Progress in in vitro culture and gene editing of porcine spermatogonial stem cells

Research on in vitro culture and gene editing of domestic spermatogonial stem cells (SSCs) is of considerable interest but remains a challenging issue in animal science. In recent years, some progress on the isolation, purification, and genetic manipulation of porcine SSCs has been reported. Here, we summarize the characteristics of porcine SSCs as well current advances in their in vitro culture, potential usage, and genetic manipulation. Furthermore, we discuss the current application of gene editing in pig cloning technology. Collectively, this commentary aims to summarize the progress made and obstacles encountered in porcine SSC research to better serve animal husbandry, improve livestock fecundity, and enhance potential clinical use.

Normal and Degenerated Rabbit Nucleus Pulposus Cells in in vitro Cultures: A Biological Comparison

This study examined the biological characteristics of normal and degenerated rabbit nucleus pulposus （NP） cells in vitro in order to provide seed cells for intervertebral disc （IVD） tissue engineering. A total of 8 adult New Zealand white rabbits underwent annulus puncture to establish models ofintervertebral disc degeneration （IDD）. Four weeks later, normal and degenerated NP cells were obtained. Cell morphology was observed by light and electron microscopy. Cell viability was measured by MTT assay. Cell cycle and expression of extracellular matrix （ECM）-related genes （aggrecan and type II col- lagen） were determined by using flow cytometry and RT-PCR respectively. The growth curve of normal NP cells showed that the cells at passage 4 tended to slowly grow on the fifth day of culture. The density of normal NP cells at passages 5 to 7 was significantly less than that of the first-passage cells 2 or 3 days after seeding （P〈0.05）. The degenerated NP cells at passage 3 showed slow growth at 4th day. After 5 passages, the degenerated NP cells assumed stagnant growth and the growth seemed to stop at passage 7. The MTT assay revealed that for both normal and degenerated NP cells, the absorbance （.4） value at passages 4-7 was obviously decreased as compared with that at passage 1 （P〈0.05）. Cell cycle analysis showed that the proportion of normal NP cells at G1 phase was 65.4%-3.5%, significantly lower than that of degenerated NP cells at the same cell cycle phase With the value being 77.6%-4.8%. The degen- erated NP cells were predominantly arrested at Gt phase and failed to enter S phase. The expression of type II collagen and aggrecan was significantly decreased with passaging. It was concluded that normal NP cells possessed good viability and proliferative capacity by the third passage, and they could secrete large amounts of ECM within this period. The normal NP cells may serve as seed cells for IVD tissue engineering.

In vitro long-term culture and differentiation of mouse spermatogonia stem cells

The studies from 7 or 8 days old mice were used to prepare the spermatogonial stem cells. The isolation and purification of spermatogonial stem cells were done by means of the Percoll discontinual density gradient concentration. The cells of the 3rd band were collected and cultured in vitro in DMEM supplemented with 2.5% or 10% fetal bovine serum （FBS）. The results showed that with the feeder layer and 2.5% serum, the spermatogonial stem cells could proliferate, differentiate last more than 4 months.

EFFECT OF RADIX SALVIAE MILTIORRHIZAE ON GROWTH OF ISOLATED CELLS FROM EMBRYONIC CHICKEN FRONTAL BONE CULTURED IN VITRO (A HISTOCHEMICAL STUDY) Ⅱ.THE DEVELOPMENT AND MATURATION OF OSTEOBLAST-LIKE CELLS

The isolated osteoblast-like cells from embryonic chicken frontal bone werecultured in vitro and histochemical methods adopted to observe the effect of RadixSalviac Miltiorrhizae (RSM) on proliferation, differentiation, and osteogenic capacity ofthese cells. It was found that: 1. The mitosis and proliferation of the osteoblast-like cellscould be accelerated by RSM, resulting in increased density of the cells in RSM groupas compared with the control. 2. After 48 h, the pseudopodia stretched out and drew backactively in osteoblast-like cells in RSM group. Small particles produced in the cells weresecreted through exocytosis to the extracellular medium. However, in the control group,the capacity to form and secrete these particles was limited. These particles showed posi-tive Alcian blue staining in Alcian blue-Sirius red reaction, so they were acidmucopolysaccharide particles. 3. The osteoblast-like cells could secrete vesicular particles 3micra in diameter. These vesicular particles could be stained with Alcian blue in earlystage, then they could be stained with Sirius red, and finally by Alizarin red S. Thesevesicular particles could aggregate and fuse around the cell colonies, forming bonenodules and bone flakes. The quantity and volume of the bone nodules and flakes inRSM group were larger than in the control group. 4. The bone nodules and flakes couldbe labeled vitally with tetracycline, and show strong yellow fluorescence under thefluorescence microscope. Therefore, these substances were the newly formed bone sub-stances.

