Protein O-GlcNAcylation in cardiovascular diseases.

O-GlcNAcylation is a post-translational modification of protein in response to genetic variations or environmental factors, which is controlled by two highly conserved enzymes, i.e. O-GlcNAc transferase (OGT) and protein O-GlcNAcase (OGA). Protein O-GlcNAcylation mainly occurs in the cytoplasm, nucleus, and mitochondrion, and it is ubiquitously implicated in the development of cardiovascular disease (CVD). Alterations of O-GlcNAcylation could cause massive metabolic imbalance and affect cardiovascular function, but the role of O-GlcNAcylation in CVD remains controversial. That is, acutely increased O-GlcNAcylation is an adaptive heart response, which temporarily protects cardiac function. While it is harmful to cardiomyocytes if O-GlcNAcylation levels remain high in chronic conditions or in the long run. The underlying mechanisms include regulation of transcription, energy metabolism, and other signal transduction reactions induced by O-GlcNAcylation. In this review, we will focus on the interactions between protein O-GlcNAcylation and CVD, and discuss the potential molecular mechanisms that may be able to pave a new avenue for the treatment of cardiovascular events.

Transcriptomic and physiological analysis of the effect of octanoic acid on Meloidogyne incognita.

Root knot nematodes are the most devastating root pathogens, causing severe damage and serious economic losses to agriculture worldwide. Octanoic acid has been reported as one of the nematicides, and its mode of action is not fully understood. The main objective of this study was to elucidate the effect of octanoic acid on Meloidogyne incognita by transcriptomic analysis combined with physiological and biochemical assays. In the toxicity assays with octanoic acid, the threshold concentration with nematicidal activity and the maximum concentration to which nematodes could respond were 0.03 µL/mL and 0.08 µL/mL respectively. Microscopic observation combined with protein and carbohydrates assays confirmed that the structure of the second-stage juveniles (J2s) was severely disrupted after 72 h of immersion in octanoic acid. Transcriptome analysis has shown that octanoic acid can interfere with the nematode energy metabolism, lifespan and signaling. Although the effects are multifaceted, the findings strongly point to the cuticle, lysosomes, and extracellular regions and spaces as the primary targets for octanoic acid. In addition, nematodes can withstand the negative effects of low concentration of octanoic acid to some extent by up-regulating the defense enzyme system and heterologous metabolic pathways. These findings will help us to explore the nematicidal mechanism of octanoic acid and provide important target genes for the development of new nematicides in the future.

Long-term efficacy and patient satisfaction of Le Fort colpocleisis for the treatment of severe pelvic organ prolapse.

INTRODUCTION AND HYPOTHESIS: The objective was to investigate the long-term efficacy and patient satisfaction of Le Fort colpocleisis for the treatment of severe pelvic organ prolapse. METHODS: This was a retrospective study of patients who underwent Le Fort colpocleisis from January 2007 to August 2018 in our hospital. Follow-up was conducted via outpatient visits or the telephone. Records were reviewed for anatomical recurrence, complications, urinary and intestinal symptoms post-operation, reoperation rate, patient satisfaction, Patient Global Impression of Improvement (PGI-I) score, regret rate etc. RESULTS: A total of 208 patients underwent follow-up. The follow-up time was 60.7 ± 34.18 (12-140) months. There were no intraoperative complications. Postoperative urinary retention occurred in 3.8% of patients (8 out of 208). There was no anatomical recurrence. New or more severe urinary symptoms occurred in 8.7% of patients (18 out of 208); new or more severe intestinal symptoms occurred in 1.9% of patients (4 out of 208). The reoperation rate was 1.44% (3 out of 208). Three cases of reoperation occurred for the following reasons: a case of severe stress urinary incontinence, a case of abscess in the vaginal septum, and a case of uterine malignancy after 2 years of colpocleisis. Patient satisfaction was as follows: 98.6% (205 out of 208) of patients were very satisfied. The PGI-I score was very much improved or improved in 99.5% (207 out of 208) of patients. A total of 0.96% (2 out of 208) of patients regretted undergoing colpocleisis. CONCLUSIONS: The long-term follow-up results showed that Le Fort colpocleisis was a safe and effective surgical procedure associated with high satisfaction. There was a very low regret rate, but the procedure should be taken seriously.

Dynamic protein-RNA interactions in mediating splicing catalysis.

