Key Transport Proteins Research Articles

Metagenomic analysis reveals enhanced sludge dewaterability through acidified sludge inoculation: Regulation of Fe (II) oxidation electron transport pathway

The bioleaching utilizing indigenous microbial inoculation can continuously improve the dewaterability of sludge. In this study, metagenomic analysis was innovative employed to identify the key microorganisms and functional genes that affect the dewatering performance of sludge in the bioleaching conditioning process. The results demonstrated that long-term repeated inoculation of acidified sludge resulted in increased abundance of many functional genes associated with the transport of carbohydrate and amino acid. Additionally, genes encoding key iron transport proteins (such as afuA, fhuC, and fhuD) and genes related to electron transfer carriers in ferrous iron oxidation process (such as rus and cyc2) were significantly enriched, thereby promoting the improvement of sludge dewatering performance through enhanced iron oxidation. Notably, Acidithiobacillus, Betaproteobacteria, and Hyphomicrobium were the major sources of functional genes. This study reveals the microscopic mechanisms underlying the improvement of sludge dewaterability through bioleaching based on mixed culture from a novel perspective of gene metabolism.

Molecular interaction of a protease inhibitor, leupeptin, with human serum albumin: Insights from calorimetry, spectroscopy, microscopy, and computational approaches

Leupeptin (LPN) possesses anti-inflammatory and inhibitory effects on periodontitis and gingivitis, and it also inhibits human coronavirus and SARS-CoV-2 in cells. The characterisation of its interaction with human serum albumin (HSA), the key transport protein in the blood circulation of the human body, contributes essential information to the drug's pharmacokinetic properties. Various techniques, such as isothermal titration calorimetry (ITC), circular dichroism (CD) spectroscopy, atomic force microscopy (AFM), molecular docking, and molecular dynamics simulation (MDS), were employed to characterise the LPN-HSA interaction. The ITC result revealed a moderate binding affinity in the LPN-HSA interaction with a binding constant (Ka) value of 4.27 ± 0.27 × 106 M−1. The thermodynamic analysis indicated that LPN binding to HSA was spontaneous, resulting from a negative Gibbs free energy change (∆G° = − 37.91 ± 0.04 kJ mol−1) and involving an exothermic reaction due to a combination of a negative enthalpy change (∆H° = − 11.4 ± 0.9 kJ mol−1) and a positive entropy change (∆S° = 88.82 ± 3.4 J mol−1K−1). The HSA secondary structure remained unaltered upon the addition of LPN, as evident from the far-UV CD results. AFM results showed HSA morphological changes induced by LPN binding due to the occurrence of aggregates in the LPN-HSA complex. Molecular docking results predicted that LPN preferably binds to site III of HSA, involving hydrogen bonds, electrostatic, van der Waals forces, and hydrophobic forces. The MDS demonstrated a slight deviation and fluctuation, which supported the overall stability of the LPN-HSA system. Thus, these findings provide additional information on the pharmacokinetics of this drug and contribute to designing new drugs for clinical use, particularly those related to inflammatory diseases.

Advance in Iron Metabolism, Oxidative Stress and Cellular Dysfunction in Experimental and Human Kidney Diseases.

Kidney diseases pose a significant global health issue, frequently resulting in the gradual decline of renal function and eventually leading to end-stage renal failure. Abnormal iron metabolism and oxidative stress-mediated cellular dysfunction facilitates the advancement of kidney diseases. Iron homeostasis is strictly regulated in the body, and disturbance in this regulatory system results in abnormal iron accumulation or deficiency, both of which are associated with the pathogenesis of kidney diseases. Iron overload promotes the production of reactive oxygen species (ROS) through the Fenton reaction, resulting in oxidative damage to cellular molecules and impaired cellular function. Increased oxidative stress can also influence iron metabolism through upregulation of iron regulatory proteins and altering the expression and activity of key iron transport and storage proteins. This creates a harmful cycle in which abnormal iron metabolism and oxidative stress perpetuate each other, ultimately contributing to the advancement of kidney diseases. The crosstalk of iron metabolism and oxidative stress involves multiple signaling pathways, such as hypoxia-inducible factor (HIF) and nuclear factor erythroid 2-related factor 2 (Nrf2) pathways. This review delves into the functions and mechanisms of iron metabolism and oxidative stress, along with the intricate relationship between these two factors in the context of kidney diseases. Understanding the underlying mechanisms should help to identify potential therapeutic targets and develop novel and effective therapeutic strategies to combat the burden of kidney diseases.