<i>In Vitro</i>Culture of Shell Gland Epithelial Cells in Japanese Quail (<i>Coturnix coturnix japonica</i>)

To investigate the secretion of protoporphyrin IX (PpIX), superficial eggshell pigment, from shell gland cells of Japanese quail, the epithelial cells of the gland were collected and isolated for cultivation in vitro. An analysis of a peak for PpIX in the cells was performed using a fluorescence microplate reader. The measurement showed that PpIX has a peak of excitation wavelength at 410 nm and emission wavelength at 606 nm in the culture medium (HamF12 + 4% HCl). Volumes of PpIX in the medium after 4 hour culture of the cells were measured with a microplate reader using filter set of excitation wavelength 400/30nm and emission wavelength 620/40nm. However the cells did not secrete significantly PpIX during 4 hour incubation in this culture system, addition of quail plasma to the medium resulted in significantly higher secretion. A cultivation system in this study is able to use for the study on the mechanism of the secretion of eggshell pigment, PpIX from Japanese quail shell gland epithelial cells.

Comparison on In-Vitro Culture Methods of Yak Endometrial Gland Epithelial Cells

[ Objective] To develop in-vitro culture methods of yak endometrial gland epithelial cells. [Method] The gland epithelial cells were isolated from yak endometrium by explant culture method and digestion culture method, respectively. [ Result] In the first method, the cells isolated from the endometrium explant could merge into monolayer after 8-d culture, and they could be purified by gradation digestion with trypsin. In the second method, the endometrium explant were first digested by collagenase II by incubation at 37℃ for 2.5 h and then further digested in fresh 2 g/L colla- genase II for another 2.5 h. The cell suspension was leached through 74 pm filter and centrifuged at 400 r/min for 5 min. Then the cell pellet was re-suspended, followed by natural sedimentation to collect purified gland epithelial cells. The isolated cells were cytokeratin-positive as detected by immunocytochemical staining, and the positive rate could reach 95%. [Conclusion] The yak endometrial gland epithelial cells can be isolated and purified by both the explant culture method and digestion culture method.

Preparation, cryopreservation and in vitro culture of spermatogonial stem cells of new born calves

The experiment was designed to study the preparation, cryopreservation and culture of calf spermatogonial stem cells in order to provide some data for theoretical research and practical use of calf spermatogonial stem cells. As for enzymolysis of testis tissue, two digestive method A and B. The cryopreservation cooling procedure was that spermatogonial stem cells was equilibrated at 4℃ for lh, at -20℃ for lh, at -40℃ for 2h, at -80℃ overnight and then stored in liquid nitrogen. The different concentration of three eryoprotectants were compared. The results indicated that both method A and method B achieved the same high motility rates of cells with method B needing time longer, calf spermatogonial stem cells could be well cryopreserved by the stage cooling procedure. Satisfactory cryopreservative results were gotten by adding 10% DMSO or 10% EG to cryopreservative medium, the former was better and adding sucrose could improved cryopreservative effect. The culture behaviors of spermatogonial stem cells kept the same before and after cryopreservation. It was concluded that an effective method was verified for preparation, cryopreservation and culture of new calf spermatogonial stem cells.

