Rice LIKE EARLY STARVATION1 cooperates with FLOURY ENDOSPERM6 to modulate starch biosynthesis and endosperm development.

In cereal grains, starch is synthesized by the concerted actions of multiple enzymes on the surface of starch granules within the amyloplast. However, little is known about how starch-synthesizing enzymes access starch granules, especially for amylopectin biosynthesis. Here, we show that the rice (Oryza sativa) floury endosperm9 (flo9) mutant is defective in amylopectin biosynthesis, leading to grains exhibiting a floury endosperm with a hollow core. Molecular cloning revealed that FLO9 encodes a plant-specific protein homologous to Arabidopsis (Arabidopsis thaliana) LIKE EARLY STARVATION1 (LESV). Unlike Arabidopsis LESV, which is involved in starch metabolism in leaves, OsLESV is required for starch granule initiation in the endosperm. OsLESV can directly bind to starch by its C-terminal tryptophan (Trp)-rich region. Cellular and biochemical evidence suggests that OsLESV interacts with the starch-binding protein FLO6, and loss-of-function mutations of either gene impair ISOAMYLASE1 (ISA1) targeting to starch granules. Genetically, OsLESV acts synergistically with FLO6 to regulate starch biosynthesis and endosperm development. Together, our results identify OsLESV-FLO6 as a non-enzymatic molecular module responsible for ISA1 localization on starch granules, and present a target gene for use in biotechnology to control starch content and composition in rice endosperm.

Behavioural activity pattern, genetic factors, and the risk of nonalcoholic fatty liver disease: A prospective study in the UK Biobank.

BACKGROUND & AIMS: Physical activity, sedentary behaviour, and genetic variants have been associated with the nonalcoholic fatty liver disease (NAFLD). However, whether and how the degree of healthy activity patterns may modify the impact of genetic susceptibility on NAFLD remains unknown. METHODS: Behaviour activity factors were determined according to total physical activity (TPA) and sedentary time. The polygenic risk score (PRS) was calculated by variants in PNPLA3, TM6SF2, MBOAT7, and GCKR. Cox regression was used to analyse the associations of genetic and behaviour activity factors with incident NAFLD in the UK Biobank (N = 338 087). RESULTS: During a median follow-up of 12.4 years, 3201 incident NAFLD cases were ascertained. Analyses of TPA and sedentary time simultaneously showed a dose-response association with the risk of NAFLD (ptrend < .001). The association of behaviour activity patterns with NAFLD varied by genetic variants. Of the subjects with high genetic risk, we observed a null protective effect of moderate or high TPA on NAFLD risk, while sitting less than three hours a day significantly decreased the risk of NAFLD (p = 3.50 × 10-4 ). The high genetic risk of NAFLD can also be offset by the combination of moderate physical activity and shorter sedentary time. Moreover, the high genetic risk group has the greatest reduction of 10-year absolute risk (6.95 per 1000 person-years) if reaching both healthy activities. CONCLUSIONS: Moderate-to-high physical activity and favourable sedentary behaviour may be lifestyle modifications in preventing NAFLD, which could offset the harmful effect of predisposing genetic factors.

Du13 encodes a C2 H2 zinc-finger protein that regulates Wxb pre-mRNA splicing and microRNA biogenesis in rice endosperm.

Amylose content is a crucial physicochemical property responsible for the eating and cooking quality of rice (Oryza sativa L.) grain and is mainly controlled by the Waxy (Wx) gene. Previous studies have identified several Dull genes that modulate the expression of the Wxb allele in japonica rice by affecting the splicing efficiency of the Wxb pre-mRNA. Here, we uncover dual roles for a novel Dull gene in pre-mRNA splicing and microRNA processing. We isolated the dull mutant, du13, with a dull endosperm and low amylose content. Map-based cloning showed that Du13 encodes a C2 H2 zinc-finger protein. Du13 coordinates with the nuclear cap-binding complex to regulate the splicing of Wxb transcripts in rice endosperm. Moreover, Du13 also regulates alternative splicing of other protein-coding transcripts and affects the biogenesis of a subset of microRNAs. Our results reveal an evolutionarily conserved link between pre-mRNA splicing and microRNA biogenesis in rice endosperm. Our findings also provide new insights into the functions of Dull genes in rice and expand our knowledge of microRNA biogenesis in monocots.

The risk stratification and predictive performance of a new combined polygenic risk score for hepatocellular carcinoma.

