The effectiveness of corticosteroids (GCs) varies greatly in interstitial lung diseases (ILDs). In this study, we aimed to compare the gene expression profiles of patients with cryptogenic organizing pneumonia (COP), idiopathic pulmonary fibrosis (IPF), and non-specific interstitial pneumonia (NSIP) and identify the molecules and pathways responsible for GCs sensitivity in ILDs. Three datasets (GSE21411, GSE47460, and GSE32537) were selected. Differentially expressed genes (DEGs) among COP, IPF, NSIP, and healthy control (CTRL) groups were identified. Functional enrichment analysis and protein-protein interaction network analysis were performed to examine the potential functions of DEGs. There were 128 DEGs when COP versus CTRL, 257 DEGs when IPF versus CTRL, 205 DEGs when NSIP versus CTRL, and 270 DEGs when COP versus IPF. The DEGs in different ILDs groups were mainly enriched in the inflammatory response. Further pathway analysis showed that "interleukin (IL)-17 signaling pathway" (hsa04657) and "tumor necrosis factor (TNF) signaling pathway" were associated with different types of ILDs. A total of 10 genes associated with inflammatory response were identified as hub genes and their expression levels in the IPF group were higher than those in the COP group. Finally, we identified two GCs' response-related differently expressed genes (FOSL1 and DDIT4). Our bioinformatics analysis demonstrated that the inflammatory response played a pathogenic role in the progression of ILDs. We also illustrated that the inflammatory reaction was more severe in the IPF group compared to the COP group and identified two GCs' response-related differently expressed genes (FOSL1 and DDIT4) in ILDs.
Extensive inflammation and apoptosis in structural cells of the lung are responsible for the progression and pathogenesis of chronic obstructive pulmonary disease (COPD). Myotubularin-related protein 14 (MTMR14) has been shown to participate in various biological processes, including apoptosis, inflammation, and autophagy. Nonetheless, the role of MTMR14 in COPD remains elusive. In the present study, we explored the expression of MTMR14 in human lung tissues and investigated the effects of overexpressed MTMR14 on in vitro and in vivo COPD models. Moreover, one of the possible mechanisms of MTMR14 alleviating COPD was explored based on mitochondrial function and mitophagy homeostasis. The results showed that MTMR14 expression was reduced in COPD patients’ lungs in comparison to control subjects. MTMR14 overexpression inhibited cigarette smoke extract-induced inflammation and apoptosis and improved mitochondrial function and mitophagy in vitro. Further verification was carried out in COPD model mice. MTMR14 overexpression inhibited lung inflammation and reduced levels of IL-6 and KC in bronchoalveolar lavage fluid, as well as prevented emphysema and a decline in lung function. Furthermore, MTMR14 overexpression improved mitochondrial function and mitophagy to a certain extent. Collectively, our data support the hypothesis that MTMR14 participates in the pathogenesis of COPD. Improving mitochondrial function and mitophagy homeostasis may be one of the mechanisms by which MTMR14 alleviates COPD and may potentially be a novel therapeutic target for COPD.
Cyclic guanosine monophosphate (cGMP) modulates the speed of recovery from anoxia in adult Drosophila and mediates hypoxia-related behaviors in larvae. Cyclic nucleotide-gated channels (CNG) and cGMP-activated protein kinase (PKG) are two cGMP downstream targets. PKG is involved in behavioral tolerance to hypoxia and anoxia in adults, however little is known about a role for CNG channels. We used a CNGL (CNG-like) mutant with reduced CNGL transcripts to investigate the contribution of CNGL to the hypoxia response. CNGL mutants had reduced locomotor activity under normoxia. A shorter distance travelled in a standard locomotor assay was due to a slower walking speed and more frequent stops. In control flies, hypoxia immediately reduced path length per minute. Flies took 30–40 min in normoxia for >90% recovery of path length per minute from 15 min hypoxia. CNGL mutants had impaired recovery from hypoxia; 40 min for ∼10% recovery of walking speed. The effects of CNGL mutation on locomotor activity and recovery from hypoxia were recapitulated by pan-neuronal CNGL knockdown. Genetic manipulation to increase cGMP in the CNGL mutants increased locomotor activity under normoxia and eliminated the impairment of recovery from hypoxia. We conclude that CNGL channels and cGMP signaling are involved in the control of locomotor activity and the hypoxic response of adult Drosophila.
