Multipronged regulation of autophagy and apoptosis: emerging role of TRIM proteins.

TRIM proteins are characterized by their conserved N-terminal RING, B-box, and coiled-coil domains. These proteins are efficient regulators of autophagy, apoptosis, and innate immune responses and confer immunity against viruses and bacteria. TRIMs function as receptors or scaffold proteins that target substrates for autophagy-mediated degradation. Most TRIMs interact with the BECN1-ULK1 complex to form TRIMosomes, thereby efficiently targeting substrates to autophagosomes. They regulate the functions of ATG proteins through physical interactions or ubiquitination. TRIMs affect the lipidation of MAP1LC3B1 to form MAP1LC3B2, which is a prerequisite for phagophore and autophagosome formation. In addition, they regulate MTOR kinase and TFEB, thereby regulating the expression of ATG genes. TRIM proteins are efficient regulators of apoptosis and are crucial for regulating cell proliferation and tumor formation. Many TRIM proteins regulate intrinsic and extrinsic apoptosis via the cell surface receptors TGFBR2, TNFRSF1A, and FAS. Mitochondria modulate the anti- and proapoptotic functions of BCL2, BAX, BAK1, and CYCS. These proteins use a multipronged approach to regulate the intrinsic and extrinsic apoptotic pathways, culminating in coordinated activation or inhibition of the initiator and executor CASPs. Furthermore, TRIMs can have a dual effect in determining cell fate and are therefore crucial for cellular homeostasis. In this review, we discuss mechanistic insights into the role of TRIM proteins in regulating autophagy and apoptosis, which can be used to better understand cellular physiology. These findings can be used to develop therapeutic interventions to prevent or treat multiple genetic and infectious diseases.

Thymoquinone Ameliorates Carfilzomib-Induced Renal Impairment by Modulating Oxidative Stress Markers, Inflammatory/Apoptotic Mediators, and Augmenting Nrf2 in Rats.

Chemotherapy-induced kidney damage is an emerging problem that restricts cancer treatment effectiveness. The proteasome inhibitor carfilzomib (CFZ) is primarily used to treat multiple myeloma and has been associated with severe renal injury in humans. CFZ-induced nephrotoxicity remains an unmet medical need, and there is an urgent need to find and develop a nephroprotective and antioxidant therapy for this condition. Thymoquinone (TQ) is a bioactive compound that has been isolated from Nigella sativa seeds. It has a wide range of pharmacological properties. Therefore, this experimental design aimed to study the effectiveness of TQ against CFZ-induced renal toxicity in rats. The first group of rats was a normal control (CNT); the second group received CFZ (4 mg/kg b.w.); the third and fourth groups received TQ (10 and 20 mg/kg b.w.) 2 h before receiving CFZ; the fifth group received only TQ (20 mg/kg b.w.). This experiment was conducted for 16 days, and at the end of the experiment, blood samples and kidney tissue were collected for biochemical assays. The results indicated that administration of CFZ significantly enhanced serum marker levels such as BUN, creatinine, and uric acid in the CFZ group. Similarly, it was also noticed that CFZ administration induced oxidative stress by reducing antioxidants (GSH) and antioxidant enzymes (CAT and SOD) and increasing lipid peroxidation. CFZ treatment also enhanced the expression of IL-1ß, IL-6, and TNF-α production. Moreover, CFZ increased caspase-3 concentrations and reduced Nrf2 expression in the CFZ-administered group. However, treatment with 10 and 20 mg/kg TQ significantly decreased serum markers and increased antioxidant enzymes. TQ treatment considerably reduced IL-1ß, IL-6, TNF-α, and caspase-3 concentrations. Overall, this biochemical estimation was also supported by histopathological outcomes. This study revealed that TQ administration significantly mitigated the negative effects of CFZ treatment on Nrf2 expression. Thus, it indicates that TQ may have utility as a potential drug to prevent CFZ-induced nephrotoxicity in the future.

Nephroprotective Effect of Diosmin against Cisplatin-Induced Kidney Damage by Modulating IL-1ß, IL-6, TNFα and Renal Oxidative Damage.

