Short-term prone positioning for severe acute respiratory distress syndrome after cardiopulmonary bypass: A case report and literature review.

BACKGROUND: Aortic dissection is a complex and dangerous cardiovascular disease, with many complications in the perioperative period, including severe acute respiratory distress syndrome (ARDS), which affects prognosis and increases mortality. Despite the effect of prone positioning (PP) in improving oxygenation in patients with severe ARDS, reports about PP early after cardiac surgery are few and such an option may be an issue in cardiac surgery patients because of the recent sternotomy. CASE SUMMARY: A 40-year-old male patient diagnosed with acute type A aortic dissection on October 22, 2021 underwent ascending artery replacement plus total aortic arch replacement plus stent elephant trunk implantation under cardiopulmonary bypass. Unfortunately, he developed ARDS on postoperative day 1. Despite comprehensive treatment with aggressive pulmonary protective ventilation, fluid management with continuous renal replacement therapy, the condition continued to deteriorate and rapidly progressed to severe ARDS with a minimum oxygenation index of 51. We are ready to implement salvage therapy, including PP and extracorporeal membrane oxygenation (ECMO). Due to the large amount of pericardial mediastinal and thoracic drainage after thoracotomy, ECMO may result in massive postoperative bleeding. Prolonged prone ventilation is often inappropriate after thoracotomy. Therefore, we chose short-term PP for < 6 h. Finally, the oxygenation index greatly improved and the diffuse exudation in both lungs of the patient was significantly reduced with short-term prone positioning. CONCLUSION: Intermittent short-term PP can improve early postoperative severe ARDS after acute aortic dissection.

FGL1 as a Novel Mediator and Biomarker of Malignant Progression in Clear Cell Renal Cell Carcinoma.

Clear cell renal cell carcinoma (ccRCC), which is the most prevalent renal cell carcinoma subtype, has a poor prognosis. Emerging strategies for enhancing the immune response in ccRCC therapy are currently being investigated. Fibrinogen-like Protein 1(FGL1) is a novel mechanism that tumors may use to evade the immune system by binding LAG-3 and negatively regulating T cells. In this study, we aimed at investigating the underlying mechanism of FGL1 in ccRCC, and its expression and prognostic value. We found that FGL1 was upregulated in tumor tissues and plasma specimens of ccRCC patients. High FGL1 expression predicted a poor prognosis for ccRCC patients. We also discovered that overexpression of FGL1 enhances RCC cell migration, invasion, and metastasis by activating the epithelial-to-mesenchymal transition (EMT). Consistent with these results, we identified a significant positive correlation between expression of FGL1 and EMT-related genes through tissue microarray analysis. Gene-expression analysis revealed that FGL1-deficient ccRCC cell lines had altered transcriptional output in inflammatory response, cell-cell signaling, negative regulation of T cell activation, and intracellular signal transduction. Depletion of FGL1 significantly inhibited tumor growth and lung metastasis in orthotopic xenograft mouse model. Infiltration of myeloid-derived CD11b+ and Ly6G+ immune cells in tumor microenvironment (TME) was strikingly decreased when FGL1 expression reduced. Therefore, increased FGL1 expression in ccRCC is positively correlated with poor prognosis. Mechanistically, FGL1 facilitates the EMT process and modulates TME, which promotes ccRCC progression and metastasis. Consequently, targeting FGL1 can potentially improve clinical outcome of ccRCC patients.

Analysis of Factors Related to Distal Proximal Caries on the Distal Surface of the Mandibular Second Molar Induced by an Impacted Mandibular Third Molar.

OBJECTIVE: To analyze the factors related to distal proximal caries of the mandibular second molar (MSM) induced by an impacted mandibular third molar (MTM). METHODS: A total 500 panoramic radiographs of patients with impacted MTMs who were treated in the Department of Stomatology of the Affiliated Hospital of Yanbian University between October 2017 and October 2019 were selected. Descriptive and bivariate analyses were conducted, and the diagnosis of caries in the MSM and the position of the MTM were evaluated. RESULTS: The posterior margin space of the MSM was larger in males (13.5 mm) than females (11.1 mm, P < 0.001) and correlated with the MTM's impacted depth and eruption degree (P < 0.001). The prevalence of distal proximal caries of the MSM was 37.6%, and a χ 2 test showed that age, impacted depth, impacted direction, impacted angle, degree of occurrence, and CEJ distance were correlated with caries in the distal adjacent surface of the MSM (P < 0.001). Logistic multivariate analysis showed that the impacted depth was at position A or B, the impacted direction was mesioangular, and the impacted angle was <80°. Distal adjacent caries of MSMs were prone to occur when entirely or partially emergent. CEJ distance was not an independent factor for caries. The severity of caries in an MSM's distal adjacent surface had statistical significance on the impacted depth and impacted angle (P < 0.001). CONCLUSION: The posterior margin space of the MSM influences the impacted condition of the MTM. Preventive extraction can be considered if the impacted angle is <80°, especially in the case of a fully or partially emergent MTM at position A or B and mesioangular impacted areas.