The osmoregulatory mechanism in response to hypoosmotic stress and the key role of ABCC1 in osmoregulation in the mud crab, Scylla paramamosain

Scylla paramamosain is an important mariculture animal. In the present study, we examined the physiological and biochemical characteristics of juvenile S. paramamosain under hypoosmotic stress and further verified the function of ABCC1, a key transport protein in gill tissue. The results showed that Na+/K+-ATPase, Ca2+-ATPase, and Na+/K+/2Cl- cotransporter in gill tissues increased first and then decreased. In addition, SOD and CAT activities also began to gradually increase, protecting gill tissues from oxidative damage. The hemolymph osmolarity decreased rapidly from 792 mOsm/kg to 560 mOsm/kg within 6 h, and then rose to 626.25 mOsm/kg at 48 h, and then remained stable. At the same time, Na+, Cl-, K+, and Ca2+ concentrations were decreased to varying degrees. There were significant changes in free amino acids such as aspartic acid, glutamic acid, and asparagine in hemolymph in response to acute salt depletion. By injection of ABCC1 inhibitor/activator, it was found that while ABCC1 transporter activity in the MK-571 group showed a decreasing trend at 9 h, Na+/K+ -ATPase activity began to increase and reached a peak at 48 h. Compared with the control group, the levels of aspartic acid, glutamic acid, asparagine, glycine, arginine, alanine, lysine, and proline in the MK-571 group showed significant differences at 6 h; Significant differences in glutamate, asparagine, arginine, alanine, lysine, and proline appeared at 12 h in the Thiethylperazine group. These results suggested that the dynamic changes of gill ion transport enzymes, antioxidant enzymes, inorganic ions, and free amino acids in hemolymph occurred in S. paramamosain under hypoosmotic stress, and the ABCC1 transporter played an important role in this regulatory process.

ZmARF1 positively regulates low phosphorus stress tolerance via modulating lateral root development in maize.

Phosphorus (P) deficiency is one of the most critical factors for plant growth and productivity, including its inhibition of lateral root initiation. Auxin response factors (ARFs) play crucial roles in root development via auxin signaling mediated by genetic pathways. In this study, we found that the transcription factor ZmARF1 was associated with low inorganic phosphate (Pi) stress-related traits in maize. This superior root morphology and greater phosphate stress tolerance could be ascribed to the overexpression of ZmARF1. The knock out mutant zmarf1 had shorter primary roots, fewer root tip number, and lower root volume and surface area. Transcriptomic data indicate that ZmLBD1, a direct downstream target gene, is involved in lateral root development, which enhances phosphate starvation tolerance. A transcriptional activation assay revealed that ZmARF1 specifically binds to the GC-box motif in the promoter of ZmLBD1 and activates its expression. Moreover, ZmARF1 positively regulates the expression of ZmPHR1, ZmPHT1;2, and ZmPHO2, which are key transporters of Pi in maize. We propose that ZmARF1 promotes the transcription of ZmLBD1 to modulate lateral root development and Pi-starvation induced (PSI) genes to regulate phosphate mobilization and homeostasis under phosphorus starvation. In addition, ZmERF2 specifically binds to the ABRE motif of the promoter of ZmARF1 and represses its expression. Collectively, the findings of this study revealed that ZmARF1 is a pivotal factor that modulates root development and confers low-Pi stress tolerance through the transcriptional regulation of the biological function of ZmLBD1 and the expression of key Pi transport proteins.

