significant difference between the rates of PD-L1 expression in TAMs and survival time (log-rank = 10.46, P = 0.015), clinical stage 2 ( P = 0.038), and primary tumor 3 and primary tumor 4 cases ( P = 0.004, P = 0.013). The risk of mortality was 4.070 times higher in patients with a PD-L1 expression rate of ≥1% in CD163 + TAMs. High PD-L1 expression in CD163 + TAMs is associated with poor overall survival. Therefore, blocking PD-L1 in CD163 + TAMs can be used as a target for immunotherapy.

Postweaning Social Isolation Alters Puberty Onset by Suppressing Electrical Activity of Arcuate Kisspeptin Neurons.

INTRODUCTION: Postweaning social isolation (PWSI) in rodents is an advanced psychosocial stress model in early life. Some psychosocial stress, such as restrain and isolation, disrupts reproductive physiology in young and adult periods. Mechanisms of early-life stress effects on central regulation of reproduction need to be elucidated. We have investigated the effects of PWSI on function of arcuate kisspeptin (ARCKISS1) neurons by using electrophysiological techniques combining with monitoring of puberty onset and estrous cycle in male and female Kiss1-Cre mice. METHODS: Female mice were monitored for puberty onset with vaginal opening examination during social isolation. After isolation, the estrous cycle of female mice was monitored with vaginal cytology. Anxiety-like behavior of mice was determined by an elevated plus maze test. Effects of PWSI on electrophysiology of ARCKISS1 neurons were investigated by the patch clamp method after intracranial injection of AAV-GFP virus into arcuate nucleus of Kiss1-Cre mice after the isolation period. RESULTS: We found that both male and female isolated mice showed anxiety-like behavior. PWSI caused delay in vaginal opening and extension in estrous cycle length. Spontaneous-firing rates of ARCKISS1 neurons were significantly lower in the isolated male and female mice. The peak amplitude of inhibitory postsynaptic currents to ARCKISS1 neurons was higher in the isolated mice, while frequency of excitatory postsynaptic currents was higher in group-housed mice. CONCLUSION: These findings demonstrate that PWSI alters pre- and postpubertal reproductive physiology through metabolic and electrophysiological pathways.

Opioidergic signaling contributes to food-mediated suppression of AgRP neurons.

Opioids are generally known to promote hedonic food consumption. Although much of the existing evidence is primarily based on studies of the mesolimbic pathway, endogenous opioids and their receptors are widely expressed in hypothalamic appetite circuits as well; however, their role in homeostatic feeding remains unclear. Using a fluorescent opioid sensor, deltaLight, here we report that mediobasal hypothalamic opioid levels increase by feeding, which directly and indirectly inhibits agouti-related protein (AgRP)-expressing neurons through the µ-opioid receptor (MOR). AgRP-specific MOR expression increases by energy surfeit and contributes to opioid-induced suppression of appetite. Conversely, its antagonists diminish suppression of AgRP neuron activity by food and satiety hormones. Mice with AgRP neuron-specific ablation of MOR expression have increased fat preference without increased motivation. These results suggest that post-ingestion release of endogenous opioids contributes to AgRP neuron inhibition to shape food choice through MOR signaling.

AgRP neurons encode circadian feeding time.

Food intake follows a predictable daily pattern and synchronizes metabolic rhythms. Neurons expressing agouti-related protein (AgRP) read out physiological energetic state and elicit feeding, but the regulation of these neurons across daily timescales is poorly understood. Using a combination of neuron dynamics measurements and timed optogenetic activation in mice, we show that daily AgRP-neuron activity was not fully consistent with existing models of homeostatic regulation. Instead of operating as a 'deprivation counter', AgRP-neuron activity primarily followed the circadian rest-activity cycle through a process that required an intact suprachiasmatic nucleus and synchronization by light. Imposing novel feeding patterns through time-restricted food access or periodic AgRP-neuron stimulation was sufficient to resynchronize the daily AgRP-neuron activity rhythm and drive anticipatory-like behavior through a process that required DMHPDYN neurons. These results indicate that AgRP neurons integrate time-of-day information of past feeding experience with current metabolic needs to predict circadian feeding time.

The effects of berberine on ischemia-reperfusion injuries in an experimental model of ovarian torsion.

