First Report of Enterobacter cloacae Causing Stem, Leaf and Fruit Rot on Tomato in China.

Tomato (Solanum lycopersicum L.), as one of the most economically important and highly nutritious vegetable crops across the world, is widely cultivated in China, one of the largest tomato-concuming countries in the world (Ye et al., 2020; Wang and Liu, 2021). At present, major bacterial diseases in tomato include bacterial speck disease, tomato bacterial wilt and bacterial canker, all of which affect the tomato production around the world (Rosli et al., 2021; Peritore-Galve et al., 2021; Wang et al., 2022). In April 2022, a new bacterial disease was discovered on leaves, stems and fruits of tomato in a farmer's greenhouse located in Longfeng District in DaQing (125°07`-125°15`E, 46°28`-46°32`N), Heilongjiang Province, China. This field had tomato disease incidences approximately 50%. Apparent brown discolorations were found on fruits, leaves and stems in tomato plants. Symptoms were similar to fungal brown spots caused by Phytophthora infestans of tomato (Zhi et al.,2021; Liu et al.,2021) (Supplementary Figure S1). To isolate and identify the pathogen, the tissues of infected fruits, leaves and stems with typical symptoms were excised from diseased plants separately, and were disinfected with 75% ethanol for 10 s followed by 2% NaClO for 3 min and then washed five to eight times with sterile water (Wang et al., 2017). Afterwards, the samples were plated on nutrient agar (NA) solid medium and incubated. After incubation at 30°C for 2-3 days, bacterial colonies were isolated, then purified on nutrient agar (NA) solid medium at least twice by a streak plate method (Dou et al., 2019; Li et al, 2021; Zhao et al., 2022). White colonies grew on the NA medium after incubating for 2 days, showing round, opaque and smooth, which was similar to characteristics described as Enterobacter cloacae (García-González et al., 2018; Li et al, 2021). To further confirm the speculation on the identity of the isolated bacterium, the fragments of 16S rRNA were amplified and sequenced. The sequence of 16S rRNA was uploaded into GeneBank with accession numbers (OP077195.1). BLAST analysis of the sequence showed 97.68% identity with one corresponding sequence of E. cloacae in GeneBank (namely MK937637.1). Furthermore, a phylogenetic tree based on the sequence of 16S rRNA gene revealed that the isolate was grouped in the same clade as E. cloacae (Supplementary Figure S2). Based on Koch postulates to test pathogenicity of isolated bacteria, bacteria were inoculated on 30 day-old healthy tomato plants with three leaves stages, and the re-isolation of bacteria were carried out after 2 days of inoculation. To confirm pathogenicity, the isolates were cultured on LB medium at 30℃ for 2 days to prepare suspensions and adjusted to an optical density (OD) of 0.2 at A600, with a final concentration of 1ⅹ108 CFU/ml. Eight potted tomato plants were sprayed with bacteria suspensions, and eight control potted plants were sprayed with sterile distilled water. These seedlings were incubated in a chamber at 30°C with a 12 h light/dark photoperiod, with 85% relative humidity. After 2 days, inoculated tomato seedlings showed irregular small spots in leaves and brown necrosis at blade tips, and 8 to 10 days later, the leaves of tomato plants browned and died. The symptoms were the same with those of the initial diseased leaves of tomato plants (Supplementary Figure S1). No symptoms were observed on the control leaves (Supplementary Figure S3). Pathogenicity tests were repeated three biological times with same results. Meanwhile, the bacteria strains were re-isolated from symptomatic inoculated seedlings and confirmed as E. cloacae by culture and sequence methods as above. In China, there are no detailed records about the causal agent of this disease on tomato in a published paper in Chinese and English. To our knowledge, this is the first report of Enterobacter leaf brown necrosis caused by E. cloacae on tomato in China. Those results are of great significance for the production and management of tomato in greenhouse and control of the disease.

N6-methyladenosine modification-tuned lipid metabolism controls skin immune homeostasis via regulating neutrophil chemotaxis.

Disrupted N6-methyladenosine (m6A) modification modulates various inflammatory disorders. However, the role of m6A in regulating cutaneous inflammation remains elusive. Here, we reveal that the m6A and its methyltransferase METTL3 are down-regulated in keratinocytes in inflammatory skin diseases. Inducible deletion of Mettl3 in murine keratinocytes results in spontaneous skin inflammation and increases susceptibility to cutaneous inflammation with activation of neutrophil recruitment. Therapeutically, restoration of m6A alleviates the disease phenotypes in mice and suppresses inflammation in human biopsy specimens. We support a model in which m6A modification stabilizes the mRNA of the lipid-metabolizing enzyme ELOVL6 via the m6A reader IGF2BP3, leading to a rewiring of fatty acid metabolism with a reduction in palmitic acid accumulation and, consequently, suppressing neutrophil chemotaxis in cutaneous inflammation. Our findings highlight a previously unrecognized epithelial-intrinsic m6A modification-lipid metabolism pathway that is essential for maintaining epidermal and immune homeostasis and lay the basis for potential therapeutic targeting of m6A modulators to attenuate inflammatory skin diseases.