An Effective and Efficient Sample Preparation Method for 2-Methyl-Isoborneol and Geosmin in Fish and Their Analysis by Gas Chromatography-Mass Spectrometry.

The intensive aquaculture strategy and recirculating aquaculture system often lead to the production of off-flavor compounds such as 2-methyl-isoborneol (2-MIB) and Geosmin (GSM). The regular purge and trap extraction followed by analysis with gas chromatography-mass spectrometry (GC-MS) usually involve a complicated assembly of facilities, more working space, long sample preparation time, and headspace solid-phase microextraction (SPME). In this work, a method with easier sample preparation, fewer and simplified facilities, and without SPME on GC-MS analysis is developed for the determination of 2-MIB and GSM in fish samples. Unlike previous methods, solvent extract from samples, QuEChERS-based cleanup, and solid-phase extraction for concentration are applied. The LOD (S/N > 3) and LOQ (S/N > 10) of this method were validated at 0.6 µg/kg and 1.0 µg/kg for both 2-MIB and GSM, which are under the sensory limit (1 µg/kg). Application of this method for incurred fish samples demonstrated acceptable analytical performance. This method is suitable for large-scale determination of 2-MIB and GSM in fish samples, owing to the use of simple facility and easy-to-operate procedure, rapid sample preparation, and shorter time for GC-MS analysis without SPME.

Apigenin Inhibits Proliferation, Migration, and Invasion of Human Tongue Carcinoma Tca8113 Cells Through Regulating the MAPK Signaling Pathways.

OBJECTIVE: This study aimed to examine the effects of apigenin (API) on the proliferation, migration, and invasion of human tongue squamous cell carcinoma Tca8113 cells and explore its probable mechanisms. METHODS: After treating Tca8113 cells with API, the cell proliferation, migration, and invasive capacities were identified by tetrazolium salt colorimetry (MTT) assay, cell scratch test, and Transwell chamber test. Cellular immunofluorescence staining was used to localize mitogen-activated protein kinase 1 (MAPK1) and extracellular regulated protein kinase (ERK) 1/2 proteins. Western blot was used to detect the variations of the related protein expression levels. RESULTS: 1)Through the MTT assay, API significantly inhibited cell proliferation (P<0.01). 2) In the cell scratch test, the distance of lateral migration after the API treatment was significantly shorter compared to the control group (P<0.01). 3) The invasion rate in the lower chamber of the Transwell chamber was lower in the API group (P<0.01). 4) Cellular immunofluorescence staining presented that the total-MEKK1 was localized in the cytoplasm, p-MEKK1 was localized in the nuclear membrane and cytoplasm, and p-ERK1/2 was localized in the cytoplasm and nucleus. ⑤ After API was applied to cells, the expressions of p-MEKK1 and p-ERK1/2 proteins significantly reduced (P<0.01). CONCLUSION: Apigenin (API) significantly inhibits the proliferation, migration, and invasion of Tca8113 cells and its mechanism may be associated with the MAPK signaling pathway.

[Intervention of phlegm and blood stasis inhibits TGF-ß1/Smad3 signaling pathway in the kidney of diabetic rats].

