Collagen is a major structural protein in the matrix of animal cells and the most widely distributed and abundant functional protein in mammals. Collagen’s good biocompatibility, biodegradability and biological activity make it a very valuable biomaterial. According to the source of collagen, it can be broadly categorized into two types: one is animal collagen; the other is recombinant collagen. Animal collagen is mainly extracted and purified from animal connective tissues by chemical methods, such as acid, alkali and enzyme methods, etc. Recombinant collagen refers to collagen produced by gene splicing technology, where the amino acid sequence is first designed and improved according to one’s own needs, and the gene sequence of improved recombinant collagen is highly consistent with that of human beings, and then the designed gene sequence is cloned into the appropriate vector, and then transferred to the appropriate expression vector. The designed gene sequence is cloned into a suitable vector, and then transferred to a suitable expression system for full expression, and finally the target protein is obtained by extraction and purification technology. Recombinant collagen has excellent histocompatibility and water solubility, can be directly absorbed by the human body and participate in the construction of collagen, remodeling of the extracellular matrix, cell growth, wound healing and site filling, etc., which has demonstrated significant effects, and has become the focus of the development of modern biomedical materials. This paper firstly elaborates the structure, type, and tissue distribution of human collagen, as well as the associated genetic diseases of different types of collagen, then introduces the specific process of producing animal source collagen and recombinant collagen, explains the advantages of recombinant collagen production method, and then introduces the various systems of expressing recombinant collagen, as well as their advantages and disadvantages, and finally briefly introduces the application of animal collagen, focusing on the use of animal collagen in the development of biopharmaceutical materials. In terms of application, it focuses on the use of animal disease models exploring the application effects of recombinant collagen in wound hemostasis, wound repair, corneal therapy, female pelvic floor dysfunction (FPFD), vaginal atrophy (VA) and vaginal dryness, thin endometritis (TE), chronic endometritis (CE), bone tissue regeneration in vivo, cardiovascular diseases, breast cancer (BC) and anti-aging. The mechanism of action of recombinant collagen in the treatment of FPFD and CE was introduced, and the clinical application and curative effect of recombinant collagen in skin burn, skin wound, dermatitis, acne and menopausal urogenital syndrome (GSM) were summarized. From the exploratory studies and clinical applications, it is evident that recombinant collagen has demonstrated surprising effects in the treatment of all types of diseases, such as reducing inflammation, promoting cell proliferation, migration and adhesion, increasing collagen deposition, and remodeling the extracellular matrix. At the end of the review, the challenges faced by recombinant collagen are summarized: to develop new recombinant collagen types and dosage forms, to explore the mechanism of action of recombinant collagen, and to provide an outlook for the future development and application of recombinant collagen.

Selenoproteins, as the active form of selenium, play an important role in various physiological and pathological processes, such as anti-oxidation, anti-tumor, immune response, metabolic regulation, reproduction and aging. Although the expression level of selenoproteins in adipose tissue is significantly influenced by dietary selenium intake, it is closely related to the homeostasis of adipose tissue. In this review, we summarized the role of selenoproteins in the physiological function of adipose tissue and the pathogenesis of obesity in recent years, in order to provide a rationale for developing potential therapeutic agents for the treatment of obesity and related metabolic diseases.
Selenoproteins/metabolism* ; Adipose Tissue/physiology* ; Obesity/metabolism* ; Humans ; Animals ; Selenium

Acute respiratory distress syndrome (ARDS) is a common respiratory emergency, but current clinical treatment remains at the level of symptomatic support and there is a lack of effective targeted treatment measures. Our previous study confirmed that inhalation of hydrogen gas can reduce the acute lung injury of ARDS, but the application of hydrogen has flammable and explosive safety concerns. Drinking hydrogen-rich liquid or inhaling hydrogen gas has been shown to play an important role in scavenging reactive oxygen species and maintaining mitochondrial quality control balance, thus improving ARDS in patients and animal models. Coral calcium hydrogenation (CCH) is a new solid molecular hydrogen carrier prepared from coral calcium (CC). Whether and how CCH affects acute lung injury in ARDS remains unstudied. In this study, we observed the therapeutic effect of CCH on lipopolysaccharide (LPS) induced acute lung injury in ARDS mice. The survival rate of mice treated with CCH and hydrogen inhalation was found to be comparable, demonstrating a significant improvement compared to the untreated ARDS model group. CCH treatment significantly reduced pulmonary hemorrhage and edema, and improved pulmonary function and local microcirculation in ARDS mice. CCH promoted mitochondrial peripheral division in the early course of ARDS by activating mitochondrial thioredoxin 2 (Trx2), improved lung mitochondrial dysfunction induced by LPS, and reduced oxidative stress damage. The results indicate that CCH is a highly efficient hydrogen-rich agent that can attenuate acute lung injury of ARDS by improving the mitochondrial function through Trx2 activation.

