NIH אימונולוגיה הדרכה גרנט T32 AI 60,573 (KRG) ו-NIH מענק GM 41,514 (MDC)

לפני תחילת הניסוי: <ul style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> לקבל אישור IACUC </li><li style=";text-align:right;direction:rtl"> לעקר כלי ניתוח ו-Q-טיפים </li></ul> I. רקמות התורם קציר <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> להרדים עכבר התורם (בהתאם SOP של המוסד) </li><li style=";text-align:right;direction:rtl"> שיער רטוב חזרה מהבסיס של האוזן עם אלכוהול </li><li style=";text-align:right;direction:rtl"> התורם קציר העור על ידי חיתוך האוזן את בבסיס </li><li style=";text-align:right;direction:rtl"> מניחים בצלחת רקמה על הקרח </li><li style=";text-align:right;direction:rtl"> האוזן פיצול: הצדדים קמצוץ הגחון ועל הגב של רקמת בבסיס של האוזן עם עכברוש שיניים מלקחיים, משוך בעדינות בנפרד רקמות; רקמות לצוף הגב, משטח פנימי למטה, PBS על קרח; להשליך דש הגחון collagenous </li></ol> השנייה. הכן מקבל עבור להשתלות <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> עכבר הרדימי באמצעות הליך אישור </li><li style=";text-align:right;direction:rtl"> ניהול כאבים להקלה על כאב לאחר הניתוח (כלומר 0.05-0.1 מ&quot;ג / g ip Bupernex) </li><li style=";text-align:right;direction:rtl"> המקום העכבר במצב לרוחב </li><li style=";text-align:right;direction:rtl"> בצע קמצוץ הבוהן כדי להבטיח חיים הוא מסומם מספיק </li><li style=";text-align:right;direction:rtl"> שיער רטוב עם אלכוהול לגלח החזה </li><li style=";text-align:right;direction:rtl"> נגב אזור נקי עם ספוגית אלכוהול </li></ol> ג. עור להשתלות <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> ודא ~ 1 ס&quot;מ חתך: עור אוהל עם עכברוש שיניים מלקחיים ולחתוך ~ 0.25-0.5 ס&quot;מ מתחת מלקחיים </li><li style=";text-align:right;direction:rtl"> הסרת העור תורם PBS, במקום על גבי המיטה שתל (עם המשטח הפנימי של העור אוזן מול המיטה שתל), ולהסיר PBS עם עודף סטרילי Q-קצה </li><li style=";text-align:right;direction:rtl"> בזהירות לחתוך עור עודף תורם כל כך השתלת שנמצאת ביובש בתוך המיטה שתל (מוודא קצוות השתל אינם מכורבלת מתחת שתל שאינו הנגאובר על העור גזע של הנמען) </li><li style=";text-align:right;direction:rtl"> גלישת הנמען תחבושת סטרילית (עם קטע שאינו דבק גזה הניח על שתל העור) </li><li style=";text-align:right;direction:rtl"> ודא תחבושת כי הוא לא חזק מדי (להעריך נשימה של החיה) והזרועות, כי הם ניידים בחופשיות </li><li style=";text-align:right;direction:rtl"> תחבושת Secure עם תפר 2-0 יחיד משי </li><li style=";text-align:right;direction:rtl"> חיה מקום בכלוב נקי (תחת מנורת חימום עד שהחיה התאוששה מספיק מן ההרדמה) </li><li style=";text-align:right;direction:rtl"> צג הנמען 1-2/day סימנים של מצוקה ולנהל משכך כאבים לפי הצורך להקלה על הכאב </li></ol> IV. הסרת תחבושת (6-7 ימים לאחר ההשתלה) <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> עכבר הרדימי באמצעות הליך אישור </li><li style=";text-align:right;direction:rtl"> גזור להסיר תפר משי </li><li style=";text-align:right;direction:rtl"> בעזרת מספריים סוף בוטה, לחתוך בזהירות באמצעות תחבושת (כדי לוודא שלא לשבש את השתל) בעדינות להסיר </li><li style=";text-align:right;direction:rtl"> חזור העכבר לכלוב נקי </li><li style=";text-align:right;direction:rtl"> בדוק ~ שתל 8 שעות לאחר הסרת התחבושת סימנים של scabbing או התכווצות. אם כיום, שתל עשוי נכשלו vascularize ואת צריכה להיחשב כשל טכני. </li><li style=";text-align:right;direction:rtl"> מעקב יומי אחר סימנים של דחייה (בדרך כלל מגדירים נמק ~ 80% של רקמת התורם) </li><li style=";text-align:right;direction:rtl"> השתלות עור allogeneic בדרך כלל דוחים בין D8-12 מנותחות </li></ol> ו &#39;עצות שימושיות <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> מסיק רקמות התורם קרוב לבסיס של האוזן יהיה: 1) למקסם את גודל השתל, ו 2) לספק הסככה הגחון אחיד שיאפשר פיצול </li><li style=";text-align:right;direction:rtl"> השתמש תמיד סכין גילוח חדש גילוח הנמען </li><li style=";text-align:right;direction:rtl"> אם כאבים תינתן ip, לנהל הליך לפני ההשתלה כדי לצמצם מנותחות טיפול (למזער סיכוי לשבש את השתל) </li><li style=";text-align:right;direction:rtl"> במידת האפשר, להסיר את הכפפות לפני החלת את התחבושת. כפפות נוטים לתקוע את התחבושת לסבך את הבקשה </li><li style=";text-align:right;direction:rtl"> הנחת תפר בודד בסוף תחבושת יהיה למזער מוקדמת הסרת </li><li style=";text-align:right;direction:rtl"> לעטוף כמו תחבושת הדוקה כפי שמותר להעריך נשימה לפני הנחת תפר. אם תחבושת הדוקה מדי, בעלי חיים יפסיק לנשום. אם תחבושת רופפת מדי, בעלי חיים תסיר אותו. </li></ol>

