Mesenchymal Stem Cells from Bone Marrow Improve Liver Function and Reduce Liver Scarring in Patients with Alcoholic Cirrhosis


Dr Soon Koo Baik from the Yonsei University Wonju College of Medicine, and Dr. Si Hyun Bae from The Catholic University of Korea and their colleagues have conducted an important phase 2 clinical trial that tests the ability of mesenchymal stem cells from bone marrow to treat cirrhosis of the liver. In this trial, seventy-two patients who had established cirrhosis of the liver participated in a multicenter, randomized, open-label, phase 2 trial (published in the journal Hepatology, DOI:10.1002/hep.28693).

The liver is a hugely important organ. Not only is it the largest internal organ in our bodies, but it serves as the main metabolic factory of the body because of the outsized role it plays in metabolism. The liver takes up and stores and processes nutrients from food. Once it processes fats, sugars, and amino acids, the liver delivers them to the rest of the body. The liver also makes new proteins, such as clotting and immune factors, produces bile, which helps the body absorb fats, cholesterol, and fat-soluble vitamins, and removes waste products the kidneys cannot remove, such as fats, cholesterol, toxins, and medications.

The condition known as cirrhosis is a condition in which the liver gradually deteriorates and becomes unable to function normally due to chronic, or long-lasting, injury. The accumulation of scar tissue in the liver is typically slow and gradual and as scar tissue replaces more healthy liver tissue, the liver begins to fail. Scar tissue also partially blocks the flow of blood through the liver. Chronic liver failure (also known as end-stage liver disease) culminates in the inability of the liver to perform important functions. Since the liver is an organ that have a good deal of regenerative ability, end-stage liver disease essentially becomes so damaged that it cannot effectively replace damaged cells.

Cirrhosis is most commonly called by chronic alcoholism, but so can chronic viral infections by viruses like hepatitis B virus and hepatitis C virus.  Additionally, particular genetic diseases can also cause cirrhosis in children or young adults.

Mesenchymal stem cells have the ability to secrete cocktails of pro-healing molecules that might be able to support the growth and survival of liver cells. A variety of experiments in animals have established that the administration of mesenchymal stem cells (MSCs) from bone marrow (Truong, NH, et al., Stem Cells Int. 2016;2016:5720413. doi: 10.1155/2016/5720413; Almeida-Porada G, et al., Exp Hematol. 2010;38:574–580; Berardis S, et al., World J Gastroenterol. 2015;21:742–758), and other sources (De Ugarte DA, et al., Cells Tissues Organs. 2003;174:101–109; in ‘t Anker PS, etr al., Haematologica. 2003;88:845–852; Lee OK, et al., Blood. 2004;103:1669–1675) can decrease inflammation within the liver, inhibit the death of liver cells and promote their survival, and promote the regeneration of residential liver cells.

In clinical trials, administration of MSCs to cirrhosis patients has established the safety of MSC-based treatments (Amin MA, et al., Clin Transplant. 2013;27:607–612; El-Ansary M, et al., Stem Cell Rev. 2012;8:972–981; Jang YO, et al., Liver Int. 2014;34:33–41; Kharaziha P, et al., Eur J Gastroenterol Hepatol. 2009;21:1199–1205; Mohamadnejad M, et al., Arch Iran Med. 2007;10:459–466). Unfortunately, the design of these trials involved the mixing of patients with alcohol-based cirrhosis, viral-based cirrhosis, and other types of cirrhosis. Therefore, it is impossible to draw any conclusions about the efficacy of MSC transplantations on the basis of these trials. However, one trial, by Jang, et al, examined the effect of MSCs from bone marrow in patients with alcoholic cirrhosis. After 11 patients received MSC implantations, improvements in liver tissue architecture were observed in 6/11 patients, and 10 patients showed recovery of liver function. These 10 patients had decreased expression of molecules that induce scarring in the liver (i.e. TGF-β1, collagen type I, and α-smooth muscle actin). Significantly, Jang and others observed these improvements in the absence of significant complications or side effects during the study period. On the strength of these results, a larger phase 2 study is certainly warranted (see F. Ezquer, et al., World J Gastroenterol. 2016 Jan 7; 22(1): 24–36).

In this Bak and Bae clinical trials, 72 patients were randomly assigned to three groups that consisted of a control group and two autologous bone marrow-based MSC groups that underwent either one-time or two-time hepatic arterial injections of 5 × 10[7] MSCs, 30 days after bone marrow aspiration. All patients also underwent a follow-up biopsy 6 months after enrollment and adverse events were monitored for 12 months.

The primary endpoint in this study was the improvement in the amount of scar tissue in biopsies (as assayed by Picrosirius-red staining). The secondary endpoints included liver function tests, a measure of the severity of cirrhosis called the Child-Pugh score, and another score called the Model for End-stage Liver Disease (MELD) score. The outcomes were analyzed by per-protocol analysis.

When it comes to the amount of scar tissue in the patient’s livers, patients that received one-time and two-time bone marrow-based MSC administrations, showed 25% (19.5±9.5% vs. 14.5±7.1%) and 37% (21.1±8.9% vs. 13.2±6.7%) reductions in the amount of liver scar after MSC administration, respectively (P0.05). The Child-Pugh scores of both BM-MSC groups (one-time: 7.6±1.0 vs. 6.3±1.3 and two-time: 7.8±1.2 vs. 6.8±1.6) were also significantly improved following BM-MSC transplantation (P<0.05) compared to the control group that did not receive MSCs. Most significantly, perhaps, is that the proportion of patients with adverse events did not differ among the three groups.