OBJECTIVE: Ovarian torsion is a gynecological disorder that causes ischemia-reperfusion injuries in the ovary. Our study investigated berberine's short- and long-term effects on ovarian ischemia-reperfusion injuries. METHODS: This study included 28 Wistar albino female rats weighing 180 to 220 g, which were divided into four groups: sham (S), torsion/detorsion (T/D), torsion/ detorsion+single dose berberine (T/D+Bb), and torsion/detorsion+15 days berberine (T/D+15Bb). The torsion and detorsion model was applied in all non-sham groups. In the T/D+Bb group, a single dose of berberine was administered, while in the T/D+15Bb group, berberine was administered over a period of 15 days. After the rats were euthanized, their ovaries were excised. The left ovaries were used for histopathologic evaluation, which included ovarian injury scoring and follicle count, while the right ovaries were used for biochemical analyses (tissue transforming growth factor-ß [TGF-ß] and alpha-smooth muscle actin [α-SMA] levels). RESULTS: The histopathologic evaluation scores for the ovaries were significantly lower in the T/D+B group (p<0.05) and the T/D+15B group (p<0.005) than in the T/D group. The follicle counts in the T/D group were lower than those in both the sham and treated groups (p<0.005). The TGF-ß levels were significantly lower in the T/D+15B group (p<0.005), whereas the α-SMA levels did not show a significant difference. CONCLUSION: Both short- and long-term berberine use could potentially have therapeutic effects on ovarian torsion. Long-term berberine use exhibited anti-inflammatory effects by reducing TGF-ß levels, thereby preventing ischemia-reperfusion injuries. Therefore, we suggest that long-term berberine use could be beneficial for ovarian torsion.

Adrenergic modulation of melanocortin pathway by hunger signals.

Norepinephrine (NE) is a well-known appetite regulator, and the nor/adrenergic system is targeted by several anti-obesity drugs. To better understand the circuitry underlying adrenergic appetite control, here we investigated the paraventricular hypothalamic nucleus (PVN), a key brain region that integrates energy signals and receives dense nor/adrenergic input, using a mouse model. We found that PVN NE level increases with signals of energy deficit and decreases with food access. This pattern is recapitulated by the innervating catecholaminergic axon terminals originating from NTSTH-neurons. Optogenetic activation of rostral-NTSTH → PVN projection elicited strong motivation to eat comparable to overnight fasting whereas its inhibition attenuated both fasting-induced & hypoglycemic feeding. We found that NTSTH-axons functionally targeted PVNMC4R-neurons by predominantly inhibiting them, in part, through α1-AR mediated potentiation of GABA release from ARCAgRP presynaptic terminals. Furthermore, glucoprivation suppressed PVNMC4R activity, which was required for hypoglycemic feeding response. These results define an ascending nor/adrenergic circuit, NTSTH → PVNMC4R, that conveys peripheral hunger signals to melanocortin pathway.

A step toward precision gerontology: Lifespan effects of calorie and protein restriction are consistent with predicted impacts on entropy generation.

Understanding aging is a key biological goal. Precision gerontology aims to predict how long individuals will live under different treatment scenarios. Calorie and protein restriction (CR and PR) extend lifespan in many species. Using data from C57BL/6 male mice under graded CR or PR, we introduce a computational thermodynamic model for entropy generation, which predicted the impact of the manipulations on lifespan. Daily entropy generation decreased significantly with increasing CR level, but not PR. Our predictions indicated the lifespan of CR mice should increase by 13 to 56% with 10 to 40% CR, relative to ad libitum-fed animals. This prediction was broadly consistent with the empirical observation of the lifespan impacts of CR in rodents. Modeling entropy fluxes may be a future strategy to identify antiaging interventions.

Clinicopathological and prognostic significance of PD-L1 expression in colon adenocarcinoma tumor budding.