#5837 MOLECULAR AND FUNCTIONAL CHARACTERIZATION OF THE PERITONEAL MESOTHELIAL AND ENDOTHELIAL CELL BARRIER

Abstract Background and Aims Solute transport across cellular levels is mediated by paracellular and transcellular pores, channels and carriers. Knowledge on their cell specific expression, regulation and function in peritoneal dialysis (PD) is limited. Method Polarized primary (HPMC) and immortalized human peritoneal mesothelial (MeT-5A), microvascular (HCMEC) and umbilical vein endothelial (HUVEC) cells underwent RNA sequencing and gene enrichment analysis. Key findings were confirmed by western blotting (WB), confocal and single molecule localization microscopy (SMLM). Arteriolar transcriptome and proteome datasets of non-CKD, CKD5 and PD children (n = 6/group) underwent targeted transport pathways analysis. Key transporter proteins were quantified in parietal peritoneum (n = 20–30/group) and related to peritoneal transport rates available in 23 children. Barrier function was studied in vitro (transepithelial electrical resistance, TER, and molecular weight dependent flux), ex vivo and in vivo. Results Junction, transmembrane and transcytotic transporter expression was highly cell type specific on RNA and protein level. Sealing Claudin (CLDN)1 was only expressed in mesothelial cells, sealing CLDN5 in endothelial cells. TER which reflects functional junction status, was 50% lower in HCMEC compared to HUVEC and the two mesothelial cell lines; 4- and 10-kDa dextran permeability was higher in HCMEC. At nanoscale, SMLM yielded highest distance of junction molecules in HCMEC and different spatial organisation, reflecting the low TER. In sheep peritoneum, removal of the mesothelium abolished tissue TER. In mice, short-term LPS exposure to modify mesothelial permeability resulted in faster transperitoneal 4- and 70-kDa dextran transport, suggesting a specific barrier function of the mesothelium. In human parietal peritoneum, total endothelial surface area per section was age dependently 1.5- to 2-fold higher than the respective mesothelial surface area, and further increased with double-chamber PD fluid, due to major hypervascularisation. Tight junction proteins CLDN-1 to -5, and -15, ZO-1, occludin and tricellulin, and transcellular transporter ENaC, PIT1, and SGLT1 were detected in mesothelial and arteriolar endothelial cells. In CKD mesothelial CLDN-1 and arteriolar CLDN-2 and -3 were more abundant than in non-CKD controls, and PD patients had highest mesothelial and arteriolar CLDN-1 and mesothelial CLDN-2, lower mesothelial and arteriolar claudin-3 and lower arteriolar ENaC. D/P creatinine and D/D0 glucose correlated with arteriolar CLDN-2 and with mesothelial CLDN-4 and -15, which are pore forming junctions, and for creatinine with mesothelial PIT-1, a sodium/phosphate co-transporter. Conclusion We provide the first in-depth analysis of peritoneal determinants of solute transport. The molecular expression pattern of the mesothelial and endothelial cell barrier and transporter proteins differs substantially. Disruption of the mesothelial layer increases peritoneal solute absorption rate. In the human peritoneum, peritoneal transporter status is modified by CKD and PD, and pore forming junction proteins are associated with dialytic solute transport function. These represent a promising target for therapeutic intervention.

Furosemide rescues hypercalciuria in familial hypomagnesaemia with hypercalciuria and nephrocalcinosis model

