tRNA-derived fragments: Key determinants of cancer metastasis with emerging therapeutic and diagnostic potentials

Metastasis is a significant clinical challenge responsible for cancer mortality and non-response to treatment. However, the molecular mechanisms driving metastasis remain unclear, limiting the development of efficient diagnostic and therapeutic approaches. Recent breakthroughs in cancer biology have discovered a group of small non-coding RNAs called tRNA-derived fragments (tRFs), which play a critical role in the metastatic behavior of various tumors. tRFs are produced from cleavage modifications of tRNAs and have different functional classes based on the pattern of these modifications. They perform post-transcriptional regulation through microRNA-like functions, displacing RNA-binding proteins, and play a role in translational regulation by inducing ribosome synthesis, translation initiation, and epigenetic regulation. Tumor cells manipulate tRFs to develop and survive the tumor mass, primarily by inducing metastasis. Multiple studies have demonstrated the potential of tRFs as therapeutic, diagnostic, and prognostic targets for tumor metastasis. This review discusses the production and function of tRFs in cells, their aberrant molecular contributions to the metastatic environment, and their potential as promising targets for anti-metastasis treatment strategies.

Comparing The Effect Of Electroacupuncture And Glibenclamide On Blood Glucose Level And Histological Markers Of Pancreas In Streptozotocin-Induced Diabetic Rats

BACKGROUND

Diabetes lowers the quality of life and leads to several complications. Glibenclamide is a commonly used step-two treatment in diabetes but it causes weight gain, hypoglycemia and cardiovascular problems. Electroacupuncture (EA) can enhance insulin sensitivity and reduce blood glucose levels.

OBJECTIVES

To compare the effects of EA plus glibenclamide (G) with single therapy by G or EA on blood glucose, pancreas volume, islet volume, ratio of islet volume to pancreas volume, apoptotic and beta cells numbers and body weight in diabetic rats.

METHODS

Sixty adult male Wistar rats were randomly divided to 10 groups: 2 non-diabetic control groups and 8 diabetic groups (1 control and 7 experimental groups; D/G 2.5, D/G 5, D/G 10 mg/kg, EA, D/EA/G 2.5, D/EA/G 5, and D/EA/G 10). Diabetes was induced by intraperitoneal injection of 35 mg/kg streptozotocin with high-fat diet. At the end of the course, blood samples were obtained and pancreases were dissected.

RESULTS

EA was as effective as D/G 5 and D/G 10 in all outcomes. Combination therapy of EA and glibenclamide 5 and 10 mg/kg resulted in a better glucose-lowering effect, greater islet volume and ratio of islet volume to pancreas volume than single therapies (P < .05). EA increased the pancreas volume as much as the combination therapies (P > .05).

CONCLUSION

Combination of EA and glibenclamide 5 showed the best effects on blood glucose, islet volume and ratio of islet to pancreas volume. Combination of EA and glibenclamide 2.5 illustrated the best effects on apoptotic and beta cell number of diabetic rats.

Effect of Electroacupuncture and Glibenclamide on Blood Glucose Level and Oxidative Stress Parameters in Streptozotocin-Induced Diabetic Rats and Possible Human Implications