BACKGROUND: Recent genome-wide association studies (GWASs) in liver diseases have generated some polygenic risk scores (PRSs), but their predictive effectiveness on hepatocellular carcinoma (HCC) risk assessment remains unclear. METHODS: Here, we constructed a novel combined polygenic risk score and evaluated its increment to the well-established risk model. We used 15 HCC-associated genetic loci from two PRSs and FinnGen GWAS data to calculate a PRS-combined score and to fit the related PRS model in the UK Biobank cohort (N = 436,162). The PRS-combined score was further assessed for risk stratification for HCC integrating with the recommended clinical risk scores. RESULTS: The PRS-combined model achieved a better AUC (0.657) than that of PRS-HFC (0.637) and PRS-cirrhosis (0.645). The top 20% of the PRS-combined distribution had a 3.25 increased risk of HCC vs. the middle decile (45-55%). At the population level, the addition of PRS-combined to the CLivD score significantly increased the C-statistic (from 0.716 to 0.746) and provided a remarkable improvement in reclassification (NRI = 0.088) at the 10-year risk threshold of 0.2%. In clinic, additional assessment of PRS-combined would reclassify 34,647 intermediate-risk participants as high genetic risk, corresponding to an increase of 63.92% (62/97) of the HCC events classified at high risk using the Fibrosis-4 alone. CONCLUSIONS: The PRS may enhance HCC risk prediction effectiveness in the general population and refine risk stratification of the conventional clinical indicator.

Association of Mosaic Chromosomal Alterations and Genetic Factors with the Risk of Cirrhosis.

Background and Aims: Age-related mosaic chromosomal alterations (mCAs) detected from genotyping of blood-derived DNA are structural somatic variants that indicate clonal hematopoiesis. This study aimed to investigate whether mCAs contribute to the risk of cirrhosis and modify the effect of a polygenic risk score (PRS) on cirrhosis risk prediction. Methods: mCA call sets of individuals with European ancestry were obtained from the UK Biobank. The PRS was constructed based on 12 susceptible single-nucleotide polymorphisms for cirrhosis. Cox proportional hazard models were applied to evaluate the associations between mCAs and cirrhosis risk. Results: Among 448,645 individuals with a median follow-up of 12.5 years, we identified 2,681 cases of cirrhosis, 1,775 cases of compensated cirrhosis, and 1,706 cases of decompensated cirrhosis. Compared to non-carriers, individuals with copy-neutral loss of heterozygosity mCAs had a significantly increased risk of cirrhosis (hazard ratio (HR) 1.42, 95% confidence interval (CI) 1.12-1.81). This risk was higher in patients with expanded cell fractions of mCAs (cell fractions ≥10% vs. cell fractions <10%), especially for the risk of decompensated cirrhosis (HR 2.03 [95% CI 1.09-3.78] vs. 1.14 [0.80-1.64]). In comparison to non-carriers of mCAs with low genetic risk, individuals with expanded copy-neutral loss of heterozygosity and high genetic risk showed the highest cirrhosis risk (HR 5.39 [95% CI 2.41-12.07]). Conclusions: The presence of mCAs is associated with increased susceptibility to cirrhosis risk and could be combined with PRS for personalized cirrhosis risk stratification.

Association between exposure to per- and polyfluoroalkyl substance and liver injury in American adults.

Epidemiological data is scarce regarding the association between exposure to mixtures of per- and polyfluoroalkyl substances (PFASs) and liver injury in the general populace. The current research used data from the National Health and Nutrition Examination Survey (2009-2018). The PFAS exposure levels were defined by the serum concentrations of PFASs with > 70% detection in samples, namely perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS), perfluorodecanoic acid (PFDeA), and perfluorooctane sulfonic acid (PFOS). Liver injury was assessed from two aspects: first, the degree of liver inflammation was determined based on serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), glutamyltransferase (GGT), and total bilirubin (TBIL) levels; second, the degree of liver fibrosis was determined based on fibrosis-4 (FIB-4) index. We assessed the associations between individual or total PFAS exposure and these outcomes using multivariable linear regression models and logistic regression models, restricted cubic splines, and weighted quantile sum regression. Among the samples of 7484 American adults, the median concentration of PFOS was the highest, followed by PFOA and PFHxS. Using multivariable linear regression, a positive correlation was observed between all PFASs and liver enzymes such as ALT, AST, and TBIL. Additionally, the weighted quantile sum model indicated an overall positive association between the five PFASs and liver injury indicators. For liver function biomarkers and liver fibrosis, PFNA and PFOS were the most heavily weighting chemicals, respectively. Our findings provide new epidemiological evidence indicating a potential association between PFAS exposure and adverse effects on liver injury biomarkers, highlighting the potentially harmful effects of PFAS exposure on liver health.

Diet and Risk of Non-Alcoholic Fatty Liver Disease, Cirrhosis, and Liver Cancer: A Large Prospective Cohort Study in UK Biobank.