The authors have nothing to disclose.

כפי שמודגם במאמר-video זה, המודל השתלת עור היא שיטה מהירה וקלה לניטור allogeneic T התגובות התא. השתלה אלוגנאית העור יש מגוון רחב של יישומים נוצל עד assay את היעילות של מגוון רחב של סוכני מדכאות חיסון ואינדוקציה סובלנות פרוטוקולים, וכן כדי לחקור את ההשפעות הביולוגיות של נוגדנים חסימה שונים.

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<td>Micro-dissecting forceps (curved)</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>F4142</td>
<td>&nbsp;</td>
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<td>Rat-tooth forceps (1x2 teeth, straight)</td>
<td>&nbsp;</td>
<td>Fine Science Tools</td>
<td>11053-10</td>
<td>n=2</td>
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<td>Strabismus scissors (blunt end)</td>
<td>&nbsp;</td>
<td>Fine Science Tools</td>
<td>14074-11</td>
<td>&nbsp;</td>
<tr>
<td>Iris forceps (curved)</td>
<td>&nbsp;</td>
<td>Fine Science Tools</td>
<td>11065-07</td>
<td>&nbsp;</td>
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<td>&nbsp;</td>
<td>Fine Science Tools</td>
<td>15006-09</td>
<td>&nbsp;</td>
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<td>Halsey micro needle holder</td>
<td>&nbsp;</td>
<td>Fine Science Tools</td>
<td>12500-12</td>
<td>&nbsp;</td>
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<td>10 cm plates</td>
<td>&nbsp;</td>
<td>Corning</td>
<td>430167</td>
<td>&nbsp;</td>
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<td>&nbsp;</td>
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<td>517201</td>
<td>&nbsp;</td>
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<td>Insulin syringes (29 Ga)</td>
<td>&nbsp;</td>
<td>Monoject</td>
<td>8881 600145</td>
<td>&nbsp;</td>
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<td>Q-tips</td>
<td>&nbsp;</td>
<td>Solon</td>
<td>362</td>
<td>&nbsp;</td>
<tr>
<td>Single edge razor blades (#9)</td>
<td>&nbsp;</td>
<td>Smith</td>
<td>67-0238</td>
<td>&nbsp;</td>
<tr>
<td>Silk suture (2-0; PS-2)</td>
<td>&nbsp;</td>
<td>Ethicon</td>
<td>583H</td>
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murine skin transplantation

בתור אחד המודלים המחמירים ביותר והפחות מאתגר מבחינה טכנית, השתלת עור היא שיטה רגילה לארח assay T התגובות התא MHC-אנטיגנים שונים התורם. מטרת מאמר-video זה היא לספק את הצופה עם הפגנה צעד אחר צעד ויזואלית של השתלת עור באמצעות מודל העכבר. הפרוטוקול מחולק 5 מרכיבים עיקריים: 1) התורם קצירת העור; 2) הכנת הנמען להשתלה; 3) להשתלת עור; 4) הסרת התחבושת דחיית שתל ניטור: 5) עצות מועילות. בקיאים פעם, את ההליך עצמו צריך לקחת &lt;10 דקות לבצע.