Travelling wave structures for lossless ion manipulations(TW-SLIM)employ travelling wave electric fields to propel ions forward,enabling exceptionally long transmission paths and holding great potential for applications in material transportation and separation.In this study,different from previous studies focusing on the transport performance of macromolecules such as proteins in TW-SLIM,the transmission performance of small molecules(<200 amu)was investigated and analyzed in the turning TW-SLIM through the COMSOL simulation platform,to explore the influence of electrostatic field of protective electrode and radio frequency(RF)electric field on ion transport efficiency,and obtain the optimal value.Compared to macromolecules,small molecules required lower voltage amplitudes from guard electrodes but stricter requirements in terms of the peak-to-peak amplitude and frequency of RF voltage for lossless transmission.Using dimethyl methylphosphonate(DMMP)as a sample and testing it on the TW-SLIM experimental platform,when the protective voltage amplitude was 5 V and the peak-to-peak voltage of the radio-frequency electrode was 440 V at 1.5 MHz,the ion transmission efficiency reached 100%,achieving lossless transmission.The experimental results provided valuable references for application of TW-SLIM in separation and detection of small molecular substances,such as explosives and drugs.

In recent years,more and more researches has focused on the correlation between cognitive activity and physiological variables.The change of pupil is regarded as an important target in the cognitive process,and has become a hot research field.This review focuses on the three key brain regions that regulate pupil change,and reflects the neurophysiological mechanism behind pupil change by elaborating the neural pathways related to pupil change and cognitive performance.Based on recent studies on pupil change in cognitive diseases,it aims to promote the application of pupil change in the field of cognitive science in the future.

Objective To find out whether photobiomodulation(PBM)can mitigate cognitive dysfunction caused by chronic stress by affecting levels of adenosine triphosphate(ATP)and adenosine receptors.Methods Twenty-four C57BL/6J mice were randomly divided into a control group,a stress group,and a treatment group.Chronic unpredictable mild stress was used to establish a mouse model of stress.Six weeks into modeling,the treatment group was subjected to one week of PBM interventions.Behavioral tests were conducted to observe behavioral changes in the mice.Western blotting(WB)was used to detect the expressions of A1,A2B,and A3 adenosine receptors in the hippocampus and prefrontal cortex of mice in the three groups.Twelve C57BL/6J mice were randomly divided into a control group and an intervention group.The intervention group received a week of PBM interventions and underwent behavioral testing.WB was used to detect the expression changes of A1,A2B,and A3 adenosine receptors in the hippocampus and prefrontal cortex in both groups.Immunofluorescence assay was adopted to detect the expression of c-Fos in the hippocampus of mice in the two groups.The ATP assay kit made by Beyotime Biotechnology Co.,Ltd.was used to measure changes in ATP contents in the hippocampus and prefrontal cortex tissues of mice.Cell experiments were conducted to verify the effect of PBM on intracellular ATP contents.Results Mice in the stress group covered a similar distance to the control group,but finished far fewer platform crossings.There was no significant difference between the treatment group and the control group in the number of times of platform crossings,but compared favorably with the stress group where the levels of adenosine receptors in the hippocampus and prefrontal cortex were lower,but were increased by PBM.After PBM interventions in normal mice,platform crossings were increased significantly compared to the control group.PBM also raised adenosine receptor levels and ATP contents in the hippocampus and prefrontal cortex,and increased hippocampal c-Fos expressions.In vitro,PBM elevated intracellular ATP levels.Conclusion PBM may improve chronic stress-induced cognitive dysfunction by regulating ATP levels and adenosine receptor expressions,thereby modulating neuronal responsiveness in the hippocampus.

