The Effects of Age and Alcohol on Lipid Metabolism in the Liver

Background: Alcohol-associated liver disease (ALD) encompasses the liver manifestation of chronic alcohol abuse, characterized by different stages of liver damage that progresses from fat accumulation to steatohepatitis, fibrosis and eventually cirrhosis. The severity of liver damage is influenced by age, which is also a predictor for ALD-related mortality. Thus, the purpose of this study was to investigate how aging and alcohol affect lipid metabolism in the liver. Methods: Rats aged 4 months, 8 months, 12 months, and 22 months-old were pair-fed Lieber-DeCarli control or ethanol diet for 6 weeks. Serum and liver were collected for analyses when rats were euthanized. Analyses included histopathology, measurements of non-esterified fatty acid content and hepatic triglyceride content, and gene expression.https://digitalcommons.unmc.edu/surp2022/1034/thumbnail.jp

Antihypercholesterolemic and Antioxidative Potential of an Extract of the Plant, Piper betle

Hypercholesterolemia is a dominant risk factor for atherosclerosis and cardiovascular diseases. In the present study, the putative antihypercholesterolemic and antioxidative properties of an ethanolic extract of Piper betle and of its active constituent, eugenol, were evaluated in experimental hypercholesterolemia induced by a single intraperitoneal injection of Triton WR-1339 (300 mg/kg b.wt) in Wistar rats. Saline-treated hypercholesterolemic rats revealed significantly higher mean blood/serum levels of glucose, total cholesterol, triglycerides, low density and very low density lipoprotein cholesterol, and of serum hepatic marker enzymes; in addition, significantly lower mean serum levels of high density lipoprotein cholesterol and significantly lower mean activities of enzymatic antioxidants and nonenzymatic antioxidants were noted in hepatic tissue samples from saline-treated hypercholesterolemic rats, compared to controls. However, in hypercholesterolemic rats receiving the Piper betle extract (500 mg/kg b.wt) or eugenol (5 mg/kg b.wt) for seven days orally, all these parameters were significantly better than those in saline-treated hypercholesterolemic rats. The hypercholesterolemia-ameliorating effect was better defined in eugenol-treated than in Piper betle extract-treated rats, being as effective as that of the standard lipid-lowering drug, lovastatin (10 mg/kg b.wt). These results suggest that eugenol, an active constituent of the Piper betle extract, possesses antihypercholesterolemic and other activities in experimental hypercholesterolemic Wistar rats

Deletion of Specific Conserved Motifs from the N-Terminal Domain of αB-Crystallin Results in the Activation of Chaperone Functions

Smaller oligomeric chaperones of α-crystallins (αA- and αB-) have received increasing attention due to their improved therapeutic potential in preventing protein aggregating diseases. Our previous study suggested that deleting 54–61 residues from the N-terminal domain (NTD) of αB-crystallin (αBΔ54–61) decreases the oligomer size and increases the chaperone function. Several studies have also suggested that NTD plays a significant role in protein oligomerization and chaperone function. The current study was undertaken to assess the effect of deleting conserved 21–28 residues from the activated αBΔ54–61 (to get αBΔ21–28, Δ54–61) on the structure–function of recombinant αBΔ21–28, Δ54–61. The αBΔ21–28, Δ54–61 mutant shows an 80% reduction in oligomer size and 3- to 25-fold increases in chaperone activity against model substrates when compared to αB-WT. Additionally, the αB∆21–28, ∆54–61 was found to prevent β-amyloid (Aβ1–42) fibril formation in vitro and suppressed Aβ1–42-induced cytotoxicity in ARPE-19 cells in a more effective manner than seen with αB-WT or αB∆54–61. Cytotoxicity and reactive oxygen species (ROS) detection studies with sodium iodate (SI) showed that the double mutant protein has higher anti-apoptotic and anti-oxidative activities than the wild-type or αB∆54–61 in oxidatively stressed cells. Our study shows that the residues 21–28 and 54–61 in αB-crystallin contribute to the oligomerization and modulate chaperone function. The deletion of conserved 21–28 residues further potentiates the activated αBΔ54–61. We propose that increased substrate affinity, altered subunit structure, and assembly leading to smaller oligomers could be the causative factors for the increased chaperone activity of αBΔ21–28, Δ54–61

Effect of Structural Changes Induced by Deletion of 54FLRAPSWF61 Sequence in αB-crystallin on Chaperone Function and Anti-Apoptotic Activity