The classic eye-color gene white ( w ) in Drosophila melanogaster (fruitfly) has unexpected behavioral consequences. How w affects locomotion of adult flies is largely unknown. Here, we show that a mutant allele ( w 1118 ) selectively increases locomotor components at relatively high frequencies (> 0.1 Hz). The w 1118 flies had reduced transcripts of w + from the 5′ end of the gene. Male flies of w 1118 walked continuously in circular arenas while the wildtype Canton-S walked intermittently. Through careful control of genetic and cytoplasmic backgrounds, we found that the w 1118 locus was associated with continuous walking. w 1118 -carrying male flies showed increased median values of path length per second (PPS) and 5-min path length compared with w + -carrying males. Additionally, flies carrying 2–4 genomic copies of mini- white + (m w + ) in the w 1118 background showed suppressed median PPSs and decreased 5-min path length compared with controls, and the suppression was dependent on the copy number of m w + . Analysis of the time-series (i.e., PPSs over time) by Fourier transform indicated that w 1118 was associated with increased locomotor components at relatively high frequencies (> 0.1 Hz). The addition of multiple genomic copies of m w + (2–4 copies) suppressed the high-frequency components. Lastly, the downregulation of w + in neurons but not glial cells resulted in increased high-frequency components. We concluded that mutation of w modified the locomotion in adult flies by selectively increasing high-frequency locomotor components.
Chronic obstructive pulmonary disease (COPD) is composed of chronic airway inflammation and emphysema. Recent studies show that Class IA phosphatidylinositol 3-kinases (PI3Ks) play an important role in the regulation of inflammation and emphysema. However, there are few studies on their regulatory subunits. p55PIK is a regulatory subunit of Class IA PI3Ks, and its unique NH2-terminal gives it special functions. p55PIK expression in the lungs of nonsmokers, smokers, and patients with COPD was examined. We established a fusion protein TAT-N15 from the NH2-terminal effector sequence of p55PIK and TAT (the transduction domain of HIV transactivator protein) and investigated the effects of silencing p55PIK or adding TAT-N15 on cigarette smoke exposure at the cellular and animal level. p55PIK expression was increased in patients with COPD. p55PIK deficiency and TAT-N15 significantly inhibited the cigarette smoke extract-induced IL-6, IL-8, and activation of the Akt and the NF-κB pathway in BEAS-2B. p55PIK deficiency and TAT-N15 intranasal administration prevented emphysema and the lung function decline in mice exposed to smoke for 6 mo. p55PIK deficiency and TAT-N15 significantly inhibited lung inflammatory infiltration, reduced levels of IL-6 and KC in mice lung homogenate, and inhibited activation of the Akt and the NF-κB signaling in COPD mice lungs. Our studies indicate that p55PIK is involved in the pathogenesis of COPD, and its NH2-terminal derivative TAT-N15 could be an effective drug in the treatment of COPD by inhibiting the activation of the Akt and the NF-κB pathway.
Drosophila provides an excellent opportunity to explore the genetic basis for behavioral and CNS responses to hypoxia. Cyclic guanosine monophosphate (cGMP) modulates the speed of recovery from anoxia in adults and mediates hypoxia-related behaviors in larvae. Cyclic nucleotide-gated channels (CNG) and cGMP-activated protein kinase (PKG) are two cGMP downstream targets. PKG is involved in behavioral tolerance to hypoxia and anoxia in adults, however little is known about CNG channels. We used a CNGL mutant with reduced CNGL transcripts to investigate the contribution of CNGL to the hypoxia response. In control flies (w1118), hypoxia immediately reduced path length per minute in a locomotor assay. Flies took 30-40 mins in air to recover from 15 mins hypoxia. CNGL mutants had reduced locomotion under normoxia and impaired recovery from hypoxia, similar to the effects of pan-neural CNGL knockdown. In the CNGL mutants hypoxia caused an acute increase in path length per minute followed by a gradual increase during hypoxia. Basal levels of CNS extracellular K + concentrations were reduced in the mutants. In response to hypoxia, the mutants had an increased extracellular K + concentration change, reduced time to reach the K + concentration peak, and delayed recovery time. Genetic manipulation to increase cGMP in the CNGL mutants eliminated the impairment of recovery from hypoxia and partially compensated for the effects of hypoxia on CNS K + . Although the neural mechanisms have yet to be determined, CNGL channels and cGMP signaling are involved in the hypoxia response of adult Drosophila .