OBJECTIVE: To observe the effect of traditional Chinese medicine for intervention of phlegm and blood stasis in regulating TGF-ß1/Smad3 signaling and relieving nephropathy in diabetic rats. METHODS: SD rats were divided into blank group (NC), diabetic model group (MC group), intervention of phlegm and blood stasis (RPDBS) group, phlegm-removing (RP) group and blood-removing (DBS) group. Diabetic models were established in all the rats except for those in the blank group. After 4 weeks of feeding, the rats in RPDBS group, RP group and DBS group were given corresponding drug intervention for 8 weeks. HE staining was used to observe the changes in renal histopathology. Western blotting and real-time fluorescence quantitative PCR were used to detect the expression levels of transforming growth factor-ß1 (TGF-ß1) and Smad3. RESULTS: The structure and arrangement of the glomeruli and renal tubules improved significantly in the treatment groups in comparison with those in the MC group. The expression levels of TGF-ß1, Smad3 and p-Smad3 were significantly downregulated at both the protein and mRNA levels in the treatment groups (P < 0.05), and the down-regulation was more obvious in RPDBS group than in RP group and DBS group (P < 0.05). CONCLUSIONS: Intervention of phlegm and blood stasis may inhibit the activation of TGF-ß1/Smad3 signaling pathway and delay diabetic nephropathy and fibrosis to protect the renal function in diabetic rats.

TGF-ß downregulation overcomes gemcitabine resistance in oral squamous cell carcinoma.

OBJECTIVE: The aim of this study was to explore the mechanisms by which oral cancer acquires resistance to gemcitabine. METHODS: Oral squamous cell carcinoma (OSCC) cells were treated with gemcitabine upon infection or with a lentivirus harboring short hairpin RNA (shRNA) targeted to transforming growth factor-ß (TGF-ß). Then, Western blot, ELISA, migration assay, MTT assay, and animal experiments were used to explore the mechanism of resistance to gemcitabine treatment. RESULTS: After the treatment of non-transfected cells with gemcitabine, NF-κB and AKT activities were increased, which may have induced the OSCC resistance to gemcitabine. Then, we found that TGF-ß downregulation effectively reduced NF-κB and AKT phosphorylation levels after the administration of gemcitabine and increased the OSCC sensitivity to gemcitabine, resulting in cell death and the blunting of OSCC resistance to gemcitabine. The EMT was also reduced by TGF-ß downregulation combined with gemcitabine treatment. CONCLUSION: Cellular levels of TGF-ß constitute an important factor in gemcitabine resistance and TGF-ß silencing might represent a novel and potent strategy for overcoming OSCC resistance to gemcitabine.

Transcriptome analysis based on a combination of sequencing platforms provides insights into leaf pigmentation in Acer rubrum.

BACKGROUND: Red maple (Acer rubrum L.) is one of the most common and widespread trees with colorful leaves. We found a mutant with red, yellow, and green leaf phenotypes in different branches, which provided ideal materials with the same genetic relationship, and little interference from the environment, for the study of complex metabolic networks that underly variations in the coloration of leaves. We applied a combination of NGS and SMRT sequencing to various red maple tissues. RESULTS: A total of 125,448 unigenes were obtained, of which 46 and 69 were thought to be related to the synthesis of anthocyanins and carotenoids, respectively. In addition, 88 unigenes were presumed to be involved in the chlorophyll metabolic pathway. Based on a comprehensive analysis of the pigment gene expression network, the mechanisms of leaf color were investigated. The massive accumulation of Cy led to its higher content and proportion than other pigments, which caused the redness of leaves. Yellow coloration was the result of the complete decomposition of chlorophyll pigments, the unmasking of carotenoid pigments, and a slight accumulation of Cy. CONCLUSIONS: This study provides a systematic analysis of color variations in the red maple. Moreover, mass sequence data obtained by deep sequencing will provide references for the controlled breeding of red maple.

Associations between abnormal vitamin D metabolism pathway function and non-small cell lung cancer.

Lung cancer is a type of malignant tumor derived from the respiratory system, which is the leading cause of cancer-associated mortality worldwide, of which ~80% of cases are attributable to non-small cell lung cancer (NSCLC). A previous study demonstrated that 1α,25-Dihydroxyvitamin D3 (1α,25(OH)2D3), derived from the vitamin D metabolic pathway contributes an antitumor effect. Aberrant expression of the essential enzyme encoding genes, Cytochrome P450 Family 27 Subfamily A Member 1 (CYP27A1), Cytochrome P450 Family 27 Subfamily B Member 1 (CYP27B1), and Cytochrome P450 Family 24 Subfamily A Member 1 (CYP24A1) may be associated with lung cancer. However, a lack of evidence exists concerning the association between CYP27A1, CYP27B1, CYP24A1 expression and NSCLC. The aim of the present study was to investigate the functions of CYP27A1, CYP27B1 and CYP24A1 expression in NSCLC. Lung cancer tissue and para-carcinoma control tissue were collected from patients with NSCLC. Reverse transcription-quantitative polymerase chain reaction was applied to analyze CYP27A1, CYP27B1 and CYP24A1 mRNA expression in lung cancer tissues. An association analysis was performed between the aforementioned metabolic enzymes and patients with NSCLC age, gender, tumor node metastasis (TNM) stage, pathological type, differentiation and prognosis. CYP27B1 and CYP24A1 mRNA were upregulated in NSCLC compared with controls (P<0.05). However, no significant differences in CYP27A1 expression were observed between NSCLC and control. In addition, CYP24A1 expression was not associated with age, sex, smoking or TNM stage, but was associated with pathological type, differentiation and prognosis (P<0.05). CYP27B1 expression was significantly associated with TNM stage, differentiation, and prognosis, but not age, sex, smoking or pathological type. In conclusion, CYP27B1 and CYP24A1 may be considered as independent prognostic factors of NSCLC and may be novel therapeutic targets to assist clinical diagnosis, treatment and prognosis of the disease.