Previously, we showed that the removal of the 54–61 residues from αB-crystallin (αBΔ54–61) results in a fifty percent reduction in the oligomeric mass and a ten-fold increase in chaperone-like activity. In this study, we investigated the oligomeric organization changes in the deletion mutant contributing to the increased chaperone activity and evaluated the cytoprotection properties of the mutant protein using ARPE-19 cells. Trypsin digestion studies revealed that additional tryptic cleavage sites become susceptible in the deletion mutant than in the wild-type protein, suggesting a different subunit organization in the oligomer of the mutant protein. Static and dynamic light scattering analyses of chaperone–substrate complexes showed that the deletion mutant has more significant interaction with the substrates than wild-type protein, resulting in increased binding of the unfolding proteins. Cytotoxicity studies carried out with ARPE-19 cells showed an enhancement in anti-apoptotic activity in αBΔ54–61 as compared with the wild-type protein. The improved anti-apoptotic activity of the mutant is also supported by reduced caspase activation and normalization of the apoptotic cascade components level in cells treated with the deletion mutant. Our study suggests that altered oligomeric assembly with increased substrate affinity could be the basis for the enhanced chaperone function of the αBΔ54–61 protein

Pseudomonas aeruginosa RRALC3 Enhances the Biomass, Nutrient and Carbon Contents of Pongamia pinnata Seedlings in Degraded Forest Soil.

The study was aimed at assessing the effects of indigenous Plant Growth Promoting Bacterium (PGPB) on the legume Pongamia pinnata in the degraded soil of the Nanmangalam Reserve Forest (NRF) under nursery conditions. In total, 160 diazotrophs were isolated from three different nitrogen-free semi-solid media (LGI, Nfb, and JMV). Amongst these isolates, Pseudomonas aeruginosa RRALC3 exhibited the maximum ammonia production and hence was selected for further studies. RRALC3 was found to possess multiple plant growth promoting traits such as nitrogen accumulation (120.6ppm); it yielded a positive amplicon with nifH specific primers, tested positive for Indole Acetic Acid (IAA; 18.3μg/ml) and siderophore production, tested negative for HCN production and was observed to promote solubilization of phosphate, silicate and zinc in the plate assay. The 16S rDNA sequence of RRALC3 exhibited 99% sequence similarity to Pseudomonas aeruginosa JCM5962. Absence of virulence genes and non-hemolytic activity indicated that RRALC3 is unlikely to be a human pathogen. When the effects of RRALC3 on promotion of plant growth was tested in Pongamia pinnata, it was observed that in Pongamia seedlings treated with a combination of RRALC3 and chemical fertilizer, the dry matter increased by 30.75%. Nitrogen, phosphorus and potassium uptake increased by 34.1%, 27.08%, and 31.84%, respectively, when compared to control. Significant enhancement of total sugar, amino acids and organic acids content, by 23.4%, 29.39%, and 26.53% respectively, was seen in the root exudates of P. pinnata. The carbon content appreciated by 4-fold, when fertilized seedlings were treated with RRALC3. From the logistic equation, the rapid C accumulation time of Pongamia was computed as 43 days longer than the control when a combination of native PGPB and inorganic fertilizer was applied. The rapid accumulation time of N, P and K in Pongamia when treated with the same combination as above was 15, 40 and 33 days longer, respectively, as compared to the control

Effects of different treatments on the dry matter accumulation of <i>Pongamia pinnata</i> seedlings.

<p>¹ DMA, dry matter accumulation. Values represent the mean ± SD of three replicates. ² Values mentioned on the bar-chart are significantly different (<i>P</i> < 0.05) among treatments. ³ T1, inorganic fertilizer (N:P:K, 2:1:1) + <i>P</i>. <i>aeruginosa</i> RRALC3; T2, inorganic fertilizer (N:P:K, 2:1:1) + commercial biofertilizer; T3, inorganic fertilizer (N:P:K, 2:1:1); T4, <i>P</i>. <i>aeruginosa</i> RRALC3; T5, control (no biofertilizer or inorganic fertilizer).</p

Logistic equations and other parameters for nutrient accumulation in the aboveground biomass of <i>Pongamia pinnata</i> seedlings.

