Sources apportionments of heavy metal(loid)s in the farmland soils close to industrial parks: Integrated application of positive matrix factorization (PMF) and cadmium isotopic fractionation.

Understanding the source identification and distribution of heavy metal(loid)s in soil is essential for risk management. The sources of heavy metal(loid)s in farmland soil, especially in areas with rapid economic development, were complicated and need to be explored urgently. This study combined geographic information system (GIS) mapping, positive matrix factorization (PMF) model and cadmium (Cd) isotope fingerprinting methods to identify heavy metal(loid) sources in a typical town in the economically developed Yangtze River Delta region of China. Cd, As, Cu, Zn, Pb, Ni and Co in different samples were detected. The results showed that Cd was the most severely contaminated element, with an exceedance rate of 78.0 %. GIS mapping results indicated that the hotspot area was located in the northeastern area with prolonged operational histories of electroplating and non-ferrous metal smelting industries. The PMF model analysis also identified emissions from smelting and electroplating enterprises as the main sources of Cd in the soil, counted for 49.28 %, followed by traffic (25.66 %) and agricultural (25.06 %) sources. Through further isotopic analysis, it was found that in soil samples near the industrial park, the contribution of electroplating and non-ferrous metal smelting enterprises to cadmium pollution was significantly higher than other regions. The integrated use of various methodologies allows for precise analysis of sources and input pathways, offering valuable insights for future pollution control and soil remediation endeavors.

Differences in the activities of six soil enzymes in response to cadmium contamination of paddy soils in high geological background areas.

East Yunnan province in southwest China is a region with elevated natural abundance (high geological background levels) of Cd due to high metal (loid) contents in the soils. Enzyme activities are useful indicators of metal (loid) toxicity in contaminated soils and whether Cd inhibits enzyme activities in paddy soils in high geological background areas is of considerable public concern. A pot experiment combined with field investigation was conducted to assess the effects of Cd on six soil enzymes that are essential to the cycling of C, N, and P in soils. Inhibitory effects of Cd fractions on enzyme activities were assessed using ecological dose-response models. The impact of soil properties on the inhibition of sensitive soil enzymes by Cd were assessed using linear and structural equation models. Cadmium was enriched in the paddy soils with 72.2 % of soil samples from high geological background areas exceeding the Chinese threshold values (GB 15618-2018) of Cd. Enzyme responses to Cd contamination varied markedly with a negative response by catalase but a positive response by invertase. Urease, ß-glucosidase, and alkaline phosphatase activities were stimulated at low Cd concentrations and inhibited at high concentrations. The average inhibition ratios of ß-glucosidase, urease, and catalase in high Cd levels were 19.9, 38.9, and 51.9%, respectively. Ecological dose-response models indicate that catalase and urease were the most Cd-sensitive of the enzymes studied and were suitable indicators of soil quality in high geological background areas. Structural equation modeling (SEM) indicates that soil properties influenced sensitive enzymes through various pathways, indicating that soil properties were factors determining Cd inhibition of enzyme activities. This suggests that Cd concentrations and soil physicochemical properties under a range of environmental conditions should be considered in addressing soil Cd pollution.

Phosphatidic acid-enabled MKL1 contributes to liver regeneration: Translational implication in liver failure.

Liver regeneration following injury aids the restoration of liver mass and the recovery of liver function. In the present study we investigated the contribution of megakaryocytic leukemia 1 (MKL1), a transcriptional modulator, to liver regeneration. We report that both MKL1 expression and its nuclear translocation correlated with hepatocyte proliferation in cell and animal models of liver regeneration and in liver failure patients. Mice with MKL1 deletion exhibited defective regenerative response in the liver. Transcriptomic analysis revealed that MKL1 interacted with E2F1 to program pro-regenerative transcription. MAPKAPK2 mediated phosphorylation primed MKL1 for its interaction with E2F1. Of interest, phospholipase d2 promoted MKL1 nuclear accumulation and liver regeneration by catalyzing production of phosphatidic acid (PA). PA administration stimulated hepatocyte proliferation and enhanced survival in a MKL1-dependent manner in a pre-clinical model of liver failure. Finally, PA levels was detected to be positively correlated with expression of pro-regenerative genes and inversely correlated with liver injury in liver failure patients. In conclusion, our data reveal a novel mechanism whereby MKL1 contributes to liver regeneration. Screening for small-molecule compounds boosting MKL1 activity may be considered as a reasonable approach to treat acute liver failure.

Does phytoextraction with Sedum plumbizincicola increase cadmium leaching from polluted agricultural soil?