OBJECTIVE: In this study, we investigated the relationship between programmed cell death ligand 1 (PD-L1) and programmed cell death protein 1 (PD-1) expression in colon adenocarcinoma tumor budding. METHODS: This study included 122 patients with colon adenocarcinomas. The largest sample of formaldehyde-fixed paraffin-embedded tumor tissues was selected for analysis. Expression of membranous PD-L1 (clone 22C3) and the Combined Positive Score (CPS) in tumor tissues was calculated and graded according to the percentages of peritumoral and intratumoral tumor cells (0 %, 1 %, 1-5 %, >5 %). The effects of these factors on the prognosis were analyzed. RESULTS: Tumor budding was associated with adverse clinicopathological features and poor overall survival. PD-L1 (CPS%) peritumoral tumor budding (1 %/<1 %) was statistically significant in the univariate model (p = 0.004). Age, organ metastases (liver, lung, liver, lung, and peritoneum), and metastases were statistically significant in the multivariate model (p = 0.001, p = 0.004, p = 0.001, p = 0.002, p = 0.004, and p = 0.032, respectively). PD-L1 positive staining was mostly observed around the tumor and during tumor budding. PD-L1 peritumoral tumor budding rates and patients' survival rates differed significantly (log-rank = 12.07, p = 0.007). CONCLUSION: We found that patients with PD-L1 (CPS%) > 1 % in tumor budding had a shortened life expectancy and demonstrated the importance of including tumor budding areas in the samples used for biomarker evaluation. We previously reported that PD-L1 expression in tumor budding is associated with more aggressive cancer biology and poor survival, although overall survival is of limited statistical significance.

How does exercise affect energy metabolism? An in silico approach for cardiac muscle.

We explored an in silico model of muscle energy metabolism and demonstrated its theoretical plausibility. Results indicate that energy metabolism triggered by activation can capture the muscle condition, rest, or exercise, and can respond accordingly adjusting the rates of their respiration and energy utilization for efficient use of the nutrients. Our study demonstrated during exercise higher respiratory activity causes a substantial increase in exergy release with an increase in exergy destruction, and entropy generation rate. The thermodynamic analysis showed that at the resting state when the exergy destruction rate was 0.66 W/kg and the respiratory metabolism energetic efficiency was 36% and exergetic efficiency was 32%; whereas, when the exergy destroyed was 1.24 W/kg, the energetic efficiency was 58% and exergetic efficiency was 50% during exercise. The efficiency results suggest the ability of the system to regulate itself in response to higher work demand and become more efficient in terms of converting energy coming from nutrients to useable energy when the circulating medium has sufficient energy precursor.

Effect of methylphenidate on the onset of puberty and reproductive organ development in rats.

Methylphenidate (MPH) is the first-line therapy for attention deficit hyperactivity disorder (ADHD) in children and adolescents. The aim of this study was to investigate the effects chronic MPH administration on reproductive parameters in both male and female pre-pubertal rats and reversibility of these effects. Sprague-Dawley rats were administered with 5 mg/kg MPH or saline orally from postnatal day (PND) 21 to PND60 and from PND21 to PND90. In addition, recovery groups from both sexes, in which MPH administration was stopped from PND60 to PND90 were included. Puberty onset, serum luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone and estradiol levels were determined. Histopathology of male and female reproductive organs was examined. Puberty onset was significantly early in the males (p<0.01), but late in females (p<0.05). In males, serum LH and FSH levels were similar. Testosterone levels tended to decrease in MPH-treated animals. Morphology of testes, epididymis and vas deferens was disrupted in MPH-treated animals, while it was improved in the recovery group. In females, estradiol levels decreased in MPH-treated group compared to controls, and elevated LH levels were detected in recovery group. Similar to the males, disruption in the reproductive organ histology was seen with morphological deterioration in basement membrane of the ovaries of MPH-treated groups. These adverse effects of MPH were recovered after drug cessation for 30 days. The present results demonstrate that MPH could affect the reproductive functions in both male and female rats. However, our findings also suggest that those effects are transient.

The Effects of Chronic Asprosin Administration on Sense of Smell and Sexual Behavior in Female Rats.

INTRODUCTION: Asprosin is an adipokine released from white adipose tissue during fasting and acts through the olfactory receptor. It is known that adipokines play roles in reproductive physiology in mammals. However, there are very few studies conducted on role of asprosin in reproductive functions. There are no studies on its relationship with sexual motivation. It was shown in the literature that administration of asprosin to male mice improves olfaction. It is also known that there is a strong correlation between smell and sexual desire. In view of this, it was hypothesized that chronic administration of asprosin would improve olfactory performance and increase sexual incentive motivation in female rats for male partners. METHODS: This hypothesis was tested by applying the hidden cookie test, sexual incentive test, active research test, and sexual behavior test. The changes in serum hormone levels in female rats that chronically received asprosin were also measured and compared. RESULTS: Chronic asprosin exposure increased olfactory performance, male preference ratio, male investigation preference ratio, activity index, and anogenital investigation behavior. Also, serum oxytocin and estradiol levels increased following chronic administration of asprosin in female rats. CONCLUSION: These data suggest that chronic administration of asprosin can result in increased sexual incentive motivation for opposite sex in female rats over increased olfactory performance and changes in reproductive hormones.

