Reduction in Obesity-Related Hepatic Fibrosis by SR1664

Peroxisome-proliferator-activated receptor gamma (PPARγ) is a transcription factor with adipogenic, insulin-sensitizing, and antifibrotic properties. Strong PPARγ activators, such as the thiazolidinediones, can induce unwanted effects such as edema, weight gain, and bone loss, and therefore selective modulators of PPARγ are in development. We previously reported that one selective PPARγ modulator, SR1664, reduced toxin-induced hepatic fibrosis and the activation of hepatic stellate cells (HSCs), the main collagen-producing liver cell in fibrosis. In this study, we used a high fat and high carbohydrate (HFHC) model of hepatic steatosis and fibrosis to determine the effect of SR1664. Mice were placed on a standard chow or HFHC diet for 16 weeks, with SR1664 or control treatment for the final 4 weeks. SR1664 did not alter weight gain or fasting insulin or glucose levels. The size of lipid droplets in the HFHC group was reduced by SR1664, but there was no effect on total liver triglyceride levels. The degree of fibrosis was significantly reduced by SR1664 in mice on the HFHC diet, and this was accompanied by a decrease in activated HSC. In summary, SR1664 improved insulin sensitivity and reduced fibrosis in the HFHC diet, suggesting selective PPARγ modulation is effective in obesity-related liver fibrosis.

A Selective PPARγ Modulator Reduces Hepatic Fibrosis

Hepatic fibrosis is the accumulation of excess collagen as a result of chronic liver injury. If left unabated, hepatic fibrosis can lead to the disruption of the liver architecture, portal hypertension, and increased risk of progression to cirrhosis and hepatocellular carcinoma. The thiazolidinedione class of antidiabetic drugs, through their target peroxisome proliferator-activated receptor γ (PPARγ), have protective effects against liver fibrosis, and can inhibit the profibrotic activity of hepatic stellate cells, the major collagen-producing liver cells. However, these drugs have been ineffective in the treatment of established fibrosis, possibly due to side effects such as increased weight and adiposity. Recently, selective PPARγ modulators that lack these side effects have been identified, but their role in treating fibrosis has not been studied. In this study, we tested the effectiveness of one of these selective modulators, SR1664, in the mouse carbon tetrachloride model of established hepatic fibrosis. Treatment with SR1664 reduced the total and type 1 collagen content without increasing body weight. The abundance of activated hepatic stellate cells was also significantly decreased. Finally, SR1664 inhibited the profibrotic phenotype of hepatic stellate cells. In summary, a selective PPARγ modulator was effective in the reduction of established hepatic fibrosis and the activated phenotype of hepatic stellate cells. This may represent a new treatment approach for hepatic fibrosis.

Serelaxin increases the antifibrotic action of rosiglitazone in a model of hepatic fibrosis

AIM

To determine the effect of combined serelaxin and rosiglitazone treatment on established hepatic fibrosis.

METHODS

Hepatic fibrosis was induced in mice by carbon tetrachloride administration for 6 wk, or vehicle alone (nonfibrotic mice). For the final 2 wk, mice were treated with rosiglitazone, serelaxin, or both rosiglitazone and serelaxin. Serum liver enzymes and relaxin levels were determined by standard methods. The degree of liver collagen content was determined by histology and immunohistochemistry. Expression of type I collagen was determined by quantitative PCR. Activation of hepatic stellate cells was assessed by alpha-smooth muscle actin (SMA) levels. Liver peroxisome proliferator activated receptor-gamma coactivator 1 alpha (PGC1α) was determined by Western blotting.

RESULTS

Treatment of mice with CCl₄ resulted in hepatic fibrosis as evidenced by increased liver enzyme levels (ALT and AST), and increased liver collagen and SMA. Monotherapy with either serelaxin or rosiglitazone for 2 wk was generally without effect. In contrast, the combination of serelaxin and rosiglitazone resulted in significantly improved ALT levels (P < 0.05). Total liver collagen content as determined by Sirius red staining revealed that only combination treatment was effective in reducing total liver collagen (P < 0.05). These results were supported by immunohistochemistry for type I collagen, in which only combination treatment reduced fibrillar collagen levels (P < 0.05). The level of hepatic stellate cell activation was modestly, but significantly, reduced by serelaxin treatment alone, but combination treatment resulted in significantly lower SMA levels. Finally, while hepatic fibrosis reduced liver PGC1α levels, the combination of serelaxin and rosiglitazone resulted in restoration of PGC1α protein levels.

