Low-dose FK506 Research Articles

Disrupted BMP-9 Signaling Impairs Pulmonary Vascular Integrity in Hepatopulmonary Syndrome.

Rationale: Hepatopulmonary syndrome (HPS) is a severe complication of liver diseases characterized by abnormal dilation of pulmonary vessels, resulting in impaired oxygenation. Recent research highlights the pivotal role of liver-produced BMP-9 (bone morphogenetic protein-9) in maintaining pulmonary vascular integrity. Objectives: This study aimed to investigate the involvement of BMP-9 in human and experimental HPS. Methods: Circulating BMP-9 levels were measured in 63 healthy control subjects and 203 patients with cirrhosis with or without HPS. Two animal models of portal hypertension were employed: common bile duct ligation with cirrhosis and long-term partial portal vein ligation without cirrhosis. Additionally, the therapeutic effect of low-dose BMP activator FK506 was investigated, and the pulmonary vascular phenotype of BMP-9-knockout rats was analyzed. Measurements and Main Results: Patients with HPS related to compensated cirrhosis exhibited lower levels of circulating BMP-9 compared with patients without HPS. Patients with severe cirrhosis exhibited consistently low levels of BMP-9. HPS characteristics were observed in animal models, including intrapulmonary vascular dilations and an increase in the alveolar-arterial gradient. HPS development in both rat models correlated with reduced intrahepatic BMP-9 expression, decreased circulating BMP-9 level and activity, and impaired pulmonary BMP-9 endothelial pathway. Daily treatment with FK506 for 2 weeks restored the BMP pathway in the lungs, alleviating intrapulmonary vascular dilations and improving gas exchange impairment. Furthermore, BMP-9-knockout rats displayed a pulmonary HPS phenotype, supporting its role in disease progression. Conclusions: The study findings suggest that portal hypertension-induced loss of BMP-9 signaling contributes to HPS development.

FK506 bypasses the effect of erythroferrone in cancer cachexia skeletal muscle atrophy

Skeletal muscle atrophy is a hallmark of cachexia, a wasting condition typical of chronic pathologies, that still represents an unmet medical need. Bone morphogenetic protein (BMP)-Smad1/5/8 signaling alterations are emerging drivers of muscle catabolism, hence, characterizing these perturbations is pivotal to develop therapeutic approaches. We identified two promoters of "BMP resistance" in cancer cachexia, specifically the BMP scavenger erythroferrone (ERFE) and the intracellular inhibitor FKBP12. ERFE is upregulated in cachectic cancer patients' muscle biopsies and in murine cachexia models, where its expression is driven by STAT3. Moreover, the knock down of Erfe or Fkbp12 reduces muscle wasting in cachectic mice. To bypass the BMP resistance mediated by ERFE and release the brake on the signaling, we targeted FKBP12 with low-dose FK506. FK506 restores BMP-Smad1/5/8 signaling, rescuing myotube atrophy by inducing protein synthesis. In cachectic tumor-bearing mice, FK506 prevents muscle and body weight loss and protects from neuromuscular junction alteration, suggesting therapeutic potential for targeting the ERFE-FKBP12 axis.

Induction of Skin Allograft Chimerism by Pharmacological Mobilization of Endogenous Bone Marrow-Derived Stem Cells.

Skin substitutes including allografts remain a standard therapeutic approach to promote healing of both acute and chronic large wounds. However, none have resulted in the regrowth of lost and damaged tissues and scarless wound healing. Here, we demonstrate skin allograft chimerism and repair through the mobilization of endogenous bone marrow-derived stem and immune cells in rats and swine. We show that pharmacological mobilization of bone marrow stem cells and immune cells into the circulation promotes host repopulation of skin allografts and restoration of the skin's normal architecture without scarring and minimal contracture. When skin allografts from DA rats are transplanted into GFP transgenic Lewis recipients with a combination of AMD3100 and low-dose FK506 (AF) therapy, host-derived GFP-positive cells repopulate and/or regenerate cellular components of skin grafts including epidermis and hair follicles and the grafts become donor-host chimeric skin. Using AF combination therapy, burn wounds with skin allografts were healed by newly regenerated chimeric skin with epidermal appendages and pigmentation and without contracture in swine.