Background and Aims: Epidemiological evidence has shown the association between nutritional habits and liver disease. However, results remain conflicting. This study investigated the influence of dietary factors on the risk of incident non-alcoholic fatty liver disease (NAFLD), cirrhosis, and liver cancer. Methods: Data from the UK Biobank database were analyzed (n = 372,492). According to baseline data from the food frequency questionnaire, two main dietary patterns (Western and prudent) were identified using principal component analysis. We used cox proportional hazards models to explore the associations of individual food groups and dietary patterns with NAFLD, cirrhosis, and liver cancer. Results: During a median follow-up of 12 years, 3527 hospitalized NAFLD, 1643 cirrhosis, and 669 liver cancer cases were recorded among 372,492 participants without prior history of cancer or chronic liver diseases at baseline. In multivariable adjusted analysis, participants in the high tertile of Western dietary pattern score had an 18% (95%CI = 1.09−1.29), 21% (95%CI = 1.07−1.37), and 24% (95%CI = 1.02−1.50) higher risk of incident NAFLD, liver cirrhosis, and liver cancer, respectively, compared with the low tertile. Participants in the high tertile of prudent scores had a 15% (95%CI = 0.75−0.96) lower risk of cirrhosis, as compared with those in the low tertile. In addition, the higher consumption of red meat and the lower consumption of fruit, cereal, tea, and dietary fiber were significantly associated with a higher risk of NAFLD, cirrhosis, and liver cancer (ptrend < 0.05). Conclusions: This large prospective cohort study showed that an increased intake of food from the Western dietary pattern could be correlated with an increased risk of chronic liver diseases, while the prudent pattern was only correlated with a reduced liver cirrhosis risk. These data may provide new insights into lifestyle interventions for the prevention of chronical liver diseases.

Healthy Lifestyle Is Associated with Reduced Mortality in Patients with Non-Alcoholic Fatty Liver Disease.

Background and Aims: It is unclear whether a healthy lifestyle impacts mortality in the presence of non-alcoholic fatty liver disease (NAFLD). The present study aimed to examine the joint association of several modifiable lifestyle factors with mortality risk for NAFLD patients. Methods: We collected lifestyle behavior data form the National Health and Nutrition Examination Survey (NHANES) III from 1988 to 1994 and follow-up data form NHANES III-linked mortality data through 2015. We estimated joint association between four healthy lifestyle factors (non-smoking, non-drinking, regular physical activity, a healthy diet) after NAFLD diagnosis and mortality using Cox proportional hazards regression models. Results: During a median of 22.83 years of follow-up, 2932 deaths occurred. The risk of all-cause mortality decreased significantly with the healthy lifestyle scores increasing (p < 0.001). NAFLD patients with a favorable lifestyle (3 or 4 healthy lifestyle factors) reduced 36% of all-cause mortality and 43% of cardiovascular disease (CVD) mortality compared with those with an unfavorable lifestyle (0 or 1 healthy lifestyle factor) (HR, 0.64 [95% CI, 0.50−0.81], 0.57 [95% CI, 0.37−0.88]). Compared with the non-NAFLD group, the number of NAFLD patients required to adhere to a favorable lifestyle to prevent one cardiovascular disease death in 20 years was fewer (77 vs. 125). Conclusions: For the NAFLD patients, adopting a healthy lifestyle could significantly reduce their risk of death.

Weight Change across Adulthood in Relation to Non-Alcoholic Fatty Liver Disease among Non-Obese Individuals.

BACKGROUND: To investigate the associations of weight change patterns across adulthood with the risk of non-alcoholic fatty liver disease (NAFLD). METHODS: Using data from the National Health and Nutrition Examination Survey (NHANES) 2017-2018 cycle, we performed a retrospective cohort study with 2212 non-obese participants aged 36 years old over. Weight change patterns were categorized as "stable non-obese", "early adulthood weight gain", "middle and late adulthood weight gain" and "revert to non-obese" according to the body mass index (BMI) at age 25, 10 years prior and at baseline. Vibration-controlled transient elastography (VCTE) was performed to diagnose NAFLD. Modified Poisson regression was used to quantify the associations of weight change patterns with NAFLD. RESULTS: Compared with participants in the "stable non-obese" group, those who gained weight at early or middle and late adulthood had an increased risk of NAFLD, with an adjusted rate ratio (RR) of 2.19 (95% CI 1.64-2.91) and 1.92 (95% CI 1.40-2.62), respectively. The risk of NAFLD in "revert to the non-obese" group showed no significant difference with the stable non-obese group. If the association of weight change and NAFLD was causal, we estimated that 73.09% (95% CI 55.62-82.93%) of incident NAFLD would be prevented if the total population had a normal BMI across adulthood. CONCLUSIONS: Weight gain to obese at early or middle and late adulthood was associated with an evaluated risk of NAFLD. A large proportion would have been prevented with effective weight intervention.