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1.
Mar Drugs ; 19(3)2021 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-33801204

RESUMEN

Our previous studies have found that (±)-(E)-12-hydroxyoctadec-10-enoic acid (HOEA) isolated from the red alga Tricleocarpa jejuensis showed cytotoxic effects on various living organisms including harmful microalgae, Gram-positive bacteria, and mammalian tumor cells. Since natural products with apoptosis-inducing ability can be promising anti-cancer agents, in this study, we investigated the cytotoxic mechanism of HOEA on U937 cells focusing on apoptosis induction. HOEA showed much stronger cytotoxic and cytolytic effects on U937 cells than elaidic acid, which has similar structure but no 12-hydroxy group, suggesting that hydroxy group is important for the cytotoxicity of HOEA. HOEA induced apoptotic nuclear morphological changes, DNA fragmentation, and decrease in mitochondrial membrane potential. Furthermore, time-dependent increase in annexin V+/PI+ cell population in HOEA-treated U937 cells was detected. Among the apoptosis-related reagents, caspase-family inhibitor almost completely inhibited HOEA-induced DNA fragmentation. In the analyses using specific caspase-substrates, extremely high cleavage activity toward caspase-3/7/8 substrate was observed in HOEA-treated U937 cells, and weak activities of caspase-1 and -3 were detected. Analyses using specific caspase inhibitors suggested that caspase-3 and caspase-8 might be predominantly responsible for the cleavage activity. Activation of these caspases were also confirmed by western blotting in which significant levels of cleaved forms of caspase 3, caspase 8, and PARP were detected in HOEA-treated U937 cells. Our results suggest that HOEA is capable of inducing apoptosis in U937 cells in which caspase-3 and caspase-8 might play important roles. Since the cytotoxic effect of HOEA is not strictly specific to tumor cells, development of appropriate drug delivery system for selective tumor targeting is necessary for the clinical applications to reduce the possible side effects.

2.
Medicine (Baltimore) ; 100(13): e24922, 2021 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-33787579

RESUMEN

RATIONAL: Ovarian sertoli-leydig cell tumor (OSLCT) is extremely rare. We reported a OSLCT case in whom postmenopausal vaginal bleeding was the first symptom. PATIENT CONCERNS: The patient came to our hospital due to postmenopausal vaginal bleeding. DIAGNOSES: Serum tumor markers and color Doppler ultrasound for her pelvic cavity were negative. The patient was finally diagnosed with left OSLCT by pathology. It was difficult to make a definite diagnosis before operation, the diagnosis of OSLCT required postoperative pathology in the patients. INTERVENTIONS: the patient underwent laparoscopic hysterectomy+bilateral adnexectomy+lysis of pelvic adhesions. OUTCOMES: Postoperative laboratory examinations were normal. The patient was discharged from our hospital on the seventh day after operation and came to our hospital for follow-up check in April 2020. Physical and laboratory examinations were normal. LESSONS: OSLCT can show different endocrine abnormalities, which are related to the various types of tumor tissues. Missed diagnosis and misdiagnosis are likely to occur in the patients who only have elevated serum testosterone. For the menopausal women with elevated serum testosterone, ovarian tumor shoule be highly suspected after excluding adrenal gland-related diseases.

3.
J Orthop Res ; 2021 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-33788325

RESUMEN

Adult human meniscus fibrocartilage is avascular and non-healing after injury. Meniscus tissue engineering aims to replace injured meniscus with lab grown fibrocartilage. Dynamic culture systems may be necessary to generate fibrocartilage of sufficient mechanical properties for implantation; however, the optimal static pre-culture conditions prior to initiation of dynamic culture are unknown. This study thus investigated the time course of fibrocartilage formation by human meniscus fibrochondrocytes on a 3D biomaterial scaffold under various static conditions. Human meniscus fibrochondrocytes from partial meniscectomy were expanded to P1 or P2 (3.0±0.4 or 6.5±0.6 population doublings), seeded onto type I collagen scaffolds, and grown in hypoxia (HYP, 3% O2 ) or normoxia (NRX, 20% O2 ) for 3, 6, or 9 weeks. Mechanical properties were not different between P1 and P2 cell-based constructs. Mechanical properties were lower in HYP, increased continually in NRX only, and were positively correlated with glycosaminoglycan content and accumulation of hyaline cartilage-like matrix components. The most mechanically competent tissues (NRX/9 weeks) reached 1/5 of the native meniscus instantaneous compression modulus but had an increasingly hypertrophic matrix-forming phenotype. HYP consistently suppressed the hypertrophic phenotype. The results provide baselines of engineered meniscus fibrocartilage properties under static conditions, which can be used to select a pre-culture strategy for dynamic culture depending on the desired combination of mechanical properties, hyaline cartilage-like matrix abundance, and hypertrophic phenotype. This article is protected by copyright. All rights reserved.

