Regulatory mechanisms of iron homeostasis in maize mediated by ZmFIT

Regulation of iron homeostasis in maize remains unclear,despite the known roles of FER-Like Fe deficiency-induced transcription factor(FIT)in Arabidopsis and rice.ZmFIT,like At FIT and Os FIT,interacts with iron-related transcription factors 2(ZmIRO2).Here,we investigate the involvement of ZmFIT in iron homeostasis.Mutant ZmFIT lines exhibiting symptoms of Fe deficiency had reduced shoot iron content.Transcriptome analysis revealed downregulation of Fe deficiency-responsive genes in the roots of a Zmfit mutant.ZmFIT facilitates the nuclear translocation of ZmIRO2 to activate transcription of downstream genes under Fe-deficient conditions.Our findings suggest that ZmFIT,by interaction with ZmIRO2,mediates iron homeostasis in maize.Notably,the binding and activation mechanisms of ZmFIT resemble those in Arabidopsis but differ from those in rice,whereas downstream genes regulated by ZmFIT show similarities to rice but differences from Arabidopsis.In brief,ZmFIT,orthgologs of Os FIT and At FIT in rice and maize,respectively,regulates iron uptake and homeostasis in maize,but with variations.

Latest assessment methods for mitochondrial homeostasis in cognitive diseases

Mitochondria play an essential role in neural function,such as supporting normal energy metabolism,regulating reactive oxygen species,buffering physiological calcium loads,and maintaining the balance of morphology,subcellular distribution,and overall health through mitochondrial dynamics.Given the recent technological advances in the assessment of mitochondrial structure and functions,mitochondrial dysfunction has been regarded as the early and key pathophysiological mechanism of cognitive disorders such as Alzheimer’s disease,Parkinson’s disease,Huntington’s disease,mild cognitive impairment,and postoperative cognitive dysfunction.This review will focus on the recent advances in mitochondrial medicine and research methodology in the field of cognitive sciences,from the perspectives of energy metabolism,oxidative stress,calcium homeostasis,and mitochondrial dynamics(including fission-fusion,transport,and mitophagy).

Ruxolitinib improves the inflammatory microenvironment,restores glutamate homeostasis,and promotes functional recovery after spinal cord injury

The inflammatory microenvironment and neurotoxicity can hinder neuronal regeneration and functional recovery after spinal cord injury.Ruxolitinib,a JAK-STAT inhibitor,exhibits effectiveness in autoimmune diseases,arthritis,and managing inflammatory cytokine storms.Although studies have shown the neuroprotective potential of ruxolitinib in neurological trauma,the exact mechanism by which it enhances functional recovery after spinal cord injury,particularly its effect on astrocytes,remains unclear.To address this gap,we established a mouse model of T10 spinal cord contusion and found that ruxolitinib effectively improved hindlimb motor function and reduced the area of spinal cord injury.Transcriptome sequencing analysis showed that ruxolitinib alleviated inflammation and immune response after spinal cord injury,restored EAAT2 expression,reduced glutamate levels,and alleviated excitatory toxicity.Furthermore,ruxolitinib inhibited the phosphorylation of JAK2 and STAT3 in the injured spinal cord and decreased the phosphorylation level of nuclear factor kappa-B and the expression of inflammatory factors interleukin-1β,interleukin-6,and tumor necrosis factor-α.Additionally,in glutamate-induced excitotoxicity astrocytes,ruxolitinib restored EAAT2 expression and increased glutamate uptake by inhibiting the activation of STAT3,thereby reducing glutamate-induced neurotoxicity,calcium influx,oxidative stress,and cell apoptosis,and increasing the complexity of dendritic branching.Collectively,these results indicate that ruxolitinib restores glutamate homeostasis by rescuing the expression of EAAT2 in astrocytes,reduces neurotoxicity,and effectively alleviates inflammatory and immune responses after spinal cord injury,thereby promoting functional recovery after spinal cord injury.

Wnt/β-catenin signaling components and mechanisms in bone formation,homeostasis,and disease

Wnts are secreted,lipid-modified proteins that bind to different receptors on the cell surface to activate canonical or non-canonical Wnt signaling pathways,which control various biological processes throughout embryonic development and adult life.Aberrant Wnt signaling pathway underlies a wide range of human disease pathogeneses.