<p>¹ In the logistic equation, <i>W</i> represents the nutrient accumulation of plants (mg/plant), <i>t</i> denotes days after the emergence of seedlings, <i>T</i>_<i>a</i> and <i>T</i>_<i>b</i> explain the onset and termination of the rapid nutrient accumulation period, and <i>V</i>_m denotes the maximum nutrient accumulation (mg plant⁻¹ day⁻¹) rate.</p><p>² Values followed by different uppercase letters in a column are significantly different (<i>P</i> < 0.05) among treatments.</p><p>Native PGPR, <i>P</i>. <i>aeruginosa</i> RRALC3. T1, inorganic fertilizer (N:P:K, 2:1:1) + <i>P</i>. <i>aeruginosa</i> RRALC3; T2, inorganic fertilizer (N:P:K, 2:1:1) + commercial biofertilizer; T3, inorganic fertilizer (N:P:K, 2:1:1); T4, <i>P</i>. <i>aeruginosa</i> RRALC3; T5, control (no biofertilizer or inorganic fertilizer).</p><p>³Correlation coefficient (<i>R</i>) between the predicted and observed values</p><p>Logistic equations and other parameters for nutrient accumulation in the aboveground biomass of <i>Pongamia pinnata</i> seedlings.</p

Total uptake of different nutrients and carbon content in <i>Pongamia pinnata</i> seedlings after180 days of growth.

<p>¹ Values followed by different uppercase letters in a column are significantly different (<i>P</i> < 0.05) among treatments.</p><p>T1, Inorganic fertilizer (N: P: K– 2:1:1) + <i>P</i>. <i>aeruginosa</i> RRALC3; T2, Inorganic fertilizer (N: P: K– 2:1:1) + commercial biofertilizer; T3, Inorganic fertilizer (N: P: K– 2:1:1); T4, <i>P</i>. <i>aeruginosa</i> RRALC3; T5, control (no biofertilizer and inorganic fertilizer)</p><p>Total uptake of different nutrients and carbon content in <i>Pongamia pinnata</i> seedlings after180 days of growth.</p

Root exudates componanents at 180 days after the emergence of <i>Pongamia pinnata</i> seedlings.

<p>¹ Values followed by different uppercase letters in a column are significantly different (<i>P</i> < 0.05) with in treatments.</p><p>T1, inorganic fertilizer (N:P:K, 2:1:1) + <i>P</i>. <i>aeruginosa</i> RRALC3; T2, inorganic fertilizer (N:P:K, 2:1:1) + commercial biofertilizer; T3, inorganic fertilizer (N:P:K, 2:1:1); T4, <i>P</i>. <i>aeruginosa</i> RRALC3; T5, control (no biofertilizer or inorganic fertilizer)</p><p>Root exudates componanents at 180 days after the emergence of <i>Pongamia pinnata</i> seedlings.</p

Deletion of Specific Conserved Motifs from the N-Terminal Domain of αB-Crystallin Results in the Activation of Chaperone Functions

Smaller oligomeric chaperones of α-crystallins (αA- and αB-) have received increasing attention due to their improved therapeutic potential in preventing protein aggregating diseases. Our previous study suggested that deleting 54–61 residues from the N-terminal domain (NTD) of αB-crystallin (αBΔ54–61) decreases the oligomer size and increases the chaperone function. Several studies have also suggested that NTD plays a significant role in protein oligomerization and chaperone function. The current study was undertaken to assess the effect of deleting conserved 21–28 residues from the activated αBΔ54–61 (to get αBΔ21–28, Δ54–61) on the structure–function of recombinant αBΔ21–28, Δ54–61. The αBΔ21–28, Δ54–61 mutant shows an 80% reduction in oligomer size and 3- to 25-fold increases in chaperone activity against model substrates when compared to αB-WT. Additionally, the αB∆21–28, ∆54–61 was found to prevent β-amyloid (Aβ1–42) fibril formation in vitro and suppressed Aβ1–42-induced cytotoxicity in ARPE-19 cells in a more effective manner than seen with αB-WT or αB∆54–61. Cytotoxicity and reactive oxygen species (ROS) detection studies with sodium iodate (SI) showed that the double mutant protein has higher anti-apoptotic and anti-oxidative activities than the wild-type or αB∆54–61 in oxidatively stressed cells. Our study shows that the residues 21–28 and 54–61 in αB-crystallin contribute to the oligomerization and modulate chaperone function. The deletion of conserved 21–28 residues further potentiates the activated αBΔ54–61. We propose that increased substrate affinity, altered subunit structure, and assembly leading to smaller oligomers could be the causative factors for the increased chaperone activity of αBΔ21–28, Δ54–61