4.
Mol Plant ; 2021 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-33741527

RESUMEN

Grain number per panicle (GNP) is an important agronomic trait that contributes to rice grain yield. Despite its importance in rice breeding, the molecular mechanism underlying GNP regulation remains largely unknown. Here, we report that genetic variation in the CArG box-containing inverted repeat (IR) sequence of OsREM20 promoter alters its expression level and contributes to GNP variation among rice varieties through genetic analysis and transgenic validation. We revealed that the IR sequence regulates OsREM20 expression by affecting the direct binding of OsMADS34 to the CArG box within the IR sequence. The divergent pOsREM20IR and pOsREM20ΔIR alleles originated from different O. rufipogon accessions, and were independently inherited into the japonica and indica subspecies respectively during domestication. We further determined that IR sequence variations in the OsREM20 promoter can be utilized for germplasm improvement through either genome editing or traditional breeding. Our findings highlight exciting implications not only for characterizing the novel genetic variation that responsible for GNP diversity in rice, but also for revealing the molecular mechanism and potential application of the cis-regulatory element-containing IR sequence in the regulation of agronomically important gene expression.

5.
BMC Med Genomics ; 14(1): 81, 2021 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-33731098

RESUMEN

BACKGROUND: To investigate the clinical and genetic characteristics of patients with glycogen storage disease type Ib (GSD Ib). CASE PRESENTATION: This report retrospectively analyzed the clinical data of 3 patients with GSD Ib admitted into our hospital, and summarized their onset characteristics, clinical manifestations, related examinations and treatment as well as mutational spectrum. After gene sequencing, the diagnosis of GSD Ib was confirmed in all 3 patients. Five variants of SLC37A4 gene were detected, of which c. 572C > T was the common variant and c. 680G > A was a novel variant. The 3 cases of GSD Ib were mainly affected by liver enlargement, growth retardation, etc., and all had a history of repeated infections. At the onset, patients mainly manifested as mildly elevated alanine-aminotransferase (ALT), accompanied by decreased absolute neutrophil count (ANC), hypertriglyceridemia, and metabolic disorders (hypoglycemia, hyperlactic acidemia, metabolic acidosis, etc.). After long-term treatment by oral uncooked cornstarch, the abnormal liver enzymes gradually returned to normal, and metabolic abnormalities were basically controlled most of the time. With increasing age, ANC of 2 patients decreased progressively, whereas the times of infections was reduced. CONCLUSIONS: We reported 3 cases with GSD Ib and a novel SLC37A4 variant. The possibility of GSD type Ib should be kept on alert when a patient suffers recurrent infections, accompanied by hepatomegaly, elevated liver enzymes, hypoglycemia, dyslipidemia, and metabolic disorders.

6.
Ying Yong Sheng Tai Xue Bao ; 32(3): 878-886, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33754553

RESUMEN

Establishing monoculture of native broadleaved tree species and mixed coniferous broadleaved plantations is the tendency for forest management in subtropical China. The variations of structure and function of soil bacterial community in monoculture and mixed tree plantations are still not clear. We examined soil bacterial community structure and function under different soil layers (0-20, 20-40 and 40-60 cm) in three planted forests, including broadleaved Castanopsis hystrix, coniferous Pinus massoniana and their mixed plantation, in south subtropical China, using 16S rRNA gene high-throughput sequencing and PICRUSt prediction. The results showed that soil bacterial community structure of mixed plantation and P. massoniana plantation were similar but being significant different from that in C. hystrix plantation. The diversity, biological pathways metabolic function, and nitrogen cycling function of soil bacterial community in C. hystrix plantation were lower than those in P. massoniana plantation and mixed plantation. Soil total nitrogen, nitrate nitrogen and C/N were the main factors driving the variations of soil bacterial community structure and function among different forest types. Our results suggested that the mixed plantation of C. hystrix and P. massoniana is better than C. hystrix plantation in this area in terms of soil bacterial community structure and function.