Sedum plumbizincicola is a cadmium (Cd) and zinc hyperaccumulator that can activate Cd by rhizosphere acidification. However, there is little understanding of the Cd leaching risk from polluted soil during phytoextraction process. Here, pot and column experiments were conducted to monitor soil Cd leaching characteristics under different rainfall simulation conditions during S. plumbizincicola phytoextraction. Soil Cd leaching increased significantly with increasing simulated rainfall intensity. Compared with normal rainfall (NR), weak rainfall (WR) resulted in a 34.3% decrease in Cd uptake by S. plumbizincicola and also led to a 68.7% decline in Cd leaching. In contrast, Cd leaching under heavy rainfall (HR) was 2.12 times that of NR in the presence of S. plumbizincicola. After two successive growing periods, phytoextraction resulted in a 53.5-66.4% decline in the amount of soil Cd leached compared with controls in which S. plumbizincicola was absent. Even compared with maize cropping as a control, S. plumbizincicola did not instigate a significant increase in Cd leaching. The contribution of Cd leaching loss to the decline in soil total Cd concentration was negligible after phytoextraction in the pot experiment. Overall, the results contribute to our understanding of soil Cd leaching risk by phytoextraction with S. plumbizincicola.

Repeated phytoextraction by hyperaccumulator Sedum plumbizincicola is an important remediation technology to remove Cd from contaminated soils. At the same time, Sedum plumbizincicola can also activate soil Cd by rhizosphere acidification. However, studies on the leaching risk of soil activated Cd during the phytoextraction process are very few. This study looked at the effects of Sedum plumbizincicola growth on soil Cd leaching with the changes in rainfall simulation and plant type. Results showed that repeated phytoextraction with Sedum plumbizincicola did not increase Cd leaching from contaminated soil.

Inflammasome activation and metabolic remodelling in p16-positive aging cells aggravates high-fat diet-induced lung fibrosis by inhibiting NEDD4L-mediated K48-polyubiquitin-dependent degradation of SGK1.

BACKGROUND: Chronic changes caused by a high-fat diet (HFD) may be associated with weakened lung function in obese patients. However, few studies have focused on the role of senescent cells in HFD-induced pulmonary fibrosis. This study aimed to determine whether (i) obesity causes the accumulation of aging cells in the lungs, (ii) p16 accumulation in aging epithelial cells or fibroblasts exacerbates long-term HFD-induced senescence-associated pulmonary fibrosis (SAPF) and (iii) p16 deletion or clearance of aging cells ameliorates HFD-induced SAPF through inactivation of the inflammasome and metabolic remodelling. METHODS: Twelve-month old male mice of p16INK4a (hereafter p16) knockout (p16-- ) and wild-type (WT), ApoE knockout (ApoE-- ) and ApoE-- p16-- were fed a HFD to induce obesity, and the effects of treatment with the senolytic drug ABT263 or the SGK1 specific inhibitor EMD638683 on fibrosis, inflammaging, gene expression, integrin-inflammasome signalling and metabolism were examined. A549 and IMR-90 cells were transduced with p16-overexpressing adenovirus, and treated with palmitic and oleic acids (P&O) to induce steatosis in vitro. RESULTS: We found that long-term HFD promoted the expression of p16 and the increase of senescent cells in the lung. P16 knockout or ABT263 treatment alleviated pulmonary fibrosis, the increase of senescent cells and senescence-associated secretory phenotype (SASP) in HFD-fed mice, as well as in P&O-treated A549 and IMR-90 cells. RNA sequencing and bioinformatics analyses revealed that p16 knockout inhibited activation of the integrin-inflammasome pathway and cellular glycolysis. Mass spectrometry, co-immunoprecipitation and GST pull-down assays demonstrated that p16 bound to the N-terminal of SGK1, thereby interfering with the interaction between the E3 ubiquitin ligase NEDD4L and SGK1, and subsequently inhibiting K48-polyubiquitin-dependent degradation of SGK1 mediated by the NEDD4L-Ubch5 complex. EMD638683 was found to alleviate HFD-induced pulmonary fibrosis and activation of the integrin-inflammasome pathway. CONCLUSION: P16 accumulation promoted activation of integrin- inflammasome pathway and cell glycolysis by binding to the N- terminal of SGK1, intefering with the interaction between the E3 ubiquitin ligase NEDD4L and SGK1, thereby inhibiting K48- polyubiquitin- dependent degradation of SGK1 mediated by the NEDD4L-Ubch5 complex. ABT263 or EMD638683 could be used as potential drugs to treat pulmonary fibrosis in obese patients.

Zinc Supply Affects Cadmium Uptake and Translocation in the Hyperaccumulator Sedum Plumbizincicola as Evidenced by Isotope Fractionation.