Aim: Impaired calcium homeostasis limits life expectancy and quality in familial hypomagnesaemia with hypercalciuria and nephrocalcinosis (FHHNC). This rare disease is caused by loss-of-function mutations in CLDN16 or CLDN19 genes leading to impaired paracellular reabsorption of divalent cations along the cortical thick ascending limb (cTAL). The ensuing late distal nephron and collecting duct system partially compensate for the defect in cTAL by increased transcellular Ca 2+ reabsorption via the luminal transient receptor potential channel V5 (TRPV5), as well as basolateral plasma membrane calcium ATPase (PMCA) and sodium-potassium exchanger (NCX1). The loop diuretic furosemide induces compensatory activation in these distal segments due to blockade of NaCl and divalent cation reabsorption in the preceeding TAL. Although furosemide enhances urinary calcium excretion via inhibition of the aforementioned cTAL in general population, this effect is not expected in FHHNC patients with already severely impaired Ca 2+ transport in the cTAL. The present study follows the hypothesis that furosemide may alleviate hypercalciuria in this disease by activation of the distal transcellular Ca 2+ transport proteins. Methods: Cldn16-deficient mice (Cldn16-/- ) served as a FHHNC model. Wild-type (WT) and Cldn16-/- mice were treated with furosemide (7 days of 40 mg/kg bw) or vehicle. We assessed renal electrolyte handling (metabolic cages) and key divalent transport proteins. Results: Cldn16-/- mice show increased Ca 2+ excretion than WT and compensatory stimulation of Cldn2 in the proximal tubule, as well as of TRPV5, and NCX1 in the distal nephron at baseline. Furosemide reduced hypercalciuria in Cldn16-/- mice and enhanced TRPV5 and PMCA levels in Cldn16-/- but not in WT mice. Conclusions: Furosemide alleviated hypercalciuria in a mouse FHHNC model, likely via stimulation of transcellular luminal and basolateral Ca 2+ transport systems in the distal nephron and collecting duct. These results may have a clinical implication in FHHNC patients. No conflict of interests This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Consideration of Kinase Inhibitors for the Treatment of Hydrocephalus.

Hydrocephalus is a devastating condition characterized by excess cerebrospinal fluid (CSF) in the brain. Currently, the only effective treatment is surgical intervention, usually involving shunt placement, a procedure prone to malfunction, blockage, and infection that requires additional, often repetitive, surgeries. There are no long-term pharmaceutical treatments for hydrocephalus. To initiate an intelligent drug design, it is necessary to understand the biochemical changes underlying the pathology of this chronic condition. One potential commonality in the various forms of hydrocephalus is an imbalance in fluid-electrolyte homeostasis. The choroid plexus, a complex tissue found in the brain ventricles, is one of the most secretory tissues in the body, producing approximately 500 mL of CSF per day in an adult human. In this manuscript, two key transport proteins of the choroid plexus epithelial cells, transient receptor potential vanilloid 4 and sodium, potassium, 2 chloride co-transporter 1, will be considered. Both appear to play key roles in CSF production, and their inhibition or genetic manipulation has been shown to affect CSF volume. As with most transporters, these proteins are regulated by kinases. Therefore, specific kinase inhibitors are also potential targets for the development of pharmaceuticals to treat hydrocephalus.

Furosemide rescues hypercalciuria in familial hypomagnesaemia with hypercalciuria and nephrocalcinosis model.

Perturbed calcium homeostasis limits life expectancy in familial hypomagnesaemia with hypercalciuria and nephrocalcinosis (FHHNC). This rare disease occurs by loss-of-function mutations in CLDN16 or CLDN19 genes, causing impaired paracellular reabsorption of divalent cations along the cortical thick ascending limb (cTAL). Only partial compensation takes place in the ensuing late distal convoluted tubule, connecting tubule, and collecting duct, where the luminal transient receptor potential channel V5 (TRPV5), as well as basolateral plasma membrane calcium ATPase (PMCA) and sodium-potassium exchanger (NCX1) mediate transcellular Ca2+ reabsorption. The loop diuretic furosemide induces compensatory activation in these distal segments. Normally, furosemide enhances urinary calcium excretion via inhibition of the aforementioned cTAL. As Ca2+ reabsorption in the cTAL is already severely impaired in FHHNC patients, furosemide may alleviate hypercalciuria in this disease by activation of the distal transcellular Ca2+ transport proteins. Cldn16-deficient mice (Cldn16-/- ) served as a FHHNC model. Wild-type (WT) and Cldn16-/- mice were treated with furosemide (7 days of 40 mg/kg bw) or vehicle. We assessed renal electrolyte handling (metabolic cages) and key divalent transport proteins. Cldn16-/- mice show higher Ca2+ excretion than WT and compensatory stimulation of Cldn2, TRPV5, and NCX1 at baseline. Furosemide reduced hypercalciuria in Cldn16-/- mice and enhanced TRPV5 and PMCA levels in Cldn16-/- but not in WT mice. Furosemide significantly reduces hypercalciuria, likely via upregulation of luminal and basolateral Ca2+ transport systems in the distal nephron and collecting duct in this model for FHHNC.