The classic eye-color gene white + ( w +) in Drosophila melanogaster (fruitfly) has unexpected behavioral consequences. How w + affect locomotion of adult flies is largely unknown. Here, we show that w + selectively suppresses locomotor components at relatively high frequencies (> 0.1 Hz). The wildtype Canton-S male flies walked intermittently in circular arenas while the white-eyed w 1118 flies walked continuously. Through careful control of genetic and cytoplasmic backgrounds, we found that w + was associated with intermittent walking. w +-carrying male flies had smaller median values of path length per second (PPS) and reduced 5-min path length compared with w 1118-carrying males. Additionally, flies carrying 2-4 genomic copies of mini- white + (m w +) showed reduced median PPSs and decreased 5-min path length compared with w 1118 flies, and the suppression was dependent on the copy number of m w +. Fourier transform of the time series (i.e. PPSs over time) indicated that w +/m w + specifically suppressed the locomotor components at relatively high frequencies (> 0.1 Hz). Lastly, the downregulation of w + in neurons but not glial cells resulted in an increased percentage of high-frequency locomotor components. We concluded that w + suppressed the locomotion of adult flies by selectively reducing the high-frequency locomotor components.
Sexual behavior is a routine among animal species. Sexual experience has several behavioral consequences in insects, but its physiological basis is less well-understood. The episodic motor activity with a periodicity around 19 s was unintentionally observed in the wildtype Canton-S flies and was greatly reduced in the white-eyed mutant w(1118) flies. Episodic motor activity co-exists with several consistent locomotor performances in Canton-S flies whereas reduced episodic motor activity is accompanied by neural or behavioral abnormalities in w(1118) flies. The improvements of both episodic motor activity and locomotor performance are co-inducible by a pulsed light illumination in w(1118). Here we show that mating experience of w(1118 )males promoted fast and consistent locomotor activities and increased the power of episodic motor activities. Compared with virgin males, mated ones showed significant increases of boundary preference, travel distance over 60 s, and increased path increments per 0.2 s. In contrast, mated males of Canton-S showed decreased boundary preference, increased travel distance over 60 s, and increased path increments per 0.2 s. Additionally, mated males of w(1118 )displayed increased power amplitude of periodic motor activities at 0.03-0.1 Hz. These data indicated that mating experience promoted fast and consistent locomotion and improved episodic motor activities in w(1118) male flies.
Animal food wastes are a concern due to the large amounts of commercial food required for model animals during the biological and biomedical research. Searching for sustainable food alternatives with negligible physiological effects on animals is critical to solve or reduce this challenge. Microalgae have been demonstrated to be suitable for both human consumption and animal feed. In this study, the possibility of using Chlorella vulgaris and Senedesmus obliquus as a feed replacement to Drosophila melanogaster, one of the fly models commonly used in biomedical studies, was investigated. Characteristics including the fly locomotor activity, motor pattern, feeding behavior, lifespan and body weight were assessed. Results showed that compared to control, the flies fed on 80% microalga (80-flies) in the total weight (w/w) had the double increased apparent step size, while both 60-flies and 80-flies exhibited longer travel distances (60%: 27.77 ± 1.99 cm; 80%: 31.50 ± 3.70 cm) most likely due to the starvation and varied serotonin levels in flies fed on high percentages microalgae. Subsequently, 40-flies exhibited less optimal growth performance with decreased body weights (0.51 ± 0.006 mg vs 0.60 ± 0.005 mg for control) and shorter mean lifespan (36 days vs 55.8 days for control. However, 20-flies showed no statistical differences in all parameters tested with respect to control flies, indicating that 20% microalgae treatment did not greatly change the primary food component such as carbohydrate which might play a critical role in fly performance. Therefore, the inclusion of 20% microalgae could be an alternative to fly standard food without compromising fly physiological performance.