Watch this Scientific Journal Video about Murine Skin Transplantation at JoVE.com

Murine Skin Transplantation

השתלה אלוגנאית העור הוא מודל סטנדרטי לארח assay T התגובות התא MHC-אנטיגנים שונים התורם. זה וידאו המאמר מספק הדרכה ויזואלית של כל צעד מעורב בביצוע BALB/c--&gt; השתלת C57BL / 6 העור.

השתלת עור Murine

As one of the most stringent and least technically challenging models, skin transplantation is a standard method to assay host T cell responses to ...

Research

JoVE Journal

Biology

22.2K Views.  University of California, Irvine (UCI). השתלה אלוגנאית העור הוא מודל סטנדרטי לארח assay T התגובות התא MHC-אנטיגנים שונים התורם. זה וידאו המאמר מספק הדרכה ויזואלית של כל צעד מעורב בביצוע BALB/c--> השתלת C57BL / 6 העור.

Video: Murine Skin Transplantation

Isolation and Transplantation of Hematopoietic Stem Cells (HSCs)

Isolation and Transplantation of Hematopoietic Stem Cells HSCs

בידוד והשתלות של בתאי גזע hematopoietic (HSCs)

Heterotopic Heart Transplantation in Mice

The mouse heterotopic heart transplantation has been used widely since it was introduced by Drs. Corry and Russell in 1973. It is particularly valuable for studying rejection and immune response now that newer transgenic and gene knockout mice are available, and a large number of immunologic reagents have been developed. The heart transplant model is less stringent than the skin transplant models, although technically more challenging. We have developed a modified technique and have completed over 1000 successful cases of heterotopic heart transplantation in mice. When making anastomosis of the ascending aorta and abdominal aorta, two stay sutures are placed at the proximal and distal apexes of recipient abdominal aorta with the donor s ascending aorta, then using 11-0 suture for anastomosis on both side of aorta with continuing sutures. The stay sutures make the anastomosis easier and 11-0 is an ideal suture size to avoid bleeding and thrombosis.
When making anastomosis of pulmonary artery and inferior vena cava, two stay sutures are made at the proximal apex and distal apex of the recipient s inferior vena cava with the donor s pulmonary artery. The left wall of the inferior vena cava and donor s pulmonary artery is closed with continuing sutures in the inside of the inferior vena cava after, one knot with the proximal apex stay suture the right wall of the inferior vena cava and the donor s pulmonary artery are closed with continuing sutures outside the inferior vena cave with 10-0 sutures. This method is easier to perform because anastomosis is made just on the one side of the inferior vena cava and 10-0 sutures is the right size to avoid bleeding and thrombosis. In this article, we provide details of the technique to supplement the video.

The mouse heterotopic heart transplantation model has been proven by many investigators to be an important method for studying mechanisms of rejection and immune response. However, the techniques involved are still challenging. By modifying standard techniques we have had success with more than 1000 transplants.

השתלת הלב Heterotopic ב עכברים

The mouse heterotopic heart transplantation has been used widely since it was introduced by Drs. Corry and Russell in 1973. It is particularly valuable ...