Cisplatin (CP) is a platinum compound of the alkylating agent class that is used for the treatment of various types of cancer. However, CP treatments in cancer patients are accountable for nephrotoxicity, as it is a major adverse effect. Hence, this research study was proposed to investigate the nephroprotective effect of diosmin, a flavonoid glycoside of hesperidin derivatives against cisplatin-induced kidney damage. Wistar rats received a single intraperitoneal (i.p) injection of CP (7.5 mg/kg, i.p) to induce nephrotoxicity. The administration of CP significantly (p < 0.001) increased the markers of kidney function test (creatinine, blood urea nitrogen, and uric acid) and demonstrated histopathological changes in the kidney of the CP-treated nephrotoxic group. In addition, the CP-treated nephrotoxic group demonstrated a significant (p < 0.001) increase in lipid peroxidation (LPO) levels and depleted activities of reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD) and catalase (CAT).However, diosmin (100 and 200 mg/kg) treatments significantly reduced the elevated levels of kidney function test parameters and restored structural changes in the kidney (p < 0.001). The administration of diosmin (100 and 200 mg/kg) significantly (p < 0.001) reduced LPO levels, increased GSH content and showed improvements in the activities of GPx, GR, SOD and CAT. The markers of inflammatory cytokines such as IL-1ß, IL-6 and TNFα significantly (p < 0.001) increased in the CP-treated nephrotoxic group, whereas diosmin (100 and 200 mg/kg) treatments significantly (p < 0.001) reduced the elevated levels of these cytokines. The findings of this research demonstrate the nephroprotective effect of diosmin against CP-induced kidney damage. Therefore, we conclude that diosmin may be used as a supplement in the management of nephrotoxicity associated with CP treatments in cancer patients.

Assessment of the Phytochemical Profile, Antioxidant Capacity, and Hepatoprotective Effect of Andrographis paniculata against CCl4-Induced Liver Dysfunction in Wistar Albino Rats.

Recent studies have highlighted the necessity to thoroughly evaluate medicinal plants due to their therapeutic potential. The current study delves into the phytochemical profile, antioxidant capacity, and hepatoprotective effect of Andrographis paniculata. The investigation specifically targets its effectiveness in mitigating liver dysfunction induced by carbon tetrachloride (CCl4) in Wistar albino rats, aiming to uncover its promising role as a natural remedy for liver-related ailments. A. paniculata leaf extract was screened for phytoconstituents and antioxidant and hepatoprotective effects in Wistar albino rats against CCl4-induced liver dysfunction. Phytochemical analysis revealed the presence of flavonoids, alkaloids, and phenolic compounds in all extracts. The phenolic concentration ranged from 10.23 to 19.52 mg gallic acid per gram of the sample, while the highest flavonoid concentration was found in the ethanol fraction (8.27 mg rutin equivalents per gram). The antioxidant activity varied from 10.23 to 62.23. GC-MS analysis identified several phytochemicals including octadecanoic acid, stigmasterol, phenanthrenecarboxylic acid, and others. Effects of the ethanol extract of A. paniculata were evaluated in four groups of animals. Biochemical estimations of serum glutamine oxaloacetate transaminase, serum glutamine pyruvate transaminase, and serum bilirubin were significantly higher (p < 0.05) in the CCl4-treated group. Treatment with 300 mg/kg b.w. of the ethanol extract of A. paniculata significantly (p < 0.05) decreased these serum enzymes. Lipid peroxidation levels in carbon tetrachloride-treated animals showed a substantial (p < 0.05) rise when compared to untreated animals, while the lipid peroxidation levels were considerably (p < 0.05) reduced after treatment with ethanol extract at 300 mg/kg b.w. Liver biochemical catalase activities were significantly reduced in the carbon tetrachloride-treated animals. The results of this study conclusively demonstrate that A. paniculata extracts are a rich source of phytochemicals and possess significant antioxidant, free radical scavenging, and hepatoprotective properties.

Zingerone Attenuates Carfilzomib-Induced Cardiotoxicity in Rats through Oxidative Stress and Inflammatory Cytokine Network.

