Formation of (2E)-4-Hydroxy-2-nonenal and (2E)-4-Hydroxy-2-hexenal by Plant Enzymes: A Review Suggests a Role in the Physiology of Plants

It is demonstrated that (3Z)-nonenal (NON) and (3Z)-hexenal (HEX) are oxidized in a cascade by lipoxygenase (LOX) and hydroperoxide peroxygenase (HP peroxygenase) into (2E)-4-hydroxy-2- nonenal (HNE) and (2E)-4-hydroxy-2-hexenal (HHE), respectively. In turn, HNE inactivates LOX terminating the cascade. The hydroxy-alkenals produced serve to inhibit plant pathogens, which initiated the cascade. In addition to LOX, other unknown oxygenases may be involved in the cascade.

Role of Cathepsin G in the Degradation of Glyceraldehyde-3-Phosphate Dehydrogenase Triggered by 4-Hydroxy-2-Nonenal in U937 Cells

Degradation of oxidized or oxidatively modified proteins is an essential part of the cellular antioxidant defense system. 4-Hydroxy-2-nonenal (HNE), a major reactive aldehyde formed by lipid peroxidation, causes many types of cellular damage. HNE-modified proteins are degraded by the ubiquitin-proteasome pathway or the lysosomal pathway. However, our previous studies using U937 cells showed that HNE-modified glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is degraded by cathepsin G. In the present study, we examined whether GAPDH in U937 cells treated with HNE in culture is degraded similarly to that incubated with HNE and U937 cell extract. Treatment with HNE for 10 min in culture decreased GAPDH activity in a concentration dependent manner, but did not affect GAPDH degradation. The proteasome activities were not affected by HNE, but culturing with HNE decreased cathepsin G activity and protein level in a concentration dependent manner. These results suggest that HNE-induced oxidative stress leads to decreased cathepsin G activity and results in the loss of GAPDH degradation. Taken together, our findings indicate that cathepsin G has an important role in the degradation of oxidatively modified GAPDH in U937 cells.

2-苯基/环己基环十二酮的还原选择性及trans-1,2-二取代环十二烷的构象分析

通过研究2-苯基/环己基环十二酮在不同还原剂和温度下的还原反应证实了2-取代环十二酮的还原反应具有cis-选择性.在此基础上,通过2-取代环十二酮的Na BH4还原反应、1,2-环氧环十二烷的开环反应及cis-2-苯基环十二醇的Mitsunobu反应和水解反应制备了一系列trans-1,2-二取代环十二烷;采用1H NMR、13C NMR、X射线衍射和量子化学计算等方法对其优势构象进行了分析.结果表明,trans-1,2-二取代环十二烷的优势构象为[3333]方形构象,1个取代基位于边碳外向位(Side-exo),另1个位于角碳反向位(Corneranti).cis-2,12-二取代环十二酮的Li Al H4还原产物的X射线衍射分析结果表明,生成的1,2,3-三取代环十二烷保持了环十二烷的[3333]方形构象,2个取代基位于边碳外向位,羟基位于角碳顺向位(Corner-syn),取代基呈现出cis-cis关系.

被修饰环糊精模版控制的trans-2-苯乙烯吡啶的分子内环化

环糊精(CDs)是由6,7或8吡喃葡萄糖与上下环绕的羟基组成的环状低聚糖,具有内疏水外亲水的结构特征。合成了一种酰化的γ-环糊精(CDs),并将酰化的环糊精衍生物与trans-2-苯乙烯吡啶分子包合,比较了固态、液态及凝胶态中包合物的光反应结果,发现修饰的环糊精对其分子内光环化产物的生成具有选择性,其中固态产物的选择性最好,可以得到产率较高的苯并[f]喹啉。

Solubility of trans-1,2-Cyclohexanediol in Some Solvents

The solubility of trans-1,2-cyclohexanediol in water, methyl acetate, acetic ester, propyl acetate, butyl acetate, methyl acrylate, ethyl acrylate, 2-pentanone and acetoacetic ester was measured at temperatures ranging from about 300 K to 330 K, using a modification of the experimental technique of laser monitoring observation system. The solubilities were calculated by λh method, in which new parameters were introduced to express the activity coefficients of trans-1,2-cyclohexanediol, and determined from the experimental data. The new parameters provide good calculated results. The experimental data were also correlated with a simple model, and results were compared with present λh model.