Drosophila egg-derived tyrosine phosphatase (EDTP), a lipid phosphatase that removes 3-position phosphate at the inositol ring, has dual functions in oogenesis and muscle performance in adults. A mammalian homologous gene MTMR14, which encodes the myotubularin-related protein 14, negatively regulates autophagy. Mutation of EDTP/MTMR14, however, causes at least three deleterious consequences: (1) the lethality in early embryogenesis in Drosophila; (2) a "jumpy" phenotype with apparently impaired motor functions; and (3) an association with a rare genetic disorder called centronuclear myopathy. The potential benefit of EDTP/MTMR14 downregulation is likely masked by the lethality or severe muscle defects due to ubiquitous loss of this gene. Here we show that flies carrying a heterozygous EDTP mutation had increased survivorship to prolonged anoxia; tissue-specific downregulation of EDTP in non-muscle tissues, particularly motoneurons, extended lifespan and improved survivorship to beta-amyloid peptides (Aβ42) and polyglutamine protein aggregates. These data highlight the significance of selective downregulation of EDTP in non-muscles for beneficial consequences. MTMR14 expression was evident in the hippocampus and cortex in C57BL/6 J and APP/PS1 mice. Compared with C57BL/6 J mice, APP/PS1 mice had reduced MTMR14 in the cortex. Hippocampal expression of MTMR14 was increased and plateaued at 9-17 months compared with 2-6 months in C57BL/6 J mice. Additionally, MTMR14 was inducible by Aβ42 in the rat primarily hippocampal neurons and mouse Neuro2a neuroblasts. We demonstrate a novel approach of tissue-specific downregulation of the disease-associated gene EDTP/MTMR14 for extended lifespan and improved survivorship to cellular protein aggregates. This approach could be extended from insects to mammals.
It has been known for over 20 years that Drosophila melanogaster flies with twelve additional copies of the hsp70 gene encoding the 70 kD heat shock protein lives longer after a non-lethal heat treatment. Since the heat treatment also induces the expression of additional heat shock proteins, the biological effect can be due either to HSP70 acting alone or in combination. This study used the UAS/GAL4 system to determine whether hsp70 is sufficient to affect the longevity and the resistance to thermal, oxidative or desiccation stresses of the whole organism. We observed that HSP70 expression in the nervous system or muscles has no effect on longevity or stress resistance but ubiquitous expression reduces the life span of males. We also observed that the down-regulation of hsp70 using RNAi did not affect longevity.
Many insects enter coma upon exposure to anoxia, a feature routinely exploited by experimentalists to handle them. But the genetic and physiological bases of anoxic coma induction and recovery are only partially understood, as are the long-term consequences for the animal’s performance. We examined three populations of Drosophila melanogaster (designated B) that have been inadvertently under selection for rapid recovery from CO2 exposure for nearly 40 years (around 1000 generations) resulting from routine maintenance practices. We contrasted CO2 and N2 (presumed a less reactive gas) knockdown and recovery times of these B flies with six populations of common ancestry (A and C populations) that were not exposed toCO2 over the sameperiod.We found that B populations showed faster and more consistent locomotor recovery than A or C populations after CO2 knockdown, a result also observed with N2 knockdown. A and C populations showed much higher variance in recovery time after CO2 exposure than after N2 exposure, suggesting gas-specific effects on pathways associated with locomotor recovery. Although these selection treatments result in considerable variation in life history attributes and body size, with the characteristic intermediacy of B populations, their superiority in resistance to gas exposure and locomotor recovery suggests that this is a direct consequence of prior repeated exposure to anoxia, broadly, and CO2, specifically. Hencewe describe a powerful new evolutionary model for the genetic and physiological investigation of anoxic coma in insects.