Diabetes mellitus is a metabolic disorder with increasing global prevalence. It is characterized by impaired glucose utilization that leads to chronic hyperglycemia which is a result of the body's inability to produce insulin (diabetes type I) or inability to make use of insulin (diabetes type II). Long-term hyperglycemia can cause damage to multiple systems, and microvascular and macrovascular complications lead to myocardial infarction, blindness, stroke and renal failure. Diabetes affected 382 million people globally in 2013, and it is estimated to rise up to 592 million by 2035. In spite of its management, both microvascular and macrovascular complications partly linked to oxidative stress are not efficiently prevented. Glibenclamide was approved on the U. S. market for treatment of diabetes type II in 1984. ATP-sensitive potassium channels (KATP) are widely distributed and present in a number of tissues including muscle, pancreatic beta cells and the brain. Glibenclamide closed KATP channels, which leads to depolarization of the cells and insulin secretion. Acupuncture is also a very significant therapeutic method in the complementary medicine. ST36 (Zusanli), CV4 (Guanyuan) and CV12 (Zhongwan) are several acupoints that have been used for treatment of diabetes. In this study for evaluating the effects of glibenclamide and electroacupuncture, 3 parameters such as malondialdehyde, ferric reducing antioxidant power and thiol will be measured. Malondialdehyde (MDA) is the organic compound and it is a marker for oxidative stress. Antioxidants are compounds that inhibit oxidation. Oxidation is a chemical reaction that can produce free radicals, thereby leading to chain reactions that may damage the cells of organisms. Antioxidants such as FRAP and thiol are useful parameters of assessment of oxidative stress. The aim of this study was to evaluate the effects of Electroacupuncture (EA) plus glibenclamide (G) as a novel therapy on diabetic rats and maybe for human. Fifty-four male Wistar rats were randomly divided to 9 groups: 1 non-diabetic control group and 8 diabetic groups (1 sham control group and 7 experimental groups; D/G 2.5 mg/kg, D/G 5 mg/kg, D/G 10 mg/kg, EA, D/EA/G 2.5 mg/kg, D/EA/G 5 mg/kg, and D/EA/G 10 mg/kg). Diabetes was induced by intraperitoneal injection of streptozotocin with high-fat diet. At the end of course, blood samples were obtained. Combination therapy of EA and glibenclamide 5 mg/kg decreased blood glucose better than single therapies (p<0.05) and showed 41 percent decrease in blood glucose as compared to D/G 5 mg/kg group. Combination of EA and glibenclamide 10 mg/kg showed the best effect for decreasing the malondialdehyde level (p<0.05) and also showed 43 percent decrease in comparison to D/G 10 mg/kg group. Combination of glibenclamide 2.5 mg/kg and EA increased the FRAP level better than other treatment groups (P<0.001) andachieved the ferric reducing antioxidant power level near to normal range. Combination of glibenclamide 10 mg/kg with EA increased the thiol concentration better than other treatment groups (P<0.001) and showed 4 percent increase in thiol concentration as compared to D/G 10 mg/kg group. These findings suggest that EA potentiates the effect of glibenclamide to protect animal model and maybe human against oxidative stress and damage.

Effects of Thymoquinone on Sperm Parameters, Apoptosis, Testosterone Level, and Oxidative Stress in a Mouse Model of D-Galactose-Induced Aging

Background: The aging process is accompanied by low secretion of sex hormones and testicular apoptosis. The antioxidant properties of thymoquinone (TQ) may prevent the effects of aging. Therefore, in the present study, the effects of different doses of TQ were investigated on sperm parameters, testosterone level, apoptosis, and oxidative stress in a mouse model of D-galactose-induced aging. Methods: In this experimental study, 30 adult male mice were randomly divided into 5 groups. The control group did not receive any injections, while the D-galactose group received an intraperitoneal injection of 300 mg/kg of D-galactose for 42 days. The TQ1-TQ3 groups received intraperitoneal injections of 5, 2.5, and 1.25 mg/kg of TQ plus D-galactose, respectively for 14 days (from the 1st to the 14th day of the experiment). The morphometric analysis, testicular apoptosis examination, and sperm analysis were performed, and testosterone level, total antioxidant capacity, and malondialdehyde level were evaluated on day 42 of the experiment. Data were analyzed using SPSS. Results: Administration of TQ in the TQ1 group caused a significant difference in sperm parameters, compared to the D-galactose group (P<0.05). The lowest amount of positive tunnel cells was related to 5 mg/kg of TQ and the highest to 2.5 mg/kg of TQ. There was no significant difference in the parameters of seminal vesicles, epididymis, prostate, and testis between the groups (P>0.05). The malondialdehyde level were decreased in the TQ1-TQ3 groups, compared to the D-galactose group (P<0.001). On the other hand, the total antioxidant capacity was increased significantly in the TQ1 group, compared to the D-galactose group (P<0.001). Conclusion: Administration of 5 mg of TQ for 14 days improved sperm quality and biochemical parameters, while reducing apoptotic cells of the testes in a mouse model of aging.