Alterations of protein homeostasis in Alzheimer's disease:beyond Procrustean bed of endoplasmic reticulum stress and unfolded protein response

Alzheimer’s disease(AD)is a major age-related form of dementia with a number of cases exponentially growing,causing enormous social and economic impact on individuals and society.Neuropathological hallmarks of AD,evident in postmortem AD brains,include a massive loss of the grey matter in the neocortex,extracellular deposition of amyloid-β(Aβ)in the form of senile plaques and cerebrovascular amyloid angiopathy,and intra-neuronal accumulation of neurofibrillary tangles,formed by hyper-phosphorylated tau protein.

A dysregulated calcium homeostasis as the earliest pathological sign in stem cell-derived Parkinson's disease neurons?

Parkinson’s disease(PD) is characterized by the slow and progressive demise of dopamine(DA)-synthesizing neurons in the substantia nigra pars compacta(SNc),a nucleus located in the human ventral midbrain.Neuron death also affects other regions in the brain at later stages of PD.The concomitant lack of DA in the human forebrain(striatum) leads to the typical motor symptoms of this still uncurable neurodegenerative disorder.

Apoer2/Lrp8:the undercover cop of synaptic homeostasis

Apolipoprotein E receptor 2(ApoER2)is a receptor for the protein ApoE,the most common genetic risk factor for late-onset Alzheimer's disease(AD).It is also a key modulator of syna ptic homeostasis,in part through its effect on the expression of neuronal genes including those implicated in AD and other neuropsychiatric disorders.In this perspective,we highlight several genes affected by ApoER2 and its alternatively spliced forms and how aberrant expression can be rescued by the reintroduction of the ApoER2 intracellular domain in the mouse hippocampus.

A wheat germ-rich diet preserves bone homeostasis by regulating gut microbiota and plasma metabolites in aged rats

Bone loss caused by ageing has become one of the leading health risk factors worldwide.Wheat germ(WG)is consists of high amounts of bioactive peptides,polyunsaturated fatty acids,and dietary fibre.Currently,WG has been proven to possess strong antioxidant and anti-infl ammatory properties.We recently explored the beneficial effects and relevant mechanisms of a WG-rich diet(2.5%and 5%WG,m/m)on bone homeostasis in aged rats.Our results showed that 5%WG supplementation for 12 months effectively attenuated ageing-induced microstructural damage and differentiation activity changes in the femur.The 5%WG supplementation also signifi cantly increased the levels of total antioxidant capacity(T-AOC),glutathione peroxidase(GSH-Px)(P<0.01),and superoxide dismutase(SOD)(P<0.05),and decreased infl ammatory cytokine levels(tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6))(P<0.01).Furthermore,the WG-rich diet reshaped the composition of the gut microbiota,enhancing short-chain fatty acids(SCFAs)-producing microbes and reducing infl ammation-related microbes.In addition,metabolomics analysis showed that 5%WG supplementation improved plasma metabolites related to bone metabolism.Conclusively,our study purports long-term WG-rich diet may preserve bone homeostasis by regulating gut microbiota and plasma metabolites in aged rats.

Dietary fat supplementation relieves cold temperature-induced energy stress through AMPK-mediated mitochondrial homeostasis in pigs

Background Cold stress has negative effects on the growth and health of mammals, and has become a factor restricting livestock development at high latitudes and on plateaus. The gut-liver axis is central to energy metabolism, and the mechanisms by which it regulates host energy metabolism at cold temperatures have rarely been illustrated. In this study, we evaluated the status of glycolipid metabolism and oxidative stress in pigs based on the gut-liver axis and propose that AMP-activated protein kinase(AMPK) is a key target for alleviating energy stress at cold temperatures by dietary fat supplementation.Results Dietary fat supplementation alleviated the negative effects of cold temperatures on growth performance and digestive enzymes, while hormonal homeostasis was also restored. Moreover, cold temperature exposure increased glucose transport in the jejunum. In contrast, we observed abnormalities in lipid metabolism, which was characterized by the accumulation of bile acids in the ileum and plasma. In addition, the results of the ileal metabolomic analysis were consistent with the energy metabolism measurements in the jejunum, and dietary fat supplementation increased the activity of the mitochondrial respiratory chain and lipid metabolism. As the central nexus of energy metabolism, the state of glycolipid metabolism and oxidative stress in the liver are inconsistent with that in the small intestine. Specifically, we found that cold temperature exposure increased glucose transport in the liver, which fully validates the idea that hormones can act on the liver to regulate glucose output. Additionally, dietary fat supplementation inhibited glucose transport and glycolysis, but increased gluconeogenesis, bile acid cycling, and lipid metabolism. Sustained activation of AMPK, which an energy receptor and regulator, leads to oxidative stress and apoptosis in the liver;dietary fat supplementation alleviates energy stress by reducing AMPK phosphorylation.Conclusions Cold stress reduced the growth performance and aggravated glycolipid metabolism disorders and oxidative stress damage in pigs. Dietary fat supplementation improved growth performance and alleviated cold temperature-induced energy stress through AMPK-mediated mitochondrial homeostasis. In this study, we high-light the importance of AMPK in dietary fat supplementation-mediated alleviation of host energy stress in response to environmental changes.