Drosophila egg-derived tyrosine phosphatase (EDTP), a lipid phosphatase that removes 3-position phosphate at the inositol ring, has dual functions in the oogenesis and the muscle performance during adult stages. A mammalian homologous gene MTMR14 , which encodes the myotubularin-related protein 14, negatively regulates autophagy. Mutation of EDTP/MTMR14 , however, causes at least three deleterious consequences: (1) lethality in the early embryogenesis in Drosophila ; (2) “jumpy” phenotype with apparently impaired motor functions; and (3) association with a rare genetic disorder called centronuclear myopathy. Here we show that flies carrying a heterozygous EDTP mutation had increased survivorship to prolonged anoxia; tissue-specific downregulation of EDTP in non-muscle tissues, particularly motoneurons, extended the lifespan; and tissue-specific downregulation of EDTP in motoneurons improved the survivorship to beta-amyloid peptides (Aβ42) and polyglutamine (polyQ) protein aggregates. MTMR14 expression was evident in the hippocampus and cortex in C57BL/6J and APP/PS1 mice. Compared with C57BL/6J mice, APP/PS1 mice had reduced MTMR14 in the cortex but not in the hippocampus. Hippocampal expression of MTMR14 was increased and plateaued at 9-17 months compared with 2-6 months in C57BL/6J mice. Aβ42 treatment increased the expression of MTMR14 in the primarily cultured hippocampal neurons of Sprague/Dawley rats and mouse Neuro2a neuroblasts. We demonstrated a novel approach of tissue-specific manipulation of the disease-associated gene EDTP/MTMR14 for lifespan extension and the improvement of survivorship to cellular protein aggregates.
We describe persistent one-way walking of Drosophila melanogaster in a circular arena. Wild-type Canton-S adult flies walked in one direction, counter-clockwise or clockwise, for minutes, whereas white-eyed mutant w 1118 changed directions frequently. Locomotion in the circular arena could be classified into four components: counter-clockwise walking, clockwise walking, nondirectional walking and pausing. Genetic analysis revealed that while wild-type genetic background was associated with reduced directional change and reduced numbers of one-way (including counterclockwise and clockwise) and nondirectional walks, the white ( w + ) locus promoted persistent oneway walking by increasing the maximal duration of one-way episodes. The promoting effect of w + was further supported by the observations that (1) w + duplicated to the Y chromosome, (2) four genomic copies of mini-white inserted on the autosomes, and (3) pan-neuronal overexpression of the White protein increased the maximal duration of one-way episodes, and that RNAi knockdown of w + in the neurons decreased the maximal duration of one-way episodes. These results suggested a pleiotropic function of w + in promoting persistent one-way walking in the circular arena.
The Drosophila melanogaster white-eyed w 1118 line serves as a blank control, allowing genetic recombination of any gene of interest along with a readily recognizable marker. w 1118 flies display behavioral susceptibility to environmental stimulation such as light. It is of great importance to characterize the behavioral performance of w 1118 flies because this would provide a baseline from which the effect of the gene of interest could be differentiated. Little work has been performed to characterize the walking behavior in adult w 1118 flies. Here we show that pulsed light stimulation increased the regularity of walking trajectories of w 1118 flies in circular arenas. We statistically modeled the distribution of distances to center and extracted the walking structures of w 1118 flies. Pulsed light stimulation redistributed the time proportions for individual walking structures. Specifically, pulsed light stimulation reduced the episodes of crossing over the central region of the arena. An addition of four genomic copies of mini- white , a common marker gene for eye color, mimicked the effect of pulsed light stimulation in reducing crossing in a circular arena. The reducing effect of mini- white was copy-number-dependent. These findings highlight the rhythmic light stimulation-evoked modifications of walking behavior in w 1118 flies and an unexpected behavioral consequence of mini- white in transgenic flies carrying w 1118 isogenic background.