Effect of methamphetamine exposure during pregnancy and lactation on polysialic acid-neural cell adhesion molecule expression in rat's offspring hippocampus

Pregnant women constitute about half the users of methamphetamine (MA), in whom the consumption may continue during breastfeeding. This study aimed to evaluate the effects of MA use during pregnancy and lactation on the hippocampus of pups. 35 pregnant Wistar rats were divided into seven groups, including three experimental groups daily administered with 5 mg/kg of MA (i.p.) during the prenatal and/or postnatal period (PND1-22). In addition, three sham control groups received normal saline at the same dose, and one normal control group received no interventions since early pregnancy until the end of lactation. After the interventions, two pups (aged one and 22 days) were randomly selected from each mother and their brain tissue sections were prepared to determine the expression of PSA-NCAM molecules and sialic acids using immunohistochemical and lectinhistochemical techniques, respectively. In one-day infant rats with MA exposure during pregnancy, a significant decrease was observed in the number of PSA-NCAM positive cells in the CA1 (P = 0.047), CA3 (P = 0.05) and DG (P = 0.006) hippocampus regions compared to control and expression intensity of these molecules in all the three regions (P ≤ 0.05). Moreover, in 22-day pups with MA exposure during pregnancy and lactation, number of PSA-NCAM positive cells and expression intensity of these molecules significantly reduced in all the three regions of the hippocampus (P ≤ 0.05). Findings regarding the intensity of sialic acid expression were aligned with PSA-NCAM expression. According to our results, MA administration during pregnancy and lactation may effect on polysialic acid-neural cell adhesion molecule expression in rat's offspring hippocampus.

Maternal exposure to titanium dioxide nanoparticles during pregnancy and lactation alters offspring hippocampal mRNA BAX and Bcl-2 levels, induces apoptosis and decreases neurogenesis

INTRODUCTION

The usage of Titanium dioxide nanoparticles (TiO₂-NPs) covers a vast area in different fields ranging from cosmetics and food to the production of drugs. Maternal exposure to TiO₂-NPs during developmental period has been associated with hippocampal injury and with a decrease in learning and memory status of the offspring. However, little is known about its injury mechanism. This paper describes the in vivo neurotoxic effects of TiO₂-NPs on rat offspring hippocampus during developmental period.

MATERIAL AND METHODS

Pregnant and lactating Wistar rats received intragastric TiO₂-NPs (100mg/kg body weight) daily from gestational day (GD) 2 to (GD) 21 and postnatal day (PD) 2 to (PD) 21 respectively. Animals in the control groups received an equal volume of distilled water via gavage. At the end of the treatment process, offspring were deeply anesthetized and sacrificed. Then brains of each group were collected and sections of the rat offspring's brains were stained using TUNEL staining (for detection of apoptotic cells) and immunostaining (for neurogenesis). Moreover, the right hippocampus (n=6 per each group) were removed from the right hemisphere for evaluating the expression of Bax and Bcl-2 level.

RESULTS

Results of histopatological examination by TUNEL staining showed that maternal exposure to TiO₂-NPs during pregnancy and lactation periods increased apoptotic cells significantly (P<0.01) in the offspring hippocampus. The immunolabeling of double cortin (DCX) protein as neurogenesis marker also showed that TiO₂-NPs reduced neurogenesis in the hippocampus of the offspring (P<0.05). Moreover, in comparison with the control group, the mRNA levels of Bax and Bcl-2 in the TiO₂-NPs group significantly increased and decreased, respectively (P<0.01).

CONCLUSION

These findings provide strong evidence that maternal exposure to TiO₂-NPs significantly impact hippocampal neurogenesis and apoptosis in the offspring. The potential impact of nanoparticle exposure for millions of pregnant mothers and their offspring across the world is potentially devastating.

The prevention and treatment effects of egg yolk high density lipoprotein on the formation of atherosclerosis plaque in rabbits

OBJECTIVES

Atherosclerosis is the main leading cause of cardiovascular diseases. The purpose of this study was to assess the potential preventive effect of egg yolk HDL on the atherosclerosis plaque formation.

MATERIALS AND METHODS

Thirty rabbits were divided into five groups: A; normal diet, B; hyper-cholesterolemic diet, C; hypercholesterolemic + 400 mg/kg egg yolk HDL D; hypercholesterolemic +100 mg/kg egg yolk HDL and E; 200 mg/kg egg yolk HDL. At the end of the experiment, the lipid profiles were measured by spectrophotometric method. The histological sections of thoracic aorta also were taken and analyzed under light microscope.