This study employs stable isotope analysis to investigate the mechanisms of cadmium (Cd) and zinc (Zn) interaction in the metal hyperaccumulating plant species Sedum plumbizincicola. To this end, the Cd and Zn isotope compositions of root, stem, leaf, and xylem sap samples were determined during metal uptake and translocation at different Cd and Zn concentrations. The enrichment of light isotopes of both elements in plants during uptake was less pronounced at low metal supply levels, likely reflecting the switch from a low-affinity to a high-affinity transport system at lower levels of external metal supply. The lower δ114/110Cd values of xylem sap when treated with a metabolic inhibitor decreasing the active Cd uptake further supports the preference of heavier Cd isotopes during high-affinity transport. The Δ66Znplant-initial solution or Δ66Znplant-final solution values were similar at different Cd concentrations, indicating negligible interaction of Cd in the Zn uptake process. However, decreasing Zn supply levels significantly increased the enrichment of light Cd isotopes in plants (Δ114/110Cd = -0.08‰) in low-Cd treatments but reduced the enrichment of light Cd isotopes in plants (Δ114/110Cd = 0.08‰) under high Cd conditions. A systematic enrichment of heavy Cd and light Zn isotopes was found in root-to-shoot translocation of the metals. The Cd concentrations of the growth solutions thereby had no significant impact on Zn isotope fractionation during root-to-shoot translocation. However, the Δ114/110Cdtranslocation values hint at possible competition between Cd and Zn for transporters during root-to-shoot transfer and this may impact the transport pathway of Cd. The stable isotope data demonstrate that the interactions between the two metals influenced the uptake and transport mechanisms of Cd in S. plumbizincicola but had little effect on those of Zn.

Bmi-1 Overexpression Improves Sarcopenia Induced by 1,25(OH)2 D3 Deficiency and Downregulates GATA4-Dependent Rela Transcription.

Sarcopenia increases with age, and an underlying mechanism needs to be determined to help with designing more effective treatments. This study aimed to determine whether 1,25(OH)2 D3 deficiency could cause cellular senescence and a senescence-associated secretory phenotype (SASP) in skeletal muscle cells to induce sarcopenia, whether GATA4 could be upregulated by 1,25(OH)2 D3 deficiency to promote SASP, and whether Bmi-1 reduces the expression of GATA4 and GATA4-dependent SASP induced by 1,25(OH)2 D3 deficiency in skeletal muscle cells. Bioinformatics analyses with RNA sequencing data in skeletal muscle from physiologically aged and young mice were conducted. Skeletal muscles from 2-month-old young and 2-year-old physiologically aged wild-type (WT) mice and 8-week-old WT, Bmi-1 mesenchymal transgene (Bmi-1Tg ), Cyp27b1 homozygous (Cyp27b1-/- ), and Bmi-1Tg Cyp27b1-/- mice were observed for grip strength, cell senescence, DNA damage, and NF-κB-mediated SASP signaling of skeletal muscle. We found that muscle-derived Bmi-1 and vitamin D receptor (VDR) decreased with physiological aging, and DNA damage and GATA4-dependent SASP activation led to sarcopenia. Furthermore, 1,25(OH)2 D3 deficiency promoted DNA damage-induced GATA4 accumulation in muscles. GATA4 upregulated Rela at the region from -1448 to -1412 bp at the transcriptional level to cause NF-κB-dependent SASP for aggravating cell senescence and muscular dysfunction and sarcopenia. Bmi-1 overexpression promoted the ubiquitination and degradation of GATA4 by binding RING1B, which prevented cell senescence, SASP, and dysfunctional muscle, and improved sarcopenia induced by 1,25(OH)2 D3 deficiency. Thus, Bmi-1 overexpression improves sarcopenia induced by 1,25(OH)2 D3 deficiency, downregulates GATA4-dependent Rela transcription, and sequentially inhibits GATA4-dependent SASP in muscle cells. Therefore, Bmi-1 overexpression could be used for translational gene therapy for the ubiquitination of GATA4 and prevention of sarcopenia. © 2023 American Society for Bone and Mineral Research (ASBMR).

USP1/UAF1-Stabilized METTL3 Promotes Reactive Astrogliosis and Improves Functional Recovery after Spinal Cord Injury through m6A Modification of YAP1 mRNA.