Drosophila egg-derived tyrosine phosphatase (EDTP) is a lipid phosphatase essential for oogenesis and muscle function. Loss-of-EDTP is lethal at early developmental stages. Hypomorphic mutation of EDTP causes impaired muscle performance and shortened lifespan. Mutation of MTMR14, a mammalian homolog to EDTP, is associated with muscle fatigue in rodents and a rare genetic disease called centronuclear myopathy in humans. Despite the deleterious consequences, downregulation of MTMR14 promotes autophagy. It is proposed that selective downregulation of EDTP/MTMR14 in non-muscle tissues improves the survivorship to cellular wastes and extends lifespan. Here, we show that downregulation of EDTP in glial cells suppressed the expression of polyglutamine (polyQ) protein aggregates and improved survival. Downregulation of EDTP in glial cells also extended lifespan. These effects were not observed by targeting pan-neurons in the nervous system, suggesting the significance of tissue-specificity. Additionally, flies carrying an EDTP mutant had increased survival to prolonged anoxia and altered dynamics of polyQ expression. These data supported the proposal that selective downregulation of EDTP in non-muscle tissues improved survivorship to cellular protein aggregates and extended lifespan. Our findings suggest that EDTP/MTMR14 could be a novel molecular target for the treatment of neurodegeneration.
Aging has significant effects on the locomotor performance of insects including Drosophila. Using a protocol for the high-throughput analysis of fly locomotion in a circular arena, we examined age-dependent behavioral characteristics in adult flies. There are widely used wild-type and genetically engineered background lines including the Canton-S strain and the w1118 strain, which has a null mutation of the white gene. Under standard rearing conditions, we found similar survival and median lifespans in Canton-S (50days) and w1118 (54days) strains, however, w1118 flies maintained stable body mass for up to 43days, whereas Canton-S flies gained body mass at young age, followed by a gradual decline. We also tested the behavioral performance of young and old flies. Compared with young w1118 flies (5-10days), old w1118 flies (40-45days) had an increased boundary preference during locomotion in small circular arenas, and increased speed of locomotor recovery from anoxia. Old Canton-S files, however, exhibited unchanged boundary preference and reduced recovery speed from anoxia relative to young flies. In addition, old w1118 flies showed decreased path length per minute and reduced 0.2s path increment compared with young flies, whereas old Canton-S flies displayed the same path length per minute and the same 0.2s path increment compared with young flies. We conclude that age-dependent behavioral and physiological changes differ between Canton-S and w1118 flies. These results illustrate that phenotypic differences between strains can change qualitatively, as well as quantitatively, as the animals age.
Increasing evidence indicates that the white (w) gene in Drosophila possesses extra-retinal functions in addition to its classical role in eye pigmentation. We have previously shown that w(+) promotes fast and consistent locomotor recovery from anoxia, but how w(+) modulates locomotor recovery is largely unknown. Here we show that in the absence of w(+), several PDE mutants, especially cyclic guanosine monophosphate (cGMP)-specific PDE mutants, display wildtype-like fast locomotor recovery from anoxia, and that during the night time, locomotor recovery was light-sensitive in white-eyed mutant w1118, and light-insensitive in PDE mutants under w1118 background. Data indicate the involvement of cGMP in the modulation of recovery timing and presumably, light-evoked cGMP fluctuation is associated with light sensitivity of locomotor recovery. This was further supported by the observations that w-RNAi-induced delay of locomotor recovery was completely eliminated by upregulation of cGMP through multiple approaches, including PDE mutation, simultaneous overexpression of an atypical soluble guanylyl cyclase Gyc88E, or sildenafil feeding. Lastly, prolonged sildenafil feeding promoted fast locomotor recovery from anoxia in w1118. Taken together, these data suggest that a White-cGMP interaction modulates the timing of locomotor recovery from anoxia.
During anoxia, proper energy maintenance is essential in order to maintain neural operation. Starvation activates AMP-activated protein kinase (AMPK), an evolutionarily conserved indicator of cellular energy status, in a cascade which modulates ATP production and consumption. We investigated the role of energetic status on anoxia tolerance in Drosophila and discovered that starvation or AMPK activation increases the speed of locomotor recovery from an anoxic coma. Using temporal and spatial genetic targeting we found that AMPK in the fat body contributes to starvation-induced fast locomotor recovery, whereas, under fed conditions, disrupting AMPK in oenocytes prolongs recovery. By evaluating spreading depolarization in the fly brain during anoxia we show that AMPK activation reduces the severity of ionic disruption and prolongs recovery of electrical activity. Further genetic targeting indicates that glial, but not neuronal, AMPK affects locomotor recovery. Together, these findings support a model in which AMPK is neuroprotective in Drosophila.