Bone marrow-derived macrophages are associated with androgen modulated prostate regeneration

A dose response analysis of a specific bone marrow concentrate treatment protocol for knee osteoarthritis

Background

Prior studies describing the treatment of symptomatic knee osteoarthritis with injections of bone marrow concentrate have provided encouraging results. The relationship between the cellular dose contained within the bone marrow concentrate and efficacy of the treatment, however, is unclear. In the present study we describe clinical outcomes for symptomatic knee osteoarthritis in relation to higher and lower cell concentrations contained within a bone marrow concentrate treatment protocol.

Methods

Data from an ongoing patient registry was culled to identify 373 patients that received bone marrow concentrate injections for the treatment of 424 osteoarthritic knee joints. The clinical scales for these patients were assessed at baseline and then tracked post-procedure at 1, 3, 6 and 12 months, and annually thereafter. Tracked outcomes included the numeric pain scale; a lower extremity functional questionnaire; an International Knee Documentation Committee scale; and a subjective improvement rating scale. Using pain and functional outcome measures, a receiver operating characteristic analysis was used to define an optimal clinical outcome threshold at which bone marrow nucleated cell count could be divided into either a lower or higher cell count group within a treatment protocol.

Results

The lower and higher cell count groups were defined using a threshold of 4 × 10⁸ cells. There were 224 and 185 knee joints treated in the lower (≤4 × 10⁸) and higher (>4 × 10⁸) cell count groups respectively. Most joints were diagnosed with early stage knee osteoarthritis. Both the lower and higher cell count groups demonstrated significant positive results with the treatment for all of the pain and functional metrics. The higher cell count group reported lower post treatment numeric pain scale values, in comparison with the lower cell count group (1.6 vs. 3.2; P < 0.001). No significant differences were detected for the other metrics, however.

Conclusions

Improved function and reduced pain was observed in patients treated with a bone marrow concentrate protocol regardless of cellular dose; however, patients receiving a higher concentration of cells reported a better pain outcome in comparison with the lower dose group. These preliminary findings suggest that cell dose may be an important factor governing clinical outcomes in autologous bone marrow concentrate treatment of knee osteoarthritis. Further studies using a larger patient population may help elucidate these findings.

Bone marrow-derived cells contribute to regeneration of injured prostate epithelium and stroma

BACKGROUND

Recent studies have reported that bone marrow-derived cells (BMDCs), which are recruited to sites of tissue injury and inflammation, can differentiate into epithelial cells, such as liver, lung, gastrointestinal tract, and skin cells. We investigated the role of BMDCs in contributing to regeneration of injured prostate epithelium.

METHODS

Using chimera rats that received allogenic bone marrow grafts from green fluorescent protein (GFP) transgenic rats after lethal whole-body irradiation, we investigated the existence of epithelial marker-positive BMDCs in injured prostate tissue caused by transurethral injection of lipopolysaccharide.

RESULTS

Prostate tissues were harvested 2 weeks after transurethral lipopolysaccharide injection. Immunofluorescence staining showed that some cells in the stroma co-expressed GFP and pan-cytokeratin, which suggested the existence of epithelial marker-positive BMDCs. To confirm the existence of such cells, we collected bone marrow-derived non-hematopoietic cells (GFP+/CD45- cells) from the prostate by fluorescence-activated cell sorter analysis and analyzed the characteristics of the GFP+/CD45- cells. The number of cells in this population significantly increased from 0.042% to 0.492% compared with normal prostate tissue. We found by immunofluorescent analysis and RT-PCR that GFP+/CD45- cells expressed cytokeratin, which suggested that these cells have some features of epithelial cells. In the prostate obtained from the chimera rats 34 weeks after lipopolysaccharide injection, GFP- and cytokeratin-positive cells were observed in the prostate gland, which suggested that some of the cells in the prostate gland regenerated after prostate inflammation derived from bone marrow.

CONCLUSIONS

BMDCs might be able to differentiate into prostate epithelial cells after prostatic injury.

Differentiation of human umbilical cord mesenchymal stem cells into prostate-like epithelial cells in vivo

Although human umbilical cord mesenchymal stem cells (hUC-MSCs) have been identified as a new source of MSCs for potential application in regenerative medicine, their full potential of differentiation has not been determined. In particular, whether they have the capability to differentiate into epithelial cells of endodermal origin such as the prostate epithelial cells is unknown. Here we report that when hUC-MSCs were combined with rat urogenital sinus stromal cells (rUGSSs) and transplanted into the renal capsule in vivo, they could differentiate into prostate epithelial-like cells that could be verified by prostate epithelial cell-specific markers including the prostate specific antigen. The prostatic glandular structures formed in vivo displayed similar cellular architecture with lumens and branching features as seen for a normal prostate. In addition, the human origin of the hUC-MSCs was confirmed by immunocytochemistry for human nuclear antigen. These findings together indicate that hUC-MSCs have the capability to differentiate into epithelial-like cells that are normally derived from the endoderm, implicating their potential applications in tissue repair and regeneration of many endoderm-derived internal organs.

Development of animal models underlining mechanistic connections between prostate inflammation and cancer

The characterization of animal models has indicated that the genetic, dietary and environmental factors and hormonal imbalance may influence the risk to develop prostate inflammatory lesions and prostate cancer (PC) confirming human epidemiologic data. It is now established that the prostate inflammatory response typically results in major changes in the local microenvironment of epithelial cells of the prostate gland, including an intense stromal remodeling, activation of fibroblasts, infiltration of immune cells such as mast cells, macrophages and B and T lymphocytes and collagen deposition. The immune cells recruited at prostate inflammatory lesions and myofibroblasts may contribute to the release of numerous pro-inflammatory cytokines and chemokines that in turn can promote the oxidative stress, genomic instability and proliferation of epithelial cells. The accumulation of additional genetic and/or epigenetic alterations in prostatic stem/progenitor cells may subsequently culminate to their malignant transformation and PC initiation and progression and more particularly with advancing age. The potential mechanistic relationships between the molecular events associated with the persistent inflammatory response and prostate carcinogenesis have important implications for optimizing the current therapies against different prostatic disorders and PCs.

The stroma-a key regulator in prostate function and malignancy

Prostate cancer is a very common and highly unpredictable form of cancer. Whereas many prostate cancers are slow growing and could be left without treatment, others are very aggressive. Additionally, today there is no curative treatment for prostate cancer patients with local or distant metastasis. Identification of new, improved prognostic and diagnostic biomarkers for prostate cancer and the finding of better treatment strategies for metastatic prostate cancer is therefore highly warranted. Interactions between epithelium and stroma are known to be important already during prostate development and this interplay is critical also in development, progression of primary tumors and growth of metastases. It is therefore reasonable to expect that future biomarkers and therapeutic targets can be identified in the prostate tumor and metastasis stroma and this possibility should be further explored.