RNA N6-methyladenosine (m6A) modification is involved in diverse biological processes. However, its role in spinal cord injury (SCI) is poorly understood. The m6A level increases in injured spinal cord, and METTL3, which is the core subunit of methyltransferase complex, is upregulated in reactive astrocytes and further stabilized by the USP1/UAF1 complex after SCI. The USP1/UAF1 complex specifically binds to and subsequently removes K48-linked ubiquitination of the METTL3 protein to maintain its stability after SCI. Moreover, conditional knockout of astrocytic METTL3 in both sexes of mice significantly suppressed reactive astrogliosis after SCI, thus resulting in widespread infiltration of inflammatory cells, aggravated neuronal loss, hampered axonal regeneration, and impaired functional recovery. Mechanistically, the YAP1 transcript was identified as a potential target of METTL3 in astrocytes. METTL3 could selectively methylate the 3'-UTR region of the YAP1 transcript, which subsequently maintains its stability in an IGF2BP2-dependent manner. In vivo, YAP1 overexpression by adeno-associated virus injection remarkably contributed to reactive astrogliosis and partly reversed the detrimental effects of METTL3 knockout on functional recovery after SCI. Furthermore, we found that the methyltransferase activity of METTL3 plays an essential role in reactive astrogliosis and motor repair, whereas METTL3 mutant without methyltransferase function failed to promote functional recovery after SCI. Our study reveals the previously unreported role of METTL3-mediated m6A modification in SCI and might provide a potential therapy for SCI.SIGNIFICANCE STATEMENT Spinal cord injury is a devastating trauma of the CNS involving motor and sensory impairments. However, epigenetic modification in spinal cord injury is still unclear. Here, we propose an m6A regulation effect of astrocytic METTL3 following spinal cord injury, and we further characterize its underlying mechanism, which might provide promising strategies for spinal cord injury treatment.

Aberrant Expressions of PSMD14 in Tumor Tissue are the Potential Prognostic Biomarkers for Hepatocellular Carcinoma after Curative Resection.

Introduction: Hepatocellular carcinoma (HCC) has a high mortality rate, with curative resection being the primary treatment. However, HCC patients have a large possibility of recurrence within 5 years after curative resection. Methods: Thus, identifying biomarkers to predict recurrence is crucial. In our study, we analyzed data from CCLE, GEO, and TCGA, identifying eight oncogenes associated with HCC. Subsequently, the expression of 8 genes was tested in 5 cases of tumor tissues and the adjacent non-tumor tissues. Then ATP6AP1, PSMD14 and HSP90AB1 were selected to verify the expression in 63 cases of tumor tissues and the adjacent non-tumor tissues. The results showed that ATP6AP1, PSMD14, HSP90AB1 were generally highly expressed in tumor tissues. A five-year follow-up of the 63 clinical cases, combined with Kaplan-Meier Plotter's relapse-free survival (RFS) analysis, found a significant correlation between PSMD14 expression and recurrence in HCC patients. Subsequently, we analyzed the PSMD14 mutations and found that the PSMD14 gene mutations can lead to a shorter disease-free survival time for HCC patients. Results: The results of enrichment analysis indicated that the differentially expressed genes related to PSMD14 are mainly enriched in the signal release pathway. Conclusion: In conclusion, our research showed that PSMD14 might be related to recurrence in HCC patients, and the expression of PSMD14 in tumor tissue might be a potential prognostic biomarker after tumor resection in HCC patients.

Cadmium isotope fractionation during transport processes within agricultural soil profiles in a mining area: Implications for source tracing.

Cadmium (Cd) isotope fractionation patterns within soil profiles and the underlying mechanisms remain unclear and poorly documented. Here, Cd concentrations and isotope compositions of metal ore, surface soils and soil profile samples around a lead-zinc mine in southwest China were determined, and the relationships between soil properties and Cd isotope fractionation within the soil profiles were investigated. Cadmium concentrations of eleven surface soil samples were 0.49-66.1 mg kg-1 and the samples with high Cd concentrations had Cd isotope compositions similar to the metal ore (δ114/110Cd = 0.02‰), indicating that mining activity was the main Cd source at the study areas. Within three soil profiles with different Cd pollution levels the δ114/110Cd values gradually increased with increasing depth from 0 to 40 cm (Δ114/110Cd = 0.08-0.18‰), reaching a maximum at 30-40 cm depth, and then remained fairly constant or decreased with increasing soil depth below 40 cm. Soil δ114/110Cd values were negatively correlated with free iron and manganese oxides contents, which decreased at 0-40 cm depth then increased below 40 cm. This indicates that light Cd isotopes within 0-40 cm depth preferentially migrated downward with free iron and manganese oxides, leaving the soils at a depth of 0-40 cm enriched in heavy Cd isotopes. At 40-90 cm depth the preferential retention of heavy Cd isotopes by hydroxides may be responsible for the gradual decrease in δ114/110Cd values with increasing soil depth. These observations demonstrate that the vertical migration of Cd can induce detectable isotope fractionation within soil profiles and alter the δ114/110Cd values including those of the surface soils. Our study highlights the need to consider Cd mobilization and transport in soil profiles when tracing metal sources using isotope techniques.

