New long-non coding RNAs related to fat deposition based on pig model

lncRNA TUG1 transcript levels and psychological disorders: insights into interplay of glycemic index and glycemic load

BACKGROUND

There is an association between obesity and psychological disorders such as depression, anxiety, and stress. Environmental factors and genetics play a crucial role in this regard. Several long non-coding RNAs (lncRNAs) are involved in the pathophysiology of the nervous system. Additionally, we intend to investigate how dietary glycemic index and load relate to psychological disorders in women with obesity and overweight by identifying the possible interaction with metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) and taurine upregulated gene 1 (TUG1).

METHODS

267 overweight or obese women between the ages of 18 and 48 were recruited for the current study. A reliable and validated food frequency questionnaire (FFQ) consisting of 147 items assessed food consumption, glycemic load (GL), and glycemic index (GI). Depression-Anxiety-Stress Scales (DASS-21) were used to assess mental well-being. A real-time polymerase chain reaction (PCR) was used to assess transcript levels for lncRNAs MALAT1 and TUG1.

RESULTS

In obese and overweight women, a positive correlation was found between anxiety and MALAT1 mRNA levels (P = 0.007, CC = 0.178). Age, energy intake, physical activity, total fat, income, marriage, thyroid, and BMI were adjusted, and GI and TUG1 were positively correlated on DASS-21 (β = 0.006, CI = 0.001, 0.01, P = 0.031), depression (β = 0.002, CI = 0.001, 0.004, P = 0.019), Stress (β = 0.003, CI = 0.001, 0.005, P = 0.027). The interaction of GL and TUG1 on stress was also observed (β = 0.03, CI = 0.001, 0.07, P = 0.048).

CONCLUSIONS

The lncRNA TUG1 appears to be associated with depression and stress through interaction with GI and correlated with stress by interaction with GL. To establish this concept, further research is required.

MALAT1: A Long Non-Coding RNA with Multiple Functions and Its Role in Processes Associated with Fat Deposition

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) belongs to the lncRNA molecules, which are involved in transcriptional and epigenetic regulation and the control of gene expression, including the mechanism of chromatin remodeling. MALAT1 was first discovered during carcinogenesis in lung adenocarcinoma, hence its name. In humans, 66 of its isoforms have been identified, and in pigs, only 2 are predicted, for which information is available in Ensembl databases (Ensembl Release 111). MALAT1 is expressed in numerous tissues, including adipose, adrenal gland, heart, kidney, liver, ovary, pancreas, sigmoid colon, small intestine, spleen, and testis. MALAT1, as an lncRNA, shows a wide range of functions. It is involved in the regulation of the cell cycle, where it has pro-proliferative effects and high cellular levels during the G1/S and mitotic (M) phases. Moreover, it is involved in invasion, metastasis, and angiogenesis, and it has a crucial function in alternative splicing during carcinogenesis. In addition, MALAT1 plays a significant role in the processes of fat deposition and adipogenesis. The human adipose tissue stem cells, during differentiation into adipocytes, secrete MALAT1 as one the most abundant lncRNAs in the exosomes. MALAT1 expression in fat tissue is positively correlated with adipogenic FABP4 and LPL. This lncRNA is involved in the regulation of PPARγ at the transcription stage, fatty acid metabolism, and insulin signaling. The wide range of MALAT1 functions makes it an interesting target in studies searching for drugs to prevent obesity development in humans. In turn, in farm animals, it can be a source of selection markers to control the fat tissue content.