Solid-Liquid Equilibria of trans-1,2-Cyclohexanediol＋Butyl Acetate＋ Water Ternary System

Using a laser observation technique,the solubilities of trans-1,2-cyclohexanediol in butyl acetate+wa- ter were measured at the temperature range from 298.15K to 323.15K by a synthetic method at atmospheric pres- sure.It is shown that the solubilities of trans-1,2-cyclohexanediol in butyl acetate+water were affected greatly by the proportion of butyl acetate and water,and presented maximum value at given temperature.The UNIFAC model was used to correlate the experimental data.The average relative deviation(ARD)between experimental and calculated values is 3.03%.

Determination of trans-4-hydroxy-2-alkenals in thermally treated soybean oil by SPE-HPLC

Trans-4-hydroxy-2-hexenal(4-HHE) and trans-4-hydroxy-2-nonenal(4-HNE) are secondary lipid peroxidation products in edible oils, which are cytotoxic and genotoxic. They could covalently bind with protein, phospholipids and DNA, further disrupting the normal function of liver, lung and brain.Derivation process was generally conducted during pretreatment before detection and quantification of 4-HHE and 4-HNE. However, the derivation procedures were time consuming and chemical degradation may occur during the process. Hence, this paper aims to establish a simple solid phase extractionhigh performance liquid chromatography(SPE-HPLC) method to determine the 4-HHE and 4-HNE contents in thermally treated soybean oil. C18 solid phase extraction was applied in the pretreatment process. Firstly, the reliability of the method was evaluated. Good linearity was observed in the range of 0.1–0.5 μg/m L and 0.5–10 μg/m L for 4-HHE and 4-HNE. The limit of detection(LOD) of 4-HHE and 4-HNE were 0.0486 and 0.0129 μg/m L, respectively. And the limit of quantitation(LOQ) of4-HHE and 4-HNE were 0.1458 and 0.0431 μg/m L, respectively. Recovery rate were in the range of89.11%–91.58% and 71.83%–79.40% for 4-HHE and 4-HNE, respectively. The method achieved the extraction, purification and detection of 4-HHE and 4-HNE simultaneously and had the advantages of simple operation, effectiveness, high precision, good repeatability. Then, the method was applied to monitor the concentrations of 4-HHE and 4-HNE in soybean oil heated at 180 °C for 40 h. The contents of 4-HHE and 4-HNE were 0–0.32 μg/g and 0–6.97 μg/g, respectively, which provided guidance for evaluating health risks of thermally treated soybean oil during heating.

Synthesis and Crystal Structure of Trans-4-[(5-(2,4-Dichlorophenoxy)-3-methyl-1-phenyl-1H-pyrazol-4-yl)methyleneamino]-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one

The title compound trans-4-[（5-（2,4-dichlorophenoxy）-3-methyl- 1-phenyl-1H-pyrazol-4-yl）methyleneamino]- 1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one 3 （C28H23Cl2N5O2, Mr = 532.41） has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group P1- with a = 8.9438（4）, b = 11.6065（5）, c = 14.2215（6）A, α = 112.566（1）, β = 92.324（2）, γ = 102.91（1）°, V= 1315.65（10） A^3, Z = 2, Dc = 1.344 g/cm^3,μ（MoKa） = 0.282 mm^-1, λ = 0.71073 A, F（000） = 552, the final R = 0.0587 and wR = 0.1578 for 5071 observed reflections （I 〉 2σ（I））. X-ray analysis reveals that the product is a thermodynamically stable trans isomer. Intra- and intermolecular C（ 12）-H（12）…O（1） and C（28）-H（28）...O（1）# 1 hydrogen bonds were observed in the title compound.

Dimer of Bis[trans-5-methyl-2-[2-(4-methoxylphenyl)ethenyl]-benzoxazole]di-μ-nitratosilver(I)

The title complex [AgNO3(C17H15NO2)2]2 was synthesized and characterized by X-ray diffraction analysis. The compound crystallizes in triclinic, space group P with a = 11.226(7), b = 11.906(7), c = 12.144(7) , = 99.796(10), = 91.631(10), = 101.225(10), V = 1565.6(16) 3, Z = 1, Mr = 1400.96, Dc = 1.486 g/cm3, F(000) = 716 and (Mo-K? = 0.697 mm-1. The final R and wR are 0.0401 and 0.0995, respectively for 5492 independent observable reflections with I > 2(I). The results show that the central Ag atom is four-coordinated with two O atoms from two distinct NO3- anions and two N atoms from two trans-5-methyl-2-[2-(4-methoxylphenyl)ethenyl]- benzoxazole ligands, and the two Ag atoms bridged with two O atoms give an interesting Ag-O-Ag-O parallelogram structure. The coordination sphere of Ag atom exhibits a heavily distorted tetrahedral geometry and the coordination angles lie in the range of 66.73(12)～129.59(10). The intra- molecular dihedral angles between the benzoxazolyl and phenyl planes are 4.1(3) and 2.9(3), respectively.