Cutaneous immune-related adverse events to immune checkpoint inhibitors: from underlying immunological mechanisms to multi-omics prediction.

The development of immune checkpoint inhibitors (ICIs) has dramatically altered the landscape of therapy for multiple malignancies, including urothelial carcinoma, non-small cell lung cancer, melanoma and gastric cancer. As part of their anti-tumor properties, ICIs can enhance susceptibility to inflammatory side effects known as immune-related adverse events (irAEs), in which the skin is one of the most commonly and rapidly affected organs. Although numerous questions still remain unanswered, multi-omics technologies have shed light into immunological mechanisms, as well as the correlation between ICI-induced activation of immune systems and the incidence of cirAE (cutaneous irAEs). Therefore, we reviewed integrated biological layers of omics studies combined with clinical data for the prediction biomarkers of cirAEs based on skin pathogenesis. Here, we provide an overview of a spectrum of dermatological irAEs, discuss the pathogenesis of this "off-tumor toxicity" during ICI treatment, and summarize recently investigated biomarkers that may have predictive value for cirAEs via multi-omics approach. Finally, we demonstrate the prognostic significance of cirAEs for immune checkpoint blockades.

FGD5-AS1 facilitates the osteogenic differentiation of human bone marrow-derived mesenchymal stem cells via targeting the miR-506-3p/BMP7 axis.

BACKGROUND: Osteoporosis is a systemic disease characterized by impaired bone formation, increased bone resorption, and brittle bone fractures. The osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs) is considered to be a vital process for bone formation. Numerous studies have reported that long non-coding RNAs (lncRNAs) are involved in the osteogenic differentiation of hBMSCs. The present study aimed to investigate the effect of FGD5 antisense RNA 1 (FGD5-AS1) on osteogenic differentiation. METHODS: RT-qPCR was performed to detect the expression of FGD5-AS1, miR-506-3p, and osteogenesis-related genes OCN, OPN, OSX, and RUNX2. Western blotting was carried out to detect the protein levels of osteogenesis-related markers. In addition, the regulatory effect of FGD5-AS1 on osteogenic differentiation was detected through alkaline phosphatase (ALP) activity, Alizarin Red S (ARS) staining, and Cell Counting Kit-8 (CCK-8). Bioinformatics analysis and luciferase reporter assay were used to predict and validate the interaction between FGD5-AS1 and miR-506-3p as well as miR-506-3p and bone morphogenetic protein 7 (BMP7). RESULTS: The RT-qPCR analysis revealed that FGD5-AS1 was upregulated in hBMSCs following induction of osteogenic differentiation. In addition, FGD5-AS1 knockdown attenuated hBMSC viability and osteogenic differentiation. Bioinformatics analysis and luciferase reporter assays verified that FGD5-AS1 could directly interact with microRNA (miR)-506-3p. Furthermore, miR-506-3p could directly target the 3'-untranslated region (3'-UTR) of BMP7. Additionally, functional assays demonstrated that miR-506-3p silencing could restore the suppressive effect of FGD5-AS1 knockdown on osteogenic differentiation and viability of hBMSCs, and miR-506-3p could attenuate osteogenic differentiation via targeting BMP7. CONCLUSIONS: Taken together, the results of the present study suggested that FGD5-AS1 could positively regulate the osteogenic differentiation of hBMSCs via targeting the miR-506-3p/BMP7 axis.

MRI analysis of the ISOBAR TTL internal fixation system for the dynamic fixation of intervertebral discs: a comparison with rigid internal fixation.

OBJECTIVES: Using magnetic resonance imaging (MRI), we analyzed the efficacy of the posterior approach lumbar ISOBAR TTL internal fixation system for the dynamic fixation of intervertebral discs, with particular emphasis on its effects on degenerative intervertebral disc disease. METHODS: We retrospectively compared the MRIs of 54 patients who had previously undergone either rigid internal fixation of the lumbar spine or ISOBAR TTL dynamic fixation for the treatment of lumbar spondylolisthesis. All patients had received preoperative and 6-, 12-, and 24-month postoperative MRI scans of the lumbar spine with acquisition of both routine and diffusion-weighted images (DWI). The upper-segment discs of the fusion were subjected to Pfirrmann grading, and the lumbar intervertebral discs in the DWI sagittal plane were manually drawn; the apparent diffusion coefficient (ADC) value was measured. RESULTS: ADC values in the ISOBAR TTL dynamic fixation group measured at the 6-, 12-, and 24-month postoperative MRI studies were increased compared to the preoperative ADC values. The ADC values in the ISOBAR TTL dynamic fixation group at 24 months postoperatively were significantly different from the preoperative values (P < 0.05). At 24 months, the postoperative ADC values were significantly different between the rigid fixation group and the ISOBAR TTL dynamic fixation group (P < 0.05). CONCLUSION: MRI imaging findings indicated that the posterior approach lumbar ISOBAR TTL internal fixation system can prevent or delay the degeneration of intervertebral discs.