Mechanisms of proton pump inhibitor-induced hypomagnesemia.

Proton pump inhibitors (PPIs) reliably suppress gastric acid secretion and are therefore the first‐line treatment for gastric acid‐related disorders. Hypomagnesemia (serum magnesium [Mg2+] <0.7 mmol/L) is a commonly reported side effect of PPIs. Clinical reports demonstrate that urinary Mg2+ excretion is low in PPI users with hypomagnesemia, suggesting a compensatory mechanism by the kidney for malabsorption of Mg2+ in the intestines. However, the exact mechanism by which PPIs cause impaired Mg2+ absorption is still unknown. In this review, we show that current experimental evidence points toward reduced Mg2+ solubility in the intestinal lumen. Moreover, the absorption pathways in both the small intestine and the colon may be reduced by changes in the expression and activity of key transporter proteins. Additionally, the gut microbiome may contribute to the development of PPI‐induced hypomagnesemia, as PPI use affects the composition of the gut microbiome. In this review, we argue that the increase of the luminal pH during PPI treatment may contribute to several of these mechanisms. Considering the fact that bacterial fermentation of dietary fibers results in luminal acidification, we propose that targeting the gut microbiome using dietary intervention might be a promising treatment strategy to restore hypomagnesemia in PPI users.

Empagliflozin Accelerates Escape from Vasopressin in Rats

The syndrome of inappropriate antidiuretic hormone secretion (SIADH) consists of unregulated, elevated vasopressin levels and can lead to hyponatremia. Vasopressin escape is the body’s defense mechanism to limit hyponatremia. The sodium‐glucose transporter (SGLT‐2) inhibitor, empagliflozin, was identified as a treatment for hyponatremia; however, the mechanism of empagliflozin’s effect is unclear. This project investigates empagliflozin’s impact on vasopressin escape in rats with the hypothesis that empagliflozin accelerates escape via key transport protein alteration. Rats were implanted with vasopressin mini‐pumps to mimic SIADH. The first cohort consisted of male rats and a second cohort compared responses in female rats. On day 2, half the rats were given empagliflozin (~15 mg/kg) via diet. Rats were sacrificed on days 7 or 14. Blood and kidney tissue were collected. Total Aquaporin‐2 (AQP2), pSer‐Aquaporin‐2, and NKCC2 were analyzed by western blot. At day 7, serum sodium levels for the female rats were: empagliflozin 110.1+1.7 mmol/L vs 93.3+1.1 mmol/L for the controls (n=5, p&lt;0.001). Serum sodium levels for the male rats were: empagliflozin 136.0+4.8 mmol/L vs 121.4+3.0 mmol/L for the controls (n=4, p&lt;0.05). NKCC2 abundance in the empagliflozin group was 60% lower than control on day 7 (n=5, p&lt;0.05) for female rats, and 77% lower than control in male rats (n =4, p&lt;0.001). Because changes in the AQP2 levels were similar between the sexes, these data were combined. Total AQP2 abundance was 2.3 fold increased in the empagliflozin group on day 7 and 8 fold greater in the empagliflozin group at day 14 (n=9) compared to the control group. Both pSer256‐AQP2 and pSer261‐AQP2 were increased in the empagliflozin groups at both 7 and 14 days vs their respective control groups. pSer256‐AQP2 increased 2.1 (day 7) and 8.5 fold (day 14); pSer261‐AQP2 increased 3.2 fold (day 7) and 5.0 fold (day 14) (n=9/group). We conclude that empagliflozin accelerates vasopressin escape during SIADH primarily through a decrease in NKCC2 abundance in both male and female rats. This will hasten recovery from hyponatremia in SIADH.