Asunto(s)
Pinus , Suelo , China , Bosques , ARN Ribosómico 16S
7.
Plant Dis ; 2021 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-33761771

RESUMEN

Rice sheath blight (SB) disease is a global issue that causes great yield losses each year. To explore whether SB field resistance can be predicted, 273 rice genotypes were inoculated and evaluated for SB field resistance across nine environments (2012-2019) to identify loci associated with SB resistance by association mapping. A total of 80 significant marker-trait associations were detected in nine environments, among which six loci (D130B, D230A, D304B, D309, D427A, and RM409) were repeatedly detected in at least two environments. A linear regression model for predicting SB lesion length was developed using genotypic data of these 6 loci and SB field resistance data of the 273 rice genotypes: y = 34.44 - 0.56 x, where y is the predicted value of lesion length, and x is the total genotypic value of the six loci. A recombinant inbred line (RIL) population consisting of 219 lines that was grown in six environments (from 2013 to 2018) for evaluation of SB field resistance was used to check the prediction accuracy of the prediction model. The average absolute error between the predicted lesion length and real lesion length for the RIL population was 6.67 cm. The absolute errors between predicted and real lesion lengths were below 6 cm for 51.22% of the lines, and were below 9 cm for 71.22% of the lines. An SB visual rating prediction model was also developed, the average absolute error between the predicted visual rating and real visual rating for the RIL population was 0.94. These results indicated that the rice SB lesion length can be predicted by the development of a linear regression model using both genotypic and phenotypic data.

8.
Hepatol Res ; 2021 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-33772988

RESUMEN

AIM: To assess the role of consolidation therapy after nucleos(t)ide analogues (NAs) cessation for off-treatment outcome and to explore the optimal consolidation period in HBeAg-positive chronic hepatitis B (CHB) patients. METHODS: We performed a prospective, observational cohort study including HBeAg-positive CHB patients discontinuing NAs. Virological relapse was the primary endpoint of the current study and was defined as a serum HBV DNA more than 104 copies/ml (another assay was performed for confirmation at least 2 weeks later). Propensity score matching analysis (PSM) was used to balance the baseline characteristics between HBeAg-positive CHB patients with different consolidation periods. RESULTS: A total of 190 HBeAg-positive CHB patients were included. Fifty-four patients relapsed during follow-up and the cumulative relapse rates at years 1, 3, 5 and 10 were 19.5%, 24.1%, 27.2% and 32.1%, respectively. Most patients (61.1%) relapsed in the first 6 months. After PSM, significant lower cumulative relapse rates were observed in patients with consolidation period ≥ 36months compared with patients with consolidation period < 36 months (29.3% vs. 52.8% at year 10, p = 0.012). CONCLUSIONS: NAs cessation after HBeAg seroconversion and long-term consolidation is generally safe and feasible in HBeAg-positive CHB patients. Three years of consolidation should be preferred in clinical practice. This article is protected by copyright. All rights reserved.

10.
Arthritis Rheumatol ; 2021 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-33682379

RESUMEN

Systemic lupus erythematosus (SLE) is a prototype of systemic autoimmune diseases, characterized by loss of self-tolerance and production of multiple autoantibodies. Although the mechanism of SLE has remained elusive, accumulating evidence indicates that altered follicular helper T (Tfh) cells differentiation, function, and regulation may have an important role in SLE pathogenesis [1-3].