Mechanistic Study on the Monofunctional Binding of Hydrolysis Products of Non-planar Heterocyclic Complexes Trans-[PtCl_2NH_3(piperidine)] and Trans-[PtCl_2(piperidine)_2] to DNA Purine Bases

The monofunctional substitution reactions between trans-[PtCl（H2O）（NH3）（pip）]＋,trans-[Pt（H2O）2（NH3）（pip）]2＋,trans-[PtCl（H2O）（pip）2]＋,trans-[Pt（H2O）2（pip）2]2＋ （pip = piperidine） and adenine/guanine nucleotides are explored by using B3LYP hybrid functional and IEF-PCM salvation models. For the trans-[Pt（H2O）2（NH3）（pip）]2＋ and trans-[PtCl（H2O）（NH3）（pip）]＋ complexes,the computed barrier heights in aqueous solution are 13.5/13.5 and 11.6/11.6 kcal/mol from trans-Pt-chloroaqua complex to trans/cis-monoadduct for adenine and guanine,and the corresponding values are 20.7/20.7 and 18.8/18.8 kcal/mol from trans-Pt-diaqua complex to trans/cis-monoadduct for adenine and guanine,respectively. For trans-[PtCl（H2O）（pip）2]＋ and trans-[Pt（H2O）2（pip）2]2＋,the corresponding values are 21.5/21.3 and 19.4/19.4 kcal/mol,and 26.0/26.0 and 20.7/20.8 kal/mol for adenine and guanine,respectively. Our calculations demonstrate that the barrier heights of chloroaqua are lower than the corresponding values of diaqua for adenine and guanine. In addition,the free energies of activation for guanine in aqueous solution are all smaller than that for adenine,which predicts a preference of 1.9 kcal/mol when trans-[PtCl（H2O）（NH3）（pip）]＋ and trans-[Pt（H2O）2（NH3）（pip）]2＋ are the active agents and ～1.9 and ～ 5.3 kcal/mol when trans-[PtCl（H2O）（pip）2]＋ and trans-[Pt（H2O）2（pip）2]2＋ are the active agents,respectively. For the reaction of trans-Pt-chloroaqua （or diaqua） to cis-monoadduct,we obtain the same transition-state structure as from the reaction of trans-Pt-chloroaqua （or diaqua） to trans-monoadduct,which seems that the trans-Pt-chloroaqua （or diaqua） complex can generate trans-or cis-monoadduct via the same transition-state.

Facile synthesis of 9-(N-amino-4-fluoromethyl-3-pyrrolidinyl)-2-fluoro-6-aminopurine from trans-4-hydroxy-L-proline

A novel and simple procedure for synthesis of azanucleoside by Mitsunobu reaction between N-（p-nitrobenzyloxycarbonyl）- trans-4-hydroxy-D-proline methyl ester obtained from trans-4-hydroxy-L-proline after six-step reaction and 2-fluoro-6-azidopurine is described, and azanucleoside is fluorinated by new fluridizer 2,2-difluoro-1,3-dimethylimidazolidine （DFI）. All reactions could be carried out under mild condition.

Neuroprotective effects of Alda-1 mitigate spinal cord injury in mice:involvement of Alda-1-induced ALDH2 activation-mediated suppression of reactive aldehyde mechanisms