Carfilzomib (CFZ) is an anticancer medication acting as a selective proteasome inhibitor. However, it can cause cardiovascular problems, increasing mortality and morbidity. This study aimed to investigate whether zingerone (ZRN) could help reduce carfilzomib-induced cardiotoxicity in Wistar albino rats. Rats were divided into five groups of six animals each. The first group received normal saline as a control (NC); the second group received multiple doses (six) of CFZ (4 mg/kg) intraperitoneally (IP); the third and fourth groups received zingerone (50 mg/kg and 100 mg/kg oral) along with six doses of CFZ for 16 days; and the fifth group received only 100 mg/kg zingerone orally. Hematological, biochemical, oxidative stress, and histopathological studies confirmed the findings of CFZ-induced cardiotoxicity. We found that ZRN significantly attenuated the effects of CFZ on oxidative stress by enhancing the antioxidant properties of glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD). Additionally, ZRN reduces inflammatory cytokines and apoptotic markers, such as IL-1ß, IL-6, TNFα, and caspase-3. Overall, zingerone prevents carfilzomib-induced cardiotoxicity in rats, as evidenced by histopathological studies.

Triacontanol as a dynamic growth regulator for plants under diverse environmental conditions.

Triacontanol (TRIA) being an endogenous plant growth regulator facilitates numerous plant metabolic activities leading to better growth and development. Moreover, TRIA plays essential roles in alleviating the stress-accrued alterations in crop plants via modulating the activation of the stress tolerance mechanisms. The present article critically focuses on the role of exogenously applied TRIA in morpho-physiology and biochemistry of plants for example, in terms of growth, photosynthesis, enzymatic activity, biofuel synthesis, yield and quality under normal and stressful conditions. This article also enlightens the mode of action of TRIA and its interaction with other phytohormones in regulating the physio-biochemical processes in counteracting the stress-induced damages in plants.

Plant growth regulators improve growth, photosynthesis, mineral nutrient and antioxidant system under cadmium stress in menthol mint (Mentha arvensis L.).

Menthol mint (Mentha arvensis L.) cultivation is significantly affected by the heavy metals like cadmium (Cd) which also imposes severe health hazards. Two menthol mint cultivars namely Kosi and Kushal were evaluated under Cd stress conditions. Impact of plant growth regulators (PGRs) like salicylic acid (SA), gibberellic acid (GA3) and triacontanol (Tria) on Cd stress tolerance was assessed. Reduced growth, photosynthetic parameters, mineral nutrient concentration, and increased oxidative stress biomarkers like electrolyte leakage, malondialdehyde, and hydrogen peroxide contents were observed under Cd stress. Differential upregulation of proline content and antioxidant activities under Cd stress was observed in both the cultivars. Interestingly, low electrolyte leakage, lipid peroxidation, hydrogen peroxide and Cd concentration in leaves were observed in Kushal compared to Kosi. Among all the PGRs tested, SA proved to be the best in improving Cd-stress tolerance in both the cultivars but Kushal responded better than Kosi.

Salicylic acid enhances nickel stress tolerance by up-regulating antioxidant defense and glyoxalase systems in mustard plants.

The present study identified inverse relationships between nickel (Ni) levels and growth, photosynthesis and physio-biochemical attributes, but increasing levels of Ni stress enhanced methylglyoxal, electrolyte leakage, hydrogen peroxide, and lipid peroxidation content. Exogenous application of salicylic acid (SA) (10-5 M) ameliorated the ill-effects of Ni by restoring growth, photosynthesis and physio-biochemical attributes and increasing the activities of enzymes associated with antioxidant systems, especially the ascorbate-glutathione (AsA-GSH) cycle and glyoxalase system. In addition, SA application to Ni-stressed plants had an additive effect on the activities of the ascorbate and glutathione pools, and the AsA-GSH cycle enzymes (ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, glutathione reductase), superoxide dismutase, catalase, glutathione S-transferase, and osmolyte biosynthesis). This trend also follows in glyoxalase system viz. glyoxalase I and glyoxalase II enzymes. Nevertheless, exogenous SA supplementation restored mineral nutrient contents. Principal component analysis showed that growth, photosynthesis, and mineral nutrient parameters were positively correlated with each other and negatively correlated with antioxidant enzymes and oxidative stress biomarkers. Hence, SA is an alternative compound with potential application in the phytoremediation of Ni.

Antinociceptive activities of Artocarpus lacucha Buch-ham (Moraceae) and its isolated phenolic compound, catechin, in mice.