The spliceosome is assembled via sequential interactions of pre-mRNA with five small nuclear RNAs and many proteins. Recent determination of cryo-EM structures for several spliceosomal complexes has provided deep insights into interactions between spliceosomal components and structural changes of the spliceosome between steps, but information on how the proteins interact with pre-mRNA to mediate the reaction is scarce. By systematic analysis of proteins interacting with the splice sites (SSs), we have identified many previously unknown interactions of spliceosomal components with the pre-mRNA. Prp8 directly binds over the 5'SS and the branch site (BS) for the first catalytic step, and the 5'SS and 3'SS for the second step. Switching the Prp8 interaction from the BS to the 3'SS requires Slu7, which interacts dynamically with pre-mRNA first, and then interacts stably with the 3'-exon after Prp16-mediated spliceosome remodeling. Our results suggest that Prp8 plays a key role in positioning the 5'SS and 3'SS, facilitated by Slu7 through interactions with Prp8 and substrate RNA to advance exon ligation. We also provide evidence that Prp16 first docks on the intron 3' tail, then translocates in the 3' to 5' direction on remodeling the spliceosome.

Coordination-Driven Stereospecific Control Strategy for Pure Cycloisomers in Solid-State Diene Photocycloaddition.

To obtain a pure product without the isomer byproducts is a goal that many chemists are pursuing. As one kind of very important synthesis method, the photochemical reaction is simple and straightforward yet low-selective. In this work, a coordination interaction-based oriented synthesis strategy has been proposed to realize the precise stereochemical control of the isomeric cyclic compounds in the photocycloaddition reaction. Through fixing the reactants via coordination interactions, the arrangements and configurations of the reactants can be adjusted, thereby successfully producing all of the related photocycloaddition products without isomer byproducts for the first time. This work not only provides a new route to synthesize the pure cyclic compounds but also expands the application of the photocycloaddition reaction.

KCa3.1 channel mediates inflammatory signaling of pancreatic ß cells and progression of type 2 diabetes mellitus.

Chronic islet inflammation is associated with development of type 2 diabetes mellitus (T2DM). Intermediate-conductance calcium-activated K+ (KCa3.1) channel plays an important role in inflammatory diseases. However, the role and regulation of KCa3.1 in pancreatic ß cells in progression of T2DM remain unclarified. In the present study, we evaluated the effect of the specific KCa3.1 channel blocker 1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole (TRAM-34) on diabetic phenotype in the db/db model. In diabetic mice, blockade of KCa3.1 significantly improved glucose tolerance, enhanced secretion of postprandial insulin level, and reduced loss of ß-cell mass through attenuating the expression and secretion of inflammatory mediators. Furthermore, in cultured pancreatic ß cells, exposure to high levels of glucose or palmitic acid significantly increased expression and current density of the KCa3.1 channel as well as secretion of proinflammatory chemokines, and the effects were similarly reversed by preincubation with TRAM-34 or a NF-κB inhibitor pyrrolidinedithiocarbamate. Additionally, expression of KCa3.1 in pancreas islet cells was up-regulated by activation of NF-κB with IL-1ß stimulation. In summary, up-regulated KCa3.1 due to activation of NF-κB pathway leads to pancreatic inflammation via expression and secretion of chemokines and cytokines by pancreatic ß cells, thereby facilitating progression of T2DM.-Pang, Z.-D., Wang, Y., Wang, X.-J., She, G., Ma, X.-Z., Song, Z., Zhao, L.-M., Wang, H.-F., Lai, B.-C., Gou, W., Du, X.-J., Deng, X.-L. KCa3.1 channel mediates inflammatory signaling of pancreatic ß cells and progression of type 2 diabetes mellitus.

Vortex formation of spherical self-propelled particles around a circular obstacle.

A vortex is a common ratchet phenomenon in active systems. The spatial symmetry is usually broken by introducing asymmetric shapes or spontaneously by collective motion in the presence of hydrodynamic interactions or other alignment effects. Unexpectedly, we observe, by simulations, the formation of a vortex in the simplest model of a circular obstacle immersed in a bath of spherical self-propelled particles. No symmetry-breaking factors mentioned above are included in this model. The vortex forms only when the particle activity is high, i.e. large persistence. The obstacle size is also a key factor and the vortex only forms in a limited range of obstacle sizes. The sustainment of the vortex originates from the bias of the rotating particle cluster around the obstacle in accepting the incoming particles based on their propelling directions. Our results provide new understanding of and insights into the spontaneous symmetry-breaking and ratchet phenomena in active matter.