#6635 ARNT AND ALK3 MEDIATE RENO PROTECTION AFTER ISCHEMIC PRECONDITIONING

Abstract Background and Aims Ischemia and following hypoxia are a common cause of acute kidney injury (AKI). Strategies for prevention and treatment of AKI are limited. In several animal models, ischemic preconditioning (IPC) has been established as an effective intervention to prevent ischemic organ injury. An IPC protocol of ischemia and reperfusion mediates organ protection for a few hours. This first phase of organ protection is followed by a second, protective phase occurring after 24–48 h. The second phase, named second window of protection (SWOP), persists for 3–4 d. Mechanisms and transcriptional mediators during SWOP are mostly unknown. The aim of the underlying study was to investigate effectors and target genes during SWOP and to identify a potential pharmacological therapeutic target. Method 6–8-week-old C57BL/6 mice were undergoing an IPC intervention; five minutes of renal sinistra artery ischemia was followed by five minutes of reperfusion. This cycle was performed five times. Mice were sacrificed 2, 4, 8, 12, 25, 48, 72 h after IPC. Two additional groups of mice were pharmacologically preconditioned for 48 h with low dose FK506 and small molecule GPI1046. Analysis of murine kidneys were performed by SDS-Page and Western blot. Results The first phase after IPC (2–4 h) was characterized by an increasing expression of hypoxia inducible factor-1α (HIF1α); 48 h after intervention a significant increase of expression of aryl hydrocarbon receptor nuclear translocator (ARNT) and consecutive activin receptor-like kinase 3 (ALK3) was observed. Comparable induction of ARNT and ALK3 expression was obtained by pharmacological preconditioning with FK506 or GPI1046. Conclusion Affected by hypoxia, HIF1α activates transcriptional upregulation of ARNT 48 h after IPC. The increasing expression of ARNT, follows an increased ARNT homodimerization. ARNT homodimer binds to the palindromic E-box 5′-CACGTG-3′ of the proximal ALK3 promoter. By this it induces the expression of the renoprotective ALK3 during SWOP. The organ-protective effects of constitutively expressed ARNT during SWOP can be mimicked pharmacologically by administration of FK506 or GPI1046 and may be used as a future therapeutic target.

Engineered Small Extracellular Vesicles as a FGL1/PD‐L1 Dual‐Targeting Delivery System for Alleviating Immune Rejection (Adv. Sci. 3/2022)

Small Extracellular Vesicles The simultaneous high expression of LAG-3 and PD-1 on T cells in cardiac transplantation mouse models and clinical renal transplantation patients provides the possibility to establish immune tolerance by giving their ligand molecules. In article number 2102634 by Bo Jia, Fang Cheng, Hongbo Chen, and co-workers, small extracellular vesicles derived from bioengineered PD-L1/FGL1-expressed mesenchymal stem cells encapsulated with low-dose FK506 exerted a powerful synergistic inhibitory effect on T cell activation and, therefore, prolonged grafts survival.

Major Improvement in Wound Healing Through Pharmacologic Mobilization of Stem Cells in Severely Diabetic Rats.

Current therapeutic strategies for diabetic foot ulcer (DFU) have focused on developing topical healing agents, but few agents have controlled prospective data to support their effectiveness in promoting wound healing. We tested a stem cell mobilizing therapy for DFU using a combination of AMD3100 and low-dose FK506 (tacrolimus) (AF) in streptozocin-induced type 1 diabetic (T1DM) rats and type 2 diabetic Goto-Kakizaki (GK) rats that had developed peripheral artery disease and neuropathy. Here, we show that the time for healing back wounds in T1DM rats was reduced from 27 to 19 days, and the foot wound healing time was reduced from 25 to 20 days by treatment with AF (subcutaneously, every other day). Similarly, in GK rats treated with AF, the healing time on back wounds was reduced from 26 to 21 days. Further, this shortened healing time was accompanied by reduced scar and by regeneration of hair follicles. We found that AF therapy mobilized and recruited bone marrow-derived CD133+ and CD34+ endothelial progenitor cells and Ym1/2+ M2 macrophages into the wound sites, associated with enhanced capillary and hair follicle neogenesis. Moreover, AF therapy improved microcirculation in diabetic and neuropathic feet in GK rats. This study provides a novel systemic therapy for healing DFU.