Multi-omics analysis reveals the pivotal role of phytohormone homeostasis in regulating maize grain water content

Grain water content(GWC)is a key determinant for mechanical harvesting of maize(Zea mays).In our previous research,we identified a quantitative trait locus,qGWC1,associated with GWC in maize.Here,we examined near-isogenic lines(NILs)NILL and NILH that differed at the qGWC1 locus.Lower GWC in NILL was primarily attributed to reduced grain water weight(GWW)and smaller fresh grain size,rather than the accumulation of dry matter.The difference in GWC between the NILs became more pronounced approximately 35 d after pollination(DAP),arising from a faster dehydration rate in NILL.Through an integrated analysis of the transcriptome,proteome,and metabolome,coupled with an examination of hormones and their derivatives,we detected a marked decrease in JA,along with an increase in cytokinin,storage forms of IAA(IAA-Glu,IAA-ASP),and IAA precursor IPA in immature NILL kernels.During kernel development,genes associated with sucrose synthases,starch biosynthesis,and zein production in NILL,exhibited an initial up-regulation followed by a gradual down-regulation,compared to those in NILH.This discovery highlights the crucial role of phytohormone homeostasis and genes related to kernel development in balancing GWC and dry matter accumulation in maize kernels.

The role of snapin in regulation of brain homeostasis

Brain homeostasis refe rs to the normal working state of the brain in a certain period,which is impo rtant for overall health and normal life activities.Currently,there is a lack of effective treatment methods for the adverse consequences caused by brain homeostasis imbalance.Snapin is a protein that assists in the formation of neuronal synapses and plays a crucial role in the normal growth and development of synapses.Recently,many researchers have reported the association between snapin and neurologic and psychiatric disorders,demonstrating that snapin can improve brain homeostasis.Clinical manifestations of brain disease often involve imbalances in brain homeostasis and may lead to neurological and behavioral sequelae.This article aims to explo re the role of snapin in restoring brain homeostasis after injury or diseases,highlighting its significance in maintaining brain homeostasis and treating brain diseases.Additionally,it comprehensively discusses the implications of snapin in other extracerebral diseases such as diabetes and viral infections,with the objective of determining the clinical potential of snapin in maintaining brain homeostasis.

Possible Mechanism of Effects of Etimicin and Gentamicin on Intracellular Calcium Homeostasis

Aim Intracellular calcium ([Ca^(2+) ]_i) is mainly regulated by mitochondriaand endo-plasmic reticula. This study was carried out to ascertain whether the elementary mechanismof the effects of etimicin (EM) and gentamicin (GM) on [Ca^(2+) ]_i is related to their effects onmitochondrion Ca^(2+) -uptake and endoplasmic reticulum Ca^(2+) -uptake. Methods The effects of GMand EM on [Ca^(2+) ]_i in LLC-PK1 were determined with a fluorescent probe of Fura-2/AM. The effectsof EM and GM on mitochondrion Ca^(2+) -uptake and endoplasmic reticulum Ca^(2+) -uptake weredetermined by isotope indicator (^(45)Ca^(2+) ) . Results EM and GM at the concentration of 1mmol·L^(-1) had no significant effect on [Ca^(2+) ]_i(P. > 0.05) and at 10 mmol·L^(-1)significantly caused [Ca^(2+) ]_i to increase (P < 0.01). EM and GM at 1 mmol·L^(-1) causedmitochondrion Ca^(2+)-uptake to ascend dramatically (P < 0.05) and at 10 mmol·L^(-1) causedmitochondrion Ca^(2+) -uptake to descend significantly. EM and GM at more than 0.34 mrnol·L^(-1)significantly inhibited endoplasmic reticulum Ca^(2+) -uptake (P < 0.05 or 0.01). Conclusion Novariation of [Ca^(2+) ]_i caused by EM and GM at lower concentrations might relate to theequilibrium of their promotion of mitochondrion Ca^(2+) -uptake with their inhibition of endoplasmicreticulum Ca^(2+) -uptake. The elevation of [Ca^(2+) ]_i caused by EM and GM at higherconcentrations might correlate with their inhibition of mitochondrion Ca^(2+) -uptake andendoplasmic reticulum Ca^(2+) -uptake.