Spinal cord injury(SCI)is associated with high production and excessive accumulation of pathological 4-hydroxy-trans-2-nonenal(4-HNE),a reactive aldehyde,formed by SCI-induced metabolic dysregulation of membrane lipids.Reactive aldehyde load causes redox alteration,neuroinflammation,neurodegeneration,pain-like behaviors,and locomotion deficits.Pharmacological scavenging of reactive aldehydes results in limited improved motor and sensory functions.In this study,we targeted the activity of mitochondrial enzyme aldehyde dehydrogenase 2(ALDH2)to detoxify 4-HNE for accelerated functional recovery and improved pain-like behavior in a male mouse model of contusion SCI.N-(1,3-benzodioxol-5-ylmethyl)-2,6-dichlorobenzamide(Alda-1),a selective activator of ALDH2,was used as a therapeutic tool to suppress the 4-HNE load.SCI was induced by an impactor at the T9–10 vertebral level.Injured animals were initially treated with Alda-1 at 2 hours after injury,followed by once-daily treatment with Alda-1 for 30 consecutive days.Locomotor function was evaluated by the Basso Mouse Scale,and pain-like behaviors were assessed by mechanical allodynia and thermal algesia.ALDH2 activity was measured by enzymatic assay.4-HNE protein adducts and enzyme/protein expression levels were determined by western blot analysis and histology/immunohistochemistry.SCI resulted in a sustained and prolonged overload of 4-HNE,which parallels with the decreased activity of ALDH2 and low functional recovery.Alda-1 treatment of SCI decreased 4-HNE load and enhanced the activity of ALDH2 in both the acute and the chronic phases of SCI.Furthermore,the treatment with Alda-1 reduced neuroinflammation,oxidative stress,and neuronal loss and increased adenosine 5′-triphosphate levels stimulated the neurorepair process and improved locomotor and sensory functions.Conclusively,the results provide evidence that enhancing the ALDH2 activity by Alda-1 treatment of SCI mice suppresses the 4-HNE load that attenuates neuroinflammation and neurodegeneration,promotes the neurorepair process,and improves functional outcomes.Consequently,we suggest that Alda-1 may have therapeutic potential for the treatment of human SCI.Animal procedures were approved by the Institutional Animal Care and Use Committee(IACUC)of MUSC(IACUC-2019-00864)on December 21,2019.

Simultaneous determination of typical toxic aldehydes formed during food frying and digestion using isotope dilution UHPLC-QqQ-MS/MS

An isotope dilution ultra-performance liquid chromatography-triple quadrupole mass spectrometry method was developed to simultaneously detect two typical kinds ofα,β-unsaturated aldehydes,namely 4-hydroxy-2-hexenal(4-HHE)and 4-hydroxy-2-nonenal(4-HNE),in foods.The proposed method exhibited a linear range of 10-1000 ng/mL with a limit of detection of 0.1-2.0 ng/g and a limit of quantification of 0.3-5.0 ng/g.The recovery rates of these typical toxic aldehydes(i.e.,4-HHE,4-HNE)and their d3-labeled analogues were 91.54%-105.12%with a low matrix effect.Furthermore,this proposed method was successfully applied to a real frying system and a simulated digestion system,wherein the contents of 4-HHE and 4-HNE were determined for both.Overall,the obtained results provide strong support for further research into the production of 4-HHE and 4-HNE resulting from foods during oil digestion and frying.

N-[反式-2-(3,4-~3H-吡咯基)-环己基]-N-甲基-3,4-二氯-苯乙酰胺盐酸盐的合成

N-[反式-2-(1-吡咯基)环己基]-N-甲基-3,4-二氯-苯乙酰胺盐酸盐(简称U-50488H(K-I))是近年来报道的高选择性的K-阿片受体激动剂,动物实验结果表明:该化合物具有较强的镇痛活性,且成瘾性较低,呼吸抑制较弱,无吗啡样副作用的新型麻醉镇痛剂。为研究它的药理作用,我们用氚标记了U-50488(K-I)。合成该化合物开始原料是N-甲基-反式-2-(1-△~3-吡咯啉基)环己基胺,按一般还原法以氧化铂为催化剂,通氚进行氚化反应,未经分离与3,4一二氯苯乙酸在二环己基碳二亚胺(DCC)存在下进行缩合脱水反应,生成N-[反式-2-(3,4-~3H-吡咯基)环己基]-N-甲基-3,4-二氯-苯乙酰胺,再用氯化氢乙醚处理,制得了氚化的U-50488(K-I)。合成途径如下:

Role of aldehyde dehydrogenase 2 in ischemia reperfusion injury:An update

Aldehyde dehydrogenase 2(ALDH2) is best known for its critical detoxifying role in liver alcohol metabolism. However, ALDH2 dysfunction is also involved in a wide range of human pathophysiological situations and is associated with complications such as cardiovascular diseases, diabetes mellitus, neurodegenerative diseases and aging. A growing body of research has shown that ALDH2 provides important protection against oxidative stress and the subsequent loading of toxic aldehydes such as 4-hydroxy-2-nonenal and adducts that occur in human diseases, including ischemia reperfusion injury(IRI). There is increasing evidence of its role in IRI pathophysiology in organs such as heart, brain, small intestine and kidney; however, surprisingly few studies have been carried out in the liver, where ALDH2 is found in abundance. This study reviews the role of ALDH2 in modulating the pathways involved in the pathophysiology of IRI associated with oxidative stress, autophagy and apoptosis. Special emphasis is placed on the role of ALDH2 in different organs, on therapeutic "preconditioning" strategies, and on the use of ALDH2 agonists such as Alda-1, which may become a useful therapeutic tool for preventing the deleterious effects of IRI in organ transplantation.

Chronic stress causes protein kinase C epsilon-aldehyde dehydrogenase 2 signaling pathway perturbation in the rat hippocampus and prefrontal cortex,but not in the myocardium

Chronic stress is strongly associated with the occurrence and development of depression and cardiovascular disease.Stress can induce altered mitochondrial function and activation of apoptosis in the cardio-cerebral system.However,it is unknown whether the protein kinase C ε（PKCε）-aldehyde dehydrogenase 2（ALDH2） pathway is altered under chronic stress,and this study sought to address this question.A rat model of depression was established using a chronic unpredictable mild stress（CUMS） protocol.After experiencing CUMS for 4 weeks,the sucrose preference test and the forced swim test verified depressive-like behaviors.Enzyme linked immunosorbent assays showed that ALDH2 activity was decreased in the rat hippocampus and prefrontal cortex,but was not altered in the myocardium.Western blot assays demonstrated reduced levels of ALDH2 and PKCε,but increased levels of 4-hydroxy-2-nonenal（4 HNE） adducts.Caspase-3 expression did not obviously alter,but active forms of caspase-3 were increased in the hippocampus and prefrontal cortex.In the myocardium,expression of ALDH2,PKCε and 4 HNE adducts did not remarkably alter;while caspase-3 expression was reduced and the active forms of caspase-3 were upregulated.Pearson＇s correlation test demonstrated that expression of 4 HNE adducts was positively correlated with levels of the active forms of caspase-3 in the hippocampus and prefrontal cortex,but not in the myocardium.In conclusion,chronic stress can damage the PKCε-ALDH2 signaling pathway in the hippocampus and prefrontal cortex,but not in the myocardium.Moreover,4 HNE is associated with active forms of caspase-3 in the hippocampus and prefrontal cortex.

Identification and functional characterization of ApisOr23 in pea aphid Acyrthosiphon pisum

Pea aphid,Acyrthosiphon pisum,is a serious pest of many different leguminous plants,and it mainly relies on its odorant receptors(Ors)to discriminate among host species.However,less is known about the role that Ors play in the host plant location.In this study,we identified a novel conserved odorant receptor clade by phylogenetic analysis,and conducted the functional analysis of ApisOr23 in A.pisum.The results showed that the homologous Ors from A.pisum,Aphis glycines and Aphis gossypii share 94.28% identity in amino acid sequences.Moreover,conserved motifs were analyzed using the annotated homologous Or23 from eight aphid species,providing further proof of the high conservation level of the Or23 clade.According to the tissue expression pattern analysis,ApisOr23 was mainly expressed in the antennae.Further functional study using a heterologous Xenopus expression system revealed that ApisOr23 was tuned to five plant volatiles,namely trans-2-hexen-1-al,cis-2-hexen-1-ol,1-heptanol,4’-ethylacetophenone,and hexyl acetate.Among them,trans-2-hexen-1-al,which is one of the main volatile organic compounds released from legume plants,activated the highest response of ApisOr23.Our findings suggest that the conserved Or23 clade in most aphid species might play an important role in host plant detection.

Synthesis and Crystal Structure of Cobalt(II) Complex [Co(H_2O)_2(bpe)(OAc)_2]·4,4'-dpdo