BACKGROUND: The present study evaluated the antinociceptive effect of the bark of Artocarpus lacucha, which is used for the treatment of stomachache, headache and boils in the traditional system of medicine. METHODS: The antinociceptive activity was investigated by the tail immersion, hot plate, acetic acid- & formalin-induced nociception and carrageenan-induced paw edema tests using a hydro-methanolic extract of A. lacucha bark. The plant extract was found to contain a substantial amount of phenolic compounds according to the total phenolic and flavonoid content assay. A phenolic metabolite, (+)-catechin, has been isolated using different chromatographic techniques. The compound was characterized with 1D and 2D NMR spectroscopic data. (+)-catechin, isolated from A. lacucha was assessed for antinociceptive effects swiss albino mice. Furthermore, the possible involvement of opioid receptors and ATP-sensitive K+ channel for the effect of the plant extract and (+)-catechin has been justified using naloxone and glibenclamide, respectively. RESULTS: Oral administration (p.o) of the plant extract (50-200 mg/Kg b.w.) resulted in significant thermal pain protection in the hot plate and tail immersion tests. The action of the plant extract was significantly antagonized by naloxone, a non-selective opioid antagonist, in the hot plate and tail immersion tests, which supports the involvement of opioid receptors. Both the plant extract and (+)-catechin, (50-200 mg/Kg b.w., p.o.) significantly diminished the acetic acid- & formalin-induced nociception, and carrageenan-induced paw edema. Glibenclamide, an ATP-sensitive K+ channel blocker, significantly reversed their effect in the acetic acid-induced writhing test which indicates the participation of ATP-sensitive K+ channel system. CONCLUSIONS: The investigation revealed potential central and peripheral antinociceptive effects of A. lacucha bark supports its applications in the traditional system of medicine.

Therapeutic potential of Vanillylacetone against CCl4 induced hepatotoxicity by suppressing the serum marker, oxidative stress, inflammatory cytokines and apoptosis in Swiss albino mice.

The aim of this research was to investigate the therapeutic potential of Vanillylacetone against carbon tetrachloride (CCl4) induced hepatotoxicity in mice through understanding the serum marker, oxidative stress mechanism and cytokine networks. Carbon tetrachloride is highly hepatotoxic used as research based on animal model. The mice were classified into five groups and each had eight mice. Group-I was controlled and the vehicle was given orally. Group-II was toxic and carbon tetrachloride (1.5 ml/kg) twice a week for 15 days was administered by intra-peritoneal injections. Group- III and IV were pre-treated with Vanillylacetone 50 & 100 mg kg-1 body weight given every day p.o. while, Group-V received only Vanillylacetone (100 mg kg-1 body weight) for 15 days orally. The finding indicates that the administration of CCl4 causes significant elevation of enzyme markers, oxidative stress, inflammatory cytokine and apoptotic markers in Group-II as compared to Group-I. The administration of Vanillylacetone (50 and100 mg kg-1) significantly suppresses the elevated serum enzymes, oxidative stress (TBARS), an inflammatory cytokine (IL2 and TNFα) and apoptotic markers (Caspase-3 and 9) in Group-III and IV as compared to Group-II. It was also noticed that the higher dose of Vanillylacetone (100 mg) is more effective than lower dose of Vanillylacetone (50 mg). There were no significant changes observed with higher dose of Vanillylacetone (100 mg kg-1) in Group-V as compared to Group-I. Histopathological analysis also supported the above findings. Overall, this results shows that Vanillylacetone has a good antioxidant and therapeutic properties which can help in preventing the chemically (CCl4) induced hepatotoxicity.

Computational investigations of physicochemical, pharmacokinetic, toxicological properties and molecular docking of betulinic acid, a constituent of Corypha taliera (Roxb.) with Phospholipase A2 (PLA2).