Fine-Tuning of Luminescence through Changes in Au-S Bond Lengths as a Function of Temperature or Solvent.

The luminescent properties of gold(I)-sulfur compounds have received much attention for their potential applications in the sensing field. The molecular level regulation of luminescence remains a challenge. It is critical to unravel the relationship between the luminescence and the structure. Herein we report a binuclear complex [Au2(dppaptc)2]Cl2 (1, dppaptc = N,N-bis(diphenylphosphanylmethyl)-amino-4-phenyl-thiocarbamide), which exhibits variations at Au-S bond lengths as a function of temperature or solvent. X-ray analysis reveals a linear decrease from 2.900(3) to 2.745(15) Å upon cooling 1·2CHCl3 from 300 to 80 K combined with a linear correlation with its luminescence intensity at 475 nm, which was confirmed by TD-DFT calculations. Compound 1, if solvated with H2O and alcohol, possesses the shorter Au-S bonds and enhanced luminescence. The close relationship between luminescence intensity and Au-S length serves as a complement to existing luminescent gold(I)-sulfur systems and provides some insight into understanding the thermochromism and solvatochromism of the gold(I)-sulfur compounds.

Tetradecanuclear and Octadecanuclear Gold(I) Sulfido Clusters: Synthesis, Structures, and Luminescent Selective Tracking of Lysosomes in Living Cells.

Reactions of the phosphanyl-gold(I) precursor [(AuCl)2(bdppmapy)] (1; bdppmapy = N,N-bis(diphenylphosphanylmethyl)-2-aminopyridine) with Na2S in a 1:1 or 1:2 molar ratio gave rise to one tetradecanuclear and one octanuclear Au(I) sulfido cluster, [Au14S6(bdppmapy)5]Cl2 (2) and [Au18S8(bdppmapy)6]Cl2 (3), respectively. The former displays a new structural framework in gold cluster chemistry. Compounds 2 and 3 showed strong green luminescence and were employed as excellent imaging probes to selectively light up the lysosomes of living cells. Their long-term tracking of lysosomes can be achieved for up to 36 h, while tracking with commercial Lyso-Tracker Red under the same conditions was limited to 3 h. Our work demonstrated the possibility of constructing novel gold(I) sulfido clusters supported by special P-N hybrid ligands and the potential application of these clusters as long-term selective trackers of lysosomes in bioimaging.

[Relationship of Cystic Fibrosis Transmembrane Conductance Regulator Expression with Clinical Features and Prognosis in Patients with Acute Leukemia].

OBJECTIVE: To investigate the expression of cystic fibrosis transmembrane conductance regulator (CFTR) protein in patients with acute leukemia and its relationship to clinical features and prognosis of acute leukemia. METHODS: A total of115 patients with acute leukemia were enrolled in the experimental group and 20 healthy individuals were used as control. Peripheral blood or bone marrow samples were collected, and mononuclear cells were isolated. The expression of CFTR protein was detected by Western blot. The relationships of CFTR protein expression to clinical features and prognosis was analyzed. RESULTS: The expression of CFTR protein was not detected in peripheral blood mononuclear cells of normal control, while it was positive in more than half of acute leukemias including acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL), but negative in the patients with acute promyelocytic leukemia (M3). In the patients with AML, there was no difference in peripheral white blood cells (WBC), peripheral blast cells, platelet and hemoglobin (HGB) between CFTR-positive and CFTR-negative patients. There was no relationship between the expression of CFTR protein and gene mutations such as NPM1, CEBPA, FLT3-ITD, and C-Kit. Complete remission (CR) rate after two course in CFTR-negative patients was slightly higher than that in positive patients. The survival time of CFTR-negative patients was little longer than that of positive patients, but the difference was not statistically significant. CONCLUSIONS: The expression of CFTR protein seems not associated with clinical features, treatment response and prognosis in the patients with acute leukemia.

Large-Scale, Bottom-Up Synthesis of Binary Metal-Organic Framework Nanosheets for Efficient Water Oxidation.