Small Bowel Transplantation In Mice

Since 1990, the development of tacrolimus-based immunosuppression and improved surgical techniques, the increased array of potent immunosuppressive medications, infection prophylaxis, and suitable patient selection helped improve actuarial graft and patient survival rates for all types of intestine transplantation. Patients with irreversible intestinal failure and complications of parenteral nutrition should now be routinely considered for small intestine transplantation. However, Survival rates for small intestinal transplantation have been slow to improve compares increasingly favorably with renal, liver, heart and lung. The small bowel transplantation is still unsatisfactory compared with other organs. Further progress may depend on better understanding of immunology and physiology of the graft and can be greatly facilitated by animal models. A wider use of mouse small bowel transplantation model is needed in the study of immunology and physiology of the transplantation gut as well as efficient methods in diagnosing early rejection. However, this model is limited to use because the techniques involved is an extremely technically challenging. We have developed a modified technique. When making anastomosis of portal vein and inferior vena cava, two stay sutures are made at the proximal apex and distal apex of the recipient s inferior vena cava with the donor s portal vein. The left wall of the inferior vena cava and donor s portal vein is closed with continuing sutures in the inside of the inferior vena cava after, after one knot with the proximal apex stay suture the right wall of the inferior vena cava and the donor s portal vein are closed with continuing sutures outside the inferior vena cave with 10-0 sutures. This method is easier to perform because anastomosis is made just on the one side of the inferior vena cava and 10-0 sutures is the right size to avoid bleeding and thrombosis.  In this article, we provide details of the technique to supplement the video.

The mouse small bowel transplantation model has been recognized as an important tool to study mechanismes of immune rejection and screen new immunosuppressive drugs. However, this model is limited to use because the techniques involved is an extremely technically challenge. Now we introduce the modified technique.

מעי והשתלות קטן עכברים

Since 1990, the development of tacrolimus-based immunosuppression and improved surgical techniques, the increased array of potent immunosuppressive ...

Murine Renal Transplantation Procedure

Renal orthotopic transplantation in mice is a technically challenging procedure. Although the first kidney transplants in mice were performed by Russell et al over 30 years ago (1) and refined by Zhang et al years later (2), few people in the world have mastered this procedure. In our laboratory we have successfully performed 1200 orthotopic kidney transplantations with &gt; 90% survival rate. The key points for success include stringent control of reperfusion injury, bleeding and thrombosis, both during the procedure and post-transplantation, and use of 10-0 instead of 11-0 suture for anastomoses.
Post-operative care and treatment of the recipient is extremely important to transplant success and evaluation. All renal graft recipients receive antibiotics in the form of an injection of penicillin immediately post-transplant and sulfatrim in the drinking water continually. Overall animal health is evaluated daily and whole blood creatinine analyses are performed routinely with a portable I-STAT machine to assess graft function.

Renal transplantation in mice is a technically challenging procedure that requires careful post-operative care and treatment for success.

Murine נוהל השתלת כליה

Renal orthotopic transplantation in mice is a technically challenging procedure. Although the first kidney transplants in mice were performed by Russell ...

Generation of Human CD40-activated B cells

CD40-activated B cells (CD40-B cells) have been identified as an alternative source of immuno-stimulatory antigen-presenting cells (APC) for cancer immunotherapy 1-3. Compared to Dendritic cells (DCs), the best characterized APC, CD40-B cells have several distinct biological and technical properties. Similar to DCs, B cells show an increased expression of MHC and co-stimulatory molecules (Fig.1b), exhibit a strong migratory capacity and present antigen presentation efficiently to T cells, after stimulation with interleukin-4 and CD40 ligand (CD40L). However, in contrast to immature or mature DCs, CD40-B cells express the full lymph node homing triad consisting of CD62L, CCR7/CXCR4, and leukocyte function antigen-1 (LFA1, CD11a/CD18), necessary for homing to secondary lymphoid organs (Fig.1a) 3. CD40-B cells can be generated without difficulties from very small amounts of peripheral blood which can be further expanded in vitro to very large amounts of highly-pure CD40-B cells (&gt;109 cells per patient) from healthy donors as well as cancer patients (Fig.1c,d) 1,4. 
In this protocol we demonstrate how to obtain fully activated CD40-B cells from human PBMC. Key molecules for the cell culture are CD40 ligand, interleukin-4 (IL-4) and cyclosporin A (CsA), which are replenished in a 3-4 day culture cycle. For laboratory purposes CD40-stimulation is provided by NIH/3T3 cells expressing recombinant human CD40 ligand (tCD40L NIH/3T3) 5. To avoid contamination with non-transfected cells, expression of the human CD40 ligand on the transfectants has to be checked regularly (Fig.2). 
After 14 days CD40-B cell cultures consist of more than 95% pure B cells and an expansion of CD40-B cells over 65 days is frequently possible without any loss of function 1, 4. CD40-B cells efficiently take up, process and present antigens to T cells 6. They do not only prime na&#970;ve, but also expand memory T cells 7,8. CD40-activated B cells can be used to study B-cell activation, differentiation and function. Moreover, they represent a promising tool for therapeutic or preventive vaccination against tumors 9.