11.
PLoS One ; 16(3): e0248292, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33690647

RESUMEN

Low oxygen and mechanical loading may play roles in regulating the fibrocartilaginous phenotype of the human inner meniscus, but their combination in engineered tissues remains unstudied. Here, we investigated how continuous low oxygen ("hypoxia") combined with dynamic compression would affect the fibrocartilaginous "inner meniscus-like" matrix-forming phenotype of human meniscus fibrochondrocytes (MFCs) in a porous type I collagen scaffold. Freshly-seeded MFC scaffolds were cultured for 4 weeks in either 3 or 20% O2 or pre-cultured for 2 weeks in 3% O2 and then dynamically compressed for 2 weeks (10% strain, 1 Hz, 1 h/day, 5 days/week), all with or without TGF-ß3 supplementation. TGF-ß3 supplementation was found necessary to induce matrix formation by MFCs in the collagen scaffold regardless of oxygen tension and application of the dynamic compression loading regime. Neither hypoxia under static culture nor hypoxia combined with dynamic compression had significant effects on expression of specific protein and mRNA markers for the fibrocartilaginous matrix-forming phenotype. Mechanical properties significantly increased over the two-week loading period but were not different between static and dynamic-loaded tissues after the loading period. These findings indicate that 3% O2 applied immediately after scaffold seeding and dynamic compression to 10% strain do not affect the fibrocartilaginous matrix-forming phenotype of human MFCs in this type I collagen scaffold. It is possible that a delayed hypoxia treatment and an optimized pre-culture period and loading regime combination would have led to different outcomes.

12.
Neuroreport ; 32(6): 507-517, 2021 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-33788813

RESUMEN

OBJECTIVE: We attempt to investigate the biological function of the discoidin, complement C1r/C1s,Uegf, and Bmp1 and Limulus factor C, Coch, and Lgl domain-containing 2 (DCBLD2) in glioblastoma, as well as its effect on the epithelial-mesenchymal transition (EMT) process. METHODS: The public expression data of glioblastoma samples and normal brain samples from The Cancer Genome Atlas database, Genotype-Tissue Expression database and Chinese Glioma Genome Atlas database were used to analyze the expression of DCBLD2 and its relationship with the survival of patients with glioblastoma. Quantitative real-time PCR and western blot were used to evaluate mRNA and protein levels of DCBLD2. Cell viabilities were tested using Cell Counting Kit-8 and clone formation assays. Cell invasive and migratory abilities were measured by transwell assays. RESULTS: DCBLD2 expression was upregulated in glioblastoma and has a significantly positive correlation with the WHO classification. In addition, high expression of DCBLD2 was closely correlated with poor prognosis in primary and recurrent patients with glioblastoma. What is more, we found that knockdown of DCBLD2 notably reduced the cell proliferative, invasive and migratory capacities by elevating the expression of E-cadherin and inhibiting the expression of vimentin, snail, slug and twist. However, overexpression of DCBLD2 presented the opposite results. CONCLUSION: The current study reveals that high expression of DCBLD2 is closely related to poor prognosis in glioblastoma and can significantly enhance the tumor cell viability and metastasis by activating the EMT process, suggesting that DCBLD2 may be a possible biomarker for glioblastoma treatment.

13.
Theranostics ; 11(9): 4281-4297, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33754061

RESUMEN

Chemotherapeutic multidrug resistance (MDR) is the major hindrance for clinical therapy of colorectal cancer (CRC). Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) with selective cytotoxicity might overcome MDR of CRC cells. Unfortunately, cross-resistance to TRAIL has been detected in many CRC cells, suggesting the need to combine TRAIL with sensitizers to combat refractory CRC. Our purpose is to explore the potential of combination therapy of TRAIL and tumor-cell targeted photodynamic therapy (PDT) in combating CRC with both chemotherapeutic MDR and TRAIL resistance. Methods: Tumor cell-targeted PDT was performed using a Ze-IR700 photosensitizer with high affinity for epidermal growth factor receptor (EGFR). The impact of PDT on the gene expression of CRC cells was revealed by RNA sequencing. The synergistic antitumor effect of long-acting TRAIL and PDT was evaluated in mice bearing tumor grafts of CRC cells with both chemotherapeutic MDR and TRAIL resistance. Results: Chemotherapeutic MDR and TRAIL resistance are common in CRC cells. Pretreatment of CRC cells with tumor cell-targeted PDT significantly (10-60 times) increased the sensitivity of these CRC cells to TRAIL by upregulating death receptors. Combination therapy, but not monotherapy, of long-acting TRAIL and PDT greatly induced apoptosis of CRC cells, thus efficiently eradicated large (~150 mm3) CRC tumor xenografts in mice. Conclusions: Tumor cell-targeted PDT extensively sensitizes CRC cells to TRAIL. Combination therapy of long-acting TRAIL and PDT is promising to combat CRC with both chemotherapeutic MDR and TRAIL resistance, which might be developed as a novel strategy for precision therapy of refractory CRC.