Three-dimensional cell culture systems as an in vitro platform for cancer and stem cell modeling

Three-dimensional(3D)culture systems are becoming increasingly popular due to their ability to mimic tissue-like structures more effectively than the monolayer cultures.In cancer and stem cell research,the natural cell characteristics and architectures are closely mimicked by the 3D cell models.Thus,the 3D cell cultures are promising and suitable systems for various proposes,ranging from disease modeling to drug target identification as well as potential therapeutic substances that may transform our lives.This review provides a comprehensive compendium of recent advancements in culturing cells,in particular cancer and stem cells,using 3D culture techniques.The major approaches highlighted here include cell spheroids,hydrogel embedding,bioreactors,scaffolds,and bioprinting.In addition,the progress of employing 3D cell culture systems as a platform for cancer and stem cell research was addressed,and the prominent studies of 3D cell culture systems were discussed.

Establishment of primary cultures of craniopharyngioma cells

Craniopharynigoma samples were collected from 36 patients. Out of the 36 samples, 29 achieved successful sub-culturing, with a success rate of 80.6%. Immunohistochemistry staining showed that cytokeratin-7 was positively expressed in the cytomembrane and cytoplasm of craniopharyngioma cells at 6-8 passages, confirming that all cultured cells were squamous epithelial cells. The doubling time of craniopharyngioma cells was 3 days, as confirmed by the 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide assay. In this study, craniopharyngioma cells cultured in vitro were established; however, establishment of immortalized craniopharyngioma cell lines requires further research.

Simplified methods to isolate,culture and purify olfactory ensheathing cells

Conventional methods for harvesting, culturing and purifying olfactory ensheathing cells are complicated, time-consuming, and poorly reproducible. Olfactory bulbs were detached from adult Sprague Dawley rats and olfactory ensheathing cells were isolated using shearing, dispersion processes. After the primary cultures reached confluence, the cells were purified using a three-step process. The olfactory ensheathing cells attached and grew rapidly. The purity of the olfactory ensheathing cells increased following the three purification steps, eventually exceeding 95%. These cells could be maintained for an extended period time in culture. This simple, inexpensive, reproducible method of harvesting, culturing and purifying olfactory ensheathing cells shortens the culture cycle and provides sufficient olfactory ensheathing cells of controllable purity.

Studies on Single Cell Culture in vitro in Wheat——The variation of grain protein content and its fractions from regenerated plants

On the basis of previous studies dealing with the variation of major agronomic and yield characteristics of regenerated plants derived from single cell culture in vitro of common wheat (Triticum aestivum L.Cultivar NE 7742), the grain protein content and its fractions from regenerated plants with stable agronomic characteristics were studied from 1992 to 1995. The results showed that the variation of grain protein content and its fractions in somaclones from single cell culture in vitro were very significant and the range was very wide (11531770%). Several types of variation were found in the studies, especially the type with higher protein content than that of cultivar NE 7742 (non-culture parent). Among them, -2069% of lines the grain protein content was significantly higher than that of NE 7742 and combined with high yielding potential. The tendency of variation of the four protein fractions showed that the variation of albumin was not obvious and maintained the same level as NE774 increased in some somaclones and decreased in others. However, the percentages both globulin and glutenin tended to increase. The variation of total amount of structural protein and the ratio between globulin and glutenin tended to increase. The variation of total amount of structural protein and the ratio between globulin and albumm was mainly influenced by globulin under the condition of culture in vitro. The variation of total amount of storage protein and the ratio between gliadin and glutenin was mainly affected by glutenin. The results mentioned above demonstrated that the induction and screening of somaclonal variation could be an effective way in wheat improvement in combining high protein content with high yield.

Enzymatic Cell Isolation and Explant Cultures of Rat Calvarial Osteoblast Cells

Osteoblast cells were isolated from the calvarial bones of newborn Wistar rats and cultured in vitro via both collagenase digestion method and explant technique, and a comparative study was carried out on the two culture methods. The biologic charwteristics of the osteoblast cells were studied via cell number counting, morphology observation, alkaline phosphatase staining of the cells and alizarine- red staining of the calcified nodules. The results show that osteoblast cells can be cultured in vitro via collagenase digestion method and explant technique, and the obtained cells ure of good biologic characteristics. In comparison with the explant technique, the operative procedure of the enzymatic digestion method is more complicated. The digestion time must be carefully controlled. However, with this method, one can obtain a lager number of cells in a short time. The operative procedure of the explant technique is simpler, but it usually takes longer time to obtain cells of desirable number.