Potential mobilization of cadmium and zinc in soils spiked with smithsonite and sphalerite under different water management regimes.

Particulate cadmium (Cd) and zinc (Zn) are ubiquitous in agricultural soils of Pb-Zn mining regions. Water management serves as an important agronomic measure altering the bioavailability of Zn and Cd in soils, but how this affects particulate Cd and Zn and the underlying mechanisms remain largely unknown. Microcosm soil incubation combined with spectroscopic and microscopic characterization was conducted. During a two-year-long incubation period we observed that the concentrations of soil CaCl2-extractable Zn and Cd increased 3-10 times in sphalerite-spiked soils and 1-2 times in smithsonite-spiked soils under periodic flooding conditions due to the long-term dissolution of sphalerite (SP) and smithsonite (SM). However, the increase in the concentration of CaCl2-extractable metals (Zn: from 0.607 mg kg-1 to 1.051 mg kg-1 and Cd: from 0.047 mg kg-1 to 0.119 mg kg-1) was found only in SP-treatment under continuous flooding conditions, indicating the mobilization of metals. Ultrafiltration analysis shows that the nanoparticulate fraction of Zn and Cd in soil pore water increased 5 and 7 times in SP-treatments under continuous flooding conditions, suggesting the increment of metal pools in soil pore water. HRTEM-EDX-SAED further reveals that these nanoparticles were mainly crystalline ZnS and Zn-bearing sulfate nanoparticles in the SP-treatment and amorphous ZnCO3 and ZnS nanoparticles in the SM-treatment. Therefore, the formation of the stable crystalline Zn-bearing nanoparticles in the SP-treatment may explain the elevation of the concentration of soil CaCl2-extractable Zn and Cd under continuous flooding. The potential mobility of particulate metals should therefore be expected in scenarios of continuous flooding such as paddy soils and wetland systems.

Activation of TREM2 attenuates neuroinflammation via PI3K/Akt signaling pathway to improve postoperative cognitive dysfunction in mice.

Postoperative cognitive dysfunction (POCD) is a common postoperative complication involving the central nervous system, but the underlying mechanism is not well understood. Neuroinflammation secondary to surgery and anesthesia is strongly correlated with POCD. A key aspect of neuroinflammation is microglia activation. Triggering receptor expressed on myeloid cells (TREM)2, which is highly expressed in microglia, is an innate immune receptor that modulates microglia function. In this study we investigated the role of TREM2 in cognitive impairment and microglia-mediated neuroinflammation using a mouse model of POCD and in vitro systems. We found that hippocampus-dependent learning and memory were impaired in POCD mice, which was accompanied by activation of microglia and downregulation of TREM2. Pretreatment with the TREM2 agonist heat shock protein (HSP)60 inhibited surgery-induced microglia activation and alleviated postoperative cognitive impairment. In BV2 microglial cells, the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 significantly reversed the attenuation of TREM2 activation on lipopolysaccharide (LPS)-induced neuroinflammation and abrogated the protective effect of activated TREM2 against LPS-induced neuronal injury in a microglia/neuron coculture system. Accordingly, the beneficial effects of TREM2 activation on cognitive function were reversed by preoperative administration of LY294002 in the POCD mouse model. These results demonstrate that TREM2 is involved in the regulation of the inflammatory response mediated by microglia and cognitive impairment following surgery. Activation of TREM2 can attenuate neuroinflammation by modulating PI3K/protein kinase B (Akt) signaling, thereby alleviating postoperative learning and memory deficits.

Chromosome painting reveals inter-chromosomal rearrangements and evolution of subgenome D of wheat.

Aegilops species represent the most important gene pool for breeding bread wheat (Triticum aestivum). Thus, understanding the genome evolution, including chromosomal structural rearrangements and syntenic relationships among Aegilops species or between Aegilops and wheat, is important for both basic genome research and practical breeding applications. In the present study, we attempted to develop subgenome D-specific fluorescence in situ hybridization (FISH) probes by selecting D-specific oligonucleotides based on the reference genome of Chinese Spring. The oligo-based chromosome painting probes consisted of approximately 26 000 oligos per chromosome and their specificity was confirmed in both diploid and polyploid species containing the D subgenome. Two previously reported translocations involving two D chromosomes have been confirmed in wheat varieties and their derived lines. We demonstrate that the oligo painting probes can be used not only to identify the translocations involving D subgenome chromosomes, but also to determine the precise positions of chromosomal breakpoints. Chromosome painting of 56 accessions of Ae. tauschii from different origins led us to identify two novel translocations: a reciprocal 3D-7D translocation in two accessions and a complex 4D-5D-7D translocation in one accession. Painting probes were also used to analyze chromosomes from more diverse Aegilops species. These probes produced FISH signals in four different genomes. Chromosome rearrangements were identified in Aegilops umbellulata, Aegilops markgrafii, and Aegilops uniaristata, thus providing syntenic information that will be valuable for the application of these wild species in wheat breeding.

