ABSTRACT
Non-image forming functions of eyes include the regulation of biological circadian rhythm and biological magnetoreception.Biological magnetoreception means that various organisms including human obtain the direction and position information through the geomagnetic field.Creatures with retina realize magnetoreception regarding retinal cryptochrome as magnetoreceptor.Hypotheses of magnetoreception contain the radical-pair theory and the biological compass theory.The two theories both reckon retinal elements as possible receptor protein of magnetoreception, and eyes as receptor organ.The radical-pair theory suggests that change of radical spin influences the structure of retinal cryptochrome, leading to different downstream chemical reaction products, which makes the variable magnetic field information perceivable.And the biological compass theory proposes a rod-like complex composed of polymerized cryptochromes and magnetoreceptor proteins, which can point to different directions due to light and magnetic signals.These changes in retina transmit geomagnetic field signal to the brain, and then sense of direction is formed.Researching biological magnetoreception promotes a novel perspective in the diagnosis and treatment of eye and brain diseases, and brings innovation in magnetic material field.In this article, non-image forming functions of eyes, hypotheses of magnetoreception and possible mechanism of non-image forming functions of eyes in magnetoreception were reviewed.
ABSTRACT
Root development in plants is affected by light and phytohormones. Different ranges of light wavelength influence rootpatterning in a particular manner. Red and white light promote overall root development, whereas blue light has bothpositive as well as negative role in these processes. Light-mediated root development primarily occurs through modulationof synthesis, signaling and transport of the phytohormone auxin. Auxin has been shown to play a critical role in rootdevelopment. It is being well-understood that components of light and auxin signaling cross-talk with each other. However,the signaling network that can modulate the root development is an intense area of research. Currently, limited informationis available about the interaction of these two signaling pathways. This review not only summarizes the current findings onhow different quality and quantity of light affect various aspects of root development but also present the role of auxin inthese developmental aspects starting from lower to higher plants.
ABSTRACT
This study aims to explore the effect and mechanism of Jiao-tai-wan (JTW) on systemic and tissue-specific inflammation and insulin resistance in obesity-resistant (OR)rats with chronic partial sleep deprivation (PSD).OR rats with PSD were orally given JTW and Estazolam for 4 weeks.The amount of food intake and metabolic parameters such as body weight increase rate,fasting plasma glucose (FPG),fasting insulin (FINS),homeostasis model assessment-insulin resistance (HOMA-IR) and plasma inflammatory markers were measured.The expression levels of circadian proteins cryptochrome 1 (Cry1)and cryptochrome 2 (Cry2) in hypothalamus,adipose and liver tissues were also determined.Meanwhile,the mRNA expression of inflammatory markers,activity of nuclear factor kappa B (NF-κB) p65 protein,as well as the expression levels of insulin signaling pathway proteins in hypothalamus,adipose and liver tissues were measured.Additionally,cyclic adenosine 3',5'-monophosphate (cAMP) and activity of vasodilator-stimulated phosphoprotein (VASP)in hypothalamus tissue were measured.JTW significantly decreased the body weight increase rate and food intake,ameliorated systemic inflammation and insulin resistance.JTW effectively ameliorated inflammation and increased PI3K/AKT signaling activation in hypothalamus,adipose and liver.Interestingly,all these changes were associated with the up-regulation of circadian gene Cryl and Cry2 protein expression.We also found that in hypothalamus tissue of P SD rats,down-regulation of Cry 1 and Cry2 activated cAMP/PKA signaling and then led to inflammation,while JTW inhibited this signaling.These results suggested that JTW has the beneficial effect on ameliorating inflammation and insulin resistance in partially sleep-deprived rats by up-regulating Cry expression.