Ultrathin metal-organic framework (MOF) nanosheets (NSs) offer potential for many applications, but the synthetic strategies are largely limited to top-down, low-yield exfoliation methods. Herein, Ni-M-MOF (M=Fe, Al, Co, Mn, Zn, and Cd) NSs are reported with a thickness of only several atomic layers, prepared by a large-scale, bottom-up solvothermal method. The solvent mixture of N,N-dimethylacetamide and water plays key role in controlling the formation of these two-dimensional MOF NSs. The MOF NSs can be directly used as efficient electrocatalysts for the oxygen evolution reaction, in which the Ni-Fe-MOF NSs deliver a current density of 10 mA cm-2 at a low overpotential of 221 mV with a small Tafel slope of 56.0 mV dec-1 , and exhibit excellent stability for at least 20 h without obvious activity decay. Density functional theory calculations on the energy barriers for OER occurring at different metal sites confirm that Fe is the active site for OER at Ni-Fe-MOF NSs.

Switchable Chemoselective Transfer Hydrogenations of Unsaturated Carbonyls Using Copper(I) N-Donor Thiolate Clusters.

Unsaturated alcohols and saturated carbonyls are important chemical, pharmaceutical, and biochemical intermediates. We herein report an efficient transfer hydrogenation protocol in which conversion of unsaturated carbonyl compounds to either unsaturated alcohols or saturated carbonyls was catalyzed by Cu(I) N-donor thiolate clusters along with changing hydrogen source (isopropanol or butanol) and base (NaOH or K2CO3). Mechanistic studies supported by DFT transition state modeling indicate that such a chemoselectivity can be explained by the relative concentrations of Cu(I) monohydride and protonated Cu(I) hydride complexes in each catalytic system.

Effects of cadmium stress on the antioxidant system and chlorophyll fluorescence characteristics of two Taxodium clones.

KEY MESSAGE: The T.118 and T.406 seedlings showed strong adaptability under Cd concentrations ≤ 50 µM. The mechanisms of photoprotection in T.118 and T.406 differed in high-Cd concentrations. To explore the physiological response characteristics of Taxodium hybrids to cadmium (Cd) stress and provide basis for screening of Cd-tolerant species, the hydroponic cultivation of T.118 and T.406 seedlings was conducted to demonstrate the effects of Cd stress on seedling growth, antioxidant system, and chlorophyll fluorescence parameters. After 35 days of Cd stress at a concentration ≤ 50 µM, the dry weight biomass of the two clones did not significantly differ from that of the control. T.406 exhibited a significant increase in POD activity compared to T.118 and maintained high SOD activity after exposure to high concentrations of Cd, whereas MDA levels showed little changes. Under low-Cd stress, chlorophyll content and fluorescence parameters remained stable, especially for T.406. Under high-Cd concentration stress, the above parameters were lower than the control, with a more significant decrease in T.118 than in T.406. The non-photochemical quenching coefficient (NPQ) of both clones increased with increasing Cd concentration. T.118 showed a greater increase than T.406, particularly under high-Cd concentration stress. The T.118 and T.406 seedlings adapted to low-Cd concentration stress by enhancing their antioxidant enzyme activity to maintain the balance of reactive oxygen metabolism and reduce cellular damage. The photochemical activity of mesophyll cells remained high to maintain photosynthetic capacity and normal seedling growth. T.406 showed stronger resistance to Cd than T.118. T.406 prevented photodamage by promoting the photochemical utilization of the excitation energy and maintaining a strong antioxidant stress ability. Enhancement of heat dissipation capability may be the main photoprotection mechanism of T.118.

D-dimers (DD) in CVST.

OBJECTIVE: We were interested in further confirming whether D-dimers (DD) are indeed elevated in cerebral venous sinus thrombosis (CVST) as reported in those studies. METHODS: CVST patients who had a plasma D-dimer test (139 cases) were included and divided into two groups: elevated D-dimer group (EDG) (>0.5 µg/mL; 65 cases) and normal D-dimer group (NDG) (≤0.5 µg/mL; 74 cases). The two groups were compared in terms of demographic data, clinical manifestation, laboratory and imaging data, using inferential statistical methods. RESULTS: The chi-squared and Fisher exact test showed that, compared to the NDG (74 cases), patients with elevated D-dimer levels were more likely to have a shorter symptom duration (SD) (30 ± 83.9 versus 90 ± 58.9 d, p = 0.003), more risk factors (75.4% versus 52.7%, p = 0.006), higher multiple venous sinus involvement (75.4% versus 59.5%, p = 0.037), increased fibrinogen (43.1% versus 18.9%, p = 0.037) and higher levels of blood glucose (18.3% versus 11%, p = 0.037). According to correlation analyses, D-dimer levels were positively correlated with number of venous sinuses involvement (NVS) (r = 0.321, p = 0.009) in the EDG. Multivariate logistic regression analysis showed that SD (OR, 0.025; 95% CI, 1.324-6.043; p = 0.000), NVS (OR, 1.573; 95% CI, 1.15-2.151; p = 0.005) and risk factors (OR, 3.321; 95% CI, 1.451-7.564; p = 0.004) were significantly different between the two groups. CONCLUSION: D-dimer is elevated in patients with acute/subacute CVST.