CONCLUSION

The combination of serelaxin and rosiglitazone treatment for 2 wk was effective in significantly reducing established hepatic fibrosis, providing a potential new treatment strategy.

Relaxin activates peroxisome proliferator-activated receptor γ (PPARγ) through a pathway involving PPARγ coactivator 1α (PGC1α)

Relaxin activation of its receptor RXFP1 triggers multiple signaling pathways. Previously, we have shown that relaxin activates PPARγ transcriptional activity in a ligand-independent manner, but the mechanism for this effect was unknown. In this study, we examined the signaling pathways of downstream of RXFP1 leading to PPARγ activation. Using cells stably expressing RXFP1, we found that relaxin regulation of PPARγ activity requires accumulation of cAMP and subsequent activation of cAMP-dependent protein kinase (PKA). The activated PKA subsequently phosphorylated cAMP response element-binding protein (CREB) at Ser-133 to activate it directly, as well as indirectly through mitogen activated protein kinase p38 MAPK. Activated CREB was required for relaxin stimulation of PPARγ activity, while there was no evidence for a role of the nitric oxide or ERK MAPK pathways. Relaxin increased the mRNA and protein levels of the coactivator protein PGC1α, and this effect was dependent on PKA, and was completely abrogated by a dominant-negative form of CREB. This mechanism was confirmed in a hepatic stellate cell line stably that endogenously expresses RXFP1. Reduction of PGC1α levels using siRNA diminished the regulation of PPARγ by relaxin. These results suggest that relaxin activates the cAMP/PKA and p38 MAPK pathways to phosphorylate CREB, resulting in increased PGC1α levels. This provides a mechanism for the ligand-independent activation of PPARγ in response to relaxin.

Ethanol affects hepatitis C pathogenesis: humanized SCID Alb-uPA mouse model

Alcohol consumption exacerbates the course of hepatitis C viral (HCV) infection, worsens outcomes and contributes to the development of chronic infection that exhibits low anti-viral treatment efficiency. The lack of suitable in vivo models makes HCV-ethanol studies very difficult. Here, we examine whether chimeric SCID Alb-uPA mice transplanted with human hepatocytes and infected with HCV develop worsening pathology when fed ethanol. After 5 weeks of feeding, such mice fed chow+water (control) or chow+20% ethanol in water (EtOH) diets mice developed oxidative stress, decreased proteasome activity and increased steatosis. Importantly, HCV(+) mice in the control group cleared HCV RNA after 5 weeks, while the infection persisted in EtOH-fed mice at the same or even higher levels compared with pre-feeding HCV RNA. We conclude that in chimeric SCID Alb-uPA mice, EtOH exposure causes the complex biochemical and histological changes typical for alcoholic liver injury. In addition, ethanol feeding delays the clearance of HCV RNA thereby generating persistent infection and promoting liver injury. Overall, this model is appropriate for conducting HCV-ethanol studies.

Relaxin decreases the severity of established hepatic fibrosis in mice

BACKGROUND & AIMS

Hepatic fibrosis is characterized by excess collagen deposition, decreased extracellular matrix degradation and activation of the hepatic stellate cells. The hormone relaxin has shown promise in the treatment of fibrosis in a number of tissues, but the effect of relaxin on established hepatic fibrosis is unknown. The aim of this study was to determine the effect of relaxin on an in vivo model after establishing hepatic fibrosis

METHODS

Male mice were made fibrotic by carbon tetrachloride treatment for 4 weeks, followed by treatment with two doses of relaxin (25 or 75 μg/kg/day) or vehicle for 4 weeks, with continued administration of carbon tetrachloride.

RESULTS

Relaxin significantly decreased total hepatic collagen and smooth muscle actin content at both doses, and suppressed collagen I expression at the higher dose. Relaxin increased the expression of the matrix metalloproteinases MMP13 and MMP3, decreased the expression of MMP2 and tissue inhibitor of metalloproteinase 2 (TIMP2) and increased the overall level of collagen-degrading activity. Relaxin decreased TGFβ-induced Smad2 nuclear localization in mouse hepatic stellate cells.

CONCLUSIONS

The results suggest that relaxin reduced collagen deposition and HSC activation in established hepatic fibrosis despite the presence of continued hepatic insult. This reduced fibrosis was associated with increased expression of the fibrillar collagen-degrading enzyme MMP13, decreased expression of TIMP2, and enhanced collagen-degrading activity, and impaired TGFβ signalling, consistent with relaxin's effects on activated fibroblastic cells. The results suggest that relaxin may be an effective treatment for the treatment of established hepatic fibrosis.