From this larger phase 2 study, it seems that transplantation of a patient’s own bone marrow-based MSCs can safely improve the degree of scarring in the liver of cirrhosis patients and also improve liver function in patients with alcoholic cirrhosis. This study seems to confirm what was observed in preclinical studies in laboratory animals and extends what was observed in the phase 1 studies. While more work is certainly required, these results are certainly hopeful.

An Efficient Method for Converting Fat Cells to Liver Cells


I have a friend whose wife has systemic lupus erythematosis, and her liver has taken a beating as a result of this disease. She has never had a drop of alcohol for decades and yet she has a liver that looks like the liver of a 70-year-old alcoholic. The scarring of the liver as result of repeated damage and healing has seriously compromised her liver function. She is now a candidate for a liver transplant. Wouldn’t it be nice to simply give her liver cells to heal her liver?

This dream came a little closer to becoming reality in October of this year when scientists at Stanford University developed a fast and efficient way to convert fat cells isolated from routine liposuction into liver cells. Even though these experiments used mice, the stem cells were isolated from human liposuction procedures.

This experiment did not use embryonic stem cells or induced pluripotent stem cells to generate liver cells. Instead it used adult stem cells from fat.

Fat-based stem cells

The liver builds complex molecules, filters and breaks down waste products and toxic substances that might otherwise accumulate to dangerous concentrations.

The liver, unlike other organs, has a capacity to regenerate itself to a significant extent, but the liver’s regenerative abilities cannot overcome the consequences of acute liver poisoning, or chronic damage to the liver, as a result of hepatitis, alcoholism, or drug abuse.

For example, acetaminophen (Tylenol) is a popular pain-reliever, but abusing acetaminophen can badly damage the liver. About 500 people die each year from abuse of acetaminophen, and some 60,000 emergency-room visits and more than 25,000 hospitalizations annually are due to acetaminophen abuse. Other environmental toxins, such as poisonous mushrooms, contribute more cases of liver damage.

Fortunately, the fat-to-liver protocol is readily adaptable to human patients, according to Gary Peltz, professor of anesthesia and senior author of this study. The procedure takes about nine days, which is easily fast enough to treat someone suffering from acute liver poisoning, who might die within a few weeks without a liver transplant.

Some 6,300 liver transplants are performed annually in he United States, and approximately 16,000 patients are on the waiting list for a liver. Every year more than 1,400 people die before a suitable liver can be found for them.

Even though liver transplantations save the lives of patients, the procedure is complicated, not without risks, and even when successful, is fraught with after effects. The largest problem is the immunosuppressant drugs that live patients must take in order to prevent their immune system from rejecting the transplanted liver. Acute rejection is an ongoing risk in any solid organ transplant, and improvements in immunosuppressive therapy have reduced rejection rates and improved graft survival. However, acute rejection still develops in 25% to 50% of liver transplant patients treated with immunosuppressants. Chronic rejection is somewhat less frequent and is declining and occurs in approximately 4% of adult liver transplant patients.

Peltz said, “We believe our method will be transferable to the clinic, and because the new liver tissue is derived from a person’s own cells, we do not expect that immunosuppressants will be needed.”

Peltz also noted that fat-based stem cells do not normally differentiate into liver cells. However, in 2006, a Japanese laboratory developed a technique for converting fat-based stem cells into induced liver cells (called “i-Heps” for short). This method, however, is inefficient, takes 30 days, and relies on chemical stimulation. In short, this technique would not provide enough material to regenerate a liver.

The Stanford University group built upon the Japanese work and improved it. Peltz’s group used a spherical culture and were able to convert fat-bases stem cells into i-Heps in nine days and with 37% efficiency (the Japanese group only saw a 12% rate). Since the publication of their paper, Peltz said that workers in his laboratory have increased the efficiency to 50%.

Dan Xu, a postdoctoral scholar and the lead author of this study, adapted the spherical culture methodology from early embryonic-stem-cell literature. However, instead of growing on flat surfaces in a laboratory dish, the harvested fat cells are cultured in a liquid suspension in which they form spheroids. Peltz noted that the cells were much happier when they were grown in small spheres.

Once they had enough cells, Peltz and his co-workers injected them into immune-deficient laboratory mice that accept human grafts. These mice were bioengineered in 2007 as a result of a collaboration between Peltz and Toshihiko Nishimura from the Tokyo-based Central Institute for Experimental Animals. These mice had a viral thymidine kinase gene inserted into their genomes and when treated with the drug gancyclovir, the mice experienced extensive liver damage.

After gancyclovir treatment, Peltz and his coworkers injected 5 million i-Heps into the livers of these mice, using ultrasound-guided injection procedures, which is typically used for biopsies.

Four weeks later, the mice expressed human blood proteins and 10-20 percent of the mouse livers were repopulated with human liver cells. Blood tests also showed that the mouse livers, which were greatly damaged previous to the transplantation, were processing nitrogenous wastes properly. Structurally, the mouse livers contained human cells that made human bile ducts, and expressed mature human liver cells.

Other tests established that the i-Heps made from fat-based stem cells were more liver-like than i-Heps made from induced pluripotent stem cells.

Two months are injection of the i-Heps, there was no evidence of tumor formation.

Peltz said, “To be successful, we must regenerate about half of the damaged liver’s original cell count.” With the spherical culture, Peltz is able to produce close to one billion injectable i-Heps from 1 liter of liposuction aspirate. The cell replication that occurs after injection expands that number further to over 100 billion i-Heps.

If this is possible, then this procedure could potentially replace liver transplants. Stanford University’s Office of Technology Licensing has filed a patent on the use of spherical culture for hepatocyte (liver cell) induction. Peltz’s group is optimizing this culture and injection techniques,talking to the US Food and Drug Administration, and gearing up for safety tests on large animals. Barring setbacks, the new method could be ready for clinical trials within two to three years, according the estimations by Peltz.