ABSTRACT
This study aims to explore the effect and mechanism of Jiao-tai-wan (JTW) on systemic and tissue-specific inflammation and insulin resistance in obesity-resistant (OR)rats with chronic partial sleep deprivation (PSD).OR rats with PSD were orally given JTW and Estazolam for 4 weeks.The amount of food intake and metabolic parameters such as body weight increase rate,fasting plasma glucose (FPG),fasting insulin (FINS),homeostasis model assessment-insulin resistance (HOMA-IR) and plasma inflammatory markers were measured.The expression levels of circadian proteins cryptochrome 1 (Cry1)and cryptochrome 2 (Cry2) in hypothalamus,adipose and liver tissues were also determined.Meanwhile,the mRNA expression of inflammatory markers,activity of nuclear factor kappa B (NF-κB) p65 protein,as well as the expression levels of insulin signaling pathway proteins in hypothalamus,adipose and liver tissues were measured.Additionally,cyclic adenosine 3',5'-monophosphate (cAMP) and activity of vasodilator-stimulated phosphoprotein (VASP)in hypothalamus tissue were measured.JTW significantly decreased the body weight increase rate and food intake,ameliorated systemic inflammation and insulin resistance.JTW effectively ameliorated inflammation and increased PI3K/AKT signaling activation in hypothalamus,adipose and liver.Interestingly,all these changes were associated with the up-regulation of circadian gene Cryl and Cry2 protein expression.We also found that in hypothalamus tissue of P SD rats,down-regulation of Cry 1 and Cry2 activated cAMP/PKA signaling and then led to inflammation,while JTW inhibited this signaling.These results suggested that JTW has the beneficial effect on ameliorating inflammation and insulin resistance in partially sleep-deprived rats by up-regulating Cry expression.
ABSTRACT
Mounting research evidence demonstrates a significant negative impact of circadian disruption on human health. Shift work, chronic jet lag and sleep disturbances are associated with increased incidence of metabolic syndrome, and consequently result in obesity, type 2 diabetes and dyslipidemia. Here, these associations are reviewed with respect to liver metabolism and disease.
ABSTRACT
Background The cryptochrom 2 (Cry2)in mammalian retina is a main influential factor of circadian clock.Objective Purpose of this study was to investigate the effect of light exposure rhythm on expression of Cry2 in retina.Methods Thirty clean healthy Sprague Dawley(SD)rats were collected and divided into two groups randomly.The rats of the control group exposed to natural light with the normal rhythm for 30 days,but rats of the experimental group exposed to the artificial light (light: dark =18 hours:6 hours) for 3 months with the light intensity of(533± 16)lx.The histopathological change and ultrastructural alteration of rat retina in both groups were examined under the light microscope and transmission electron microscope at the end of the experiment.Expressions of Cry2 protein and its mRNA were assayed by immunohistochemistry and quantitative PCR(Q-PCR).Results The rat retinal morphology and ultrastructure were clear and order-arranged under the light microscope and transmission electron microscope in the control group.However,atrophy and disorganization of retina were found under the light microscope,and liquefaction and vacuole of outer segments of photoreceptors were observed.The vacuolar degeneration of mitochondria in the inner segments of photoreceptors,cellular nuclear shrinkage,chromatin margination,nuclear notch and destruction were seen in the outer nuclear layer under the transmission electron microscope.Immunohistochemistry showed that the expression of Cry2 protein located in cytoplasm and nuclei membrane of the retinal ganglion cell layer and inner nuclear layer in both normal rats and experimental rats.The scores of Cry2 protein expression were 0.833±0.197 in the experimental group,and 1.700±0.245 in the control group,with a significant difference between them (P=0.009).The quantities of Cry2 mRNA were 0.962 ± 0.125 in the control group and 0.615±0.100 in the experimental group,showing a significant difference between the two groups (P =0.006).Conclusions Long-term light exposure under the 533 lx leads to retinal structural and functional damage probably by down-regulating Cry2 expression in retina.Whether the regulation of Cry2 expression is helpful for stabilizing the biorhythm or not is a worthy question to explore.
ABSTRACT
Studies employing model species have elucidated several aspects of photoperception and light signal transduction that control plant development. However, the information available for economically important crops is scarce. Citrus genome databases of expressed sequence tags (EST) were investigated in order to identify genes coding for functionally characterized proteins responsible for light-regulated developmental control in model plants. Approximately 176,200 EST sequences from 53 libraries were queried and all bona fide and putative photoreceptor gene families were found in citrus species. We have identified 53 orthologs for several families of transcriptional regulators and cytoplasmic proteins mediating photoreceptor-induced responses although some important Arabidopsis phytochrome- and cryptochrome-signaling components are absent from citrus sequence databases. The main gene families responsible for phototropin-mediated signal transduction were present in citrus transcriptome, including general regulatory factors (14-3-3 proteins), scaffolding elements and auxin-responsive transcription factors and transporters. A working model of light perception, signal transduction and response-eliciting in citrus is proposed based on the identified key components. These results demonstrate the power of comparative genomics between model systems and economically important crop species to elucidate several aspects of plant physiology and metabolism.