BACKGROUND: Betulinic acid (BA) is a natural triterpenoid compound and exhibits a wide range of biological and medicinal properties including anti-inflammatory activity. Therefore, this theoretical investigation is performed to evaluate (a) physicochemical properties such as acid dissociation constant (pKa), distribution coefficient (logD), partition coefficient (logP), aqueous solubility (logS), solvation free energy, dipole moment, polarizability, hyperpolarizability and different reactivity descriptors, (b) pharmacokinetic properties like human intestinal absorption (HIA), cellular permeability, skin permeability (PSkin), plasma protein binding (PPB), penetration of the blood brain barrier (BBB), (c) toxicological properties including mutagenicity, carcinogenicity, risk of inhibition of hERG gene and (d) molecular mechanism of anti-inflammatory action which will aid the development of analytical method and the synthesis of BA derivatives. METHODS: The physicochemical properties were calculated using MarvinSketch 15.6.29 and Gaussian 09 software package. The pharmacokinetic and toxicological properties were calculated on online server PreADMET. Further, the molecular docking study was conducted on AutoDock vina in PyRx 0.8. RESULTS: The aqueous solubility increased with increasing pH due to the ionization of BA leading to decrease in distribution coefficient. The solvation energies in water, dimethyl sulfoxide (DMSO), acetonitrile, n-octanol, chloroform and carbon tetrachloride were - 41.74 kJ/mol, - 53.80 kJ/mol, - 66.27 kJ/mol, - 69.64 kJ/mol, - 65.96 kJ/mol and - 60.13 kJ/mol, respectively. From the results of polarizability and softness, it was clear that BA is less stable and hence, kinetically more reactive in water. BA demonstrated good human intestinal absorption (HIA) and moderate cellular permeability. Further, BA also exhibited positive CNS activity due to high permeability through BBB. The toxicological study revealed that BA was a mutagenic compound but noncarcinogenic in mice model. Moreover, molecular docking study of BA with PLA2 revealed that BA interacts with GLY22 & GLY29 through hydrogen bond formation and LEU2, PHE5, HIS6, ALA17, ALA18, HIS47 and TYR51 through different types of hydrophobic interactions. The binding affinity of BA was - 41.00 kJ/mol which is comparable to the binding affinity of potent inhibitor 6-Phenyl-4(R)-(7-Phenyl-heptanoylamino)-hexanoic acid (BR4) (- 33.89 kJ/mol). CONCLUSIONS: Our computed properties may assist the development of analytical method to assay BA or to develop BA derivatives with better pharmacokinetic and toxicological profile.

The combination of canagliflozin and omega-3 fatty acid ameliorates insulin resistance and cardiac biomarkers via modulation of inflammatory cytokines in type 2 diabetic rats.

The present study was carried out with the hypothesis that combination of canagliflozin and omega-3 fatty acid may have potential effect on insulin level, insulin resistance, cardiac biomarkers, inflammatory cytokines and histological studies in type 2 diabetes mellitus (DM). Type 2 DM was induced by injecting nicotinamide (120 mg/kg, i.p.) 15 min before STZ (60 mg/kg) injection. Canagliflozin (5 and 10 mg/kg) and omega-3 fatty acid (300 mg/kg) were given for 28 days after confirmation of diabetes. Biochemical estimations revealed elevated levels of glucose, insulin, HOMA-R and inflammatory cytokines in diabetic group. Daily dosing of alone canagliflozin and omega-3 fatty acid slightly reduced elevated levels of glucose, insulin, HOMA-R and inflammatory cytokines (IL-1ß, IL-2, and TNFα), whereas canagliflozin and omega-3 fatty acid combination has reduced these biochemical parameters significantly when compared with diabetic group. Similarly in diabetic group the levels of cardiac biomarkers such as lipid profile, LDH, CKMB and troponin were significantly increased. Elevated levels of cardiac biomarkers were significantly reduced after daily dosing of alone canagliflozin and omega-3 fatty acid. Canagliflozin and omega-3 fatty acid combination has offered better improvement in cardiac biomarkers compared to alone canagliflozin and omega-3 fatty acid. Histopathological analysis also supported the above hypothesis that combination therapy (canagliflozin and omega-3 fatty acid) offered better protection against degenerative changes in ß-cells of pancreas as compared to alone treatment with these drugs. Thus the present study revealed that canagliflozin and omega-3 fatty acid can be used as potential combination therapy in type 2 DM along with cardiac complication.

Multidrug ABC transporter Cdr1 of Candida albicans harbors specific and overlapping binding sites for human steroid hormones transport.