Effect of Enterohepatic Circulation on the Accumulation of Per- and Polyfluoroalkyl Substances: Evidence from Experimental and Computational Studies.

The pharmacokinetic characteristics of per- and polyfluoroalkyl substances (PFAS) affect their distribution and bioaccumulation in biological systems. The enterohepatic circulation leads to reabsorption of certain chemicals from bile back into blood and the liver and thus influences their elimination, yet its influence on PFAS bioaccumulation remains unclear. We explored the role of enterohepatic circulation in PFAS bioaccumulation by examining tissue distribution of various PFAS in wild fish and a rat model. Computational models were used to determine the reabsorbed fractions of PFAS by calculating binding affinities of PFAS for key transporter proteins of enterohepatic circulation. The results indicated that higher concentrations were observed in blood, the liver, and bile compared to other tissues for some PFAS in fish. Furthermore, exposure to a PFAS mixture on the rat model showed that the reabsorption phenomenon appeared during 8-12 h for most long-chain PFAS. Molecular docking calculations suggest that PFAS can bind to key transporter proteins via electrostatic and hydrophobic interactions. Further regression analysis adds support to the hypothesis that binding affinity of the apical sodium-dependent bile acid transporter is the most important variable to predict the human half-lives of PFAS. This study demonstrated the critical role of enterohepatic circulation in reabsorption, distribution, and accumulation of PFAS.

Protein Crystallization of Two Recombinant Lpt Proteins.

The prerequisite for 3D structure determination of macromolecules via X-ray crystallography is well-ordered, diffracting crystals. Here, we report the recombinant production, biophysical/biochemical protein sample characterization, and vapor diffusion sitting drop crystallization protocols for two lipopolysaccharide transport proteins: LptH from Pseudomonas aeruginosa (Pa-LptH) and an inactive LptC mutant (G153R) from Escherichia coli (EcLptC24-191G153R).

Role of pharmacogenetic factors in the development of side effects of methotrexate in the treatment of malignant tumors: A review

Methotrexate (MTX) is one of the main chemotherapeutic agents that has determined the high effectiveness of protocols for the treatment of acute lymphoblastic leukemia and non-Hodgkin lymphomas. The reverse side of the high anti-tumor activity of MTX is the adverse reactions, which require accompanying preventive therapy. But even modern accompanying therapy in some cases does not avoid severe toxicity from the skin and mucous membranes, nervous system, kidneys, liver. MTX pharmacokinetics exhibits significant individual variability, which may be a reflection of genetic variability. Numerous pharmacogenetic studies have evaluated the effect of polymorphism of various genes involved in MTX metabolism on MTX pharmacokinetics and the development of toxic manifestations in order to improve patient outcomes and decrease drug toxicity. This review presents impact of key metabolic MTX genes (ATIC, DHFR, GGH, FPGS, MTHFR, MTR, MTRR, TYMS) and transporter proteins genes (ABCB1, ABCG2, ABCC2, ABCC4, SLC19A1, SLCO1B1) in the development of MTX side effects. Polymorphic markers in SLCO1B1 gene have the most influence with MTX pharmacokinetic.

Change of zinc mobilization and gene expression of key zinc transport proteins between the yolk sac membrane and liver of duck embryonic developing