639-P: Pharmacological Mobilization and Recruitment of Bone Marrow Stem Cells Accelerates Diabetic Wound Healing in Rats with Diabetic Complications

Introduction: The lifetime incidence of foot ulcers has been estimated to be 19% to 34% among persons with diabetes. Diabetic wound healing(DWH) remains a challenge. Given the promising role of stem cells in wound healing, the current study proposed to improve DWH by mobilizing and recruiting bone marrow stem cells pharmacologically with combination of AMD3100 and low-dose FK506 (AF) in rats. Methods: T2 GK rats and STZ induced T1DM SD rats were used. To determine the role of bone marrow stem cells, bone marrow from GFP tg Lewis were transplanted into wt Lewis rats and T1 rats were induced by STZ injection at 2 months following bone marrow transplantation. Full-thickness wounds were created in the dorsal skin or in the foot skin at 6 weeks after STZ injection or GK rats at 4 month old. Wounded rats were divided into two experimental groups and received saline or a combination of AMD3100 (1mg/kg) and FK506 (0.1mg/kg) immediately after wounding and every 2 days until complete healing. Results: At the time of wounding, all animals developed peripheral artery disease and neuropathy. The back wound healing time was reduced from 27 to 19 days and the foot wound healing time was reduced from 25 to 20 days in T1DM rats treated with AF. Similarly, the back wound healing time was reduced from 26(S) to 21(AF) days in GK rats. Equally important, healing was accompanied by reduced scar and regeneration of hair follicles. Searching for the mechanisms, we found that AF therapy mobilized bone marrow stem cells to peripheral blood and recruited bone marrow-derived CD31+CD133+ endothelial progenitor cells, CD34+ stem cells and Ym1/2+ M2 macrophages into the wound sites and enhanced capillary and hair follicle neogenesis. Conclusion: Combination of AMD3100 and low-dose FK506 results in better and faster healing of diabetic wounds in rats with diabetic peripheral artery disease and neuropathy. Our findings offer a significant therapeutic approach to healing of DFU. Disclosure L. Qi: None. A.R. Ahmadi: None. J. Huang: None. Q. Lin: None. M. Chen: None. H. Kuwabara: None. K. Iwasaki: None. J. Burdick: None. Z. Sun: None.

Pharmacological Mobilization and Recruitment of Stem Cells in Rats Stops Abdominal Adhesions After Laparotomy

Adhesions are a very common complication in the abdominal surgery. Animal studies and human trials have evaluated strategies designed to reduce and prevent postsurgical adhesions but few have an evidence base that justifies routine use. A strategy to prevent adhesions effectively remains an urgent need. We studied a reproducible model of intra-peritoneal adhesion formation in rats using laparotomy with several peritoneal sutures to produce the adhesions. Here we show that entraining endogenous stem cells into injury sites using the combined effect of AMD3100 and low-dose FK-506 (AF) can reduce the adhesion score significantly and abolish peritoneal adhesions in 45% of animals in a rat model of severe postsurgical intra-abdominal adhesions, compared with saline controls. Searching for mechanisms, we found AF treatment dramatically increased SDF-1 expressing cells, HGF expressing Ym1+ M2 macrophages and CD133+ stem cells in the injury sites of peritoneal surface at day 5 post-operation. Our results demonstrate that medically induced recruitment of autologous stem cells using AF significantly reduced postsurgical intra-abdominal adhesions. These findings suggest a novel effective therapeutic approach to preventing adhesions in patients.

Activation of BMP Signaling by FKBP12 Ligands Synergizes with Inhibition of CXCR4 to Accelerate Wound Healing

The combination of AMD3100 and low-dose FK506 has been shown to accelerate wound healing invivo. Although AMD3100 is known to work by releasing hematopoietic stem cells into circulation, the mechanism of FK506 in this setting has remained unknown. In this study, we investigated the activities of FK506 in human cells and a diabetic-rat wound model using a non-immunosuppressive FK506 analog named FKVP. While FKVP was incapable of inhibiting calcineurin, wound-healing enhancement with AMD3100 was unaffected. Further study showed that both FK506 and FKVP activate BMP signaling in multiple cell types through FKBP12 antagonism. Furthermore, selective inhibition of BMP signaling abolished stem cell recruitment and wound-healing enhancement by combination treatment. These results shed new light on the mechanism of action of FK506 in acceleration of wound healing, and raise the possibility that less toxic FKBP ligands such as FKVP can replace FK506 for the treatment of chronic wounds.

