Publications by authors named "Zhi-Kun Guo"

Introduction: Dihydropyrimidine dehydrogenase (DPD) is a major determinant of cancer 5-fluorouracyl (5-FU) resistance via its direct degradation. However, the mechanisms of tumoral DPD upregulation have not been fully understood.

Objectives: This study aimed to explore the role of S1PR2 in the regulation of tumoral DPD expression, identifying S1PR2 as the potential target for reversing 5-FU resistance.

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Article Synopsis
  • The chitin extracted from the shells of the black soldier fly (Hermetia illucens L.) has significant biological potential, yet research on its applications as chitosan or oligosaccharides is limited.
  • Researchers explored various extraction processes—demineralization, deproteinization, and decolorization—determining their impact on the yield and purity of chitin and chitosan.
  • The optimal extraction method achieved the highest yields and purity levels, suggesting that farmed black soldier fly residues can be effectively recycled as a valuable source of chitin in biomaterials.
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Objective: This study aimed to investigate the protective role of the signal transducer and activator of transcription 4 (STAT4) in diabetic cardiomyopathy.

Materials And Methods: Male Sprague-Dawley (SD) rats (6-8 weeks old) were purchased from the Experimental Animal Center of Zhengzhou University. The rats were randomly divided into the control and diabetic cardiomyopathy groups.

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Aberrant sphingolipid metabolism has been implicated in chemoresistance, but the underlying mechanisms are still poorly understood. Herein we revealed a previously unrecognized mechanism of 5-fluorouracil (5-FU) resistance contributed by high SphK2-upregulated dihydropyrimidine dehydrogenase (DPD) in colorectal cancer (CRC), which is evidenced from human CRC specimens, animal models, and cancer cell lines. TMA samples from randomly selected 60 CRC specimens firstly identified the clinical correlation between high SphK2 and increased DPD (p < 0.

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Background/aims: Calcium-activated chloride channels (CaCCs) regulate numerous physiological processes including cell proliferation, migration, and extracellular matrix secretion. T16Ainh-A01 and CaCCinh-A01 are selective inhibitors of CaCCs. But it is unknown whether these two compounds have functional effects on cardiac fibroblasts (CFs).

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Aim: Glucagon-like peptide-1 (GLP-1) agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors can not only lower blood glucose levels, but also alleviate cardiac remodeling after myocardial ischemia and hypertension. In the present study, we investigated the effects of a DPP-4 inhibitor (linagliptin) and a GLP-1 activator (liraglutide) on glucose- and angiotensin II (Ang II)-induced collagen formation and cytoskeleton reorganization in cardiac fibroblasts in vitro, and elucidated the related mechanisms.

Methods: Cardiac fibroblasts were isolated from the hearts of 6-week-old C57BL/6 mice, and then exposed to different concentrations of glucose or Ang II for 24 h.

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Aim: To establish an easily-handled method to isolate mesenchymal stem cells (MSCs) from coagulated human bone marrow samples.

Methods: Thrombin was added to aliquots of seven heparinized human bone marrow samples to mimic marrow coagulation. The clots were untreated, treated with urokinase or mechanically cut into pieces before culture for MSCs.

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The adipose tissue-derived mesenchymal stem cells (ADMSCs) are extensively utilized in tissue engineering, regenerative medicine and cell therapy. ADMSCs can differentiate into cardiomyocytes, and it has been shown that over-expression of a cocktail of factors can induce ectopic heart formation and program cardiogenesis in ESCs. However, which genes are responsible for differentiation of ADMSCs into beating cardiomyocyte-like cells remains unknown.

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Objectives: To investigate the expression dynamic of nanog gene in the development of rat myocardial tissues.

Methods: SD rats were studied at 5 time points before and after birth. The techniques of immunohistochemistry, immunofluorescence, western blotting and RT-PCR were used to investigate the expression of nanog gene in the rat myocardial tissues at different embryonic (E) and postnatal (P) stages, and image analysis system was used for the quantitative analysis.

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Adipose-derived mesenchymal stem cells (ADMSCs) are an attractive adult-derived stem cell population for cardiovascular repair. ADMSCs are heterogeneous cell populations with pluripotent capacity to differentiate into different types of cells. In the present study, we investigated the biological characteristics and differentiation potential of CD73-positive (CD73(+)) and CD73-negative (CD73(-)) ADMSCs.

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The dorsal motor nucleus of vagus (DMV) plays an important role in the regulation of gastrointestinal function. Dopamine (DA) exerts potent neuromodulatory effects on the motoneurons in the DMV via dopamine receptors (DRs). However, the distribution of DRs and their neurochemical phenotypes in the DMV are unclear.

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