The present study examines the kinetics of steroids efflux mediated by the Candida drug resistance protein 1 (Cdr1p) and evaluates their interaction with the protein. We exploited our in-house mutant library for targeting the 252 residues forming the twelve transmembrane helices (TMHs) of Cdr1p. The screening revealed 65 and 58 residues critical for ß-estradiol and corticosterone transport, respectively. Notably, up to 83% critical residues for corticosterone face the lipid interface compared to 54% for ß-estradiol. Molecular docking identified a possible peripheral corticosterone-binding site made of 8/14 critical/non-critical residues between TMHs 3, 4 and 6. ß-estradiol transport was severely hampered by alanine replacements of Cdr1p core residues involving TMHs 2, 5 and 8, in a binding site made of 10/14 critical residues mainly shared with rhodamine 6G with which it competes. By contrast, TMH11 was poorly impacted, although being part of the core domain. Finally, we observed the presence of several contiguous stretches of 3-5 critical residues in TMHs 2, 5 and 10 that points to a rotation motion of these helices during the substrate transport cycle. The selective structural arrangement of the steroid-binding pockets in the core region and at the lipid-TMD interface, which was never reported before, together with the possible rotation of some TMHs may be the structural basis of the drug-transport mechanism achieved by these type II ABC transporters.

Probe-location dependent resonance energy transfer at lipid/water interfaces: comparison between the gel- and fluid-phase of lipid bilayer.

Despite significant interest in understanding the role of the local dielectric environment and lipid-bilayer fluidity/rigidity in resonance energy transfer between chromophores at lipid/water interfaces, a comprehensive approach to quantify such environmental dependence on energy transfer is missing - primarily because of the scarcity of suitable probes. Here we present the results on multi-chromophoric Förster resonance energy transfer (FRET) from a series of 4-aminophthalimide-based molecules (4AP-Cn; n = 2-10, 12) of different lipophilicity (donors), which reside at different depths across the lipid/water interfaces, to rhodamine-6G (Rh6G; acceptor) molecules that stay in a water-rich region near the lipid headgroups. We apply steady-state and time-resolved fluorescence spectroscopy, and find that multi-chromophoric FRET from the series of 4AP-Cn donors to the Rh6G acceptor occurs in a peculiar stepwise fashion at the lipid/water interface of a gel-phase (Lß') DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine) bilayer at room temperature. However, the same donor-acceptor pairs show only subtle but continuous donor-depth-dependent FRET at the lipid/water interface of a fluid-phase (Lα) DOPC (1,2-dioleoyl-sn-glycero-3-phosphocholine) bilayer. These features were found to correlate with the lipid-phase dependent local environmental polarity sensed by 4AP-Cn donors at the interfaces. Molecular dynamics (MD) simulations, combined with experimental results, show that relative depth (and angle) variation of the 4AP-Cn donors and Rh6G acceptor directly controls the FRET efficiencies through fine tuning of the emission and absorption spectra of the donors and acceptor, respectively. The results indicate that the 4AP-Cn probes are well-suited as donors for FRET studies, which allow the FRET parameters at lipid/water interfaces of gel- and fluid-phases of lipid-bilayers to be quantified and compared simultaneously.

Remediation of cadmium toxicity in field peas (Pisum sativum L.) through exogenous silicon.

Cadmium (Cd) is an important phytotoxic element causing health hazards. This work investigates whether and how silicon (Si) influences the alleviation of Cd toxicity in field peas at biochemical and molecular level. The addition of Si in Cd-stressed plants noticeably increased growth and development as well as total protein and membrane stability of Cd-stressed plants, suggesting that Si does have critical roles in Cd detoxification in peas. Furthermore, Si supplementation in Cd-stressed plants showed simultaneous significant increase and decrease of Cd and Fe in roots and shoots, respectively, compared with Cd-stressed plants. At molecular level, GSH1 (phytochelatin precursor) and MTA (metallothionein) transcripts predominantly expressed in roots and strongly induced due to Si supplementation in Cd-stressed plants compared with Cd-free conditions, suggesting that these chelating agents may bind to Cd leading to vacuolar sequestration in roots. Furthermore, pea Fe transporter (RIT1) showed downregulation in shoots when plants were treated with Si along with Cd compared with Cd-treated conditions. It is consistent with the physiological observations and supports the conclusion that alleviation of Cd toxicity in pea plants might be associated with Cd sequestration in roots and reduced Cd translocation in shoots through the regulation of Fe transport. Furthermore, increased CAT, POD, SOD and GR activity along with elevated S-metabolites (cysteine, methionine, glutathione) implies the active involvement of ROS scavenging and plays, at least in part, to the Si-mediated alleviation of Cd toxicity in pea. The study provides first mechanistic evidence on the beneficial effect of Si on Cd toxicity in pea plants.