14.
Asian J Androl ; 2021 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-33723098

RESUMEN

We aim to design a new glanuloplasty procedure combined with spongiosum to reduce the incidence of glans dehiscence and coronal fistula after proximal hypospadias repair. Patients who underwent urethroplasty by dorsal preputial island flap for proximal hypospadias between January 2014 and December 2016 were reviewed in this retrospective cohort study. Those who underwent spongiosum-combined glanuloplasty comprised the new-maneuver group, whereas those who underwent conventional glanuloplasty comprised the control group. The incidence of complications was then compared. In the new-maneuver group, dysplastic corpus spongiosum alongside lateral Buck's fascia (0.3-0.4 cm wide) on both sides of the urethral plate was separated from the proximal normal spongy tissue, joining into the glans wings to increase tissue volume and covering the neourethra in the glans penis. In the control group, the neourethra was covered with superficial fascia under the coronal sulcus. As a result, the new-maneuver and control groups comprised 47 and 28 patients, respectively. In the new-maneuver group, no glans dehiscence was detected; however, two (4.3%) patients had coronal fistula, two (4.3%) had urethral stricture, and four (8.5%) had diverticulum. In the control group, two (7.1%) patients had glans dehiscence, eight (28.6%) had coronal fistula, four (14.3%) had urethral stricture, one (3.6%) had diverticulum, and one (3.6%) had penile curvature recurrence. The new-maneuver group had less incidences of coronal fistula (P < 0.001), glans dehiscence (P = 0.033), and urethral stricture (P = 0.008) but had a higher incidence of diverticulum than the control group (P = 0.040). It clearly demonstrates that spongiosum-combined glanuloplasty can significantly reduce the incidences of coronal fistula and glans dehisce.

15.
Nanoscale ; 13(9): 4774-4784, 2021 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-33576757

RESUMEN

GNA002, a novel EZH2 inhibitor, exhibits significant anticancer efficiency in solid malignant tumor therapy; however, its poor water solubility and low enrichment at tumor sites limit its clinical application and translation. In this study, an original pH-sensitive nanocarrier (cyclo (RGDyCSH) (cRGD)-poly (ethylene glycol) (PEG)-hydrazine (Hyd)-hexa-arginine (R6)-stearic acid (SA)) was designed to precisely deliver GNA002 into the nuclei of cancer cells. The PEG-modified hydrophilic shell of the spherical GNA002-loaded nanoparticles with a mean size of 143.13 ± 0.20 nm effectively facilitated the passive target of tumor tissues and prolonged the blood circulation time. Meanwhile, cRGD was used as the active targeting ligand, which promoted the accumulation of the nanoparticles in cancer cells via ανß3-receptor-mediated endocytosis. Furthermore, the acidic environment of lysosomes triggered the rupture of the pH-sensitive hydrazine bond and the rapid formation of penetrating peptide R6-shelled secondary nanoparticles, thus enabling the lysosomal escape of the nanoparticles and the ultimate R6-mediated nuclear-targeted delivery of GNA002. Consequently, the nuclear-enriched GNA002 effectively enhanced the cytotoxicity against cancer cells both in vitro and in vivo, thus providing an original and promising drug delivery system for the targeted delivery of GNA002.

16.
Biosci Biotechnol Biochem ; 85(4): 882-889, 2021 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-33580696

RESUMEN

In this study, we found that a sulfated polysaccharide isolated from the brown alga Ascophyllum nodosum, ascophyllan, showed suppressive effects on stimulated RAW264.7 cells. Ascophyllan significantly inhibited expression of inducible nitric oxide synthase mRNA and excessive production of nitric oxide (NO) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells in a dose-dependent manner without affecting the viability of RAW264.7 cells. Ascophyllan also reduced the elevated level of intracellular reactive oxygen species (ROS) in LPS-stimulated RAW264.7 cells. Furthermore, preincubation with ascophyllan resulted in concentration-dependent decrease in ROS production in phorbol 12-myristate-13-acetate-stimulated RAW264.7 cells. Our results suggest that ascophyllan can exhibit anti-inflammatory effects on stimulated macrophages mainly through the attenuation of NO and ROS productions.