The role of KCa3.1 channels in cardiac fibrosis induced by pressure overload in rats.

The intermediate-conductance Ca(2+)-activated K(+) (KCa3.1) channels play a pivotal role in the proliferation and collagen secretion of cardiac fibroblasts. However, their contribution in cardiac fibrosis remains unknown. This study was designed to investigate whether KCa3.1 channels mediate the development of cardiac fibrosis. Pressure-overloaded rats were induced by abdominal aortic constriction and treated without or with KCa3.1 blocker (TRAM-34) or angiotensin type 1 receptor blocker (losartan) for 2 weeks. Besides the increase of blood pressure, angiotensin (Ang) II level in the plasma and myocardium, left ventricle mass and hydroxyproline concentration, myocardial hypertrophy, as well as significant collagen deposition in the perivascular regions and interstitium of the myocardium were observed in pressure-overloaded rats. The expression of leukocyte differentiation antigens (CD45 and CD3), macrophage surface marker (F4/80), tumor necrosis factor alpha, and monocyte chemotactic protein-1 (MCP-1) also significantly increased. All these alterations were prevented by losartan and TRAM-34. TRAM-34 also reduced the increase of renin and angiotensinogen in the plasma and myocardium of pressure-overloaded rats. Ang II promoted the migration of monocytes through endothelial cells and the secretion of MCP-1 from human umbilical vein endothelial cells in vitro, which was inhibited by TRAM-34. In conclusion, the present study demonstrates that TRAM-34 alleviates cardiac fibrosis induced by pressure overload, which is related to its inhibitory action on KCa3.1 channels and Ang II level. Our findings indicate that the inhibition of KCa3.1 channels may represent a novel approach of preventing the progression of cardiac fibrosis, and also add to the already developing literature of promising targets for TRAM-34.

[The mechanisms of heparin-derived oligosaccharide on the inhibition of smooth muscle cells proliferation induced by platelet-derived growth factor].

In this study, the effect of heparin-derived oligosaccharide (HDO) on platelet-derived growth factor (PDGF) induced vascular smooth muscle cells (VSMCs) proliferation and the related signal transduction mechanisms were investigated. MTT assays were used to measure VSMCs proliferation. Cell cycle distribution was analyzed by flow cytometry. The level of key regulatory proteins in PKC, MAPK and Akt/PI3K pathways were determined by RT-PCR, Western blot and immunocytochemical methods. Meanwhile, mRNA expressions of some proto-oncogenes were assayed by RT-PCR method. Our data showed that HDO (0.01, 0.1 and 1 µmol · L(-1)) inhibited 30 ng · mL(-1) PDGF-induced VSMCs proliferation in a dose-dependent manner, blocked the G1/S transition and inhibited the level of key regulatory proteins and some proto-oncogenes (P < 0.05). The results showed that HDO may decrease the key regulatory proteins expression, hence suppress the transcription of proto-oncogene and G1/S transition, finally inhibiting VSMCs proliferation.

[Relief of urinary retention after radical hysterectomy for cervical cancer patients by acupressure: a randomized controlled trial].