IGF-1 mRNA expression of adult rat thyroid cell cultured in vitro

Objective: To investigate the law of age-related changes of insulin-like growth factor-1 (IGF-1) expression of rat thyroid cells cultured in vitro. Methods: Rat thyroid of different age (10, 45, 65, 100, 150 weeks) was isolated and thyrocytes cultured. Total RNA was extracted in different rat age group when thyroid cells had been cultured for two weeks. mRNA IGF-1 expression was measured with reverse-transcription polymerase chain reaction( RT-PCR) in each group and compared. Results: Quantity of total RNA in thyroid cells decreased with ageing when the rat thyroid cells had been cultured for 2 weeks. There is significant difference among groups (P<0.05). Expression of IGF-1 mRNA could be detected in thyroid cells of different age cultured in vitro. Quantity of IGF-1 mRNA expression by RT-PCR analysis increased from 10 to 45 weeks old, and then decreased with ageing. Conclusion: Rat thyroid cells from different age cultured in vitro can express IGF-1 mRNA. Quantity of total RNA in thyroid cells cultured in vitro decreased with aging. IGF-1 mRNA expression was correlated to age (r=0.401, P<0.05).

Pre-degenerated peripheral nerves co-cultured with bone marrow-derived cells: a new technique for harvesting high-purity Schwann cells

Schwann cells play an important role in the peripheral nervous system, especially in nerve repair following injury, so artificial nerve regen- eration requires an effective technique for obtaining purified Schwann cells. In vivo and in vitro pre-degeneration of peripheral nerves have been shown to obtain high-purity Schwann cells. We believed that in vitro pre-degeneration was simple and controllable, and available for the clinic. Thus, we co-cultured the crushed sciatic nerves with bone marrow-derived cells in vitro. Results demonstrated that, 3 hours after injury, a large number of mononuclear cells moved to the crushed nerves and a large number of bone marrow-derived cells infiltrated the nerve segments. These changes promoted the degradation of the nerve segments, and the dedifferentiation and proliferation of Schwann cells. Neural cell adhesion molecule and glial fibrillary acidic protein expression were detected in the crushed nerves. Schwann cell yield was 9.08 ± 2.01 ×104/mg. The purity of primary cultured Schwann cells was 88.4 ± 5.79%. These indicate a successful new method for ob- taining Schwann cells of high purity and yield from adult crushed sciatic nerve using bone marrow-derived cells.

Neutron-induced apoptosis of HR8348 cells in vitro

INTRODUCTIONTo date ,the major therapy for rectal carcinoma is extensive abdomino-perineal resection[1]. Unfortunately ,after resection of rectal carcinoma ,many patients still die of blood-borne metastases ,usually in the liver or lungs ,or local prlvic recurrence[2,3],which is the major cause of morbidity and mortality in patients with rectal carcinoma .Pre-or postoperative radiotherapy can reduce the incidence of local rdcurrence[4-7].

Initiation of primary cell culture from amphioxus Branchiostoma belcheri tsingtauense

Amphioxus, a cephalochordate, is an important model fish for studies in evolution and comparative biology. A successful cell culture from amphioxus tissues in vitro would help understanding some basic issues. To determine the optimal culture conditions for proliferation of amphioxus cells, primary cultures were initiated from buccal cirri, tail, gill, gut and metapleural fold of amphioxus Branchiostoma belcheri tsingtauense. The media tested were L-15, F-12, M 199, MEM, DMEM, PRMI 1640 and LDF, each was supplemented with 20% fetal bovine serum. The optimal conditions include tail tissue cultured in L-15 or F-12 with supplement of 20% FBS and 1.5% NaCl at about 25℃.