Zinc (Zn) deposition in egg yolk is essential for the rapid growth and complete development of the avian embryo. Thus, it is crucial to obtain maximal Zn mobilization at an appropriate time during development in favor of the survival of avian embryos. The aim of this study was to study the developmental change of Zn mobilization and gene expression related to key Zn transport proteins between the yolk sac membrane and embryonic liver from the incubation d 17 (E17) to d 32 (E32) during duck embryonic developing. The weights of duck embryo, embryo without yolk sac, and embryonic liver increased as well as the yolk sac weight decreased linearly (P < 0.0001) when incubation day increased. The Zn concentration in the yolk sac did not change from E17 to E29 and only declined significantly from E29 to E32 of duck embryos, while hepatic Zn level decreased linearly as with the increased incubation time (P < 0.01). When the incubation day increased, the decreased Zn amount in the yolk sac and the increased Zn amount in the embryonic liver were observed (P < 0.0001). The calculated transfer-out rate of Zn in the yolk sac and transfer-in rate of Zn in livers were both increased from E23-26 to E29-32 (P < 0.01). Among E17, E23 and E29, the solute carrier family 39 member (ZIP) of ZIP10, ZIP13, and ZIP14 genes mRNA expressions were increased in yolk sac membrane but were decreased in the embryonic liver, while metallothionein 1 mRNA expression was increased both in the yolk sac membrane and liver (P < 0.05). In conclusion, yolk sac membrane and embryonic liver tissues displayed the similar developmental patterns of Zn mobilization and metallothionein 1 mRNA expression from E17 to E32 during duck embryonic developing. The appropriate time of the maximal rate of Zn mobilization were observed between E29 and E32 of duck embryo, associated with the significant changes of gene expression related to some key Zn transport proteins on E29 in yolk sac membrane and liver tissues.

Regulation of Melanophilin (Mlph) gene expression by the glucocorticoid receptor (GR)

Mlph plays a crucial role in regulating skin pigmentation through the melanosome transport process. Although Mlph is a major component involved in melanosome transport, the mechanism that regulates the expression of the Mlph gene has not been identified. In this study, we demonstrate that Mlph expression is regulated by the glucocorticoid receptor (GR). Alteration of GR activity using a specific GR agonist or antagonist only regulated the expression of Mlph among the 3 key melanosome transport proteins. Translocation of GR from the cytosol into the nucleus following Dex treatment was confirmed by separating the cytosol and nuclear fractions and by immunofluorescence staining. In ChIP assays, Dex induced GR binding to the Mlph promoter and we determined that Dex induced the GR binding motif on the Mlph promoter. Our findings contribute to understanding the regulation of Mlph expression and to the novel role of GR in Mlph gene expression.

Efficiency of transporter genes and proteins in hyperaccumulator plants for metals tolerance in wastewater treatment: Sustainable technique for metal detoxification

Environmental contamination of heavy metals is now becoming increasingly a concern and a significant problem due to its harmful effects worldwide. The plant-meditated approach is encouraging to eliminate toxins avoiding side effects from polluted wastewater. For the development of appropriate plant species for the mechanisms of heavy metal absorption, transport, detoxification, identification, and signaling pathways would be important facts. Transporter genes like ATP-phosphoribosyl transferase (ATP-PRT), Yellow Stripe-like (YSL), NAS (nicotinamide synthase), SAMS (S-adenosyl-methionine synthetase), FER (ferritin Fe (III) binding), HMA (heavy metal ATPase), IREG (iron-regulated transporter), and proteins like cation diffusion facilitators (CDF), ZRT, IRT-like protein (ZIP), and natural resistance-associated macrophage protein (NRAMP) are active in heavy metal accumulation, translocalisation, sequestration, and resistance. Besides, chelating agents and metabolites can be used either to increase heavy metal bioavailability, which facilitates heavy metal accumulation in plants and further promote plant growth and fitness. This review paper addresses key roles and potential transporter genes and proteins for the remediation of heavy metals from hyperaccumulator plants. This review specifically focuses on the efficacy of transporter genes and proteins in hyperaccumulator plants in metal restoration, discussing the use of these plants for wastewater treatment processes. • Discusses the efficiency of hyperaccumulator plant for removal of metals. • Summarizes transporter gene and proteins in heavy metal uptake and tolerance. • Proposes improved prospects for wastewater treatment.

Roles of Key Ion Channels and Transport Proteins in Age-Related Hearing Loss.