RESULTS

At the end of the 2(nd) and the 4(th) weeks, there was a significant increase of cholesterol level in groups B, C, and D compared to group A (P<0.05). Following HDL treatment, triglyceride (TG) levels increased significantly versus group A and also the TG level decreased significantly in group C, D, and E versus group B (P<0.01). Egg yolk HDL significantly increased HDL-C in groups C, D, and E (P<0.01) compared to groups A and B (P<0.05). The surface area of the atherosclerotic plaque was increased significantly in group B versus group A (P<0.001). Egg yolk HDL consumption reduced the plaque size significantly (P<0.001).

CONCLUSION

Our findings indicated that treatment with egg yolk HDL increased serum HDL-C and decreased atherosclerotic plaque size in rabbits. Thus, egg yolk HDL may be considered as an anti-atherosclerotic treatment for cardiovascular diseases.

Elementary mechanisms of shear-coupled grain boundary migration

A detailed theoretical study of the elementary mechanisms occurring during the shear-coupled grain boundary (GB) migration at low temperature is performed focusing on both the energetic and structural characteristics. The migration of a Σ13(320) GB in a copper bicrystal in response to external shear displacements is simulated using a semiempirical potential. The minimum energy path of the shear-coupled GB migration is computed using the nudge elastic band method. The GB migration occurs through the nucleation and motion of GB steps identified as disconnections. Energy barriers for the GB and disconnection migrations are evaluated.

The effect of PTZ-induced epileptic seizures on hippocampal expression of PSA-NCAM in offspring born to kindled rats

BACKGROUND

Maternal epileptic seizures during pregnancy can affect the hippocampal neurons in the offspring. The polysialylated neural cell adhesion molecule (PSA-NCAM), which is expressed in the developing central nervous system, may play important roles in neuronal migration, synaptogenesis, and axonal outgrowth. This study was designed to assess the effects of kindling either with or without maternal seizures on hippocampal PSA-NCAM expression in rat offspring.

METHODS

Forty timed-pregnant Wistar rats were divided into four groups: A) Kind+/Seiz+, pregnant kindled (induced two weeks prior to pregnancy) rats that received repeated intraperitoneal (i.p.) pentylenetetrazol, PTZ injections on gestational days (GD) 14-19; B) Kind-/Seiz+, pregnant non-kindled rats that received PTZ injections on GD14-GD19; C) Kind+/Seiz-, pregnant kindled rats that did not receive any PTZ injections; and D) Kind-/Seiz-, the sham controls. Following birth, the pups were sacrificed on PD1 and PD14, and PSA-NCAM expression and localization in neonates' hippocampi were analyzed by Western blots and immunohistochemistry.

RESULTS

Our data show a significant down regulation of hippocampal PSA-NCAM expression in the offspring of Kind+/Seiz+ (p = 0.001) and Kind-/Seiz+ (p = 0.001) groups compared to the sham control group. The PSA-NCAM immunoreactivity was markedly decreased in all parts of the hippocampus, especially in the CA3 region, in Kind+/Seiz+ (p = 0.007) and Kind-/Seiz+ (p = 0.007) group's newborns on both PD1 and 14.

CONCLUSION

Our findings demonstrate that maternal seizures but not kindling influence the expression of PSA-NCAM in the offspring's hippocampi, which may be considered as a factor for learning/memory and cognitive impairments reported in children born to epileptic mothers.

Nuclear quadrupole resonance studies of transparent conducting oxides

We report (63,65)Cu spin-lattice relaxation rates measured by nuclear quadrupole resonance (NQR) in the delafossite compound CuYO(2) and CuYO(2):Ca over a temperature range from 200 to 450K. CuYO(2):Ca is a prototype transparent oxide exhibiting p-type electrical conductivity. Relaxation rates in CuYO(2):Ca are enhanced by one to two orders of magnitude relative to undoped material, exhibit much stronger temperature dependence, and contain contributions from magnetic and quadrupolar relaxation mechanisms with roughly equal strengths. Relaxation in undoped CuYO(2) is of purely quadrupolar origin and is attributed to interactions with lattice phonons. The main focus of this paper is the magnetic contribution to the relaxation rate in CuYO(2):Ca which is attributed to the hyperfine fields of carriers. It is argued that the dynamics of the hyperfine field are dominated by the hopping rate for carrier transfers between neighboring atoms in the copper planes of the delafossite structure. Comparison of the magnetic relaxation rates with the DC conductivity permits an estimate of the carrier concentration and mobility.