Cerebrospinal fluid used as culture medium prior to autologous olfactory ensheathing cell transplantation

BACKGROUND： Cerebrospinal fluid can be an inducer for neural stem cells in vitro, but few studies employ cerebrospinal fluid to culture olfactory ensheathing cells. OBJECTIVE： To investigate the growth of nasal mucosa olfactory ensheathing cells in normal cerebrospinal fluid, and to analyze the feasibility of cerebrospinal fluid for culturing olfactory ensheathing cells used for transplantation. DESIGN, TIME AND SETTING： A completely randomized, block design study was performed at the Cell Laboratory, Wuxi Third People＇s Hospital, and Jiangsu Institute of Parasitic Diseases, China, in August 2008. MATERIALS： Dulbecco＇s modified Eagle＇s medium/F12 （DMEM/F12） and fetal bovine serum （Gibco BRL, USA）, mouse anti-rat P75 monoclonal antibody and rabbit anti-glial fibrillary acidic protein polyclonal anti body （＇Santa Cruz Biotechnology, USA）, mouse anti-rat myelin basic protein monoclonal antibody （Cymbus, UK）, mouse anti-rat microtubule-associated protein-2 monoclonal antibody （Transduction Laboratories, USA）, FITC conjugated rabbit anti-mouse monoclonal antibody （Boster, China）, TRITC conjugated goat anti-rabbit monoclonal antibody （Sigma, USA） were used. METHODS： Nasal mucosa olfactory ensheathing cells were separately incubated in DMEM/F12, cerebrospinal fluid, and changing DMEM/F12 into cerebrospinal fluid. Adult female Sprague Dawley rat models of spinal hemisection were established. Nerve injury was repaired by transplantation of nasal mucosa olfactory ensheathing cells cultured in cerebrospinal fluid or DMEM/F12. MAIN OUTCOME MEASURES： The proliferative ability of olfactory ensheathing cells cultured in cerebrospinal fluid was determined by a 3-（4, 5-dimethylthiazol-2-yl）-2, 5-diphenyl tetrazolium bromide assay. The morphology and purity of olfactory ensheathing cells were detected using immunohistochemistry. Animal behavior was evaluated by the Basso, Beattie and Bresnahan locomotor rating scale. Morphological repair was assessed by a horseradish peroxidase-tetramethylbenzidine retrograde tracer technique and immunohistochemistry. RESULTS： Changing from DMEM/F12 to cerebrospinal fluid did not change overall culture morphology and purity on day 14. These cells also contributed to myelinization and the conduction velocity of regenerated axons, and improved motor abilities of denervated muscle fibers in rats with spinal cord injury. The recovery of behavioral function and neuronal regeneration was similar in the two groups. CONCLUSION： Cerebrospinal fluid culture prior to autologous olfactory ensheathing cell transplantation is feasible for clinical use.

The 3D Cell Culture System in the Study of Tumor-Applications and Prospects

Compared with 2D tumor cell culture, 3D tumor cell culture can better simulate the microenvironment of signal transduction between cells and extracellular matrix. As one of the best cell models in tumor research, it has been widely used in the study of cancer cell morphology, nanotechnology drug delivery system, and anticancer drug screening. The main theme of this paper is to review the previous research of 3D cell culture applying to tumors in vitro and the prospects for the applications of 3D cell culture system.

Comparison of biological characteristics of marrow mesenchymal stem cells in hepatitis B patients and normal adults

AIM: To establish a culture system of marrow mesenchymal stem cells (MSCs)from hepatitis B patients and normal adults and to compare their biological characteristics. METHODS: MSCs were isolated from bone marrow in 34 male hepatitis B patients and 15 male normal adults and cultivated in vitro. Their biological characteristics including surface markers, shapes and appearances, growth curves, first passage time and passage generations were compared. RESULTS: Cultivation achievement ratio of hepatitis B patients was lower than that of normal adults, no statistical significance (82.35% vs 100%, P > 0.05). Compared with MSCs of normal adults, MSCs of hepatitis B patients presented a statistical lower growth curve, longer first passage time (13.0 ± 1.6 d vs 11.4 ± 1.5 d, P < 0.05), fewer passaging generation numbers (10.5 ± 1.4 generations vs 12.3 ± 1.7 generations, P < 0.05), though both shared same appearances, shapes and surface markers. MSCs in hepatitis B patients would expand, spread out and age more easily and there were more refractive particles in the cytoplasm. CONCLUSION: MSCs from hepatitis B patients can be cultured in vitro. Although their appearance, shape and surface marker are similar to those of MSCs from normal adults, there are differences in their biological characteristics.