In this video we present the ex vivo generation and expansion of human CD40-activated B cells (CD40-B) from peripheral blood mononuclear cells (PBMC) by stimulation with CD40 ligand and interleukin-4.

הדור של האדם CD40 בתאי B המופעל

CD40-activated B cells (CD40-B cells) have been identified as an alternative source of immuno-stimulatory antigen-presenting cells (APC) for cancer ...

Generating Chimeric Zebrafish Embryos by Transplantation

One of the most powerful tools used to gain insight into complex developmental processes is the analysis of chimeric embryos. A chimera is defined as an organism that contains cells from more than one animal; mosaics are one type of chimera in which cells from more than one genotype are mixed, usually wild-type and mutant. In the zebrafish, chimeras can be readily made by transplantation of cells from a donor embryo into a host embryo at the appropriate embryonic stage. Labeled donor cells are generated by injection of a lineage marker, such as a fluorescent dye, into the one-cell stage embryo. Labeled donor cells are removed from donor embryos and introduced into unlabeled host embryos using an oil-controlled glass pipette mounted on either a compound or dissecting microscope. Donor cells can in some cases be targeted to a specific region or tissue of the developing blastula or gastrula stage host embryo by choosing a transplantation site in the host embryo based on well-established fate maps.

A step-by-step guide to generating targeted chimeric zebrafish embryos by transplantation at the blastula or gastrula stage.

יצירת עוברים דג הזברה chimeric על ידי השתלה

One of the most powerful tools used to gain insight into complex developmental processes is the analysis of chimeric embryos. A chimera is defined as an ...

Germ Cell Transplantation and Testis Tissue Xenografting in Mice

Germ cell transplantation was developed by Dr. Ralph Brinster and colleagues at the University of Pennsylvania in 19941,2. These ground-breaking studies showed that microinjection of germ cells from fertile donor mice into the seminiferous tubules of infertile recipient mice results in donor-derived spermatogenesis and sperm production by the recipient animal2. The use of donor males carrying the bacterial &beta;-galactosidase gene allowed identification of donor-derived spermatogenesis and transmission of the donor haplotype to the offspring by recipient animals1. Surprisingly, after transplantation into the lumen of the seminiferous tubules, transplanted germ cells were able to move from the luminal compartment to the basement membrane where spermatogonia are located3. It is generally accepted that only SSCs are able to colonize the niche and re-establish spermatogenesis in the recipient testis. Therefore, germ cell transplantation provides a functional approach to study the stem cell niche in the testis and to characterize putative spermatogonial stem cells. To date, germ cell transplantation is used to elucidate basic stem cell biology, to produce transgenic animals through genetic manipulation of germ cells prior to transplantation4,5, to study Sertoli cell-germ cell interaction6,7, SSC homing and colonization3,8, as well as SSC self-renewal and differentiation9,10.
Germ cell transplantation is also feasible in large species11. In these, the main applications are preservation of fertility, dissemination of elite genetics in animal populations, and generation of transgenic animals as the study of spermatogenesis and SSC biology with this technique is logistically more difficult and expensive than in rodents. Transplantation of germ cells from large species into the seminiferous tubules of mice results in colonization of donor cells and spermatogonial expansion, but not in their full differentiation presumably due to incompatibility of the recipient somatic cell compartment with the germ cells from phylogenetically distant species12. An alternative approach is transplantation of germ cells from large species together with their surrounding somatic compartment. We first reported in 2002, that small fragments of testis tissue from immature males transplanted under the dorsal skin of immunodeficient mice are able to survive and undergo full development with the production of fertilization competent sperm13. Since then testis tissue xenografting has been shown to be successful in many species and emerged as a valuable alternative to study testis development and spermatogenesis of large animals in mice14.

Protocols for germ cell transplantation and testis tissue xenografting are described. Germ cell transplantation results in donor-derived spermatogenesis in recipient testes and represents a functional reconstitution assay for identification of spermatogonial stem cells (SSCs). Testis tissue xenografting reproduces testis development and spermatogenesis of various donor species in recipient mice.