Repetitive Cerulein-Induced Chronic Pancreatitis in Growing Pigs-A Pilot Study

Chronic pancreatitis (CP) is an irreversible and progressive inflammatory disease. Knowledge on the development and progression of CP is limited. The goal of the study was to define the serum profile of pro-inflammatory cytokines and the cell antioxidant defense system (superoxidase dismutase-SOD, and reduced glutathione-GSH) over time in a cerulein-induced CP model and explore the impact of these changes on selected cytokines in the intestinal mucosa and pancreatic tissue, as well as on selected serum biochemical parameters. The mRNA expression of CLDN1 and CDH1 genes, and levels of Claudin-1 and E-cadherin, proteins of gut barrier, in the intestinal mucosa were determined via western blot analysis. The study showed moderate pathomorphological changes in the pigs' pancreas 43 days after the last cerulein injection. Blood serum levels of interleukin (IL)-1-beta, IL-6, tumor necrosis factor alpha (TNF-alpha), C-reactive protein (CRP), lactate dehydrogenase (LDH), gamma-glutamyl transpeptidase (GGTP), SOD and GSH were increased following cerulein injections. IL-1-beta, IL-6, TNF-alpha and GSH were also increased in jejunal mucosa and pancreatic tissue. In duodenum, decreased mRNA expression of CDH1 and level of E-cadherin and increased D-lactate, an indicator of leaky gut, indicating an inflammatory state, were observed. Based on the current results, we can conclude that repetitive cerulein injections in growing pigs not only led to CP over time, but also induced inflammation in the intestine. As a result of the inflammation, the intestinal barrier was impaired.

The Effect of BSCL2 Gene on Fat Deposition Traits in Pigs

BSCL2 encodes seipin, a transmembrane endoplasmic reticulum protein associated with lipodystrophy and severe metabolic complications, including diabetes and hepatic steatosis. In pigs, BSCL2 expression increases during adipocyte differentiation. In the present study, we identified significant gene variants associated with fat deposition (FD)-related processes based on subcutaneous fat tissue RNA-seq data. In the association study, to prove our hypothesis, three Polish pig breeds were included: Złotnicka White (ZW, n = 72), Polish Landrace (PL, n = 201), and Polish Large White (PLW, n = 169). Based on variant calling analysis and χ² tests, BSCL2 mutations showing significantly different genotype/allele distribution between high- and low-fat pigs were selected for a comprehensive association study. Four interesting BSCL2 variants (rs346079334, rs341493267, rs330154033, and rs81333153) belonging to downstream and missense mutations were investigated. Our study showed a significant decrease in minor allele frequency for two BSCL2 variants (rs346079334 and rs341493267) in PL pigs in 2020-2021. In ZW, BSCL2 mutations significantly affected loin and ham fats, meat redness, and growth performance traits, such as feed conversion and daily feed intake. Similar observations were noted for PLW and PL, where BSCL2 mutations influenced fat depositions and meat traits, such as loin eye area, loin mass and fat, carcass yield, and growth performance traits. Based on the observation in pigs, our study supports the theory that BSCL2 expressed in subcutaneous fat is involved in the FD process.

Variations in Fibrinogen-like 1 (FGL1) Gene Locus as a Genetic Marker Related to Fat Deposition Based on Pig Model and Liver RNA-Seq Data

The goal of this study was to evaluate the effects of mutations in the FGL1 gene associated with pig productive traits to enrich the genetic marker pool for further selection and to support the studies on FGL1 in the context of the fat deposition (FD) process. The variant calling and χ2 analyses of liver RNA-seq data were used to indicate genetic markers. FGL1 mutations were genotyped in the Złotnicka White (n = 72), Polish Large White (n = 208), Duroc (n = 72), Polish Landrace (PL) (n = 292), and Puławska (n = 178) pig breeds. An association study was performed using a general linear model (GLM) implemented in SAS® software. More than 50 crucial mutations were identified in the FGL1 gene. The association study showed a significant effect of the FGL1 on intramuscular fat (IMF), loin eye area, backfat thickness at the lumbar, ham mass (p = 0.0374), meat percentage (p = 0.0205), and loin fat (p = 0.0003). Alternate homozygotes and heterozygotes were found in the PL and Duroc, confirming the selective potential for these populations. Our study supports the theory that liver FGL1 is involved in the FD process. Moreover, since fat is the major determinant of flavor development in meat, the FGL1 rs340465447_A allele can be used as a target in pig selection focused on elevated fat levels.