Hyperthermia alters neurobehavior by affecting cell proliferation and neuronal survival in young male rats.

Maintenance of body temperature within physiological range is critical for the fetal and neonatal development. Hyperthermia is one of the most frequently encountered pediatric complaints and may cause neurological disorders due to neuronal injury. In this study, we aimed to investigate the effects of hyperthermia on behavioral alterations, neuronal survival, apoptosis, and cell proliferation in young male Sprague-Dawley rats. Twenty-one 13-day-old rats were randomly divided into three groups (n = 7 per group). Body temperature was increased to 39°C and 41°C in a hyperthermia induction chamber for 30 min, whereas the animals in control group were maintained at 36°C. Twenty-four hours after hyperthermia, animals were subjected to the open field test, elevated-O-maze test, and grip strength test to assess the locomotor activity, anxiety, and motor function. Neuronal survival, apoptosis, and cell proliferation were investigated in cortex, hippocampal dentate gyrus (DG) and CA1 regions, and corpus callosum (CC). Decreased locomotor activity and motor function and increased anxiety were observed in the hyperthermia groups, and these were more pronounced in the 41°C group. Neuronal survival was significantly decreased in DG, CA1, and CC in the hyperthermia groups (**p < 0.01). Apoptosis was significantly induced in cortex, DG, and CC of the animals exposed to heat (*p < 0.05). In addition, cell proliferation positivity decreased significantly only in DG and CC of the animals exposed to heat (*p < 0.05). Our results suggest that neurobehavioral deficits caused by hyperthermia may be due to the increased apoptosis and neuronal cell death and decreased cell proliferation in the brain of postnatal developing rats.

Effects of endocrine disruptors on the electrical activity of leptin receptor neurons in the dorsomedial hypothalamus and anxiety-like behavior in male mice.

There is increasing concern about the effects of endocrine disrupting chemicals (EDCs) on human health. Recently, some EDCs are suggested to affect energy metabolism leading to increased risk of obesity. Obesogenic effects of some EDCs on adipogenesis have been reported, however, there is no study examining their potential actions on the brain circuits controlling feeding and metabolism. We have investigated effects of tributyltin (TBT) and dichlorodiphenyltrichloroethane (p,p'-DDT) on electrical activity on dorsomedial hypothalamic leptin receptor neurons (DMHLepR), morphological adaptations in neuronal anatomy of DMHLepR, locomotion, and anxiety-like behaviors in mice. Twenty-three Lep-Cre transgenic mice were intracranially injected with GFP virus. Control animals received intraperitoneal corn oil alone while group 2 and 3 received TBT (25 µg/kg) and p,p'-DDT (2 mg/kg) for one month. Locomotor activity and anxiety-like behavior of the animals were determined by open field test. Electrophysiological effects of TBT and p,p'-DDT on DMHLepR neurons were determined by patch clamp method. Neuronal anatomy was determined by confocal microscopy. Spontaneous firing frequency of DMHLepR neurons of TBT group of mice was significantly higher than both p,p'-DDT and control groups (p < 0.01). TBT and p,p'-DDT significantly decreased frequency of the spontaneous inhibitory post-synaptic currents to DMHLepR neurons compared to the control group (p < 0.05). The time spent in the center and the number of entrances to the center by the TBT-administered mice were significantly lower than other groups (p < 0.01). The total distance traveled and mean speed of the control group of mice were significantly higher than the p,p'-DDT- and TBT-administered animals (p < 0.0001). c-Fos activity of the p,p'-DDT- and TBT-administered animals were significantly elevated compared to the control group (p < 0.001), while no change in the number of dendritic spines were observed. In conclusion, this study demonstrates that exposure to TBT and p,p'-DDT alters electrical activity in DMHLepR neurons and behavioral state in mice.

The effect of maternal period nutritional status on oro-sensorial fat perception and taste preference in rats.