17.
Biochimie ; 184: 72-87, 2021 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-33607240

RESUMEN

l-Valine, l-isoleucine, and l-leucine are three key proteinogenic amino acids, and they are also the essential amino acids required for mammalian growth, possessing important and to some extent, special physiological and biological functions. Because of the branched structures in their carbon chains, they are also named as branched-chain amino acids (BCAAs). This review will highlight the advance in studies of the enzymes involved in the biosynthetic pathway of BCAAs, concentrating on their chemical mechanisms and applications in screening herbicides and antibacterial agents. The uses of some of these enzymes in lab scale organic synthesis are also discussed.

18.
Cell ; 184(5): 1156-1170.e14, 2021 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-33539781

RESUMEN

Cultivated rice varieties are all diploid, and polyploidization of rice has long been desired because of its advantages in genome buffering, vigorousness, and environmental robustness. However, a workable route remains elusive. Here, we describe a practical strategy, namely de novo domestication of wild allotetraploid rice. By screening allotetraploid wild rice inventory, we identified one genotype of Oryza alta (CCDD), polyploid rice 1 (PPR1), and established two important resources for its de novo domestication: (1) an efficient tissue culture, transformation, and genome editing system and (2) a high-quality genome assembly discriminated into two subgenomes of 12 chromosomes apiece. With these resources, we show that six agronomically important traits could be rapidly improved by editing O. alta homologs of the genes controlling these traits in diploid rice. Our results demonstrate the possibility that de novo domesticated allotetraploid rice can be developed into a new staple cereal to strengthen world food security.

19.
Chem Asian J ; 2021 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-33619903

RESUMEN

Materials combining proton conductivity and magnetism have attracted great attention in recent years due to their intriguing application in sensors and fuel cells. Herein a two-dimensional metal-organic framework, [Cu(atz)2 (H2 O)2 ]⋅H2 O (1) (Hatz=5-aminotetrazole), has been obtained in a green synthesis method. The single-crystal structure revealed that the atz- ligands as linkers coordinate with copper ions to sql networks, between which water molecules are immobilized through hydrogen bonds. The resulting complex 1 exhibits a high proton conductivity of 1.11×10-4 and 6.19×10-4  S cm-1 at room temperature and 333 K, respectively, under 98% RH with an activation energy of 0.56 eV. Upon dehydration, the proton conductivity of 1_dg drops by an order of magnitude. Furthermore, the magnetic behavior changes from long-range ferrimagnetic ordering of 1 to canted antiferromagnetic behaviour of 1_dg.

20.
J Hazard Mater ; 412: 125212, 2021 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-33524732

RESUMEN

This study explored the change of tetracycline degradation efficiency, metabolic pathway, soil physiochemical properties and degraders in vermiremediation by two earthworm species of epigeic Eisenia fetida and endogeic Amynthas robustus. We found a significant acceleration of tetracycline degradation in both earthworm treatments, and 4-epitetracycline dehydration pathway was remarkably enhanced only by vermiremediation. Tetracycline degraders from soils, earthworm intestines and casts were different. Ralstonia and Sphingomonas were potential tetracycline degraders in soils and metabolized tetracycline through direct dehydration pathway. Degraders in earthworm casts (Comamonas, Acinetobacter and Stenotrophomonas) and intestines (Pseudomonas and Arthrobacter) dehydrated 4-epitetracycline into 4-epianhydrotetracycline. More bacterial lineages resisting tetracycline were found in earthworm treatments, indicating the adaptation of soil and intestinal flora under tetracycline pressure. Earthworm amendment primarily enhanced tetracycline degradation by neutralizing soil pH and consuming organic matters, stimulating both direct dehydration and epimerization-dehydration pathways. Our findings proved that vermicomposting with earthworms is effective to alter soil microenvironment and accelerate tetracycline degradation, behaving as a potential approach in soil remediation at tetracycline contaminated sites.

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