Pharmacological Mobilization and Recruitment of Endogenous Stem Cells Prevents Postsurgical Intra-Abdominal Adhesion in Rats

Background: Postsurgical adhesions are a very common complication causing various symptoms from pain to bowel obstruction. We have developed a stem cell mobilizing strategy that enables long-term liver and kidney allograft survival without sustained immunosuppression in animals using a combination of AMD3100 and low-dose FK506 (AF). Serendipitously we have noted a subjective decrease in adhesion formation in animals with AF combination treatment. The purpose of this study was to evaluate the effect of a new stem cell mobilizing strategy on preventing postsurgical adhesion formation in rats. Methods: Abdominal adhesions were induced by creating suture knots on the parietal peritoneum in Lewis rats. Animals were divided randomly into four experimental groups and received subcutaneous injections of saline, single drug or AF combination every other day for 10 days. On postoperative day 14, animals were euthanized and the severity of adhesions were evaluated and scored blindly by five individual surgeons. Results: Most animals treated with saline or single drug exhibited severe peritoneal adhesions around sites of suture knots. AF combination significantly reduced the formation of peritoneal adhesions, 64% animals (7/11) showed few or mild adhesion and no animal showed severe peritoneal adhesions. Searching for mechanisms, we found AF treatment dramatically increased SDF-1 expressing cells, HGF expressing Ym1 M2 macrophages and CD133 stem cells in the injury sites of peritoneal surface at day 5 post-operation. Conclusion: Pharmacological mobilization and recruitment of endogenous stem cells using AF combination significantly reduced postsurgical intra-abdominal adhesions in rats. These findings suggest a novel therapeutic approach to preventing postsurgical adhesions in patients undergoing abdominal or pelvic surgery. Funding Statement: This work was supported by a start-up fund from the surgical department at Johns Hopkins University. Declaration of Interests: None of the authors has a financial interest in any of the products, or drugs mentioned in this manuscript. Ethics Approval Statement: Animals were maintained in a pathogen-free facility of Johns Hopkins University School of Medicine and all animal experiments were performed in accordance with the United States National Institutes of Health (NIH) guidance. All animal protocols were reviewed and approved by the Johns Hopkins University Animal Care and Use Committee.

Local Attenuation of Immunoreaction in Xenogeneic Islet Transplantation by Controlled Release of a Low-Dose FK506 using Polydopamine-coated Polymeric Microspheres Immobilized on Pancreatic Islet Surface

Local Attenuation of Immunoreaction in Xenogeneic Islet Transplantation by Controlled Release of a Low-Dose FK506 using Polydopamine-coated Polymeric Microspheres Immobilized on Pancreatic Islet Surface

Pharmacological Mobilization of Endogenous Bone Marrow Stem Cells Promotes Liver Regeneration after Extensive Liver Resection in Rats

Rapid regeneration of the remnant liver is critical for preventing liver failure and promoting recovery after extensive liver resection. Numerous studies have demonstrated the involvement of bone marrow-derived stem cells in liver regeneration and the potential benefits of bone marrow stem cell therapy. To avoid the preparation of stem cells, we proposed in this study to mobilize endogenous bone marrow stem cells pharmacologically with a combination of AMD3100 (A), an antagonist of CXCR4 and low-dose FK506 (F). Here we show that AF combination therapy significantly increased lineage negative (Lin-) CD34+ and Lin-CD133+ stem cells in peripheral blood and enhanced recruitment of CD133+ cells into the remnant liver in a rat model of 85% partial hepatectomy. Recruiting CD133+ stem cells in the remnant liver was associated with increased proliferation of hepatic oval cells and paralleled the increased SDF-1, CXCR4 and HGF expression. Importantly, AF combination therapy increased the number of Ki67 positive hepatocytes and BrdU incorporation in the remnant liver and improved serum levels of albumin. Our results demonstrate that pharmacological mobilization of endogenous bone marrow stem cells with AF combination therapy can enhance endogenous stem cell mobilization to promote liver regeneration and improve liver function after extensive hepatectomy.

The effect of full dose composite tissue allotransplantation immunosuppression on allograft motor nerve regeneration in a rat sciatic nerve model.