Bmi-1-RING1B prevents GATA4-dependent senescence-associated pathological cardiac hypertrophy by promoting autophagic degradation of GATA4.

AIMS: Senescence-associated pathological cardiac hypertrophy (SA-PCH) is associated with upregulation of foetal genes, fibrosis, senescence-associated secretory phenotype (SASP), cardiac dysfunction and increased morbidity and mortality. Therefore, we conducted experiments to investigate whether GATA4 accumulation induces SA-PCH, and whether Bmi-1-RING1B promotes GATA4 ubiquitination and its selective autophagic degradation to prevent SA-PCH. METHODS AND RESULTS: Bmi-1-deficient (Bmi-1-/- ), transgenic Bmi-1 overexpressing (Bmi-1Tg ) and wild-type (WT) mice were infused with angiotensin II (Ang II) to stimulate the development of SA-PCH. Through bioinformatics analysis with RNA sequencing data from cardiac tissues, we found that Bmi-1-RING1B and autophagy are negatively related to SA-PCH. Bmi-1 deficiency promoted GATA4-dependent SA-PCH by increasing GATA4 protein and hypertrophy-related molecules transcribed by GATA4 such as ANP and BNP. Bmi-1 deficiency stimulated NF-κB-p65-dependent SASP, leading to cardiac dysfunction, cardiomyocyte hypertrophy and senescence. Bmi-1 overexpression repressed GATA4-dependent SA-PCH. GATA4 degraded by Bmi-1 was mainly dependent on autophagy rather than proteasome. In human myocardium, p16 positively correlated with ANP and GATA4 and negatively correlated with LC3B, Bmi-1 and RING1B; GATA4 positively correlated with p62 and negatively correlated with Bmi-1 and LC3B. With increased p16 protein levels, ANP-, BNP- and GATA4-positive cells or areas increased; however, LC3B-positive cells or areas decreased in human myocardium. GATA4 is ubiquitinated after combining with Bmi-1-RING1B, which is then recognised by p62, is translocated to autophagosomes to form autophagolysosomes and degraded. Downregulated GATA4 ameliorated SA-PCH and cardiac dysfunction by reducing GATA4-dependent hypertrophy and SASP-related molecules. Bmi-1 combined with RING1B (residues 1-179) and C-terminus of GATA4 (residues 206-443 including zinc finger domains) through residues 1-95, including a RING-HC-finger. RING1B combined with C-terminus of GATA4 through the C-terminus (residues 180-336). Adeno-associated viral vector serotype 9 (AAV9)-cytomegalovirus (CMV)-Bmi-1-RING1B treatment significantly attenuated GATA4-dependent SA-PCH through promoting GATA4 autophagic degradation. CONCLUSIONS: Bmi-1-RING1B maintained cardiac function and prevented SA-PCH by promoting selective autophagy for degrading GATA4. TRANSLATIONAL PERSPECTIVE: AAV9-CMV-Bmi-1-RING1B could be used for translational gene therapy to ubiquitinate GATA4 and prevent GATA4-dependent SA-PCH. Also, the combined domains between Bmi-1-RING1B and GATA4 in aging cardiomyocytes could be therapeutic targets for identifying stapled peptides in clinical applications to promote the combination of Bmi-1-RING1B with GATA4 and the ubiquitination of GATA4 to prevent SA-PCH and heart failure. We found that degradation of cardiac GATA4 by Bmi-1 was mainly dependent on autophagy rather than proteasome, and autophagy agonists metformin and rapamycin could ameliorate the SA-PCH, suggesting that activation of autophagy with metformin or rapamycin could also be a promising method to prevent SA-PCH.

Potential environmental risk of natural particulate cadmium and zinc in sphalerite- and smithsonite-spiked soils.