CD36 and GPR120 play an important role in the perception and preference for fat-rich food consumption. We aimed to investigate the relationship between oro-gustatory perception of lipids, fatty taste preference, and maternal (Gestation + Lactation)-maturation period nutrition status in offspring Sprague-Dawley rats. In our study, mother rats were fed with control (C) or high-fat diets (HFD) during gestation (21 days) and lactation (21 days) periods. After weaning, the offspring were fed with control (C) or high-fat diets (HFD) during the maturation (120 days) period. Daily calorie intake and weekly body weight measurements were monitored. Two-bottle preference (TBPT) and licking tests measured the fat perceptions and preferences. Plasma levels of insulin, leptin, glucose, and triglyceride were measured. The protein and mRNA expressions of CD36 and GPR120 in the circumvallate papillae (CVP) were determined. The 48 h TBPT results revealed that maternal HFD-exposed offspring rats significantly preferred 2% rapeseed oil solution regardless of the type of maturation diet. According to the licking test, C/C group (C diet exposed group in maternal and maturation periods) offspring licked 0.1% oleic acid-containing water more than C/HFD (C diet exposed in maternal period and HFD exposed group in maturation period) and HFD/HFD group. (HFD exposed group in maternal and maturation periods) groups. Plasma insulin and leptin concentrations significantly increased in HFD/HFD groups compared to C/C group. CD36 protein expressions were significantly lower in HFD/HFD than C/HFD and HFD/C groups. GPR120 and GNAT3 mRNA expressions in HFD/C group were significantly higher than in C/HFD group. Our results suggest that HFD exposure during maternal and maturation period may play a role in fat perception/preference through oral lipid sensors.

Thermodynamic Assessment of the Effects of Intermittent Fasting and Fatty Liver Disease Diets on Longevity.

Organisms uptake energy from their diet and maintain a highly organized structure by importing energy and exporting entropy. A fraction of the generated entropy is accumulated in their bodies, thus causing ageing. Hayflick's entropic age concept suggests that the lifespan of organisms is determined by the amount of entropy they generate. Organisms die after reaching their lifespan entropy generation limit. On the basis of the lifespan entropy generation concept, this study suggests that an intermittent fasting diet, which means skipping some meals without increasing the calories uptake in the other courses, may increase longevity. More than 1.32 million people died in 2017 because of chronic liver diseases, and a quarter of the world's population has non-alcoholic fatty liver disease. There are no specific dietary guidelines available for the treatment of non-alcoholic fatty liver diseases but shifting to a healthier diet is recommended as the primary treatment. A healthy obese person may generate 119.9 kJ/kg K per year of entropy and generate a total of 4796 kJ/kg K entropy in the first 40 years of life. If obese persons continue to consume the same diet, they may have 94 years of life expectancy. After age 40, Child-Pugh Score A, B, and C NAFLD patients may generate 126.2, 149.9, and 272.5 kJ/kg K year of entropy and have 92, 84, and 64 years of life expectancy, respectively. If they were to make a major recommended shift in their diet, the life expectancy of Child-Pugh Score A, B, and C patients may increase by 29, 32, and 43 years, respectively.

Investigation of effects of transferrin-conjugated gold nanoparticles on hippocampal neuronal activity and anxiety behavior in mice.

Gold nanoparticles (GNPs) have been widely used in medicine such as imaging, drug delivery and therapeutics due to their multifunctional properties. Alterations in neuronal function may contribute to various neurological diseases. Transferrin plays a primary role in iron transportation and delivery and has recently been utilized for drug delivery to the brain. We have investigated effects of transferrin-conjugated GNPs (Tf-GNPs) on anxiety and locomotor behavior in vivo and also hippocampal neuronal activity ex vivo. Electrophysiological effects of Tf-GNP on hippocampal neurons were determined by patch clamp method. Fifteen male young adult C57BL/6 mice were randomly divided into three groups as control (200 µL PBS), GNP (bare GNP; 2.2 µg/g in PBS) and Tf-GNPs (2.2 µg/g Tf-GNP). Animals intraperitoneally received the respective treatments for seven consecutive days and were subjected to elevated plus maze (EPM) and open field tests (OFT). Ex vivo, firing frequency of the neurons significantly increased by GNP treatment (p < 0.001). In vivo, animals in Tf-GNP group showed significantly longer distance in open arms but significantly lower number of entries to the open arms in EPM (p < 0.05). Mice received bare GNPs had significantly higher locomotor activity in OFT (p < 0.05), while Tf-GNP did not alter the locomotor activity significantly (p = 0.051). Animals in Tf-GNP group spent significantly longer time in the peripheral zone in OFT (p < 0.05). The present findings have shown that Tf-GNP induces anxiety-like behavior without altering spontaneous firing rate of hippocampal neurons. We suggest that neurobiological effects of Tf-GNP should be pre-determined before using in medical applications.