נבט השתלת ורקמות testis Xenografting ב עכברים

Germ cell transplantation was developed by Dr. Ralph Brinster and colleagues at the University of Pennsylvania in 19941,2. These ground-breaking studies ...

Planarian Immobilization, Partial Irradiation, and Tissue Transplantation

The planarian, a freshwater flatworm, has proven to be a powerful system for dissecting metazoan regeneration and stem cell biology1,2. Planarian regeneration of any missing or damaged tissues is made possible by adult stem cells termed neoblasts3. Although these stem cells have been definitively shown to be pluripotent and singularly capable of reconstituting an entire animal4, the heterogeneity within the stem cell population and the dynamics of their cellular behaviors remain largely unresolved. Due to the large number and wide distribution of stem cells throughout the planarian body plan, advanced methods for manipulating subpopulations of stem cells for molecular and functional study in vivo are needed.
Tissue transplantation and partial irradiation are two methods by which a subpopulation of planarian stem cells can be isolated for further study. Each technique has distinct advantages. Tissue transplantation allows for the introduction of stem cells, into a na&iuml;ve host, that are either inherently genetically distinct or have been previously treated pharmacologically. Alternatively, partial irradiation allows for the isolation of stem cells within a host, juxtaposed to tissue devoid of stem cells, without the introduction of a wound or any breech in tissue integrity. Using these two methods, one can investigate the cell autonomous and non-autonomous factors that control stem cell functions, such as proliferation, differentiation, and migration.
Both tissue transplantation5,6 and partial irradiation7 have been used historically in defining many of the questions about planarian regeneration that remain under study today. However, these techniques have remained underused due to the laborious and inconsistent nature of previous methods. The protocols presented here represent a large step forward in decreasing the time and effort necessary to reproducibly generate large numbers of grafted or partially irradiated animals with efficacies approaching 100 percent. We cover the culture of large animals, immobilization, preparation for partial irradiation, tissue transplantation, and the optimization of animal recovery. Furthermore, the work described here demonstrates the first application of the partial irradiation method for use with the most widely studied planarian, Schmidtea mediterranea. Additionally, efficient tissue grafting in planaria opens the door for the functional testing of subpopulations of na&iuml;ve or treated stem cells in repopulation assays, which has long been the gold-standard method of assaying adult stem cell potential in mammals8. Broad adoption of these techniques will no doubt lead to a better understanding of the cellular behaviors of adult stem cells during tissue homeostasis and regeneration.

An effective method for grafting tissue of defined and consistent size between planaria is described. Also included is a description of how the immobilization technique used for transplantation can be adapted, in conjunction with lead shields, for the partial irradiation of live animals.

Immobilization Planarian, הקרנה חלקית, השתלת רקמות

The planarian, a freshwater flatworm, has proven to be a powerful system for dissecting metazoan regeneration and stem cell biology1,2. Planarian ...

Studying Proteolysis of Cyclin B at the Single Cell Level in Whole Cell Populations