What to do before disaster strikes

The key to averting disaster or minimizing its effects is a solid data security plan. Learn the types of data risks that exist, how to develop a plan to counteract them, and your role in ensuring the safety of health and patient data.

Nurses--yes, nurses--improve physician order entry

Automated physician order entry systems can reduce medication errors and improve patient outcomes. But there are a variety of barriers--psychological, behavioral and technological--to physician adoption. Nursing not only has a stake in this issue, but plays a valuable role in resolving it.

In our hands? The future of health care technology

Use improvements in data accuracy and nursing productivity to enhance your quality of care.

There is no "I" in team, but there is one in meeting

Increasingly, emotional intelligence (EI) and one's emotional quotient, or EQ, have become critical workforce success factors. This article examines the often overlooked issue of EI and EQ in group situations. It will delineate the three types of groups that show the most variance in emotional dynamics, and explore the application of EI and EQ to these group settings.

"Techno-marvels" just around the corner

In the next 18 months, cutting-edge information technology will likely become commonplace in hospitals.

Government cracks down on billing fraud

As the largest professional caregiving group, nurses have a stake in preventing misuse of the reimbursement system. Technology also plays a crucial role, as automated billing systems can both prevent and enable billing fraud.

Using lower eyelid fascial slings for recalcitrant burn ectropion

Burns of the lower eyelid represent a difficult management problem. Even with skin grafting, scarring and contraction can result in ectropion. This condition creates a marked aesthetic deformity, poses a risk of corneal exposure, and jeopardizes the patient's vision. Historically, full-thickness skin grafts and tarsorrhaphies have been described to manage recurrent ectropion. The lower eyelid fascial sling (LEFS) uses a temporalis fascial strip to create a suspension sling for the lower eyelid. In a series of 7 patients, the LEFS procedure resolved the symptoms permanently in all patients. Because the LEFS procedure counteracts the natural scar contraction forces of lower eyelid burns, it can resolve recalcitrant ectropion successfully while preserving the function and aesthetics of the lower eyelid.

How can we keep private data private?

While technology increases the accessibility of patient data, it also compromises its confidentiality. Here, review the federal government's solutions.

Size up the big three

Before we can tackle the complexities of solid nursing IT, we need a set of standards on which to base our efforts. Learn how three groups--HIPAA, JCAHO, and the Workgroup--are building nursing a firm foundation.

Mapping an IT career: the future of nursing

In today's health care environment, nurses are finding themselves working in nontraditional roles and settings. Some fear technology will all but replace them. In some cases--given the speed at which technology has and continues to advance--that fear is well placed. For nursing to remain viable as a profession, it must incorporate information technology (IT) not only into today's practices, but also into tomorrow's unfolding roles, from advancing practice with new technology-based delivery models to moving away from direct patient care to become informaticians. Nursing administrators and managers must also embrace technology, for their ability to direct IT policy will directly influence their chances for career advancement. But what is required to map an IT career? How is the value of experience balanced against the need for education? Will nursing's core competencies remain constant over time?

Compassion meets the computer age

Computers get smarter and smarter, but they'll never replace human caring. View the nature of compassion and its unique role in nursing, as well as our challenge to measure the abstract quality. The surprising revelation: Computers are our best bet.

Stop the rise in nursing errors—systematically

The number of reported nursing errors in hospitals has increased in each of the past 5 years. Information technology can help nurses make better care decisions in today's harried hospital environment.

Burn injury in kitchen workers: a cause for prevention

Preventable thermal injuries in professional kitchen workers have been identified, and we have introduced a protective garment. Because of the nature of their occupation, kitchen workers are prone to thermal injuries. It has been our experience that the majority of these injuries are scald injuries on the ankles and dorsum of the feet. We propose that a protective garment, such as a waterproof shoe and garter, could reduce the incidence of these injuries.

The role of IT in caring for the chronically ill

This article provides a brief overview of the problem of chronic disease, presents some of the emerging models of care delivery for the chronically ill, and discusses information technology's (IT) role in supporting those models and assisting in the search for cures.

XML: Health careʼs killer application?

XML promises to be the next big thing in health care information.

Medical Errors, Airplanes, and Information Technology

The IOM says tens of thousands die each year from medical errors. Learn lessons from the aviation industry and how we can build a culture of safety with information technology and clinical information systems.