What is the protective effect of preischemic kisspeptin-10 administration against ischemia/reperfusion injury of striatum on mice?

BACKGROUND: Kisspeptin is a neuropeptide with a primary role on the onset of puberty and has beneficial effects on ischemia/ reperfusion (I/R) injury. In this study, we aimed to investigate the effect of kisspeptin administration on striatal I/R injury in mice. METHODS: Forty adult C57/BL6 mice were randomly divided into four groups: Sham, Kisspeptin, I/R, and I/R + Kisspeptin groups. The groups were administered with either physiological saline (Sham and I/R groups) or kisspeptin (Kisspeptin and I/R + Kisspeptin groups) intraperitoneally 40 min before the operation. A microdialysis probe was placed in the right striatum according to stereotaxic coordinates. During the experimental period, artificial cerebrospinal fluid was passed through the micropump. Then, transient cerebral ischemia was established by compressing both common carotid arteries with an aneurysm clip for 15 min and animals were reperfused for 2 h. Throughout the process of microdialysis (before, during and after I/R period), samples were collected to measure dopamine (DA), noradrenaline (NA), and 3,4-dihydroxyphenylglycine (DHPG) at intervals of 20 min continuously. At the end of the reperfusion period, the animals were decapitated, striatum was dissected, half of the animals were used for oxidative stress analyses (reduced glutathione, glutathione S-transferase (GST), superoxide dismutase (SOD), malondialdehyde (MDA), and the other half were used for histopathology analyses. RESULTS: Number of glial cells was significantly increased in kisspeptin-administered groups. DA levels in ischemic animals were decreased by kisspeptin administration (p < 0.0001). NA levels were reduced in animals administered with kisspeptin without I/R injury (p < 0.05). DHPG levels reduced during the reperfusion period in ischemic animals (p < 0.05). Kisspeptin did not exhibit a significant antioxidant activity in the ischemic animals, while GST and SOD levels were reduced in the I/R + kisspeptin group compared to the kisspeptin group (p < 0.05). DISCUSSION: Our results suggest that kisspeptin may be regulating the neurotransmitter release and metabolism, as well as inflammatory response in brain upon I/R injury.

Combinatorial effects of melatonin and paclitaxel differ depending on the treatment scheme in colorectal cancer in vitro.

AIMS: Colorectal carcinoma (CRC) is the third most prevalent cancer with high mortality. Besides regulating the circadian rhythm, melatonin (MTN) exerts anticancer activities. Paclitaxel (PTX) is successful against different malignancies, however, acquired resistance and variability in patient response restrict its use. mTOR and MAPK pathways are often deregulated in human cancers. We aimed to investigate whether MTN enhances or sensitizes the chemotherapeutic activity of PTX and if so, determine the underlying possible mechanisms in CRC in vitro. MAIN METHODS: Antiproliferative and cytotoxic activities of PTX and MTN were assessed alone and in combination, as well as with different treatment regimens (renewal or replacement of the treatment after 24 h), up to 48 h. Apoptosis, viability and autophagy were assessed by flow cytometry. mTOR and MAPK pathway activities were investigated by immunoblotting. KEY FINDINGS: Both drugs reduced cell viability in a dose-dependent manner at 24 and 48 h. Only the highest dose of MTN (500 µM) potentiated the cytotoxicity of PTX (50 nM). Replacement of PTX after 24 h with MTN was superior in reducing cell viability than vice versa via apoptosis induction. Renewal of MTN treatment every 24 h reduced autophagy compared to the control group, while other treatments did not alter the autophagic activity. A 24 h MTN treatment followed by 24 h PTX treatment increased S6 phosphorylation in a mTOR-independent manner and increased Erk1/2 phosphorylation. SIGNIFICANCE: The present study suggests that sequential treatment with MTN and PTX distinctly affect apoptosis and cytotoxicity via regulating mTOR and MAPK pathways differentially in CRC.