The reaction of Co(OAc)2 with bpe and 4,4?-dpdo in an aqueous-alcohol solution affords the formation of red crystals of [Co(H2O)2(bpe)(OAc)2]?4,4?-dpdo (bpe = trans-1,2-bis(4- pyridyl)ethylene, 4,4?-dpdo = 4,4?-dipyridyl N,N?-oxide). The molecular and crystal structures were determined by single-crystal X-ray diffraction. The crystal is of triclinic, space group P1 with a = 7.6146(9), b = 8.6691(11), c = 10.3440(11) ?, α = 88.311(3), β = 76.992(3), γ = 75.809(3)°, V = 644.76(13) ?3, Z = 1, C26H28CoN4O8, Mr = 583.45, Dc = 1.503 g/cm3, μ = 0.724 mm-1, F(000) = 303, T = 223(2) K, the final R = 0.0477 and wR = 0.1177 for 3199 observed reflections with I > 2σ(I). In the crystal the cobalt atom is six-coordinated by oxygen atoms from two carboxylic molecules, two nitrogen atoms from the bpe ligands and two water molecules, completing an octahedral geometry. The structure of the title complex consists of neutral chains containing cobalt(II) ions bridged by mutually trans bpe molecules. The adjacent chains are connected through weak hydrogen bonds to form a two-dimensional structure.

Use of Cucurbit [6] Uril as a Modifier in the Electrochemical Determination of Antitumor Platinum (II) Complex: <i>Trans</i>-[PtCl₂(Dimethylamine) (Isopropylamine)]. Application to Biological Samples

A square wave voltammetry (DPV) method for trans-Pt[Cl2(Dimethylamine)(isopropylamine)] determination is developed. To this end, all the chemical and instrumental variables affecting the determination of trans-Pt[Cl2(Dimethylamine) (isopropylamine)] are optimized. From studies of the mechanisms governing the electrochemical response of trans-Pt[Cl2(Dimethylamine)(isopropylamine)], it was concluded that it was an electrochemically reversible system with an adsorptive oxidation phenomenon. Under optimal conditions, the variation of analytical signal (Ip) with trans-Pt[Cl2(Dimethylamine)(isopropylamine)] concentration was linear in the 0.05 μg·mL-1 to 10 μg·mL-1 range, with a LOD 91 μg·mL-1 of and a LOQ of 303 μg·mL-1, a RSD 1.10% and Er 0.72%. The optimized method was applied to the determination of trans-Pt[Cl2(Dimethylamine)(isopropylamine)] in biological fluids, in human urine and synthetic urine.

Hydroxyproline alleviates 4-hydroxy-2-nonenal-induced DNA damage and apoptosis in porcine intestinal epithelial cells

Oxidative stress has been confirmed in relation to intestinal mucosa damage and multiple bowel diseases.Hydroxyproline (Hyp) is an imino acid abundant in sow's milk. Compelling evidence has beengathered showing the potential antioxidative properties of Hyp. However, the role and mechanism ofHyp in porcine intestinal epithelial cells in response to oxidative stress remains unknown. In this study,small intestinal epithelial cell lines of piglets (IPEC-1) were used to evaluate the protective effects of Hypon 4-hydroxy-2-nonenal (4-HNE)-induced oxidative DNA damage and apoptosis. IPEC-1 pretreated with0.5 to 5 mmol/L Hyp were exposed to 4-HNE (40 mmol/L) in the presence or absence of Hyp. Thereafter,the cells were subjected to apoptosis detection by Hoechst staining, flow cytometry, and Western blot orDNA damage analysis by comet assay, immunofluorescence, and reverse-transcription quantitative PCR(RT-qPCR). Cell apoptosis and the upregulation of cleaved-caspase-3 induced by 4-HNE (40 mmol/L) wereinhibited by 5 mmol/L of Hyp. In addition, 5 mmol/L Hyp attenuated 4-HNE-induced reactive oxygenspecies (ROS) accumulation, glutathione (GSH) deprivation and DNA damage. The elevation in transcriptionof GADD45a (growth arrest and DNA-damage-inducible protein 45 alpha) and GADD45b(growth arrest and DNA-damage-inducible protein 45 beta), as well as the phosphorylation of H2AX(H2A histone family, member X), p38 MAPK (mitogen-activated protein kinase), and JNK (c-Jun N-terminalkinase) in cells treated with 4-HNE were alleviated by 5 mmol/L Hyp. Furthermore, Hyp supplementationincreased the protein abundance of Krüppel like factor 4 (KLF4) in cells exposed to 4-HNE.Suppression of KLF4 expression by kenpaulone impeded the resistance of Hyp-treated cells to DNAdamage and apoptosis induced by 4-HNE. Collectively, our results indicated that Hyp serves to protectagainst 4-HNE-induced apoptosis and DNA damage in IPEC-1 cells, which is partially pertinent with theenhanced expression of KLF4. Our data provides an updated explanation for the nutritional values ofHyp-containing animal products.