The auditory system is a fascinating sensory organ that overall, converts sound signals to electrical signals of the nervous system. Initially, sound energy is converted to mechanical energy via amplification processes in the middle ear, followed by transduction of mechanical movements of the oval window into electrochemical signals in the cochlear hair cells, and finally, neural signals travel to the central auditory system, via the auditory division of the 8th cranial nerve. The majority of people above 60 years have some form of age-related hearing loss, also known as presbycusis. However, the biological mechanisms of presbycusis are complex and not yet fully delineated. In the present article, we highlight ion channels and transport proteins, which are integral for the proper functioning of the auditory system, facilitating the diffusion of various ions across auditory structures for signal transduction and processing. Like most other physiological systems, hearing abilities decline with age, hence, it is imperative to fully understand inner ear aging changes, so ion channel functions should be further investigated in the aging cochlea. In this review article, we discuss key various ion channels in the auditory system and how their functions change with age. Understanding the roles of ion channels in auditory processing could enhance the development of potential biotherapies for age-related hearing loss.

Characterization of drug binding with alpha1-acid glycoprotein in clinical samples using ultrafast affinity extraction

Many drugs bind to serum transport proteins, which can affect both drug distribution and activity in the body. α1-Acid glycoprotein (AGP) is a key transport protein for basic and neutral drugs. Both elevated levels and altered glycosylation patterns of AGP have been seen in clinical conditions such as systemic lupus erythematosus (SLE). This study developed, optimized, and used the method of ultrafast affinity extraction (UAE) to examine whether these changes in AGP are associated with changes in the binding by some drugs to this transport protein. This approach used affinity microcolumns to capture and measure, in serum, the free fractions of several drugs known to bind AGP. These measurements were made with pooled normal control serum and serum samples from individuals with SLE. Immunoaffinity chromatography was used to obtain the content of AGP and HSA in these samples, and CE was used to examine the glycoform pattern for AGP in each serum sample. The free drug fractions measured for normal control serum ranged from 3.5 to 29.1%, in agreement with the results of ultrafiltration, and provided binding constants of ~105–106 M−1 for the given drugs with AGP at 37⁰C. Analysis of a screening set of SLE serum samples by UAE gave decreased free fractions (relative change, 12-55%) vs normal serum when spiked with the same types and amounts of drugs. These changes were related in some cases to AGP content, with some SLE samples having AGP levels 1.3- to 2.1-fold above the upper end of the normal range. In other cases, the changes in free fractions appeared to be linked to alterations in the glycoforms and binding constants of AGP, with some affinities differing by 1.2- to 1.5-fold vs normal AGP. This approach can be employed with other solute-protein systems and to investigate binding by other drugs or transport proteins directly in clinical samples.

The Role of MicroRNAs in Lung Cancer Metabolism.

Simple SummaryTumor cells exhibit dysregulation in metabolic activities compared with normal cells. Lung cancer is one of the most commonly diagnosed cancers globally. Studies have shown that miRNAs play important roles in metabolic reprogramming and our review aims to identify the roles of different miRNAs in metabolic aberrancies of lung cancer. Potentially, a few miRNAs could serve as biomarkers and therapeutic avenues depending on their significance to lung cancer metabolism.MicroRNAs (miRNAs) are short-strand non-coding RNAs that are responsible for post-transcriptional regulation of many biological processes. Their differential expression is important in supporting tumorigenesis by causing dysregulation in normal biological functions including cell proliferation, apoptosis, metastasis and invasion and cellular metabolism. Cellular metabolic processes are a tightly regulated mechanism. However, cancer cells have adapted features to circumvent these regulations, recognizing metabolic reprogramming as an important hallmark of cancer. The miRNA expression profile may differ between localized lung cancers, advanced lung cancers and solid tumors, which lead to a varying extent of metabolic deregulation. Emerging evidence has shown the relationship between the differential expression of miRNAs with lung cancer metabolic reprogramming in perpetuating tumorigenesis. This review provides an insight into the role of different miRNAs in lung cancer metabolic reprogramming by targeting key enzymes, transporter proteins or regulatory components alongside metabolic signaling pathways. These discussions would allow a deeper understanding of the importance of miRNAs in tumor progression therefore providing new avenues for diagnostic, therapeutic and disease management applications.