Cadmium (Cd)-bearing sphalerite and smithsonite ore particles are ubiquitous in soils near metal-mining areas. Previous studies indicate that smithsonite is more readily dissolved in acidic waters and soils than sphalerite but the mobility of Cd and zinc (Zn) derived from these ores in soils is unknown. Using microcosm incubation experiments and microscopic and spectroscopic analysis, we found that the mobility of Cd and Zn derived from smithsonite is higher than from sphalerite. The mobilization rates of Cd (16.6%) and Zn (13.7%) released from smithsonite in soils after 30-day incubation experiments were higher than those from sphalerite (Cd, ~ 1.42%; Zn, ~ 0.75%). Moreover, the percentages of Cd2+ and Zn2+ in soil pore water showed a dynamic increase in smithsonite-spiked treatments but a decrease in sphalerite-spiked treatments. HRTEM-EDX-SAED analysis further indicates the occurrence of dynamic transformation of amorphous Cd and Zn species in soil pore water to crystalline ZnS and iron oxides in sphalerite-spiked soil but crystalline ZnCO3 nanoparticles were dynamically transformed to amorphous metal-bearing species in smithsonite-spiked soil. The opposite transformation trends in pore water of Zn ore-spiked soils provide new insights into the Cd environmental risks in soils affected by Zn mining.

P16 I NK 4a Deletion Ameliorates Damage of Intestinal Epithelial Barrier and Microbial Dysbiosis in a Stress-Induced Premature Senescence Model of Bmi-1 Deficiency.

This study aimed to determine whether Bmi-1 deficiency leads to intestinal epithelial barrier destruction and microbiota dysfunction, which members of the microbial community alter barrier function with age, and whether p16 INK4a deletion could reverse the damage of intestinal epithelial barrier and microbial dysbiosis. Intestines from Bmi-1-deficient (Bmi-1-/- ), Bmi-1 and p16 INK4a double-knockout (Bmi-1-/-p16 INK4a-/- ), and wild-type mice were observed for aging and inflammation. Duolink Proximity Ligation Assay, immunoprecipitation, and construction of p16 INK4a overexpressed adenovirus and the overexpressed plasmids of full-length, mutant, or truncated fragments for occludin were used for analyzing the interaction between p16 INK4a and occludin. High-throughput sequencing of V4 region amplicon of 16S ribosomal RNA was conducted using intestinal microbiota. We found Bmi-1 deficiency destructed barrier structure, barrier function, and tight junction (TJ) in intestinal epithelium; decreased the TJ proteins; increased tumor necrosis factor α (TNF-α)-dependent barrier permeability; and up-regulated proinflammatory level of macrophages induced by intestinal microbial dysbiosis. The transplantation of fecal microbiota from wild-type mice ameliorated TJ in intestinal epithelium of Bmi-1-/- and Bmi-1-/-p16 INK4a-/- mice. Harmful bacteria including Desulfovibrio, Helicobacter, and Oscillibacter were at a higher level in Bmi-1-/- mice. More harmful bacteria Desulfovibrio entered the epithelium and promoted macrophages-secreted TNF-α and caused TNF-α-dependent barrier permeability and aging. Accumulated p16 INK4a combined with occludin at the 1st-160th residue in cytoplasm of intestinal epithelium cells from Bmi-1-/- mice, which blocked formation of TJ and the repair of intestinal epithelium barrier. P16 INK4a deletion could maintain barrier function and microbiota balance in Bmi-1-/- mice through strengthening formation of TJ and decreasing macrophages-secreted TNF-α induced by Desulfovibrio entering the intestinal epithelium. Thus, Bmi-1 maintained intestinal TJ, epithelial barrier function, and microbiota balance through preventing senescence characterized by p16 INK4a accumulation. The clearance of p16 INK4a -positive cells in aging intestinal epithelium would be a new method for maintaining barrier function and microbiota balance. The residues 1-160 of occludin could be a novel therapeutic target for identifying small molecular antagonistic peptides to prevent the combination of p16 INK4a with occludin for protecting TJ.

Detection of CD8+ T cell-mediated immune responses to bacterial infection in mice.

Efficient activation of CD8+ T cells is critical for bacterial resistance and eradicating malignancy in the body. Here, we present a step-by-step protocol to use Listeria monocytogenes expressing OVA (LmOVA) to stimulate endogenous CD8+ T cells. We describe the steps for adoptive transfer of OT-I CD8+ T cells to CD45.1 mice and then detail the steps for detection of the antigen-specific CD8+ T cells in response to LmOVA. For complete details on the use and execution of this protocol, please refer to Wu et al. (2021).

Cadmium Isotopic Fractionation in the Soil-Plant System during Repeated Phytoextraction with a Cadmium Hyperaccumulating Plant Species.