The purpose of this study was to identify which triple immunosuppressive protocols, currently used for vascularized composite allotransplantation in the clinic, will have the best effect on motor function recovery following nerve allograft reconstruction. Eighty-eight Lewis rats underwent a 1-cm sciatic nerve allograft transplantation and skin graft from 44 Brown-Norway rats. Group I received 0.9% isotonic saline (control); Group II, 2 mg/kg FK506; Group III, 1 mg/kg FK506 with 15 mg/kg mycophenolate mofetil (MMF); and Group IV, 2 mg/kg FK506 with 30 mg/kg MMF and prednisone. Each group consisted of 11 rats. After 12 weeks, motor function recovery was evaluated with isometric tetanic force, muscle mass, ankle contracture angle, electrophysiology, and nerve histomorphometry. Adequacy of immunosuppression was monitored with the transplanted skin graft. All data are expressed as a percentage of the contralateral side. Isometric tetanic force showed significantly better functional recovery in all groups treated with immunosuppression compared to control. Within the immunosuppression groups no significant difference was found: 42.1 ± 6.4% (Group I), 56.1 ± 12.4% (Group II), 58.4 ± 10.7% (Group III), and 61.3 ± 11.2% (Group IV). Group IV was superior to all other groups regarding ankle contracture (P < .05) and electrophysiology (P < .001). Skin graft rejection occurred in 41 and 0% (Groups III and IV, respectively). FK506 significantly enhanced motor recovery after allograft reconstruction. This effect was comparable between combination treatment (low-dose FK506 and MMF) and triple therapy (high-dose FK506 and MMF plus prednisolone). However, triple therapy was more effective in suppressing skin rejection.

Prevention of Donor Specific Antibody Production after Skin Allografting by Mobilization of Endogenous Stem Cells Using a Combination of AMD3100 and Low-dose FK506 in Rats

Background: We have developed a stem cell mobilizing strategy that enables long-term liver and kidney allograft survival without sustained immunosuppression in small and large animals using a safe combination of two FDA approved drugs AMD3100 and low-dose FK506 (AF). Furthermore, no increase in serum DSA levels was detected in animals displaying long-term survival even after donor skin grafts were rejected. Therefore, the purpose of this study is to determine if AF combination treatment prevents de novo DSA production in a rat model of skin allograft rejection. Methods: Split thickness skin allografts from Dark Agouti (DA, RT1a) rats were transplanted into adult Lewis (RT11) recipients. Recipient animals were randomly divided into AF treatment group (AMD3100 1 mg/kg and FK506 0.1 mg/kg, s.c., every other day for 14 days) and control group (same volume of saline, s.c.). Serum levels of DSA including both IgG and IgM were measured by flow cytometry at 14 days, 1 and 2 months after skin transplantation. The sensitization to donor antigens in Lewis rats at 2 months after skin allografting was further confirmed by transplanting donor DA kidneys. Full dose FK506 (1 mg/kg/day, s.c) was given to prevent acute cellular rejection after kidney transplantation. Results: Skin allografts were rejected in 8–10 days after transplantation in both groups. Serum levels of DSA-IgG increased 6 to 10 folds in control animals (n = 10), but only 2 to 3 folds in animals treated with AF combination (n = 11) at 1 month and remained at similar levels at 2 months after skin transplantation. All control animals (n = 5) died within 7 days after kidney transplantation. DSA deposition and AMR in kidney allografts were confirmed with signs of IgG deposition in and around glomeruli with C4d deposition on peritubular capillaries. In contrast, about 64% (7/11) animals with AF treatment after skin allografting survived over three weeks without antibody mediated rejection (AMR) and no increase in serum levels of DSA at 14 days after kidney transplantation. Conclusion: Mobilizing endogenous stem cells with AF combination treatment does not prolong skin allograft survival but prevents de novo DSA production after allograft rejection. AF treatment may inhibit B cell sensitization, prevent de novo DSA production and improve long-term allograft function after organ transplantation.

IGF-1 and Chondroitinase ABC Augment Nerve Regeneration after Vascularized Composite Limb Allotransplantation.