Downregulation of PI3K-γ in a mouse model of sepsis-induced myocardial dysfunction.

A key component during sepsis is the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway, of which the PI3K-γ isoform is a major regulator in many inflammatory responses. However, the role of PI3K-γ in the development of sepsis-induced myocardial dysfunction (SIMD) is unknown. In this study, we established a model of SIMD induced by lipopolysaccharide (LPS), subsequently used the selective inhibitor LY294002 and AS605240 to block the effect of PI3K and PI3K-γ, respectively. Cardiac function was evaluated by echocardiography, hearts were obtained for histological and protein expression examinations. ELISA was used to measure the serum levels of tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), cardiac troponin I (cTnI) and heart-type fatty acid binding protein (H-FABP). LPS-treated mice showed an increase to cardiac inflammation, myocardial damage and production of TNF-α, IL-6, NF-κB, cTnI and H-FABP. Administration of AS605240 to LPS-treated mice reduced some patho-physiological characteristics of SIMD and reduced TNF-α, IL-6, cTnI and H-FABP production. However, administration of LY294002 did not improve those same conditions. The results showed that PI3K-γ is likely a crucial element in SIMD by regulating the PI3K/Akt pathway, and become a new marker of myocardial injury. Inhibition of PI3K-γ might be a potential therapeutic target in SIMD.

Inflammation elevated IL-33 originating from the lung mediates inflammation in acute lung injury.

Excessive inflammatory reactions occur with acute respiratory distress syndrome (ARDS), however, the underlying mechanisms of ARDS remain incompletely understood. Here we investigated whether interleukin (IL)-33 was elevated in ARDS patients. Serum samples were obtained from 14 ARDS patients and 24 control healthy volunteers. ELISA was used to measure the concentrations of IL-33. Besides, we established pulmonary ARDS and extrapulmonary ARDS models in mice, and serum and lung tissue samples were collected for analyses. The results showed that serum IL-33 concentrations were significantly higher in pulmonary ARDS patients compared to controls. Also, the levels of IFN-γ and IL-2 were positively correlated with IL-33 levels. We also showed that there were increased IL-33 levels in both the serum and lungs in the pulmonary ARDS model. This was not the case, however, in the extrapulmonary ARDS model. Pulmonary inflammation and injury in the pulmonary ARDS model was reduced with IL-33 neutralizing antibody treatment.

Interleukin-27 is elevated in sepsis-induced myocardial dysfunction and mediates inflammation.

INTRODUCTION: Interleukin (IL)-27 is an important cytokine involved in many human inflammatory diseases. In this study, we investigated its role in the pathogenesis of sepsis-induced myocardial dysfunction (SIMD). METHODS: Twenty patients with SIMD and 24healthy donors were prospectively enrolled. Expression of IL-27 was detected in serum from SIMD patients by ELISA. Cardiac dysfunction was induced by administration of Escherichia coli lipopolysaccharide (LPS) to C57BL/6 (wild type) or IL-27R-/- mice. IL-27 mRNA in the myocardium was measured by RT-PCR. Cytokine levels in serum were determined by ELISA. RESULTS: Expression of IL-27 in the serum was markedly increased in patients with SIMD compared with that in controls. Serum IL-27 levels and cardiac IL-27 mRNA expression were significantly increased after LPS injection compared with control specimens. Compared with wild-type mice, IL-27R-/- mice had higher expression of brain natriuretic peptide, cardiac troponin I, IL-6, IL-12, tumor necrosis factor-α and transforming growth factor-ß. CONCLUSIONS: IL-27 is an important protective mediator of SIMD.