Acupuncture, a therapeutic treatment defined as the insertion of needles into the body at specific points (ie, acupoints), has growing in popularity world-wide to treat various diseases effectively, especially acute and chronic pain. In parallel, interest in the physiological mechanisms underlying acupuncture analgesia, particularly the neural mechanisms have been increasing. Over the past decades, our understanding of how the central nervous system and peripheral nervous system process signals induced by acupuncture has developed rapidly by using electrophysiological methods. However, with the development of neuroscience, electrophysiology is being challenged by calcium imaging in view field, neuron population and visualization in vivo. Owing to the outstanding spatial resolution, the novel imaging approaches provide opportunities to enrich our knowledge about the neurophysiological mechanisms of acupuncture analgesia at subcellular, cellular, and circuit levels in combination with new labeling, genetic and circuit tracing techniques. Therefore, this review will introduce the principle and the method of calcium imaging applied to acupuncture research. We will also review the current findings in pain research using calcium imaging from in vitro to in vivo experiments and discuss the potential methodological considerations in studying acupuncture analgesia.
Calcium ; Acupuncture Therapy ; Acupuncture ; Acupuncture Analgesia/methods* ; Acupuncture Points ; Technology

Objective The volume and cortical thickness of gray matter in patients with multiple sclerosis (MS) and neuromyelitis optica (NMO) were compared and analyzed by voxel⁃based morphometry (VBM) and surface⁃based morphometry (SBM), and the differences in the structural changes of gray matter in the two diseases were discussed. Methods A total of 21 MS patients, 16 NMO patients and 19 healthy controls were scanned by routine MRI sequence. The data were processed and analyzed by VBM and SBM method based on the statistical parameter tool SPM12 of Matlab2014a platform and the small tool CAT12 under SPM12. Results Compared with the normal control group (NC), after Gaussian random field (GRF) correction, the gray matter volume in MS group was significantly reduced in left superior occipital, left cuneus, left calcarine, left precuneus, left postcentral, left central paracentral lobule, right cuneus, left middle frontal, left superior frontal and left superior medial frontal (P<0. 05). After family wise error (FWE) correction, the thickness of left paracentral, left superiorfrontal and left precuneus cortex in MS group was significantly reduced (P<0. 05). Compared with the NC group, after GRF correction, the gray matter volume in the left postcentral, left precentral, left inferior parietal, right precentral and right middle frontal in NMO group was significantly increased (P<0. 05). In NMO group, the volume of gray matter in left middle occipital, left superior occipital, left inferior temporal, right middle occipital, left superior frontal orbital, right middle cingulum, left anterior cingulum, right angular and left precuneus were significantly decreased (P<0. 05). Brain regions showed no significant differences in cortical thickness between NMO groups after FWE correction. Compared with the NMO group, after GRF correction, the gray matter volume in the right fusiform and right middle frontal in MS group was increased significantly(P<0. 05). In MS group, the gray matter volume of left thalamus, left pallidum, left precentral, left middle frontal, left middle temporal, right pallidum, left inferior parietal and right superior parietal were significantly decreased (P<0. 05). After FWE correction, the thickness of left inferiorparietal, left superiorparietal, left supramarginal, left paracentral, left superiorfrontal and left precuneus cortex in MS group decreased significantly (P<0. 05). Conclusion The atrophy of brain gray matter structure in MS patients mainly involves the left parietal region, while NMO patients are not sensitive to the change of brain gray matter structure. The significant difference in brain gray matter volume between MS patients and NMO patients is mainly located in the deep cerebral nucleus mass.