Impaired nerve regeneration and inadequate recovery of motor and sensory function following peripheral nerve repair remain the most significant hurdles to optimal functional and quality of life outcomes in vascularized tissue allotransplantation (VCA). Neurotherapeutics such as Insulin-like Growth Factor-1 (IGF-1) and chondroitinase ABC (CH) have shown promise in augmenting or accelerating nerve regeneration in experimental models and may have potential in VCA. The aim of this study was to evaluate the efficacy of low dose IGF-1, CH or their combination (IGF-1+CH) on nerve regeneration following VCA. We used an allogeneic rat hind limb VCA model maintained on low-dose FK506 (tacrolimus) therapy to prevent rejection. Experimental animals received neurotherapeutics administered intra-operatively as multiple intraneural injections. The IGF-1 and IGF-1+CH groups received daily IGF-1 (intramuscular and intraneural injections). Histomorphometry and immunohistochemistry were used to evaluate outcomes at five weeks. Overall, compared to controls, all experimental groups showed improvements in nerve and muscle (gastrocnemius) histomorphometry. The IGF-1 group demonstrated superior distal regeneration as confirmed by Schwann cell (SC) immunohistochemistry as well as some degree of extrafascicular regeneration. IGF-1 and CH effectively promote nerve regeneration after VCA as confirmed by histomorphometric and immunohistochemical outcomes.

Chimeric Allografts Induced by Short-Term Treatment With Stem Cell-Mobilizing Agents Result in Long-Term Kidney Transplant Survival Without Immunosuppression: A Study in Rats.

Transplant tolerance allowing the elimination of lifelong immunosuppression has been the goal of research for 60years. The induction of mixed chimerism has shown promise and has been extended successfully to large animals and to the clinic; however, it remains cumbersome and requires heavy early immunosuppression. In this study, we reported that four injections of AMD3100, a CXCR4 antagonist, plus eight injections of low-dose FK506 (0.05mg/kg per day) in the first week after kidney transplantation extended survival, but death from renal failure occurred at 30-90 days. Repeating the same course of AMD3100 and FK506 at 1, 2 and 3 mo after transplant resulted in 92% allograft acceptance (n=12) at 7mo, normal kidney function and histology with no further treatment. Transplant acceptance was associated with the influx of host stem cells, resulting in a hybrid kidney and a modulated host immune response. Confirmation of these results could initiate a paradigm shift in posttransplant therapy.

Application of plasmapheresis in treating the antibody-mediated acute rejection after kidney transplantation

Objective To investigate the efficacy of plasmapheresis therapy for treating the antibody-mediated acute rejection (AMR) after kidney transplantation. Methods The study group consists of 2 male patients and 3 female patients, who suffered with AMR after receiving first-time allograft renal transplantation from January 2011 to September 2013 in our hospital. The age ranged from 41 to 52 years old, average 46 years old. The preoperative diagnosis in all patients was chronic renal insufficiency (uremia stage) and the regular hemodialysis was given to them. The 5 patients received basic immunosuppressive therapy, including cyclosporine A [5 mg/(kg·d)] or FK506 [0.1 mg/(kg·d)], mycophenolate mofetil (MMF) (1.5 g/d) and steroids. All the antibody-mediated acute rejections were diagnosed by renal allograft biopsy and serum DSA determination within 2 weeks after transplantation. Seven cycles of plasmapheresis rescue therapy were given to those patients respectively after the failure therapy of high dose of corticosteroids (1 000 mg/d) and ALG (250 mg/d). 4 cases with primary glomerulonephritis, whose preoperative serum creatinine level was (784±154) μmol/L, were given plasmapheresis therapy within 2 weeks after transplantation. One case with primary anti-glomerular basement membrane disease, whose preoperative serum creatinine level was 935 μmol/L, received plasmapheresis 35 d after transplantation. The serum DSA in all patients was positive before plasmapheresis. Results After 7 cycles of plasmapheresis rescue therapy, the AMR was reversed in four 4 cases, whose plasmapheresis was given within 2 weeks after transplantation. Within three months follow-up, their renal function recovered well, which the mean serum creatinine level was (113±12) μmol/L. In the case, whose plasmapheresis was given 35 days after transplantation, rejection was not reversed. His serum creatinine was 524 μmol/L and the intermittent hemodialysis was given, subsequently. With a follow-up of 12 months, the ultrasound examination showed that the atrophy of transplanted kidney and a high level of serum creatinine (758 μmol/L). Low dose of FK506 (0.5 mg/d) was given based on those results. Conclusions Active application of plasmapheresis can effectively reverse antibody-mediated acute rejection within two weeks after transplantation. Key words: Kidney transplantation; Antibody-mediated acute rejection; Plasmapheresis

Hedgehog Signaling Restrains Bladder Cancer Progression by Eliciting Stromal Production of Urothelial Differentiation Factors