OBJECTIVE: To study whether acupressure could relieve urinary retention after radical hysterectomy in cervical cancer patients. METHODS: A randomized controlled prospective double-blinded trial was carried out in 107 urinary retention patients undergoing grade III radical hysterectomy. They were assigned to Group A (positive acupoints, 40 cases), Group B (negative acupoints, 32 cases) , and Group C (with no acupoints, 35 cases). All patients received protective 115 000 potassium permanganate sitz bath, 15 - 20 min each time, 3 times per day. Patients in Group A received acupressure at positive points [liniao point and Qihai (RN6)] combined points by syndrome typing [Guanyuan (RN4) , Zhongji (RN3) , Shenshu (BL23) , Zusanli (ST36), Sanyinjiao (SP6), and Taixi (K13)]. Patients in Group B received negative acupressure at sham-acupoints (for adjusting gastrointestinal functions). Patients in Group C only received conventional sitz bath. All medication was performed 3 times per day, 7 days as one therapeutic course, 21 days in total. The residual urine volume was detected. The recovery time for bladder function was recorded. The average residual urine volume was also recorded at day 7, 14, and 21. RESULTS: Compared with Group B and C, the time for ureter retention was shortened for mild and severe CKD patients in Group A (P <0. 01). The residual urine volume was also lessened for mild and severe CKD patients in Group A at day 7, 14, and 21 (P <0.01). CONCLUSION: Cervical cancer patients could relieve urinary retention by self-acupressure after radical hysterectomy.

[Synthesis and Properties of 1,11,15,25-Tetrahydroxy-4,8,18,22-Di (Bridged Dipropionate Carboxyl) Phthalocyanine Copper].

In this dissertation, we study the synthesis and character of new substituted Phthalocyanine. Due to the widely application of Pcs in the fields, such as the communication, medical treatment, chemical industry and so on, therefore, they have been a hot topic over several decades by scientists. Nowadays, scientists have prepared thousands of Pcs and their derivatives. However, along with the human society development and the progress in science and technology, the new phthalocyanine with novle characteristics are still the goal of the scientists. In this dissertion, the synthetic methods of the phthlocyanine is improved. The synthesis and characterization of 1,11,15,25-tetrahydroxy-4,8,18,22-di(bridged dipropionate carboxyl) phthalocyanines are reported in this paper. The mixtures of malonic acid and 3,6-dihydroxy-phthalonitrile was added to water under stiriing. Then, a catalyst amount of sulfuric acid was added. The first synthetic precursor, i. e., malonic acid 3,3'-bis(6-hydroxy phthalonitrile) butter, its molecular formula is C19H8N4O6. phthalocyanines was prepared by malonic acid 3,3'-bis(6-hydroxy phthalonitrile) butter and dihydrate zinc acetate, copper acetate monohydrate in n-amyl alcohol, using DBU as a catalyst under the 135 °C, molecular formula of phthalocyanine complexes is C38H16N8O12M. The product was characterized by Ultraviolet-visible (UV/Vis) Spectrum absorption and fluorescence, The results are agreement with the proposed structures. And electrochemical properties were studied.

Cytotoxic activity and DNA-binding properties of isoeuxanthone derivatives.

In this study, the interactions of different groups substituted isoeuxanthone derivatives with calf thymus DNA (ct DNA) were investigated by spectrophotometric methods and viscosity measurements. Results indicated that the xanthone derivatives could intercalate into the DNA base pairs by the plane of xanthone ring and the various substituents may influence the binding affinity with DNA according to the calculated quenching constant values. Furthermore, two tumor cell lines including the human cervical cancer cell line (HeLa) and human hepatocellular liver carcinoma cell line (HepG2) were used to evaluate the cytotoxic activities of xanthone derivatives by acid phosphatase assay. Analyses showed that the oxiranylmethoxy substituted xanthone exhibited more effective cytotoxic activity against the cancer cells than the other substituted xanthones. The effects on the inhibition of tumor cells in vitro agreed with the studies of DNA-binding.

[Monitoring freeze stress levels on winter wheat from hyperspectral reflectance data using principal component analysis].

In order to detect the freeze injury stress level of winter wheat growing in natural environment fast and accurately, the present paper takes winter wheat as experimental object. First winter wheat canopy hyperspectral data were treated with resampling smooth Second hyperspectral data were analyzed based on principal components analysis (PCA), a freeze injury inversion model was established, stems survival rate was dependent, and principal components of spectral data were chosen as independent variables. Third, the precision of the model was testified. The result showed that the freeze injury inversion model based on 6 principal components can estimate the winter wheat freeze injury accurately with the coefficient of determination (R2) of 0. 697 5, root mean square error (RMSE) of 0. 184 2, and the accuracy of 0. 697 5. And the model was verified. It can be concluded that the PCA technology has been shown to be very promising in detecting winter wheat freeze injury effectively, and provide important reference for detecting other stress on crop.