BACKGROUND:Croton cream can activate ERK pathways and have anti-apoptotic effects on neuronal cells.It is not clear whether it synergistically exerts anti-apoptotic effects by inhibiting the activation of JNK and p38 pathways. OBJECTIVE:To explore the effects and mechanisms of croton cream on neuronal damage and apoptosis in the ischemic cortex of rats with cerebral ischemia-reperfusion injury. METHODS:(1)Ninety Sprague-Dawley rats were randomly divided into sham operation group,model group,croton cream low-dose group,croton cream medium-dose group,croton cream high-dose group and nimodipine group,with 15 rats in each group.Except for the sham operation group,animal models of middle cerebral artery occlusion were prepared in rats by the thread method.Rats in the three croton cream groups were given 20,40,and 60 mg/kg croton cream,respectively.Rats in the sham operation and model groups were given the same amount of normal saline,once a day,for 7 consecutive days.The optimal concentration of croton cream,namely the high dose of croton cream,was selected based on neurological deficit score,TTC staining,brain tissue water content,hematoxylin-eosin staining and Nissl staining.(2)Another 120 Sprague-Dawley rats were randomly divided into sham operation group,model group,croton cream group,JNK inhibitor group,croton cream+JNK inhibitor group,p38 MAPK inhibitor group,croton cream+p38 MAPK inhibitor group,and nimodipine group,with 15 rats in each group.Animal models of middle cerebral artery occlusion were prepared using the thread method in all the groups except in the sham operation group.Thirty minutes before modeling,10 μL of SP600125(JNK inhibitor)and 10 μL of SB203580(p38 MAPK inhibitor)were injected into the lateral ventricle of the rats,respectively.Rats in croton cream groups were intragastrically given 60 mg/kg croton cream.Seven days later,the JNK/p38 MAPK signaling pathway,apoptosis-related proteins and cell apoptosis were detected by western blot,TUNEL staining and flow cytometry,respectively. RESULTS AND CONCLUSION:(1)Compared with the sham operation group,neurological deficit score,cerebral water content,cerebral infarction volume and apoptosis rate were significantly increased in the model group(P<0.05),where nerve cells showed scattered distribution.Compared with the model group,neurological deficit score,water content of brain tissue and cerebral infarction volume were significantly decreased in the croton cream medium-dose group,high-dose group and nimodipine group(P<0.05),and the pathological morphology of nerve cells was significantly improved.(2)Compared with the JNK inhibitor group,p-JNK/JNK,p-p38/p38 and Bax expressions in rat brain tissue and the apoptotic rate were significantly decreased in the croton cream+inhibitor groups(P<0.05),while the expression of and Bcl-2 was significantly increased(P<0.05).To conclude,croton cream may inhibit the activation of JNK/p38 MAPK signaling pathway and reduce neuronal apoptosis to achieve neuroprotective effects in rats with cerebral ischemia-reperfusion injury.

Objective To investigate the effects of Simo decoction on duodenal microinflammation and NOD-like receptor thermal protein domain associated protein 3(NLRP3)/cysteinyl aspartate-specific proteinase-1(Caspase-1)/gasdermin D(GSDMD)signaling pathway in rats with functional dyspepsia(FD).Methods The FD model was established by multifactorial method.SD rats were randomly divided into normal group,model group(FD model),positive control group(gavage administration of 0.305 mg·kg-1 mosapride injection)and experimental-H,-M,-L groups(gavage administration of 5.62,2.81,1.40 g·kg-1 Simo decoction).Small intestinal advancement rate and gastric emptying rate was determined;the levels of interleukin(IL)-1 β and IL-18 in serum were determined by enzyme linked immunosorbent assay(ELISA);the protein expression of NLRP3 and GSDMD in duodenal tissue was detected by Western blotting.Results The gastric emptying rates of normal,model,positive control and experimental-H,-M,-Lgroupswere(58.34±5.72)％,(29.16±8.37)％,(48.77±6.10)％,(48.35±6.04)％,(48.20±3.49)％and(39.24±4.20)％;the small intestinal propulsion rates were(82.01±7.55)％,(41.95±9.53)％,(64.61±10.18)％,(75.04±9.76)％,(60.58±7.13)％and(45.89±7.40)％;serum IL-1 β expression were(12.86±0.88),(43.73±4.60),(18.84±0.86),(24.61±1.57),(19.14±0.77)and(29.04±0.72)pg·mL-1;IL-18 expressions were(95.00±3.74),(170.60±8.78),(108.50±3.05),(118.90±3.45),(99.90±8.70)and(141.00±3.71)pg·mL-1;the relative expression levels of NLRP3 proteins were 0.32±0.02,0.84±0.05,0.42±0.03,0.48±0.02,0.61±0.04 and 0.62±0.05;the relative expression levels of GSDMD proteins were 0.34±0.05,0.93±0.06,0.35±0.03,0.52±0.02,0.53±0.06 and 0.55±0.05,respectively.Compared with the normal group,the above indexes in the model group have statistical significance;compared with the model group,the above indexes in the experimental-H group and the positive control group also have statistical significance(P＜0.01 or P＜0.05).Conclusion Simo decoction can effectively improve the general condition and duodenal microinflammation in FD rats,and the mechanism may be related to the inhibition of duodenal NLRP3/Caspase-1/GSDMD signaling pathway.