Hedgehog (Hh) pathway inhibitors are clinically effective in treatment of basal cell carcinoma and medulloblastoma, but fail therapeutically or accelerate progression in treatment of endodermally derived colon and pancreatic cancers. In bladder, another organ of endodermal origin, we find that despite its initial presence in the cancer cell of origin Sonic hedgehog (Shh) expression is invariably lost during progression to invasive urothelial carcinoma. Genetic blockade of stromal response to Shh furthermore dramatically accelerates progression and decreases survival time. This cancer-restraining effect of Hh pathway activity is associated with stromal expression of BMP signals, which stimulate urothelial differentiation. Progression is dramatically reduced by pharmacological activation of BMP pathway activity with low-dose FK506, suggesting an approach to management of human bladder cancer.

Incidental Renal Cell Carcinoma Originating From a Native Kidney After En-bloc Resection for Adrenal Carcinoma in a Kidney Transplant Recipient

BackgroundRenal transplantation is the best treatment for patients with end-stage renal disease. Although there is significantly increased risk of malignancy after renal transplantation, carcinoma of the native kidney is very rare, and moreover, the risk of endocrinologic malignancy after renal transplantation is lower than in the general population and adrenal cortical carcinoma extremely rare. We report a case of incidental renal cell carcinoma originating from a native kidney after en-bloc resection for adrenal carcinoma in a kidney transplant recipient. Case ReportA 57 year-old male patient had undergone living-donor kidney transplantation for chronic renal failure from hypertension 15 years earlier and had a right adrenal tumor diagnosed on surveillance abdomen-pelvis computerized tomography. Based on 24-hour catecholamine laboratory findings, nonfunctioning tumor was suspected. The planned en-bloc resection of right adrenal gland and right native kidney combining the perirenal tissue and Gerota fascia was performed, because the tumor was suspicious for malignancy and could possibly invade the perirenal tissue or right kidney. On the final pathology, combined adrenal cortical carcinoma and incidental renal cell carcinoma was confirmed. Renal cell carcinoma was papillary, type I, and stage T1N0M0. Adrenal cortical carcinoma was 7.6 × 6.5 cm in size, had marked nuclear atypia, and was grade IV/IV. Mitotic counts were >10 per high-power field, but it had no capsular invasion or vascular invasion, and free resection margin was confirmed. In the preoperative period, he had taken immunosuppressants FK506 and mycophenolate sodium, but after combined carcinomas were confirmed, the regimen of combination of immunosuppressants was changed to sirolimus with low-dose FK506 and half-dose mycophenolate sodium.

FK506 protects against articular cartilage collagenous extra-cellular matrix degradation

Osteoarthritis (OA) is a non-rheumatologic joint disease characterized by progressive degeneration of the cartilage extra-cellular matrix (ECM), enhanced subchondral bone remodeling, activation of synovial macrophages and osteophyte growth. Inhibition of calcineurin (Cn) activity through tacrolimus (FK506) in invitro monolayer chondrocytes exerts positive effects on ECM marker expression. This study therefore investigated the effects of FK506 on anabolic and catabolic markers of osteoarthritic chondrocytes in 2D and 3D invitro cultures, and its therapeutic effects in an invivo rat model of OA. Effects of high and low doses of FK506 on anabolic (QPCR/histochemistry) and catabolic (QPCR) markers were evaluated invitro on isolated (2D) and ECM-embedded chondrocytes (explants, 3D pellets). Severe cartilage damage was induced unilaterally in rat knees using papain injections in combination with a moderate running protocol. Twenty rats were treated with FK506 orally and compared to twenty untreated controls. Subchondral cortical and trabecular bone changes (longitudinal microCT) and macrophage activation (SPECT/CT) were measured. Articular cartilage was analyzed exvivo using contrast enhanced microCT and histology. FK506 treatment of osteoarthritic chondrocytes invitro induced anabolic (mainly collagens) and reduced catabolic ECM marker expression. In line with this, FK506 treatment clearly protected ECM integrity invivo by markedly decreasing subchondral sclerosis, less development of subchondral pores, depletion of synovial macrophage activation and lower osteophyte growth. FK506 protected cartilage matrix integrity invitro and invivo. Additionally, FK506 treatment invivo reduced OA-like responses in different articular joint tissues and thereby makes Cn an interesting target for therapeutic intervention of OA.