Identification of a group of XTHs genes responding to heavy metal mercury, salinity and drought stresses in Medicago truncatula.

Xyloglucan endotransglucosylase/hydrolases (XTH) are one of the key enzymes regulating cell wall construction, extension and metabolism. In the study, 44 XTH protein genes from Medicago truncatula genome were identified using bioinformatics, microarray and RT-PCR. Each XTH was showed to possess a highly conserved domain ((D/N)-E-(I/L/F/V)-D-(F/I/L)-E-(F/L)-L-G), and most of XTHs possess four Cys in the C terminal region, which suggests the potential for generating disulfide bonds. Based on the XTH protein sequences, these XTHscan be classified into three major families and each family can be subdivided into more groups. Examination of the genomic location of XTH genes on M. truncatula chromosomes showed that the evolutional expansion of the genes was possibly attributed to localized gene duplications. To investigate the possible involvement of the XTHs responding to heavy metals and other abiotic stresses, the XTH genes were exposed to heavy metal (Hg or Cu), salt and drought stresses. There were 28, 21 and 21 MtXTH genes found to respond to HgCl2, salt and drought stresses, respectively, but their expression were different under the stresses. Some of the XTH genes were well confirmed by quantitative RT-PCR (qRT-PCR). We further specified expression of a XTH gene Medtr4g128580 (MtXTH3) under different environmental stresses, and showed that MtXTH3 was induced by Hg exposure. These results indicated that a group of MtXTHs could be differentially expressed under the environmental stresses.

HMGB1 regulates IL-33 expression in acute respiratory distress syndrome.

The development and progression of acute respiratory distress syndrome (ARDS) has been shown to be regulated by cytokines. IL-33 and HMGB1 are conventionally considered as nuclear proteins and have a proinflammatory role. Studies have confirmed that HMGB1 has a significant role in ARDS, but few studies have provided direct evidence to confirm that IL33 is involved in ARDS. The purpose of our study was to determine whether IL-33 is elevated in ARDS and the relationship between IL-33 and HMGB1 in ARDS. We established a mouse model of LPS-induced lung inflammation/injury. Serum, bronchoalveolar lavage fluid (BALF) and lung tissues were obtained to determine the related indicators. IL-33 levels in both the serum, BALF and lungs were significantly increased at 24h after LPS administration compared to the control group. We also found that HMGB1 and other Th1 cytokine/chemokine levels in serum and BALF were also significantly elevated, but the Th2 cytokine levels in serum and BALF didn't increase. To further study the relationship between IL-33 and HMGB1, mice were pretreated with glycyrrhizin (an inhibitor of HMGB1) prior to LPS administration. We found that the expression of IL-33 and HMGB1 were markedly lower than those in the LPS group and the lung injury was ameliorated. The levels of other Th1 cytokines and chemokines in serum and BALF were also significantly decreased. The results showed that IL-33 is likely a major factor in ARDS, and the release of HMGB1 may be correlated with up-regulation of IL-33 expression.

The management of benign lymphadenopathy during video-assisted thoracic surgery lobectomy in two-port method.

Despite the lobectomy in video-assisted thoracic surgery (VATS) is widely applied, in VATS the resection of benign lymphadenopathy is still less performed because of less importance in affecting the prognosis. We report our surgery procedure of benign lymphadenopathy in lobectomy with benign pulmonary disease performed in a two-port approach. A 50-year-old male was operated on by the thoracoscopic approach through two-port incision. And the postoperative recovery was uneventful with no complications occurred.

Brain functional connectivity density and individual fluid reasoning capacity in healthy young adults.

Functional connectivity density (FCD) is a newly developed data-driven method to measure the number of functional connections of each voxel, possibly providing new insight into the neural correlates of fluid reasoning. Here, we recruited 211 healthy young adults (91 men and 120 women) to investigate associations between the global FCD and fluid reasoning capacity as measured by the Raven's Standard Progressive Matrices. Raven's Standard Progressive Matrices scores were correlated negatively with the global FCD in multiple brain regions of the frontal, parietal, occipital, and temporal cortices in male participants. No significant correlation was found in female participants. Our findings confirmed the association between fluid reasoning and functional connectivity of multiple cognitive-related brain regions. The positive correlation with the functional connectivity strength and the negative correlation between fluid reasoning and FCD suggest that individuals with superior fluid reasoning capacity may possess a small number of strong functional connections. The sex dichotomy of this association indicates that the fluid reasoning capacity of men and women may have different neural substrates.