Toward a new millennium: outlook and obligations for 21st century health care technology

This article will discuss key trends--from globalization to the culture of change and the rise of the information age--fueling development and deployment of 21st century IT. It will describe some of the new technologies, their applications, and implications for nursing.

Minding the store: how IT impacts outcomes measurement

Today, the question is not whether organizations should measure outcomes, but how. Right now, there are several initiatives, but no single, collaborative effort to tie them all together. This article will discuss the rise and early history of outcomes assessment in health care and highlight some key current initiatives (for example, OASIS [home health], QISMC [managed care organizations], HCQIP [inpatient care], ACQIP [ambulatory care], Joint Commission's ORYX accreditation initiative [hospitals, long-term care, home care, behavioral health care, and networks]). It will also delineate some of the problems with measuring outcomes and discuss where more work is needed. It will go on to discuss the role of IT in outcomes measurement, including its contributions, goals, effects, categories of IT support, infrastructure solutions, and analysis.

Nursing information systems: who needs them?

This article examines some of the reasons why--both financial and perceptual--organizations are becoming skeptical of nursing information systems. Then it delineates some key benefits and explains how nursing can and should be prepared to head off such skepticism.

Developing IT relief for chronic illness

Read about emerging models of care delivery for the chronically ill and how information technology supports them and the search for cures.

Need to know: essential survival skills for the information age

Twenty-five years ago, health care information technology was dramatically different from what it is today. Twenty-five years from now, it promises to be worlds away from what it is today. How good a job has nursing done at keeping up with this exponential change? This article addresses the evolution of technology in health care and nursing's track record of technology expertise. It also discusses the price nursing will pay if it does not keep up with technology and the benefits it can gain if it does.

R&D in the mergers and acquisitions age

Learn about an emerging shift in the way research and development (R&D) is funded and the implications of that shift for health care information technology, product innovation, and delivery.

Safety of losartan in hypertensive patients with thiazide-induced hyperuricemia

BACKGROUND

Losartan, an angiotensin II receptor antagonist, has been shown to decrease serum uric acid and to increase urinary excretion of uric acid.

METHODS

To determine if this effect can increase the risk of acute urate nephropathy, 63 hypertensive patients with thiazide-induced asymptomatic hyperuricemia (serum uric acid 7.0 to 12.0 mg/dl) were randomized double-blind to losartan 50 mg every day (q.d.), losartan 50 mg plus hydrochlorothiazide (HCTZ) 50 mg q.d., HCTZ 50 mg q.d., or placebo for three weeks. To potentiate the risk of crystal formation, patients received a 2 g/kg protein diet one day prior to each clinic visit on days 0 (baseline), 1, 7, and 21.

RESULTS

Adverse events typically associated with acute urate nephropathy, for example, flank pain, hematuria, or increased blood urea nitrogen/creatinine, were not reported. Uric acid excretion and urine pH increased four and six hours after losartan on day 1 compared with day 0. Dihydrogen urate, the primary risk factor for crystal formation, decreased at four and six hours on day 1 compared with day 0 associated with the concurrent rise in urine pH. Day 7 and 21 changes, compared with day 0, in uric acid excretion rate, urine pH, and dihydrogen urate with losartan were comparable to day 1 results but were not statistically significant. Serum uric acid was significantly reduced after 21 days of therapy with losartan.

CONCLUSION

Losartan decreased serum uric acid and increased uric acid excretion without increasing urinary dihydrogen urate, the primary risk factor for acute urate nephropathy, during 21 days of dosing in hypertensive patients with thiazide-induced hyperuricemia.

What does IT have in store for nursing?

Globalization, our culture of change, and the information age shape 21st-century information technology. Find out the applications and implications for nursing.

Nursing's role in Y2K planning

Why have more nurses not fulfilled their role in planning for the year 2000? Nurses need to apply their skills and expertise to solving often overlooked problems such as point-of-service applications, transactions with business partners, and contingency planning.

IT takes lead role in outcomes measurement

To succeed in outcomes measurement, leaders need to understand key current initiatives, barriers, and the role of information technology.

High touch vs. high tech: rediscover the human element

Communication technology makes efficiencies possible, but it can cause major personal and organizational problems when it replaces human contact.

Nursing's role in Y2K planning

Why haven't more nurses fulfilled their role in Y2K planning? Nurses need to apply their skills and expertise to solving often overlooked problems such as point-of-service applications, transactions with business partners, and contingency planning.