REPEATED EXPOSURE OF SODIUM TELLURITE ON THE RAT LIVER AND ON THE POTENTIAL MECHANISMS OF THE METALLOID-INDUCED HEPATOTOXICITY.

Tellurium (Te) is a semiconductor and is frequently doped with copper, tin, gold or silver. It is also used to color glass and ceramics and is one of the primary ingredients in blasting caps. Te is little known about its biological activity but it is well known for toxic to human and animals. It has inhibited the lipids profiles and oxidative stress in the brain of the mice. Sodium tellurite 4.15, 8.3 and 16.6 mg/kg (1/20, 1/10 and 1/5 of LD50, respectively) was given to male Wistar rats orally in saline for a period of 15 days. On day 16, the blood was collected and the livers were dissected out for biochemical assays. The hepatotoxicity biomarkers [biliru- bin, aspartate aminotransferase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP)] were ele- vated significantly and dose dependently in the serum of Te treated groups as compared to control group. The content of thiobarbituric acid reactive substances in Te treated groups was increased significantly and dose- dependently as compared to control group. Conversely, the content of glutathione and activities of antioxidant enzymes (glutathione peroxidase, glutathione reductase, glutathione-S-transferase, superoxide dismutase and catalase) were decreased significantly in Te treated groups as compared to control group. No data of effect of inorganic Te compounds on the liver toxicity of rats are available. The aim of the present study was to evalu- ate the hepatotoxicity of inorganic Te compounds. In conclusion, Te accelerated hepatotoxicity and oxidative stress in liver tissue of rats.

New insight into probe-location dependent polarity and hydration at lipid/water interfaces: comparison between gel- and fluid-phases of lipid bilayers.

Environment polarity and hydration at lipid/water interfaces play important roles in membrane biology, which are investigated here using a new homologous series of 4-aminophthalimide-based fluorescent molecules (4AP-Cn; n = 2-10, 12) having different lipophilicities (octanol/water partition coefficient - log P). We show that 4AP-Cn molecules probe a peculiar stepwise polarity (E) profile at the lipid/water interface of the gel-phase (Lß') DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine) bilayer at room temperature, which was not anticipated in earlier studies. However, the same molecules probe only a subtle but continuous polarity change at the interface of water and the fluid-phase (Lα) DOPC (1,2-dioleoyl-sn-glycero-3-phosphocholine) bilayer at room temperature. Fluorescence quenching experiments indicate that solutes with different log P values adsorb at different depths across DPPC/water and DOPC/water interfaces, which correlate with the polarity profiles observed at the interfaces. Molecular dynamics simulations performed on eight probe-lipid systems (four in each of the DPPC and DOPC bilayers - a total run of 2.6 µs) support experimental results, providing further information on the relative position and angle distributions as well as hydration of probes at the interfaces. Simulation results indicate that besides positions, probe orientations also play an important role in defining the local dielectric environment by controlling the probes' exposure to water at the interfaces especially of the gel-phase DPPC bilayer. The results suggest that 4AP-Cn probes are well suited for studying solvation properties at lipid/water interfaces of gel- and fluid-phases simultaneously.

REPEATED EXPOSURE OF SODIUM TELLURITE ON THE RAT LIVER AND ON THE POTENTIAL MECHANISMS OF THE METALLOID-INDUCED HEPATOTOXICITY.