Analysis of stable metal isotopes can provide important information on biogeochemical processes in the soil-plant system. Here, we conducted a repeated phytoextraction experiment using the cadmium (Cd) hyperaccumulator Sedum plumbizincicola X. H. Guo et S. B. Zhou ex L. H. Wu (Crassulaceae) in four different Cd-contaminated agricultural soils over five consecutive crops. Isotope composition of Cd was determined in the four soils before and after the fifth crop, in the plant shoots harvested in all soils in the first crop, and in the NH4OAc extracts of two contrasting soils with large differences in soil pH (5.73 and 7.32) and clay content (20.4 and 31.3%) before and after repeated phytoextraction. Before phytoextraction NH4OAc-extractable Cd showed a slight but significant negative isotope fractionation or no fractionation compared with total Cd (Δ114/110Cdextract-soil = -0.15 ± 0.05 (mean ± standard error) and 0.01 ± 0.01‰), and the extent of fractionation varied with soil pH and clay content. S. plumbizincicola preferentially took up heavy Cd from soils (Δ114/110Cdshoot-soil = 0.02-0.14‰), and heavy isotopes were significantly depleted in two soils after repeated phytoextraction (Δ114/110Cdsoil:P5-soil:P0 = -0.15 ± 0.02 and -0.12 ± 0.01‰). This provides evidence for the existence of specific Cd transporters in S. plumbizincicola, leading to positive isotope fractionation during uptake. After phytoextraction by five sequential crops, the NH4OAc-extractable Cd pool was significantly enriched in heavy isotopes (Δ114/110Cdextract:P5-extract:P0 = 0.07 ± 0.02 and 0.18 ± 0.05‰) despite the preferential uptake of heavy isotopes, indicating the occurrence of root-induced Cd mobilization in soils, which is supposed to favor heavy Cd in the organo-complexes with root exudates. Our results demonstrate that Cd is taken up by S. plumbizincicola via specific transporters, partly after active mobilization from the more strongly bound soil pool such as iron/manganese (hydr)oxide-bound Cd during repeated phytoextraction. This renders S. plumbizincicola a suitable plant for large-scale field phytoremediation.

Exosomal Transfer of LCP1 Promotes Osteosarcoma Cell Tumorigenesis and Metastasis by Activating the JAK2/STAT3 Signaling Pathway.

Increasing evidence indicates that lymphocyte cytosolic protein 1 (LCP1) overexpression contributes to tumor progression; however, its role in osteosarcoma (OS) remains unclear. We aimed to investigate the potential effect of LCP1 in OS and the underlying mechanisms. We first demonstrated that LCP1 is upregulated in OS cell lines and tissues. Then, we found that aberrant expression of LCP1 could induce the proliferation and metastasis of OS cells in vitro and in vivo by destabilizing neuregulin receptor degradation protein-1 (Nrdp1) and subsequently activating the JAK2/STAT3 signaling pathway. When coculturing OS cells with bone marrow-derived mesenchymal stem cells (BMSCs) in vitro, we validated that oncogenic LCP1 in OS was transferred from BMSCs via exosomes. Moreover, microRNA (miR)-135a-5p, a tumor suppressor, was found to interact upstream of LCP1 to counteract the pro-tumorigenesis effects of LCP1 in OS. In conclusion, BMSC-derived exosomal LCP1 promotes OS proliferation and metastasis via the JAK2/STAT3 pathway. Targeting the miR-135a-5p/LCP1 axis may have potential in treating OS.

Bmi-1 determines the stemness of renal stem or progenitor cells.

Renal stem or progenitor cells (RSCs), labeled with CD24 and CD133, play an important role during the repair of renal injury. Bmi-1 is a critical factor in regulating stemness of adult stem cells or progenitor cells. To investigate whether Bmi-1 determines the stemness of RSCs by inhibiting p16 and p53, and/or maintaining redox balance, RSCs were isolated, cultured and analyzed for stemness characterizations. In RSCs from Bmi-1-deficient (Bmi-1-/-) mice and wild type (WT) littermates, self-renewal, stemness, and expressions of molecules for regulating redox balance and cell cycle progression were compared. Self-renewal of RSCs from Bmi-1 and p16 double-knockout (Bmi-1-/-p16-/-), Bmi-1 and p53 double-knockout (Bmi-1-/-p53-/-) and N-acetylcysteine (NAC)-treated Bmi-1-/- mice were further analyzed for amelioration. Human renal proximal tubular epithelial cells (HK2) were also used for signaling analysis. Our results showed that third-passage RSCs from WT mice had good stemness; Bmi-1 deficiency led to the decreased stemness, and the increased apoptosis for RSCs; NAC treatment or p16/p53 deletion ameliorated the decreased self-renewal of RSCs in Bmi-1 deficiency mice by maintaining redox balance or inhibiting cell cycle arrest respectively; Oxidative stress (OS) could negatively feedback regulate the mRNA expressions of Bmi-1, p16 and p53. In conclusion, Bmi-1 determined the stemness of RSCs through maintaining redox balance and preventing cell cycle arrest. Thus, Bmi-1 signaling molecules would be novel therapeutic targets for maintaining RSCs and hampering the progression of kidney diseases to prevent renal failure.