Equal distribution of chromosomes between the two daughter cells during cell division is a prerequisite for guaranteeing genetic stability 1. Inaccuracies during chromosome separation are a hallmark of malignancy and associated with progressive disease 2-4. The spindle assembly checkpoint (SAC) is a mitotic surveillance mechanism that holds back cells at metaphase until every single chromosome has established a stable bipolar attachment to the mitotic spindle1. The SAC exerts its function by interference with the activating APC/C subunit Cdc20 to block proteolysis of securin and cyclin B and thus chromosome separation and mitotic exit. Improper attachment of chromosomes prevents silencing of SAC signaling and causes continued inhibition of APC/CCdc20 until the problem is solved to avoid chromosome missegregation, aneuploidy and malignant growths1.
Most studies that addressed the influence of improper chromosomal attachment on APC/C-dependent proteolysis took advantage of spindle disruption using depolymerizing or microtubule-stabilizing drugs to interfere with chromosomal attachment to microtubules. Since interference with microtubule kinetics can affect the transport and localization of critical regulators, these procedures bear a risk of inducing artificial effects 5.
To study how the SAC interferes with APC/C-dependent proteolysis of cyclin B during mitosis in unperturbed cell populations, we established a histone H2-GFP-based system which allowed the simultaneous monitoring of metaphase alignment of mitotic chromosomes and proteolysis of cyclin B 6.
To depict proteolytic profiles, we generated a chimeric cyclin B reporter molecule with a C-terminal SNAP moiety 6 (Figure 1). In a self-labeling reaction, the SNAP-moiety is able to form covalent bonds with alkylguanine-carriers (SNAP substrate) 7,8 (Figure 1). SNAP substrate molecules are readily available and carry a broad spectrum of different fluorochromes. Chimeric cyclin B-SNAP molecules become labeled upon addition of the membrane-permeable SNAP substrate to the growth medium 7 (Figure 1). Following the labeling reaction, the cyclin B-SNAP fluorescence intensity drops in a pulse-chase reaction-like manner and fluorescence intensities reflect levels of cyclin B degradation 6 (Figure 1). Our system facilitates the monitoring of mitotic APC/C-dependent proteolysis in large numbers of cells (or several cell populations) in parallel. Thereby, the system may be a valuable tool to identify agents/small molecules that are able to interfere with proteolytic activity at the metaphase to anaphase transition. Moreover, as synthesis of cyclin B during mitosis has recently been suggested as an important mechanism in fostering a mitotic block in mice and humans by keeping cyclin B expression levels stable 9,10, this system enabled us to analyze cyclin B proteolysis as one element of a balanced equilibrium 6.

Metaphase to anaphase transition is triggered through anaphase-promoting complex (APC/C)-dependent ubiquitination and subsequent destruction of cyclin B. Here, we established a system which, following pulse-chase labeling, allows monitoring cyclin B proteolysis in entire cell populations and facilitates the detection of interference by the mitotic checkpoint.

לומד Proteolysis של cyclin B ברמת התא הבודד באוכלוסיות תאים שלמות

Equal distribution of chromosomes between the two daughter cells during cell division is a prerequisite for guaranteeing genetic stability 1. Inaccuracies ...

Isolation, Culture, and Transplantation of Muscle Satellite Cells

Muscle satellite cells are a stem cell population required for postnatal skeletal muscle development and regeneration, accounting for 2-5% of sublaminal nuclei in muscle fibers. In adult muscle, satellite cells are normally mitotically quiescent. Following injury, however, satellite cells initiate cellular proliferation to produce myoblasts, their progenies, to mediate the regeneration of muscle. Transplantation of satellite cell-derived myoblasts has been widely studied as a possible therapy for several regenerative diseases including muscular dystrophy, heart failure, and urological dysfunction. Myoblast transplantation into dystrophic skeletal muscle, infarcted heart, and dysfunctioning urinary ducts has shown that engrafted myoblasts can differentiate into muscle fibers in the host tissues and display partial functional improvement in these diseases. Therefore, the development of efficient purification methods of quiescent satellite cells from skeletal muscle, as well as the establishment of satellite cell-derived myoblast cultures and transplantation methods for myoblasts, are essential for understanding the molecular mechanisms behind satellite cell self-renewal, activation, and differentiation. Additionally, the development of cell-based therapies for muscular dystrophy and other regenerative diseases are also dependent upon these factors.

However, current prospective purification methods of quiescent satellite cells require the use of expensive fluorescence-activated cell sorting (FACS) machines. Here, we present a new method for the rapid, economical, and reliable purification of quiescent satellite cells from adult mouse skeletal muscle by enzymatic dissociation followed by magnetic-activated cell sorting (MACS). Following isolation of pure quiescent satellite cells, these cells can be cultured to obtain large numbers of myoblasts after several passages. These freshly isolated quiescent satellite cells or ex vivo expanded myoblasts can be transplanted into cardiotoxin (CTX)-induced regenerating mouse skeletal muscle to examine the contribution of donor-derived cells to regenerating muscle fibers, as well as to satellite cell compartments for the examination of self-renewal activities.

The isolation and culture of a pure population of quiescent satellite cells, a muscle stem cell population, is essential to the understanding of muscle stem cell biology and regeneration, as well as stem cell transplantation for therapies in muscular dystrophy and other degenerative diseases.&#160;

בידוד, תרבות והשתלה של תאי לווין שריר

Muscle satellite cells are a stem cell population required for postnatal skeletal muscle development and regeneration, accounting for 2-5% of sublaminal ...