Tellurium (Te) is a semiconductor and is frequently doped with copper, tin, gold or silver. It is also used to color glass and ceramics and is one of the primary ingredients in blasting caps. Little is known about Te biological activity but it is well known for toxicity to human and animals. It has inhibited the lipids profiles and oxidative stress in the brain of mice. Sodium tellurite 4.15, 8.3 and 16.6 mg/kg (1/20, 1/10 and 1/5 of LD50, respectively) was given to male Wistar rats orally in saline for a period of 15 days. On day 16, the blood was collected and the livers were dissected out for biochemical assays. The hepatotoxicity biomarkers [bilirubin, aspartate aminotransferase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP)] were elevated significantly and dose dependently in the serum of Te treated groups as compared to control group. The content of thiobarbituric reactive substances in Te treated groups was increased significantly and dose-dependently as compared to control group. Conversely, the content of glutathione and activities of antioxidant enzymes (glutathione peroxidase, glutathione reductase, glutathione-S-transferase, superoxide dismutase and catalase) were decreased significantly in Te treated groups as compared to control group. No data of inorganic Te compounds on the liver toxicity of rats are available. The aim of the present study was to evaluate the hepatotoxicity of inorganic Te compound. In conclusion, Te accelerated hepatotoxicity and oxidative stress in liver tissue of rats.

Insight into pleiotropic drug resistance ATP-binding cassette pump drug transport through mutagenesis of Cdr1p transmembrane domains.

The fungal ATP-binding cassette (ABC) transporter Cdr1 protein (Cdr1p), responsible for clinically significant drug resistance, is composed of two transmembrane domains (TMDs) and two nucleotide binding domains (NBDs). We have probed the nature of the drug binding pocket by performing systematic mutagenesis of the primary sequences of the 12 transmembrane segments (TMSs) found in the TMDs. All mutated proteins were expressed equally well and localized properly at the plasma membrane in the heterologous host Saccharomyces cerevisiae, but some variants differed significantly in efflux activity, substrate specificity, and coupled ATPase activity. Replacement of the majority of the amino acid residues with alanine or glycine yielded neutral mutations, but about 42% of the variants lost resistance to drug efflux substrates completely or selectively. A predicted three-dimensional homology model shows that all the TMSs, apart from TMS4 and TMS10, interact directly with the drug-binding cavity in both the open and closed Cdr1p conformations. However, TMS4 and TMS10 mutations can also induce total or selective drug susceptibility. Functional data and homology modeling assisted identification of critical amino acids within a drug-binding cavity that, upon mutation, abolished resistance to all drugs tested singly or in combinations. The open and closed Cdr1p models enabled the identification of amino acid residues that bordered a drug-binding cavity dominated by hydrophobic residues. The disposition of TMD residues with differential effects on drug binding and transport are consistent with a large polyspecific drug binding pocket in this yeast multidrug transporter.

PRKAA2, MTOR, and TFEB in the regulation of lysosomal damage response and autophagy.

Lysosomes function as critical signaling hubs that govern essential enzyme complexes. LGALS proteins (LGALS3, LGALS8, and LGALS9) are integral to the endomembrane damage response. If ESCRT fails to rectify damage, LGALS-mediated ubiquitination occurs, recruiting autophagy receptors (CALCOCO2, TRIM16, and SQSTM1) and VCP/p97 complex containing UBXN6, PLAA, and YOD1, initiating selective autophagy. Lysosome replenishment through biogenesis is regulated by TFEB. LGALS3 interacts with TFRC and TRIM16, aiding ESCRT-mediated repair and autophagy-mediated removal of damaged lysosomes. LGALS8 inhibits MTOR and activates TFEB for ATG and lysosomal gene transcription. LGALS9 inhibits USP9X, activates PRKAA2, MAP3K7, ubiquitination, and autophagy. Conjugation of ATG8 to single membranes (CASM) initiates damage repair mediated by ATP6V1A, ATG16L1, ATG12, ATG5, ATG3, and TECPR1. ATG8ylation or CASM activates the MERIT system (ESCRT-mediated repair, autophagy-mediated clearance, MCOLN1 activation, Ca2+ release, RRAG-GTPase regulation, MTOR modulation, TFEB activation, and activation of GTPase IRGM). Annexins ANAX1 and ANAX2 aid damage repair. Stress granules stabilize damaged membranes, recruiting FLCN-FNIP1/2, G3BP1, and NUFIP1 to inhibit MTOR and activate TFEB. Lysosomes coordinate the synergistic response to endomembrane damage and are vital for innate and adaptive immunity. Future research should unveil the collaborative actions of ATG proteins, LGALSs, TRIMs, autophagy receptors, and lysosomal proteins in lysosomal damage response.