Restoring homeostasis of CD4^+ T cells in hepatitis-B-virusrelated liver fibrosis

Immune-mediated liver injury is widely seen during hepatitis B virus(HBV) infection. Unsuccessful immune clearance of HBV results in chronic hepatitis and increases the risk of liver cirrhosis and hepatocellular carcinoma. HBV-related liver fibrosis(HBVLF),occurring as a result of HBV-induced chronic hepatitis,is a reversible,intermediate stage of chronic hepatitis B(CHB) and liver cirrhosis. Therefore,defining the pathogenesis of HBVLF is of practical significance for achieving better clinical outcomes. Recently,the homeostasis of CD4+ T cells was considered to be pivotal in the process of HBVLF. To better uncover the underlying mechanisms,in this review,we systematically retrospect the impacts of different CD4+T-cell subsets on CHB and HBVLF. We emphasize CD4+ T-cell homeostasis and the important balance between regulatory T(Treg) and T helper 17(Th17) cells. We discuss some cytokines associated with Treg and Th17 cells such as interleukin(IL)-17,IL-22,IL-21,IL-23,IL-10,IL-35 and IL-33,as well as surface molecules such as programmed cell death protein 1,cytotoxic T lymphocyte-associated antigen 4,T cell immunoglobulin domain and mucin domain-containing molecule 3 and cannabinoid receptor 2 that have potential therapeutic implications for the homeostasis of CD4+ T cells in CHB and HBVLF.

Epididymis cholesterol homeostasis and sperm fertilizing ability

Cholesterol, being the starting point of steroid hormone synthesis, is a long known modulator of both female and male reproductive physiology especially at the level of the gonads and the impact cholesterol has on gametogenesis. Less is known about the effects cholesterol homeostasis may have on postgonadic reproductive functions. Lately, several data have been reported showing how imbalanced cholesterol levels may particularly affect the post-testicular events of sperm maturation that lead to fully fertile male gametes. This review will focus on that aspect and essentially centers on how cholesterol is important for the physiology of the mammalian epididymis and spermatozoa.

Phasic study of intestinal homeostasis disruption in experimental intestinal obstruction

AIM: To investigate the phasic alteration of intestinal homeostasis in an experimental model of intestinal obstruction.

Limbal stem cells: Central concepts of corneal epithelial homeostasis

A strong cohort of evidence exists that supports the localisation of corneal stem cells at the limbus. The distinguishing characteristics of limbal cells as stem cells include slow cycling properties, high proliferative potential when required, clonogenicity, absence of differentiation marker expression coupled with positive expression of progenitor markers, multipotency, centripetal migration, requirement for a distinct niche environment and the ability of transplanted limbal cells to regenerate the entire corneal epithelium. The existence of limbal stem cells supports the prevailing theory of corneal homeostasis, known as the XYZ hypothesis where X represents proliferation and stratification of limbal basal cells, Y centripetal migration of basal cells and Z desquamation of superficial cells. To maintain the mass of cornea, the sum of X and Y must equal Z and very elegant cell tracking experiments provide strong evidence in support of this theory. However, several recent stud-ies have suggested the existence of oligopotent stem cells capable of corneal maintenance outside of the limbus. This review presents a summary of data which led to the current concepts of corneal epithelial homeostasis and discusses areas of controversy surrounding the existence of a secondary stem cell reservoir on the corneal

Continuous positive airway pressure to improve insulin resistance and glucose homeostasis in sleep apnea

Obstructive sleep apnea syndrome(OSAS)is a relatively common disorder in the adult population.It is associated with alterations in glucose metabolism and increases the risk for diabetes mellitus.Continuous positive airway pressure(CPAP)is the treatment of choice for OSAS.It may also have a favorable effect on insulin resistance and glucose metabolism,although relevant data is conflicting.Additional research is still needed to fully establish the effect of CPAP on glucose homeostasis.It should ascertain which patients may benefit most and how long treatment takes to induce favorable changes.Finally,patient compliance is being appreciated as a major factor influencing therapeutic outcomes,and this needs to be further examined.