Functional Connectivity Density in Congenitally and Late Blind Subjects.

Visual deprivation during different developmental periods leads to different structural and functional alterations in the brain; however, the effects of visual deprivation on the spontaneous functional organization of the brain remain largely unknown. In this study, we used voxel-based functional connectivity density (FCD) analyses to investigate the effects of visual deprivation during different developmental periods on the spontaneous functional organization of the brain. Compared with the sighted controls (SC), both the congenitally blind (CB) and the late blind (LB) exhibited decreased short- and long-range FCDs in the primary visual cortex (V1) and decreased long-range FCDs in the primary somatosensory and auditory cortices. Although both the CB and LB exhibited increased short-range FCD in the dorsal visual stream, the CB exhibited greater increases in the short- and long-range FCDs in the ventral visual stream and hippocampal complex compared with the LB. Moreover, the short-range FCD of the left V1 exhibited a significant positive correlation with the duration of blindness in the LB. Our findings suggest that visual deprivation before the developmental sensitive period can induce more extensive brain functional reorganization than does visual deprivation after the sensitive period, which may underlie an enhanced capacity for processing nonvisual information in the CB.

Osteoblastic behavior to zirconium coating on Ti-6Al-4V alloy.

PURPOSE: The purpose of this study was to assess the surface characteristics and the biocompatibility of zirconium (Zr) coating on Ti-6Al-4V alloy surface by radio frequency (RF) magnetron sputtering method. MATERIALS AND METHODS: The zirconium films were developed on Ti-6Al-4V discs using RF magnetron sputtering method. Surface profile, surface composition, surface roughness and surface energy were evaluated. Electrochemical test was performed to evaluate the corrosion behavior. Cell proliferation, alkaline phosphatase (ALP) activity and gene expression of mineralized matrix markers were measured. RESULTS: SEM and EDS analysis showed that zirconium deposition was performed successfully on Ti-6Al-4V alloy substrate. Ti-6Al-4V group and Zr-coating group showed no significant difference in surface roughness (P>.05). Surface energy was significantly higher in Zr-coating group than in Ti-6Al-4V group (P<.05). No difference in cell morphology was observed between Ti-6Al-4V group and Zr-coating group. Cell proliferation was higher in Zr-coating group than Ti-6Al-4V group at 1, 3 and 5 days (P<.05). Zr-coating group showed higher ALP activity level than Ti-6Al-4V group (P<.05). The mRNA expressions of bone sialoprotein (BSP) and osteocalcin (OCN) on Zr-coating group increased approximately 1.2-fold and 2.1-fold respectively, compared to that of Ti-6Al-4V group. CONCLUSION: These results suggest that zirconium coating on Ti-6Al-4V alloy could enhance the early osteoblast responses. This property could make non-toxic metal coatings on Ti-6Al-4V alloy suitable for orthopedic and dental implants.

[Genetic variation analysis of wild populations of grass carp (Ctenopharyngodon idella) using microsatellite markers].

Twelve microsatellites were used to analyze the genetic diversity and genetic structure of eight wild populations of grass carp, among which six populations from Yangtze River (Hanjiang, Wujian, Jiujiang, Shishou, Mudong, and Wanzhou), one population from Pearl River and Heilongjiang River for each, Zhaoqing, and Nenjiang, respectively. Twelve markers showed highly polymorphic and all the eight populations contained high genetic variations. The variations of six populations of Yangtze River and Zhaoqing population of Pearl River were higher than Nenjiang population of Heilongjiang River. Bottleneck analysis revealed that four populations (Zhaoqing, Nenjiang, Mudong, and Wangzhou) had experienced a recent genetic bottleneck, and the effective population size was reduced. Pairwise FST and AMOVA analysis detected significant genetic difference among populations. The pairwise population genetic distances and the UPGMA tree demonstrated that the genetic distances between six populations of Yangtze River and Zhaoqing population were closer and clustered together earlier, as compared to those populations with Nenjiang population. The genetic structure simulation analysis suggested that there were five logic populations of all individuals. The genetic structures of Zhaoqing and Nenjiang populations were shown with independent separation, but the genetic structures of populations from Yangtze River were shown with fuzzy distribution. The high diversity was found in the wild grass carp from three major watersheds in China, which would supply a basis for future genetic improvement. However, the bottleneck effect of some populations should be taken into account in the practical breeding programs.