Chlorogenic Acid Maintains Glucose Homeostasis through Modulating the Expression of SGLT-1,GLUT-2,and PLG in Different Intestinal Segments of Sprague-Dawley Rats Fed a High-Fat Diet

Objective To reveal the effects and related mechanisms of chlorogenic acid(CGA)on intestinal glucose homeostasis.Methods Forty male Sprague-Dawley rats were randomly and equally divided into four groups:normal chow(NC),high-fat diet(HFD),HFD with low-dose CGA(20 mg/kg,HFD-LC),and HFD with high-dose CGA(90 mg/kg,HFD-HC).The oral glucose tolerance test was performed,and fast serum insulin(FSI)was detected using an enzyme-linked immunosorbent assay.The m RNA expression levels of glucose transporters(Sglt-1 and Glut-2)and proglucagon(Plg)in different intestinal segments(the duodenum,jejunum,ileum,and colon)were analyzed using quantitative real-time polymerase chain reaction.SGLT-1 protein and the morphology of epithelial cells in the duodenum and jejunum was localized by using immunofluorescence.Results At both doses,CGA ameliorated the HFD-induced body weight gain,maintained FSI,and increased postprandial 30-min glucagon-like peptide 1 secretion.High-dose CGA inhibited the HFD-induced elevation in Sglt-1 expression.Both CGA doses normalized the HFD-induced downregulation of Glut-2 and elevated the expression of Plg in all four intestinal segments.Conclusion An HFD can cause a glucose metabolism disorder in the rat intestine and affect body glucose homeostasis.CGA can modify intestinal glucose metabolism by regulating the expression of intestinal glucose transporters and Plg,thereby controlling the levels of blood glucose and insulin to maintain glucose homeostasis.

Liver-specific Reduction of Mfn2 Protein by RNAi Results in Impaired Glycometabolism and Lipid Homeostasis in BALB/c Mice

Mitofusin-2 （Mfn2） gene expression is positively correlated with insulin sensitivity in patients with type 2 diabetes. However, it is unclear if Mfn2 is involved in carbohydrate metabolism and lipid homeostasis. In order to investigate the specific functions of Mfn2 in glycometabolism and lipid homeostasis in BALB/c mice, a RNA interference technique-mediated hydrodynamic injection was developed, in which short hairpin RNAs （shRNAs） were used to inhibit the Mfn2 expression in vivo. Seventy-two mice were randomly divided into two groups： the Mfn2 reduction group （Mfn2/shRNA） and the negative control group （NC）. Intraperitoneal glucose tolerance tests and intraperitoneal insulin tolerance tests were used to evaluate glycometabolism and insulin sensitivity. D-（3-3H） glucose or 3H2O was injected into the tail vein or intraperitoneally to facilitate the calculation of the rate of hepatic glucose production and fatty acid synthesis in vivo. The results showed that, in Mfn2/shRNA mice, the liver Mfn2 protein was significantly decreased, and fasting blood glucose concentrations were increased by approximately 48%, when compared with the NC mice. In parallel with the changes in fasting glucose levels, hepatic glucose production was significantly elevated in Mfn2/shRNA mice. When insulin was administrated, these mice exhibited impaired insulin tolerance. It was also found that the reduction of Mfn2 markedly decreased the rate of fatty acid synthesis in the liver, and the Mfn2/shRNA mice exhibited hypertriglyceridema. Taken together, our results indicate that Mfn2 plays an important role in maintaining glucose and lipid homeostasis, and in the development of insulin resistance in vivo.

Fenvalerate-induced Alterations in Calcium Homeostasis in Rat Ovary

Objective To observe the effects of fenv＇,derate on calcium homeostasis in rat ovary. Methods Female SpragueDawley rats were orally given fenvalerate at dally doses of 0.00, 1.91, 9.55, and 31.80 mg/kg for four weeks. The ovary ultrastucture was observed by electron microscopy. Serum free calcium concentration was measured by atomic absorption spectrophotometry. The activities of phosphorylase a in rat ovary were evaluated by the chromatometry. The total content of calmodulin in ovary was estimated by ELISA at each stage of estrous cycle. Radioimmunoassay （R/A） was used to evaluate the level of serum progesterone. Results Histopathologically, damages of ovarian corpus luteum cells were observed. An increase in serum fi＇ee calcium concentration was observed in rats treated with 31.80mg/kg fenvalerate. The activities of phosphorylase a enhanced in all treated groups, and fenvalerate increased the total content of calmodulin significantly in estrus period. Serum progesterone levels declined in fenvalerate exposed rats in diestrus. Conclusion Fenvalerate interferes with calcium homeostasis in rat ovary. Also, the inhibitory effects of fenvalerate on serum progesterone levels may be mediated partly through calcium signals.